Publications

PublicationTypeDownloadYearAbstract:
Xie W, Mallin BM, Richards JE.
Development of brain functional connectivity and its relation
to infant sustained attention in the first year of life. Dev Sci.
2018;e12703. https://doi.org/10.1111/desc.12703
journalDownload2018The study of brain functional connectivity is crucial to understanding the neural mechanisms underlying the improved behavioral performance and amplified ERP responses observed during infant sustained attention. Previous investigations on the development of functional brain connectivity during infancy are primarily confined to the use of functional and structural MRI techniques. The current study examined the relation between infant sustained attention and brain functional connectivity and their development during infancy with high-density EEG recordings. Fifty-nine infants were tested at six (N = 15), eight (N =14), ten (N = 17), and twelve (N = 13) months. Infant sustained attention was defined by measuring infant heart rate changes during infants’ looking. Functional connectivity was estimated from the electrodes on the scalp and with reconstructed cortical source activities in brain regions. It was found that infant sustained attention was accompanied by attenuated functional connectivity in the dorsal attention and default mode networks in the alpha band. Graph theory analyses showed that there was an increase in path length and a decrease in clustering coefficient during infant sustained attention. The functional connectivity within brain networks and the graph theory measures of path length and clustering coefficient were found to increase with age. The characteristic of small-worldness was found for infants at 6 and 8 months in the alpha and beta bands. These findings suggest that infant sustained attention is accompanied by distinct patterns of brain functional connectivity. The current findings also provide convergent evidence for the rapid development of functional connectivity in brain networks during infancy.
Xie, W., & Richards. J.E. (2018). Development of Brain Functional Connectivity and Its Relation to Infant Sustained Attention in the First Year of Life. International Conference on Infant Studies, Philadelphia, July, 2018.conference2018Introduction: Infant sustained attention is a type of endogenous attention that is characterized by a deceleration in heart rate (HR) and represents the arousal state of infants (Colombo, 2001; Richards, 1989). The study of brain functional connectivity is crucial to understanding the neural mechanisms underlying the improved behavioral performance (Mallin & Richards, 2012) and amplified ERP responses (Xie & Richards, 2016a, b) observed during infant sustained attention. Previous investigations on the development of functional brain connectivity during infancy are primarily confined to the use of functional and structural MRI techniques. The current study examined the relation between infant sustained attention and brain functional connectivity and their development during infancy with high-density EEG recordings.
Method: Fifty-nine infants were tested at six (N = 15), eight (N =14), ten (N = 17), and twelve (N = 13) months. Infant sustained attention was defined by measuring infant heart rate changes during infants’ looking. Functional connectivity was estimated with the weighted phase lag index (WPLI) between electrodes on the scalp and between reconstructed cortical source activities in brain regions for infant theta (2 – 6 Hz), alpha (6 – 9 Hz), and beta (9 – 13 Hz) frequency bands. Age-appropriate average MRI templates (Richards et al., 2015) were used to create head and brain models for cortical source reconstruction. Graph theory measures (e.g., path length and clustering coefficient) were used to capture the changes in the overall architecture of brain networks. Figure 1 demonstrates the pipeline for source-space functional connectivity analysis.
Results: It was found that infant sustained attention was accompanied by attenuated functional connectivity in the dorsal attention and
default mode networks in the alpha band. Figure 2 depicts the connectivity within these two networks and how it was different between sustained attention and inattention. Graph theory analyses showed that there was an increase in path length and a decrease in clustering coefficient during infant sustained attention compared to inattention. The functional connectivity within brain networks and the graph theory measures of path length and clustering coefficient were found to increase with age. The characteristic of small-worldness was found for infants at 6 and 8 months in the alpha and beta bands.
Discussion: These findings suggest that infant sustained attention is accompanied by distinct patterns of brain functional connectivity. The attenuated within network connectivity in the alpha band for the dorsal attention and default mode networks might suggest the release of inhibition for these attention networks, which in turn influences infants’ behavioral and physiological activities. The current findings also provide convergent evidence for the rapid development of functional connectivity in brain networks during infancy. The methods used in the current study suggest that cortical source analysis with EEG data can be used with infant participants to study the functional connectivity in brain networks.
Guy. M., Richards, J.E. & Roberts, J.E. (2018). Accurate head models for cortical source analysis in infants at high risk of autism spectrum disorders. International Conference on Infant Studies, Philadelphia, July, 2018.conferenceDownload2018 The aim of this study was to develop the first realistic head models for use with infants at high risk of autism spectrum disorders (ASD) and to test these head models in the source analysis of electrophysiological data collected during face processing. The optimal approach for source analysis involves using realistic head models based upon individual participants’ structural MRIs, however, this is not always feasible. Careful selection of alternative head models is important to accurate source localization, and may be critical when examining infants at high-risk of neurodevelopmental disorders. Twelve-month-old participants included two high-risk groups, 21 infant siblings of children with ASD (ASIBs) and 15 infants diagnosed with fragile X syndrome (FXS), and 21 typically developing, low-risk control (LRC) infants. All participants completed a face processing ERP experiment. Structural MRIs were collected from a subset of the participants. Realistic head models were created from the MRIs; materials within the head were identified, segmented, and assigned a relative conductivity. Current density reconstruction (CDR) of the N290 ERP component was done with head models created from participants’ own MRIs to examine activation in regions of interest (ROIs) believed to be highly relevant to face processing. CDR activity was analyzed in an ANOVA including participant group, stimulus type, and ROI. There were main effects of stimulus type, F(1, 38) = 17.01, p = 0.0002, reflecting greater activation to faces than toys, and of ROI, F(17, 646) = 20.43, p < 0.0001, reflecting high levels of activation in the middle fusiform gyrus and anterior temporal brains areas. Subsequent source analyses were completed with ASIB and FXS groups to determine the impact of head model on CDR activation. We tested head models created from infants’ own MRIs against those created from the average of study- and group-specific MRIs, group-specific MRIs obtained from the Infant Brain Imaging Study (IBIS; 25 FXS MRIs, 53 ASIB MRIs), and MRIs collected from TD infants. An ANOVA tested effects of head model, participant group, and ROI on CDR activity. There was a significant effect of head model, F(3, 51) = 13.30, p < 0.0001, reflecting similar CDR across own-MRI and IBIS head models, but not study-specific and TD head models. There was an interaction of head model and stimulus type, F(3,51) = 3.88, p = 0.0141, reflecting similar differentiation of responses to faces and toys in the own-MRI and IBIS head models, and less differentiation in study-specific and TD head models. An interaction of head model and ROI, F(51, 867) = 6.23, p < 0.0001, indicated that while the IBIS head model was the best alternative to infants’ own MRIs, the quality of fit varied across ROI. Results indicate that head model selection is important to accurate source analysis and may be complex in high risk groups. IBIS head models proved the best match to infants’ own MRIs, possibly due to greater heterogeneity in the brains of infants at high risk of ASD that was better accounted for in a model created from a large collection of group-specific MRIs.
Richards, J.E. (2018). Development of diffuse optical tomography sensitivity in infants. International Conference on Infant Studies, Philadelphia, July, 2018.conferenceDownload2018Development of diffuse optical tomography sensitivity in infants.
‘Near-Infrared-Optical-Spectroscopy’ (NIRS) is a tool for neuroimaging in infant participants. NIRS measurement works by emitter/detector optodes placed on the scalp that measure reflected light from oxygenated / deoxygenated hemoglobin. Diffuse optical tomography (DOT) describes the scattering of light through the interior of the head. The sensitivity profile derived from DOT may be used to identify the underlying cortical anatomy that is reflected to the detector optodes. The current study used simulated photon migration methods to map the DOT sensitivity of infants in the first year. The DOT sensitivity profiles were used to complement spatial projection methods for a comprehensive database of scalp-location-to-cortical-anatomy for infants. The DOT sensitivity volumes may be used for inverse modeling of cortical activity from NIRS recordings (e.g., Homer2 and AtlasViewer) for either individuals or average MRI templates from the Neurodevelopmental MRI Database.
The structural MRI volumes came from individual infants and average templates (3, 4.5, 6, 7.5, 9, and 12 months; also 2, 4, 12, and 20-24 years) from the “Neurodevelopmental MRI Database”. The DOT sensitivity was estimated on each MRI with photon migration simulation programs (e.g. MCX; tMCimg; MMC) by projecting 100M photons from scalp locations into a segmented MRI volume and recording the flux from the projection at each voxel in the MRI. The scalp locations were scattered semi-uniformly on the scalp (10-5 EEG placements). These locations were used as emitter/detector DOT channels centered on the 81 locations of the 10-10 EEG placement system.
Figure 1 shows the fluence (summed flux) as a function of the distance from the 10-10 locations for a 6-month-old participant and for the average over all participants for this age. The peak, slope derivative location, and half-height-half-width location are marked on the graphs. These results imply that about 15-22 mm is the maximum depth sensitivity for NIRS recording (bottom panel); though this differs across the head (top panel). The fluence level was smaller and the sensitivity profile was flatter for emitter/detector distances from 30 to 40 mm, than from 15 to 29 mm. Figure 2 shows the avg peak depth for the MCX DOT sensitivity profile over age. There was a decrease in the depth of the peak location from 3 to 12 months, and this increased from 2 years through adults.
The DOT sensitivity profiles were used to estimate the contribution of cortical ROIs to the NIRS signal recorded on the scalp. Stereotaxic atlas volumes were used to define the cortical ROIs. Several methods for detecting the ROI contribution were compared (location of max DOT. average DOT in 3 mm sphere, distribution of DOT sensitivity across ROIs). ‘Lookup tables’ were constructed that have anatomical locations from three stereotaxic atlases separated by each 10-10 location, age, average or aggregated individuals. There was good consistency for the ROis across the photon simulation methods, and DOT sensitivity locations. The DOT sensitivity profiles provided a quantitative measure of the photon sensitivity across the multiple ROIs for a single emitter/detector channel.
Richards, J.E., & Stevens, M.L. (2018). Television program comprehensibility and distractibility in 24-month children. International Conference on Infant Studies, Philadelphia, July, 2018.conferenceDownload2018Distractibility during television viewing may be used to examine children’s attention. There is increasing cognitive engagement that holds fixation towards the television as long as attention is engaged by the program content. The program comprehensibility or age-appropriateness are determinants of attention engagement. The present study examined the effect of program comprehensibility on distractibility in 24-month-old children by using a variety of audio-visual television programs.
The ages of the children were 24 months. There were 7 conditions of 15 participants each (N = 105). The conditions were the presentation for 6 min of a known comprehensible and age-appropriate Sesame Street program (FTB: “Follow that Bird”), and the presentation for 6 min of one of several audio-visual stimuli that varied in language and format. These include programs such as: Backward speech FTB; Spanish-language FTB; English-Elmo; Mandarin-Elmo; Richard Scarry; Blues Clues; synchronized geometric patterns and audio wave file sounds. Distractors were presented on an adjacent TV screen at irregular intervals for 5 s. Distraction latency, distraction probability, and signal detection parameters were dependent variables. The independent variables were the type of foreground stimulus and the duration of the look at the occurrence of distractor onset.
First, there was a main effect of foreground stimulus type on distraction latency and probability. Figure 1 shows the average distraction RT and probability as a function of stimulus type. The “Follow that Bird” had the longer RTs and smaller distraction probability than the “Geometry-Waves”, Richard Scarry, or Backward-FTB. The larger RT and smaller distraction probability indicate more attention engagement to the FTB. Somewhat surprising, both the Elmo-English and Elmo-Mandarin TV programs showed the most attention engagement for all stimuli. The FTB program showed more attention engagement than the less comprehensible program for all but the Elmo video. Second, for all stimuli types, the longer the look was in progress before distractor onset, the less likely the infants were distracted by the peripheral presentation. Figure 2 shows distraction probability as a function of the duration of the look at distractor onset, separately for the comprehensible FTB and the other stimuli. The pattern of lower probability with increasing look duration was similar for both stimulus types. Figure 2 also shows the signal detection parameter, c, as a function of the duration of the look. The decreasing negative values across look durations indicate a bias against responding. The bias against responding (?, c) increased as a function of look length, whereas measures of sensitivity (d') were not different across prior look duration or comprehensibility conditions.
These results confirm the relation between distractibility and comprehensibility. The more comprehensible and age-appropriate stimulus, “Follow that Bird”, elicited enhanced attention (distraction latency and probability) compared with the other stimuli. The exception to this were the “Elmo” videos. Perhaps these videos are especially age-appropriate, even so far as to over-ride the mismatch between the child’s language and the Mandarin language. Signal detection analysis revealed an increasing bias against responding accounted for the look duration effect.
Richards, J.E. (2018). Development of Diffuse Optical Tomography sensitivity in infants: Brain localization of NIRS activity. Sackler Developental Psychobiology Meeting, Hawaii, January 2018conferenceDownload2018 ‘Near-Infrared-Optical-Spectroscopy’ (NIRS) is a tool for neuroimaging in infant participants. NIRS measurement works by source/detector optodes placed on the scalp that measure reflected light from oxygenated / deoxygenated hemoglobin. Diffuse optical tomography (DOT) is used to describe the scattering of light through the interior of the head. The sensitivity profile derived from DOT may be used to identify the underlying cortical anatomy that is reflected to the detector optodes and the relative contributions of anatomical regions. The current study uses simulated photon migration programs to map the DOT sensitivity of infants in the first year. The results map the sensitivity of the infant head to light propagation. The DOT sensitivity profiles for individual infants is used to complement spatial projection methods and adds to a comprehensive database of scalp-location-to-cortical-anatomy for infants. These results were also compared to results for older age participants, and the sensitivity profiles for an age may be used in quantitative methods that use inverse modeling to show NIRS activity in the brain.
Guy. M., Richards, J.E. & Roberts, J.E. (2018). Cortical Source Analysis of ERP Responses to Faces in Etiologically Distinct Groups of Infants at High-Risk for ASD. INSAR, Rotterdam, Netherlands, May 2018.conference2018Background:
The aim of this study was to examine cortical sources active during face processing in two groups of infants at high-risk of autism spectrum disorder (ASD). Event-related potentials (ERPs) associated with specialized face processing (i.e., N290) were measured in response to faces and toys across high-risk groups, including infant siblings of children with ASD (ASIBs) and infants diagnosed with fragile X syndrome (FXS), as well as low-risk control (LRC) infants (Guy, Richards, Tonnsen, & Roberts, 2017). All groups demonstrated greater amplitude N290 responses to faces than toys. Infants with FXS displayed the greatest amplitude N290 and most differentiated responses to faces and toys.

Objectives:
Cortical source analysis was utilized to investigate whether group differences in ERP responses corresponded to different levels of activation in brain regions most closely linked to specialized face processing or differences in areas active during face processing.

Methods:
Twelve-month-olds were recruited for this study, including 21 ASIBs, 15 infants diagnosed with FXS, and 21 LRC infants. All participants completed an ERP experiment including face and toy stimuli. Structural MRIs were collected from a subset of the participants and a group-specific (ASIB, FXS, or LRC) average head model was used to complete source analysis in infants that did not contribute their own MRI (Guy, Richards, & Roberts, 2017). Realistic head models were created from the MRIs. Current density reconstruction (CDR) of the N290 was calculated to examine activation in regions of interest (ROIs) believed to be relevant to face processing. CDR activity was analyzed in an ANOVA including the factors of participant group, stimulus type, and ROI.

Results:
There was a significant main effect of stimulus type, F(1, 55) = 21.47, p < .0001, reflecting greater activation to faces than toys. There was a stimulus type by ROI interaction, F(17, 935) = 4.91, p < .0001, due to higher levels of activation in response to faces than toys in the middle fusiform gyrus and nearby temporal and occipital brain areas. Additionally, an interaction of group, stimulus type, and ROI was observed, F(34, 935) = 1.45, p = .0465. As shown in Figure 1, LRC infants demonstrated greatest levels of activation in response to faces in brain areas most closely linked to specialized face processing (i.e., middle fusiform gyrus, anterior fusiform gyrus, parahippocampal gyrus, lingual gyrus), but infants with FXS were the only participant group to display higher levels of activation to faces than toys across all ROIs examined.

Conclusions:
The results provide evidence for unique patterns of neural activation during face processing across infants at high- and low-risk for ASD, and across distinct high-risk groups. All infants demonstrated greater activation to faces than toys in brain areas most associated with specialized face processing, but only infants with FXS consistently displayed higher levels of activation to faces across a broad range of areas analyzed. These results indicate that greater amplitude N290 responses observed in infants with FXS are due to an increased area of activation during face processing, rather than greater activation in specialized face processing areas.
Tonnsen, B., Richards, J.E., & Roberts, J.E. (2018). Heart Rate-Defined Sustained Attention in Infants at Risk for Autism. Journal of Neurodevelopmental Disorders.journal2018Background: Although aberrant visual attention has been identified in infants at high familial risk for autism, the onset and mechanisms these profiles remain unclear. Integrating biomarkers of attention into prospective high-risk infant studies may inform more nuanced developmental trajectories, clarifying the onset and course of atypical attention and potentially advancing early screening or treatment protocols. Heart rate-defined sustained attention (HDSA) is a well-validated biomarker of attentional engagement that, in non-clinical infant populations, provides incremental information about attentional engagement beyond looking behaviors alone. The present study aimed to examine the characteristics and clinical correlates of HDSA in high-risk infants, informing whether HDSA may operate as a promising biomarker of attention and clinical symptoms in this population.
Methods: We examined age-related patterns of HDSA during a passive looking task in 5-14 month old high-risk infant siblings of children with autism (n=21) compared to low risk controls (n=21), with most participants contributing multiple assessments. Emergent autism features were measured using the Autism Diagnostic Observation Schedule at 24 months. Primary dependent variables included the proportion of time in behavioral attention, proportion of time in HDSA, and average heart rate deceleration during HDSA. For each variable, we used nested multilevel models to examine whether attention differed by group, as well as whether attention predicted emergent autism features among HR infants.
Results: As expected, HDSA served as a global biomarker of attention in high-risk infants, predicting greater variability in group risk status than behavioral looking alone. Among high-risk infants, more severe ASD features were also associated with increasingly shallow HDSA decelerations across development, suggesting abnormal qualities of HDSA may inform individual differences within this population.
Conclusions: These preliminary findings provide initial evidence that HDSA may offer a sensitive, affordable, and portable biomarker of attention that may enhance understanding of atypical attention in high-risk infants. Using this method, we also provide initial evidence that atypical patterns of heart activity previously reported in children and adults with autism may emerge in the first year of life, warranting further study of how HDSA may specifically inform attention profiles in ASD.
Richards, J.E. (2018). Media effects on young children: An attention development perspective. Media Exposure and Child Development, NIH, January 2018.conferenceDownload2018Conclusions:
 
From age 3 mo to about 12 mo, minor effects of video program on extended fixations. Neural development of several “core attention systems” affecting fixation and attention. Development of brain systems for attending to the environment and likely social brain development. Synchronized audio-visual stimuli elicit most attention
 
18 and 24 months--Comprehensible and age-appropriate stimuli elicit extended fixations and hear rate indicating attention engagement.
Reynolds, G.D., & Richards J.E. (in press). Infant visual attention and stimulus repetition effects on object recognition. Child Development.journal2017This study examined behavioral, heart rate (HR), and event-related potential (ERP) correlates of attention and recognition memory for 4.5-, 6-, and 7.5-month-old infants during stimulus encoding. Attention was utilized as an independent variable using HR measures. The Nc ERP component associated with attention and the Late Slow Wave (LSW) associated with recognition memory were analyzed. 7.5-month-olds demonstrated a significant reduction in Nc amplitude with stimulus repetition and stimulus type. This reduction in Nc was not found for younger infants. Additionally, infants only demonstrated differential LSW amplitude based on stimulus type on attentive trials as defined by HR changes. These findings indicate that from 4.5 to 7.5 months, infants' attentional engagement is influenced by an increasingly broader range of stimulus characteristics.
Guy, M.W., Richards, J.E., Tonnsen, B., & Roberts, J.E. (2017). Neural correlates of face processing in etiologically-distinct 12-month-old infants at high-risk of autism spectrum disorder. Developmental Cognitive Neuroscience.journalDownload2017Neural correlates of face processing were examined in 12-month-olds at high-risk for autism spectrum disorder (ASD), including 21 siblings of children with ASD (ASIBs) and 15 infants with fragile X syndrome (FXS), as well as 21 typically developing (TD) controls. Event-related potentials were recorded to familiar and novel face and toy stimuli. All infants demonstrated greater N290 amplitude to faces than toys. At the Nc component, TD infants showed greater amplitude to novel stimuli than to their mother’s face and own toy, whereas infants with FXS showed the opposite pattern of responses and ASIBs did not differentiate based on familiarity. These results reflect developing face specialization across high-risk and TD infants and reveal neural patterns that distinguish between groups at high-risk for ASD.
Courage, M.L., Richards, J.E. Attention. In Reference Module in Neuroscience and
Biobehavioral Psychology, Elsevier, 2017. ISBN 9780128093245
chapterDownload2017
Buzzell, G. A., Richards, J. E., White, L. K., Barker, T. V., Pine, D. S., & Fox, N. A. (2017). Development of the error-monitoring system from ages 9–35: unique insight provided by MRI-constrained source localization of EEG. Neuroimage. doi:https://doi.org/10.1016/j.neuroimage.2017.05.045journalDownload2017The ability to self-detect errors and dynamically adapt behavior is a cornerstone of higher-level cognition, requiring coordinated activity from a network of neural regions. However, disagreement exists over how the error-monitoring system develops throughout adolescence and early adulthood. The present report leveraged MRI-constrained EEG source localization to detail typical development of the error-monitoring system in a sample of 9-35 year-olds. Participants performed a flanker task while high-density EEG was recorded; structural MRIs were also acquired for all participants. Analysis of the scalp-recorded EEG data revealed a frontocentral negativity (error-related negativity; ERN) immediately following errors for all participants, although the topography of the ERN varied with age. Source localization of the ERN time range revealed maximal activity within the posterior cingulate cortex (PCC) for all ages, consistent with recent evidence that the PCC provides a substantial contribution to the scalp-recorded ERN. Activity within a network of brain regions, including dorsal anterior cingulate, PCC, and parietal cortex, was predictive of improved performance following errors, regardless of age. However, additional activity within insula, orbitofrontal cortex and inferior frontal gyrus linearly increased with age. Together, these data suggest that the core error-monitoring system is online by early adolescence and remains relatively stable into adulthood. However, additional brain regions become embedded within this core network with age. These results serve as a model of typical development of the error-monitoring system from early adolescence into adulthood.
Emberson, L.E., Crosswhite, S., Richards, J.E., & Aslin, R.N. (2017). The lateral occipital cortex (LOC) is selective for object shape, not texture/color, at 6 months. Journal of Neuroscience, 37, 3698-3703; DOI: https://doi.org/10.1523/JNEUROSCI.3300-16.2017.journalDownload2017Understanding how the human visual system develops is crucial to understanding the nature and organization of our complex and varied visual representations. However, previous investigations of the development of the visual system using fMRI are largely confined to a subset of the visual system (high-level vision: faces, scenes) and relatively late in visual development (starting at 4-5 years of age). The current study extends our
understanding of human visual development by presenting the first systematic investigation of a mid-level visual region (the LOC) in a population much younger than has been investigated in the past – 6 month olds. We use fNIRS, an emerging optical method for recording cortical hemodynamics, to perform neuroimaging with this very young population. While previous fNIRS studies have suffered from imprecise neuroanatomical localization, we rely on the most rigorous MR-coregistration of fNIRS data to date to
image the infant LOC. We find surprising evidence that at 6 months the LOC has functional specialization that is highly similar to adults. Following Cant and Goodale (2007), we investigate whether the LOC tracks shape information and not other cues to object-identity (e.g., texture/material). This finding extends evidence of LOC
specialization from early childhood into infancy and earlier than developmental trajectories of high-level visual regions.
Xie, W., Mallin, B.A., & Richards, J.E. (2017). Development of infant sustained attention and its relation to EEG oscillations: An EEG and cortical source analysis study. Developmental Science.journal2017The current study examined the relation between infant sustained attention and infant EEG oscillations. Fifty-nine infants were tested at six (N=15), eight (N=17), ten (N=14), and twelve (N=13) months. Three attention phases, stimulus orienting, sustained attention, and attention termination, were defined based on infants’ heart rate changes. Frequency analysis using simultaneously recorded EEG focused on infant theta (2 – 6 Hz), alpha (6 – 9 Hz), and beta (9 – 14 Hz) rhythms. Cortical source analysis of EEG oscillations was conducted with realistic infant MRI models. Theta synchronization was found over fontal pole, temporal, and parietal electrodes during infant sustained attention for 10- and 12-months. Alpha desynchronization was found over frontal, central and parietal electrodes during sustained attention. This alpha effect started to emerge at 10 months and became well established by 12 months. The theta synchronization effect was localized to the orbital frontal, temporal pole, and ventral temporal areas. The alpha desynchronization effect was localized to the brain regions composing the default mode network including the posterior cingulate cortex and precuneus, medial prefrontal cortex, and inferior parietal gyrus. The alpha desynchronization effect also was localized to the pre- and post-central gyri. The present study demonstrates a connection between infant sustained attention and EEG oscillatory activities.
Emberson, L.E., Cannon, G., Palmeri, H., Richards, J.E., & Aslin, R.N. (2016). http://dx.doi.org/10.1016/j.dcn.2016.11.002. Using fNIRS to Examine Occipital and Temporal Responses to Stimulus Repetition in Young Infants: Evidence of Selective Frontal Cortex Involvement. Developmental Cognitive Neuroscience.journalDownload2016How does the developing brain respond to recent experience? Repetition suppression (RS) is a robust and wellcharacterized response of to recent experience found, predominantly, in the perceptual cortices of the adult brain. We use functional near-infrared spectroscopy (fNIRS) to investigate how perceptual (temporal and occipital) and frontal cortices in the infant brain respond to auditory and visual stimulus repetitions (spoken words and faces). In Experiment 1, we find strong evidence of repetition suppression in the frontal cortex but only for auditory stimuli. In perceptual cortices, we find only suggestive evidence of auditory RS in the temporal cortex and no evidence of visual RS in any ROI. In Experiments 2 and 3, we replicate and extend these findings. Overall, we provide the first evidence that infant and adult brains respond differently to stimulus repetition. We suggest that the frontal lobe may support the development of RS in perceptual cortices
Xie, W., & Richards, J. E. (2016). Effects of interstimulus intervals on behavioral, heart rate, and event-related potential indices of infant engagement and sustained attention. Psychophysiology, 53, 1128-1142. doi:10.1111/psyp.12670journalDownload2016Maximizing infant attention to stimulus presentation during an electroencephalogram (EEG) or event-related potential (ERP) experiment is important for making valid inferences about the neural correlates of infant cognition. The present study examined the effects of stimulus presentation interstimulus interval (ISI) on behavioral and physiological indices of infant attention including infants’ fixation to visual presentation, the amount of heart rate (HR) change during sustained attention, and ERP components. This study compared an ISI that is typically used in infant EEG/ERP studies (e.g., 1500 – 2000 ms) with two shorter durations (400 – 600 ms and 600 – 1000 ms). Thirty-six infants were tested cross-sectionally at 3, 4.5, and 6 months. It was found that using the short (400 – 600 ms) and medium (600 – 1000 ms) ISIs resulted in more visually fixated trials and reduced frequency of fixation disengagement per experimental block. We also found larger HR changes during sustained attention to both of the shorter ISIs compared with the long ISI, and larger ERP responses when using the medium ISI compared to using the short and long ISIs. These data suggest that utilizing an optimal ISI (e.g., 600 – 1000 ms), which increases the presentation complexity and provides sufficient time for information processing, can promote infant engagement and sustained attention during stimulus presentation.
Emberson, L., Riccio, J., Richards, J.E., Guillet, R., & Aslin, R. (2016). Comparing How Statistical Learning Supports Perceptual Expectations in Infants at Low and High Risk for Developmental Delays. Poster presented at the International Conference on Infant Studies, New Orleans, LA, May, 2016.conference2016
Buzell, G.A., Richards, J.E., White, L.K., Pine, D.S., & Fox, N.A. (2017). Development of the error-monitoring system from ages 9-35: unique insight provided by MRI-constrained source localization of EEG. Poster presented at the Cognitive Neuroscience Society, San Francisco, CA, April, 2017.conferenceDownload2016The ability to identify mistakes and dynamically adapt behavior is a cornerstone of higher-level cognition, requiring coordinated activity from a network of neural regions. However, a detailed account of how the error-monitoring system develops throughout adolescence and early adulthood remains absent from the literature. The present report leveraged MRI-constrained EEG source localization in order to detail the normative development of the error-monitoring system in a sample of 9-35 year-olds. In order to elicit errors, participants performed a flanker task while high-density EEG was recorded; structural MRIs were also acquired for all participants. Analysis of the scalp-recorded EEG data revealed a frontocentral negativity (error-related negativity; ERN) immediately following errors for all participants, although the topography of the ERN effect varied with age. Source localization of the ERN time range revealed maximal activity within the posterior cingulate cortex (PCC) for all ages, consistent with recent evidence that the PCC provides a substantial contribution to the scalp-recorded ERN. Activity within a network of brain regions, including dorsal anterior cingulate, PCC, and parietal cortex, were predictive of improved performance following errors, regardless of age. However, additional activity within insula, orbiotfronal cortex and inferior frontal gyrus linearly increased with age. Together, these data suggest that the core error-monitoring system is online by early adolescence and remains relatively stable throughout adolescence and early adulthood. However, maturity leads to additional brain regions becoming embedded within this core network. These results can serve as a model of neurotypical development of the error-monitoring system throughout adolescence and early adulthood.
Guy, M. W., Richards, J. E., & Roberts, J. E. (April, 2017). Accurate head models for cortical source analysis of face processing in infants at high risk of autism spectrum disorders. Poster to be presented at the biennial meeting of the Society for Research in Child Development, Austin, Texas.conferenceDownload2016The aim of this study was to develop the first realistic head models for use with infants at high risk of autism spectrum disorders (ASD) and to test these head models in the source analysis of electrophysiological data collected during face processing. The optimal approach for source analysis involves using realistic head models based upon individual participants’ structural MRIs, however, this is not always feasible. Careful selection of alternative head models is important to accurate source localization, and may be critical when examining development in infants at high-risk of neurodevelopmental disorders due to the possibility of greater variability in brain structure. Participants included two groups of high risk 12-month-olds, including 21 infant siblings of children with ASD (ASIBs) and 15 infants diagnosed with fragile X syndrome (FXS), contrasted to 21 typically developing (TD) 12-month-old infants. All participants completed an ERP experiment including face and toy stimuli. Structural MRIs were collected from a subset of the participants. Realistic head models were created from the MRIs, in which materials within the head were identified, segmented, and assigned a relative conductivity. Current density reconstruction (CDR) of the N290 ERP component was done with head models created from participants’ own MRIs to examine activation in regions of interest (ROIs) believed to be highly relevant to face processing. CDR activity was analyzed in an ANOVA including the factors of participant group, stimulus type, and ROI. Results replicated previous findings (Guy et al., 2016; Richards et al., 2016). There was a main effect of stimulus type, F(1, 40) = 21.99, p < .0001, reflecting greater activation to faces than toys, and a main effect of ROI, F(13, 520) = 16.24, p < .0001, reflecting high levels of activation in the middle fusiform gyrus and anterior temporal brains areas. Subsequent source analyses were completed with ASIB and FXS groups to determine the impact of head model on CDR activation. We tested head models created from infants’ own MRIs against those created from the average of study- and group-specific MRIs, group-specific MRIs obtained from the Infant Brain Imaging Study (IBIS; 25 FXS MRIs, 53 ASIB MRIs), and MRIs collected from TD infants. An ANOVA tested effects of head model, participant group, and ROI on CDR activity. There was a significant effect of head model, F(3, 54) = 10.85, p < .0001. CDR was similar across own-MRI and IBIS head models, which differed from study-specific and TD head models. An interaction of head model and ROI, F(39, 702) = 4.14, p < .0001, indicated that while the IBIS head model was the best alternative to infants’ own MRIs, the quality of fit varied across ROI. Results indicate that head model selection is important to accurate source analysis and may be complex in high risk groups. IBIS head models proved the best match to infants’ own MRIs, possibly due to greater heterogeneity in the brains of infants at high risk of ASD that was better accounted for in a model created from a large collection of group-specific MRIs.
Xie, W., & Richards, J.E. (2016).The Relation between Infant Covert Orienting, Sustained Attention and Brain Activity. Poster presented at the International Conference on Infant Studies, New Orleans, LA, May, 2016.conferenceDownload2016The current study investigated the cortical activity involved in infant covert orienting, and how it would be affected by the stimulus onset asynchrony (SOA) duration.
We measured infant ERPs and applied cortical source analysis to measure the current density amplitudes in brain ROIs that are likely involved in covert orienting 1,2.
We used the spatial cueing paradigm and tested separate groups of infants in the short and long SOA conditions to increase the number of trials and presumably enhance the power for finding a significant difference between short and long SOA conditions.
The current study also aimed to determine the effect of sustained attention on infant brain activity involved in covert orienting.
We used ECG recording to define infant sustained attention and inattention periods3,4. The ECG recording was synchronized with EEG recording.
We found the effect of cue-target validity on infant ERP responses differs with the SOA conditions.
E.g., The P1 validity effect was only shown in the short SOA condition, which is consistent with behavioral and adult ERPs research2,5,6,7.
Cortical source analysis showed that the (contralateral) inferior occipital and ventral temporal regions activated differently between the valid, invalid, and neutral conditions.
Infant sustained attention was found to modulate infants’ brain responses in covert orienting by enhancing the P1 and N1 ERP responses and current density amplitude in their cortical sources during sustained attention.
Conclusion: the neural mechanisms that underpin covert orienting already exist in 3- to 4.5-month-olds, and they could be facilitated by infant sustained attention.
Richards, J.E., Guy, M., Zieber, N., Xie, W., & Roberts, J.E. (2016). Brain changes in response to faces in the first year. Poster presented at the International Conference on Infant Studies, New Orleans, LA, May, 2016.conferenceDownload2016Young infants in the first year have dramatic changes in their processing of faces, going from simple perceptual sensitivity through recognition and preference for familiar faces. It is likely that these changes are caused by, or accompanied by, changes in the brain areas known in adults to be involved in face processing. We report data from infants from 3 through 12 months of age that shows the development of scalp-recorded event-related-potentials in response to faces and objects, in the brain areas supporting these ERP components, and in the effect of attention on the face processing / brain development. This work quantifies the specialization of brain areas for face processing in the infant.
Richards, J.E., Guy, M., Zieber, N., Xie, W., & Roberts, J.E. (2017). Brain changes in response to faces in the first year. Paper presented at the Society for Research in Child Development, Austin, TX. April, 2017.conferenceDownload2016Brain changes in response to faces in the first year

Infant’s behavioral responses to faces changes over the first year. These changes often are hypothesized to result from experience-dependent changes in the brain areas that process faces. The course of development in those brain areas has not been directly studied over the first year. The current study examined the neural response of infants to pictures of faces and objects from 4.5 months through 12 months with event-related potentials (ERP) and cortical source analysis with realistic head models.

Method: Infants were tested at 4.5 (N = 25), 6 (N = 26), 7.5 (N = 19), 9 (N = 10) or 12 (N = 24) months. The infants were presented with brief (500 ms) stimuli on a computer monitor. The stimuli were pictures of women’s faces, or infant-oriented toys. A 128-channel EEG recording system (EGI, Eugene, OR) was used for EEG recording. The ERPs in response to the faces were calculated for the P1, N290, P400, and Nc components. Cortical source analysis used the current density reconstruction (CDR) technique and realistic head models based on structural MRIs of the infant or an infant with a close-sized head.

ERP Components: Figure 1 shows the ERP responses to faces and toys in the occipital, lateral parietal, and frontal central leads. The ERP components in response to faces and toys were examined separately for the ERP components. We found the P1 amplitude at about 100 ms post-stimulus-onset was larger for faces and toys overall, but the difference between faces and toys increased over age, especially from 6 to 12 months (Figure 2a). Similarly, the N290, a negative deflection in the ongoing ERP about 290 ms following stimulus onset, also showed this increasing differentiation in responses to faces and toys, becoming larger over age to the face stimuli (Figure 2b). The P400 and Nc components differed for faces and toys at the earliest ages, but by 12 months were at the same level.

Cortical Sources: The neural sources of the ERP components were identified with cortical source analysis in “regions-of-interest” (ROIs) theoretically involved in face processing. The sources of the P1 component were generally found in the lateral occipital and posterior-lateral temporal areas (e.g., lateral inferior occipital gyrus; posterior portion of the inferior temporal gyrus). The activity of the CDR across the time interval of the P1 paralleled the P1 responses upon which the analysis was based, and showed the same increasing differentiation over age. The sources of the N290 were in the middle fusiform gyrus, anterior fusiform gyrus, parahippocampal gyrus, and temporal pole. The increase from 4.5 to 7.5 months of age in the ERP component showed an increasingly peaked response in the middle fusiform gyrus though the overall CDR amplitude to faces and toys were similar. By 9 and 12 months of age the CDR amplitude in this and adjacent neural areas differed for faces and toys, and also showed the enhanced peak around the time of the N290 peak amplitude.
Guy, M., Zieber, N, & Richards, J.E. (2016). The cortical sources of face sensitive ERP components in infancy. Poster presented at the International Conference on Infant Studies, New Orleans, LA, May, 2016.conferenceDownload2016The aim of the current study was to examine the neural development of face processing in infancy by recording event-related potentials (ERPs) and to determine the cortical sources of these neural signals. Developmental changes in the amplitude and latency of infant ERP components (i.e., N290, P400, Nc) were examined in response to faces and toys at 4.5, 6, and 7.5 months of age. ERP responses were greater in amplitude during heart rate (HR)-defined phases of attention than inattention at all components examined. The N290 was greater in amplitude to faces during attention than toys during attention. The P400 was greater in amplitude to toys than faces. The neural regions responsible for the ERP components’ activation were investigated through the application of current density reconstruction (CDR), realistic head models derived from individual infant MRIs, and age-appropriate infant head templates. Source analyses were restricted to specific cortical regions of interest (ROIs) theoretically expected to be sensitive to faces.

The linear trend to both faces and toys during the time window of the N290 likely reflects the emerging P400 and Nc activity occurring after the N290 latency, whereas the quadratic trend to faces in the older participants reflects the cortical source of the N290 deflection in the ERP. Results indicate that brain areas associated with face specific processing show greater activation with age.
The results of this study are included in the manuscript, “The cortical development of specialized face processing in infancy,” currently in press in Child Development. Additionally, the data are included in a broad analysis of the development of face processing across the first year of life
Xie, W., & Richards, J.E. (2017). The relation between infant covert orienting, sustained attention and brain activity. Brain Topography, 30, 198-219. DOI: 10.1007/s10548-016-0505-3journalDownload2016This study used measures of event-related potentials (ERPs) and cortical source analysis to examine the effect of covert orienting and sustained attention on 3- and 4.5-month-old infants’ brain activity in a spatial cueing paradigm. Cortical source analysis was conducted with current density reconstruction (CDR) using realistic head models created from age-appropriate infant MRIs. The validity effect was found in the P1 ERP component that was greater for valid than neutral trials in the electrodes contralateral to the visual targets when the stimulus onset asynchrony (SOA) was short. Cortical source analysis revealed greater current density amplitude in the primary visual cortex and ventral temporal regions for valid than neutral and invalid trials between the P1 and N1 peak latencies. The processing cost effect was found in the N1 component and current density amplitude in the extrastriate cortex, which were greater for neutral than invalid trials in the short SOA condition. Infant sustained attention was found to modulate the brain responses in covert orienting by enhancing the P1 and N1 ERP responses and current density amplitude in their cortical sources during sustained attention. These findings suggest that the neural mechanisms that underpin covert orienting already exist in 3- to 4.5-month-olds, and they could be facilitated by infant sustained attention.
Xie, W., & Richards, J.E. (2017). The Relation between Infant Sustained Attention and EEG Oscillations: An EEG Power Spectrum and Cortical Source Analysis Study.conferenceDownload2016Introduction: Infant sustained attention is characterized by a deceleration in heart rate (HR) and an increase in brain arousal (Richards, 2008). Increased brain arousal facilitates visual perception and memory encoding (Colombo, 2001). Infant EEG studies have reported alpha suppression/desynchronization in frontal electrodes during memory encoding (Bell, 2002) and in central electrodes (Mu rhythm) during action perception (Marshall et al., 2011). Infant theta synchronization was found in frontal channels during anticipatory attention (Orekhova et al., 1999). Alpha desynchronization is a robust electrical index of brain arousal in adulthood (Sadaghiani et al., 2010). Adult alpha activity has been correlated to activity in the default mode network (DMN; Knyzazev et al., 2011). The DMN shows deactivation when brain alertness increases (Mantini et al., 2007). The current study examined the potential relation between infant sustained attention (brain alertness) and alpha and theta activities using EEG and cortical source analysis.
Method: Fifty-nine infants were tested at 6 (N=15), 8 (N=17), 10 (N=14), and 12 (N=13) months of age. Participants watched Sesame Street videos that elicited different attention phases (Richards, 2010). Three attention phases were defined based on HR changes during infants’ looking. They were stimulus orienting (before HR deceleration), sustained attention (HR deceleration), and attention termination (HR acceleration). Fast Fourier Transform was applied on EEG segments (1s) and power spectrum was calculated for theta (2 – 5 Hz) and alpha (6 – 9 Hz) bands. Cortical source analysis was conducted with realistic infant MRI models and current density reconstruction (CDR) technique.
Results: Theta band: Infants at 8, 10, and 12 months showed greater theta power during sustained attention than attention termination and stimulus orienting in the frontal-pole (FP1, FP2) and occipital (O1, O2) electrodes. Cortical source analysis showed greater CDR amplitude for sustained attention in the inferior and middle temporal gyri and the orbitofrontal gyrus. Alpha band: Infants at 10 and 12 months showed lower alpha power during sustained attention in the frontal (F3, F4), central (C3, C4), and parietal (P3, P4) electrodes. Cortical source analysis showed the alpha activity was widely spread in the brain with high CDR amplitude in the occipital lobe. However, difference between attention phases (alpha suppression) was found in the posterior cingulate cortex, precuneus, and pre- and post-central gyri.
Discussion: The current study demonstrates a link between infant sustained attention and EEG oscillatory activities. The finding of alpha desynchronization during sustained attention is consistent with the alpha desynchronization found during tonic alertness in adulthood. Two cortical sources of this effect, the posterior cingulate cortex and precuneus, are major components of the adult DMN. These findings support the idea that infant sustained attention is accompanied by an increase in brain arousal. The finding of alpha suppression in the precentral gyrus suggests distinct infant Mu activity might occur during sustained attention because infants were watching videos with characters dancing. Infant theta synchronization during sustained attention is comparable to the report of theta synchronization during anticipatory attention. Theta synchronization in the orbitofrontal gyrus may reflect the activation of the anterior attention system subserving executive control.
Guy, M., Richards, J.E., Tonnsen, B., & Roberts, J.E. (2016). Neural correlates of face processing associated with risk of autism spectrum disorders in infancy. Poster presented at the International Conference on Infant Studies, New Orleans, LA, May, 2016.conferenceDownload2016Neural correlates of face processing were examined in two groups of 12-month-old infants at high-risk for autism spectrum disorders (ASD), infant siblings of children with ASD (ASIBs) and infants with fragile X syndrome (FXS), as well as a group of typically developing (TD) controls. Event-related potentials (ERPs) were recorded to familiar and novel face and toy stimuli. Atypical processing of faces has been well documented in ASD1 and research suggests that ASIBs may display different ERP responses from TD infants in the first year of life2,3. Examination of the early emergence of ASD-associated features in FXS may inform early risk factors specific to FXS, as well as broader heterogeneous pathways of ASD emergence. Our expectation that distinct electrophysiological responses would differentiate the high-risk ASD groups from each other and the TD group was supported. The Nc response was significantly greater in TD and FXS groups than ASIBs. Different patterns of Nc responses to familiar and novel stimuli indicated ASIBs were less responsive to the stimuli than other groups and infants with FXS may show immature stimulus processing. Greater amplitude N290 in response to faces than toys across participant groups reflects the developing specialization of face processing despite risk factor. Despite shared risk for ASD, infants with FXS and ASIBs exhibit distinct patterns of attention and face processing, potentially reflecting syndrome-specific pathways to similar behavioral outcomes.
Guy, M. W., Zieber, N. and Richards, J. E. (2016), The Cortical Development of Specialized Face Processing in Infancy. Child Development. doi: 10.1111/cdev.12543journalDownload2015The aim of the current study was to expand knowledge of specialized face processing in 4.5- to 7.5-month-old infants by recording event-related potentials (ERPs) in response to faces and toys, and to determine the cortical sources of these signals using realistic, age-appropriate head models. All ERP components (i.e. N290, P400, Nc) showed greater amplitude during periods of attention than inattention. Amplitude was greater to faces than toys during attention at the N290 and Nc, and greater to toys at the P400. Cortical source analysis revealed activity in occipital-temporal brain areas as the source of the N290, particularly the middle fusiform gyrus. The Nc and P400 were the result of activation in midline frontal/parietal, anterior temporal, and posterior temporal/occipital brain areas.
Ding, X.P., Richards, J.E., Xie, W., Fu, G., & Lee, K. (2015). Neurodevelopment of honesty and dishonesty: A functional near-infrared spectroscopy (fNIRS) study. Paper presented at the Society for Research in Child Development conference, Philadelphia, PA. March, 2015.conference2015
Richards, J.E. & Xie, W. (2015). Brains for all the ages: Structural neurodevelopment in infants and children from a life-span perspective. In J. Benson (Ed.), Advances in Child Development and Behavior (Volume 48, chapter 1, pps 1-52). Philadephia, PA: Elsevier. DOI:10.1016/bs.acdb.2014.11.001chapter2015Magnetic Resonance Imaging (MRI) is a non-invasive method to measure brain structure and function that may be applied to human participants of all ages. This chapter reviews our recent work creating a life-span neurodevelopmental MRI database. It provides age-specific reference data in fine-grained age-intervals from 2 weeks through 89 years. The reference data include average MRI templates, segmented tissue priors, and a common stereotaxic atlas for pediatric and adult participants. The database will be useful for neuroimaging research over a wide range of ages, and may be used to make lifespan comparisons. The chapter reviews the application of this database to the study of neurostructural development, including a new volumetric study of segmented brain tissue over the lifespan. We also show how this database could be used to create “study-specific” MRI templates for special groups and apply this to the MRIs of Chinese children. Finally we review recent use of the database in the study of brain activity in pediatric populations.
Keywords: Structural MRI, Neurodevelopmental MRI Database, brain development, brain-behavior relation, neurostructural development (or, brain structure development, structural neurodevelopment).
Emberson, L.E., Richards, J.E., & Aslin, R.N. (2015). Top-down modulation in the infant brain: Learning-induced expectations rapidly affect the sensory cortex at 6-months. Proceedings of the National Academy of Sciences.journalDownload2015Recent theoretical work emphasizes the role of expectation in neural processing, shifting the focus from feed-forward cortical hierarchies to models which include extensive feedback (e.g., predictive coding). Empirical support for expectation-related feedback is compelling but restricted to adult humans and non-human animals. Given the considerable differences in neural organization and efficiency between infant and adult brains, it is a crucial yet open question whether expectation-related feedback is an inherent property of the cortex (i.e., operational early in development) or whether expectation-related feedback develops with extensive experience and neural maturation. To determine whether an infant’s expectations about future sensory input modulates their sensory cortices without the confounds of stimulus novelty or repetition suppression, we employed a cross-modal (audiovisual) omission paradigm and used functional near-infrared spectroscopy (fNIRS) to record hemodynamic responses in the infant cortex. We show that the occipital cortex of 6-month-old infants exhibits the signature of expectation-based feedback.
Guy, M. W., Zieber, N. and Richards, J. E. (2016; Supplemental Information), The Cortical Development of Specialized Face Processing in Infancy. Child Development. Doi: 10.1111/cdev.12543journalDownload2015The aim of the current study was to expand knowledge of specialized face processing in 4.5- to 7.5-month-old infants by recording event-related potentials (ERPs) in response to faces and toys, and to determine the cortical sources of these signals using realistic, age-appropriate head models. All ERP components (i.e. N290, P400, Nc) showed greater amplitude during periods of attention than inattention. Amplitude was greater to faces than toys during attention at the N290 and Nc, and greater to toys at the P400. Cortical source analysis revealed activity in occipital-temporal brain areas as the source of the N290, particularly the middle fusiform gyrus. The Nc and P400 were the result of activation in midline frontal/parietal, anterior temporal, and posterior temporal/occipital brain areas.
Richards, J.E., Guy, M.W., & Zieber, N. (2015). Cortical sources of the face-sensitive N290 component in infants. Paper presented at the Flux Conference, Leiden, Netherlands, September 2015.conference2015Specialized processing of faces begins early in life, yet we are just beginning to understand the neural underpinnings of the development of face expertise in infancy. In infants, the N290, is a negative deflection over posterior regions peaking at 290ms that is greater in amplitude for faces than visual noise (Halit, Csibra, Volein, & Johnson, 2004). In the current study, infants’ ERPs were recorded while infants of three different ages (4.5, 6, and 7.5 months) passively viewed faces and objects (toys). Cortical source analysis with realistic head models was used to identify the location of the cortical sources of this component.
Infants viewed a series of brief stimulus presentations (500 ms) of images of their own mother, another infant’s mother, their own toy, or another infant’s toy randomly interspersed across trials. High-density EEGs were recorded using an EGI 128-channel Geodesic Sensor Net. The N290 component increased in amplitude from 4.5 to 7.5 months, and was different to faces and toys. Current Density Reconstruction (CDR) with realistic head models and anatomically-defied ROIs were used to examine the sources of the component. There was a peak in the CDR at in the middle fusiform gyrus at the time of the N290; this peak was greater for faces than toys, and increased across age. There was a generalized response across several other lateral brain areas that did not show this N290 latency peak, and these appear to be precursors of ERP components occurring later in processing (i.e.g, P400, Nc)
Richards, J.E., Sanchez, C., Phillips-Meek, M., & Xie, W. (2015). A Neurodevelopmental MRI database for neuroimaging across the lifespan. Paper presented at the Flux Conference, Leiden, Netherlands, September 2015.conferenceDownload2015The study of neurostructural development or neurofunctional development has been hampered by the lack of age-appropriate MRI reference volumes. Many of the procedures used to analyze pediatric MRIs are based on reference data derived from adults. However, the use of adult reference data for pediatric populations results in misclassification of brain tissue, misspecification of segmented atlas regions, and large variability between participants. This is true for young infants, children, and even for elderly adults. A solution to this problem has been the creation of reference MRI data based on age-segregated populations
We have created the “Neurodevelopmental MRI Database” that provides age-specific reference data from 2 weeks through 89 years of age. The data are presented in fine-grained ages (e.g., 3 months intervals through 1 year; 6 months intervals through 19.5 years; 5 year intervals from 20 through 89 years). There are four types of MRI volumes at each age. These are 1) age-specific average MRI templates, 2) segmented partial volume estimates for segmenting priors, 3) a common stereotaxic atlas for infant, pediatric, and adult participants, and 4) tools for doing electrical source analysis (EEG, e.g., electrodes, head models) and for NIRS optode locations (e.g., scalp-to-cortex mapping). The database is available online (http://jerlab.psych.sc.edu/NeurodevelopmentalMRIDatabase/).
Fillmore, P.T., Phillips-Meek, M., & Richards, J.E. (2015). Age-specific MRI brain and head templates for healthy adults from twenty through eighty-nine years of age. Frontiers in Aging Neuroscience. Front. Aging Neurosci. doi: 10.3389/fnagi.2015.00044journalDownload2015This study created and tested a database of adult, age-specific MRI brain and head templates. The participants included healthy adults from 20 through 89 years of age. The templates were done in 5-year, 10-year, and multi-year intervals from 20 through 89 years, and consist of average T1W for the head and brain, and segmenting priors for GM, WM, and CSF. It was found that age-appropriate templates provided less biased tissue classification estimates than age-inappropriate reference data and reference data based on young adult templates. This database is available for use by other investigators and clinicians for their MRI studies, as well as other types of neuroimaging and electrophysiological research (http://jerlab.psych.sc.edu/NeurodevelopmentalMRIDatabase/).
Lanfer, B., Spangler, R. Richards J.E., & Paul-Jordanov, I. (23015). Age-specific template head models for EEG source analysis. Paper presented at the Organization for Human Brain Mapping Meeting, Honolulu HA, June, 2015.conferenceDownload2015Incorporating the realistic anatomy of the head into the solution of the EEG forward problem improves the accuracy and reliability of EEG source analysis [1]. Individual realistic head models can be derived from the subject's MRI. In infants and children MRI data are often difficult to collect. However, source analysis accuracy would particularly benefit from realistic head models in children, as head tissue structure differs vastly from adults. A solution might be to use age-specific template models representing the child-typical anatomy. In this work, we describe a pipeline for EEG source analysis with age-specific head model templates. In addition, a study is presented demonstrating the feasibility of the template models.
Roberts, J.E., Tonnsen, B., Guy, M., Hahn, L, & Richards, J.E. (2015). Biobehavioral correlates of Autism Spectrum Disorder in infants with Fragile X Syndrome. 48th Annual Gatlinburg Conference, Gatlinburg, TN, April, 2015conferenceDownload2015Introduction: Young males with fragile X syndrome (FXS) are at high risk for autism spectrum disorders (ASD) with up to 70% meeting diagnostic criteria. While early identification efforts in idiopathic non-fragile X ASD have accelerated given the known benefits of early treatment, relatively little work exists focused on early detection of autism in FXS. Identification of ASD in very young children, however, is fraught with challenges given the complexity of identifying ASD amidst the rapid developmental changes in social behavior, cognition and language that occur in early childhood. Consequently, consideration of prodromal and symptom level factors during infancy has increased as has recognition of the role of biomarkers in identifying putative mechanistic factors. The overarching aim of this presentation is to identify the relationship of multiple biomarkers to ASD features in infants with FXS contrasted to typically developing infants (TD) and infants with older siblings diagnosed with ASD (SIBS). We will present data reflecting neural correlates (event-related potentials) of face processing and baseline autonomic measures (heart activity) in relation to ASD features.


Methods: Across both ongoing studies, 54 infants 12 months of age (17 FXS, 17 SIBS, 20 TD) participated. Autism symptoms were assessed using the Autism Observation Scale for Infants, and ASD diagnoses were determined using the Autism Diagnostic Observation Schedule 2. Event related potentials were measured in response to images of the child’s own mother (familiar social),favorite toy (familiar object) contrasted to an unfamiliar woman, and unfamiliar toy (500 ms duration). High-density EEG’s were recorded using a 128-channel net. Grand averages and peak amplitudes were calculated to capture the N290. The Nc was calculated from 350 to 700 ms post-stimulus onset. Heart activity was also collected during a passive viewing task as part of the larger battery in a subset of participants (9 FXS, 15 SIBS, 12 TD). Dependent measures included inter-beat interval, respiratory sinus arrhythmia, and proportion of time in heart-defined sustained attention, a period of decelerative heart rate that is associated with greater stimulus engagement in typically developing infants (e.g.Richards & Casey, 1991). We anticipate increased samples for both studies for the presentation.


Results: Results from the ERP study indicated a main effect for trial (F(1,88)=4.96; p<.01) with a larger amplitude for faces than toys for all groups for the N290. Results also indicated a marginal interaction effect (F(2,33)=2.79; p<.08) suggesting a larger effect for the toy than face stimuli for the FXS and SIBS groups. Also, evidence suggested that infants with FXS and elevated ASD symptoms showed a larger Nc to the stranger than to their mother that was not observed in the TD, SIBS and the FXS group with a low number of ASD symptoms. Preliminary heart activity data indicated that groups did not differ in inter-beat interval, respiratory sinus arrhythmia, and qualities of heart-defined sustained attention (Kruskal-Wallis p>.10). However, across groups, higher AOSI scores were associated with greater proportion of time in heart-defined sustained attention (r=.36, p=.03) and increased behavioral looking time (r=.41, p=.02).


Discussion: The larger P400 in the SIBS and FXS groups may reflect an object-based preference for processing. Also, the heightened Nc response to the stranger in the FXS group with elevated ASD symptoms could signal a relationship of ASD to neural components associated with attention and cognitive processing. Heart activity data indicate that increased heart defined sustained attention predicted elevated ASD symptoms across groups. These preliminary results indicate that biomarkers are sensitive to detect early markers of risk for ASD in vulnerable populations.

Xie, W., Richards, J.E., Lei, D., Lee, K., & Gong, Q. (2015). Comparison of brain development trajectory between Chinese and US children and adolescents. Poster presented at the Society for Research in Child Development conference, Philadelphia, PA. March, 2015.conferenceDownload2015Over the past two decades, a many studies with structural MRI have contributed to our understanding of trajectories of brain development throughout childhood and early adulthood (e.g., Giedd et al., 1999; Lenroot et al., 2007). It should be noted, however, that these studies only included data from North American or Western European participants and thus it is unclear whether the current knowledge about brain structural development reflects a universal pattern of development or specific to one specific cultural-racial group. The latter possibility cannot be ruled out due to the fact that MRI studies with adults have found brain morphometric and volumetric differences between Asian and North American adults (Lee et al., 2005; Tang et al., 2010). No study has directly compared the brain development patterns and brain anatomical features between Asian and American child populations. To bridge this important gap in the literature, this project explored differences in brain development trajectories and anatomical features between Chinese and US children and adolescents.
Our results revealed both regional and age differences in both brain/head morphological and tissue level development between Chinese and US children. Chinese children brain and head were shorter, wider, and higher than US children. There were significant differences in the gray matter (GM) and white matter (WM) intensity between the two nationalities. Chinese children were found to have higher GM intensity but lower WM intensity in general compared to age-related US cohorts. Development trajectories for cerebral volume, GM, and certain brain structures were also distinct between these two populations.
These anatomical differences between Chinese and US children found in our study suggest the necessity for population-specific brain/head templates and atlas, and data processing and analyzing for neuroimaging research with Chinese/Asian children and adolescents. Therefore, this project also developed novel T1-weighted average brain and head templates for Chinese children from 7 to 16 years of age in two-year increments using high quality MR images and well-validated image analysis techniques. A total of 138 Chinese children (51 F/ 87 M) were included in this study.
The internal validation registrations showed these Chinese age-specific templates fit Chinese children's MR images significantly better than age-appropriate templates based on US children, or adult templates based on either Chinese or US adults. An external validation confirmed the fit of the templates to Chinese children MRIs for a new set of children who were not included in the template construction. We found age-inappropriate brain templates (e.g. the Chinese56 template, the US20-24 template) or nationality- inappropriate templates (e.g. the US children templates, the US20-24 template) do not provide optimal reference MRIs for processing MR brain images for Chinese developmental cohorts. Thus, our age-specific MRI templates should be useful in neuroimaging studies with children from Chinese or other Asian populations. These templates are available for use on http://jerlab.psych.sc.edu/neurodevelopmentalmridatabase.
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Richards, J.E., Sanchez, C., Phillips-Meek, M., & Xie, W. (2015) A database of age-appropriate average MRI templates. Neuroimage, doi:10.1016/j.neuroimage.2015.04.055journalDownload2015This article summarizes a life-span neurodevelopmental MRI database. The study of neurostructural development or neurofunctional development has been hampered by the lack of age-appropriate MRI reference volumes. This causes misspecification of segmented data, irregular registrations, and the absence of appropriate stereotaxic volumes. We have created the “Neurodevelopmental MRI Database” that provides age-specific reference data from 2 weeks through 89 years of age. The data are presented in fine-grained ages (e.g., 3 months intervals through 1 year; 6 months intervals through 19.5 years; 5 year intervals from 20 through 89 years). The base component of the database at each age is an age-specific average MRI template. The average MRI templates are accompanied by segmented partial volume estimates for segmenting priors, and a common stereotaxic atlas for infant, pediatric, and adult participants. The database is available online (http://jerlab.psych.sc.edu/NeurodevelopmentalMRIDatabase/).
Xie, W., Richards, J.E., Lei, D., Zhu, H., Lee, K., & Gong, Q. (2015). The construction of MRI brain / head templates for Chinese children from 7 - 16 years of age. Developmental Cognitive Neuroscience.journalDownload2015Population-specific brain templates that provide detailed brain information are beneficial to both structural and functional neuroimaging research. However, age-specific MRI templates have not been constructed for Chinese or any Asian developmental populations. This study developed novel T1-weighted average brain and head templates for Chinese children from 7 to 16 years of age in two-year increments using high quality magnetic resonance imaging (MRI) and well-validated image analysis techniques. A total of 138 Chinese children (51 F/ 87 M) were included in this study. The internally and externally validated registrations show that these Chinese age-specific templates fit Chinese children’s MR images significantly better than age-specific templates created from U.S. children, or adult templates based on either Chinese or North American adults. It implies that age-inappropriate (e.g., the Chinese56 template, the US20-24 template) and nationality-inappropriate brain templates (e.g., U.S. children’s templates, the US20-24 template) do not provide optimal reference MRIs for processing MR brain images of Chinese pediatric populations. Thus, our age-specific MRI templates are the first of the kind and should be useful in neuroimaging studies with children from Chinese or other Asian populations. These templates can also serve as the foundations for the construction of more comprehensive sets of nationality-specific templates for Asian developmental populations. These templates are available for use in our database.
Xie, W., & Richards, J.E. (2015). The effects of interstimulus interval on infant attention and face perception: An event-related potentials study. Poster presented at the Society for Research in Child Developmen conferencet, Philadelphia, PA. March, 2015.conferenceDownload2015Introduction: Infant attention and face perception develop dramatically in the first 6 months. Electroencephalogram (EEG) and event-related potentials (ERPs) have been used as measurements of cortical responses in infant attention and face perception studies. Typical presentation sequences for infant ERP studies use interstimulus-intervals (ISI) of about 2 - 3 s; however, this presentation rate may be too long to sustain fixation and attention in young infants. Using shorter ISIs increases presentation rate and complexity may facilitate infant sustained attention and engagements in an EEG/ERP study. In this study, we examined 1) the effect of shorter ISIs on infant EEG/ERP studies; 2) infant face sensitive ERPs development from 3 to 6 months; 3) the effects of attention on infant face sensitive ERPs.

Methods. Infants at 3 or 6 months of age (N = 23) were presented with brief (500 ms) stimuli on a computer monitor. The stimuli were adult female faces, male and female infant faces, and objects. The stimuli presentations were separated by ISIs of 400 to 600 ms, 600 to 1000 ms, and 1500 ms to 2000 ms. Electrocardiogram (ECG) and EEG data were recorded. A high-density, 128-channel EEG recording system (EGI, Eugene, OR) was used for EEG recording. The ERP averages were obtained from the EEG recordings. We quantified the components separately for the faces (female, infant) and toys, attention/inattention based on heart rate changes, and age. In addition, we measured infant behavior (fixation to presentation) and heart rate (ECG) data as indexes of their attention engagement.

Results: a) behavioral results showed using shorter ISIs (shorter, medium) facilitated infant visual fixation to stimulus presentation in an EEG/ERP study. Significantly more trials were collected using shorter ISI than long ISI for all three age groups (Figure1). b) Heat rate results showed a main effect of age, that 3 mos sustained attention period was longer than older groups during an visual EEG study; the effect of ISI type is marginal. c) EEG/ERPs results showed clear development of N290 and P400 (amplitude and latency) from 3 to 6 months (Figure 2); infants at all three ages showed larger N290 and P400 responses to faces than toys; the short ISI condition resulted in more ambiguous face/toy N290 and P400 responses than longer ISI conditions for 3-month-olds; there was an interaction effect of attention and stimulus types; attention has a main effect on N290 amplitude.

Discussion: Shorter ISIs (short and medium in current study) facilitates infant attention and engagement in an EEG/ERP study. The effect of ISI was minimal on the 6-month-old ERP responses, but had a large effect on 3-month-olds. This suggests that 3-month-olds may need longer intervals to fully process these types of brief stimuli, whereas older infants direct attention efficiently to the short ISI presentation rate. Comparison of the ERPs between 3 and 6 months indicates the development of infant face processing. Interaction effect of attention and stimulus implies that attention may affect face and object perception differently.
Richards, J.E. (2015). Scalp locations projected to cortical anatomy for infant NIRS. Paper presented at the Society for Research in Child Development conference, Philadelphia, PA. March, 2015.conferenceDownload2015 Introduction : 'Near-Infrared-Optical-Spectroscopy' (NIRS) has become a popular tool for neuroimaging in infant participants. NIRS measurement works by emitter/detector optodes placed on the scalp that measure reflected light from oxygenated / deoxygenated hemoglobin. The changes in oxygenated / deoxygenated hemoglobin reflect hemodynamic responses to changes in neural activity, and may be used as a functional neuroimaging tool. NIRS measurement occurs entirely on the scalp surface. The cortical anatomical areas generating the NIRS signal cannot be identified simply with external scalp measurements. Methods have been developed for adult participants that show the relation between external scalp locations and underlying cortical anatomy. The current study presents a comprehensive database of scalp-location-to-cortical-anatomy in infants from 3 to 12 months of age. The presentation also illustrates methods to identify cortical anatomical locations for NIRS optodes/channels in individual infant participants.


Methods: Structural MRI volumes came from individual infants and from average MRI templates (3, 4.5, 6, 7.5, 9, and 12 months). The MRI volumes were either 3.0T 1x1x1 3D MRIs done at the McCausland Center for Brain Imaging (MCBI), or 1.5T 1x1x3 2D MRIs from the NIH longitudinal study of MRI (NIHPD).


First, a database of scalp locations to cortical locations was made. The 'Virtual 10-10' electrode locations were done on the scalp of individual infant or average MRI head volumes. These locations were projected inward to the extracted cortex of the MRI (Figure 1). Stereotaxic atlas volumes were used to determine the anatomical location of the projected 10-10 optode. 'Lookup tables' were constructed that have anatomical locations separated by each 10- 10 location, age, average or aggregated individuals, for four stereotaxic atlases. There was mild consistency across the averages and aggregations for the identification of cortical anatomical locations projected to by each 10-10 optode location.


Second, methods were developed for identifying optode locations and cortical projections for individual participants. This was done for participants for whom both a structural MRI and a NIRS recording was done (Lloyd-Fox et al, 2013).


Results:
The NIRS holder / optode / channels were located on the scalp for each participant MRI and the underlying cortical anatomy was identified. The identification of optodes was done for a group of infants that had a NIRS recording but did not have a structural MRI (Emberson et al, 2013, submitted). In this case the optode locations on the individuals were used to place optode locations on an age-appropriate average MRI template, or on an individual MRI with a head size similar to the NIRS participant. Figure 2 shows this NIRS holder on a 3-d rendered scalp, and the corresponding channel projections on the brain. There were discrepancies between the cortical anatomical locations based on the average MRI and individual MRI; suggesting that individual structural MRIs give some advantage to cortical identification.


Finally, these methods may be used for participants for whom the 3-D spatial locations are known, by registering the spatial locations of the optodes to the participant's own MRI, to an age-appropriate average MRI, or a MRI from a 'library' of infant MRIs.

Tonnsen, B., Richards, J.E., & Roberts, J.E. (2015). Heart-defined sustained attention in infant siblings of children with Autism. 48th Annual Gatlinburg Conference, Gatlinburg, TN, April, 2015.conferenceDownload2015See PDF
Fillmore, P.T., Richards, J.E., Phillips-Meek, M.C., Cryer, A., & Stevens, M. (2015) Stereotaxic MRI brain atlases for infants from 3 to 12 months. Developmental Neuroscience. DOI:10.1159/000438749journalDownload2015Accurate labeling of brain structures within an individual or group is a key issue in neuroimaging. Methods for labeling infant brains have depended on the labels done on adult brains or average MRI templates based on adult brains. However, the features of adult brains differ in several ways from infant brains, so the creation of a labeled stereotaxic atlas based on infants would be helpful. The current work builds on recent creation of age-appropriate average MRI templates during the first year (3, 4.5, 6, 7.5, 9, and 12 months), by creating anatomical label sets for each template. Methods: We created stereotaxic atlases for the age-specific average MRI templates. Manual delineation of cortical and subcortical areas was done on the average templates based on infants during the first year. We also applied a procedure for automatic computation of macroanatomical atlases for individual infant participants using two manually segmented adult atlases (Hammers, LPBA40). To evaluate our methods, we did manual delineation of several cortical areas on selected individuals from each age. Linear and nonlinear registration of the individual and average template was used to transform the average atlas into the individual participant’s space, and the average transformed atlas was compared to the individual manually delineated brain areas. We also applied these methods to an external dataset, not used in the atlas creation, to test generalizability of the atlases. Results: Age-appropriate manual atlases were the best fit to the individual manually delineated regions, with more error seen at greater age discrepancy. There was a close fit between the manually delineated and the automatically labeled regions for individual participants, and for the age-appropriate template based atlas transformed into participant space. There was close correspondence between automatic labeling of individual brain regions, and those from the age-appropriate template. Finally, these relationships held, even when tested on an external set of images. Conclusion: We have created age-appropriate labeled templates for use in the study of infant development at 6 ages (3, 4.5, 6, 7.5, 9, and 12 months). Comparison with manual methods was quite good. We developed three stereotaxic atlases (one manual, two automatic) for each infant age, which should allow fine-grained analysis of brain structure for these populations than was previously possible with existing tools. The template-based atlases constructed in the current study are available online (http://jerlab.psych.sc.edu/NeurodevelopmentalMRIDatabase).
Keywords: atlas, MRI, neurodevelopment, infant
Green, J. J., Gamble, M. L., & Woldorff, M. G. (in press). Resolving conflicting views: Gaze and arrow cues do not trigger rapid reflexive shifts of attention. Visual Cognition.journalDownload2014It has become widely accepted that the direction of another individual's eye gaze induces rapid, automatic, attentional orienting, due to it being such a vital cue as to where in our environment we should attend. This automatic orienting has also been associated with the directional-arrow cues used in studies of spatial attention. Here, we present evidence that the response-time cueing effects reported for spatially nonpredictive gaze and arrow cues are not the result of rapid, automatic shifts of attention. For both cue types, response-time effects were observed only for long-duration cue and target stimuli that overlapped temporally, were largest when the cues were presented simultaneously with the response-relevant target, and were driven by a slowing of responses for invalidly cued targets rather than speeding for validly cued ones. These results argue against automatic attention-orienting accounts and support a novel spatial-incongruency explanation for a whole class of rapid behavioural cueing effects.
Richards, J.E. (2014). Scalp locations projected to cortical anatomy for infant NIRS. Poster presented at the International Conference on Infant Studies, Berlin, Germany, July 2014.conferenceDownload2014 Introduction : 'Near-Infrared-Optical-Spectroscopy' (NIRS) has become a popular tool for neuroimaging in infant participants. NIRS measurement works by emitter/detector optodes placed on the scalp that measure reflected light from oxygenated / deoxygenated hemoglobin. The changes in oxygenated / deoxygenated hemoglobin reflect hemodynamic responses to changes in neural activity, and may be used as a functional neuroimaging tool. NIRS measurement occurs entirely on the scalp surface. The cortical anatomical areas generating the NIRS signal cannot be identified simply with external scalp measurements. Methods have been developed for adult participants that show the relation between external scalp locations and underlying cortical anatomy. The current study presents a comprehensive database of scalp-location-to-cortical-anatomy in infants from 3 to 12 months of age. The presentation also illustrates methods to identify cortical anatomical locations for NIRS optodes/channels in individual infant participants.


Methods: Structural MRI volumes came from individual infants and from average MRI templates (3, 4.5, 6, 7.5, 9, and 12 months). The MRI volumes were either 3.0T 1x1x1 3D MRIs done at the McCausland Center for Brain Imaging (MCBI), or 1.5T 1x1x3 2D MRIs from the NIH longitudinal study of MRI (NIHPD).


First, a database of scalp locations to cortical locations was made. The 'Virtual 10-10' electrode locations were done on the scalp of individual infant or average MRI head volumes. These locations were projected inward to the extracted cortex of the MRI (Figure 1). Stereotaxic atlas volumes were used to determine the anatomical location of the projected 10-10 optode. 'Lookup tables' were constructed that have anatomical locations separated by each 10- 10 location, age, average or aggregated individuals, for four stereotaxic atlases. There was mild consistency across the averages and aggregations for the identification of cortical anatomical locations projected to by each 10-10 optode location.


Second, methods were developed for identifying optode locations and cortical projections for individual participants. This was done for participants for whom both a structural MRI and a NIRS recording was done (Lloyd-Fox et al, 2013).


Results:
The NIRS holder / optode / channels were located on the scalp for each participant MRI and the underlying cortical anatomy was identified. The identification of optodes was done for a group of infants that had a NIRS recording but did not have a structural MRI (Emberson et al, 2013, submitted). In this case the optode locations on the individuals were used to place optode locations on an age-appropriate average MRI template, or on an individual MRI with a head size similar to the NIRS participant. Figure 2 shows this NIRS holder on a 3-d rendered scalp, and the corresponding channel projections on the brain. There were discrepancies between the cortical anatomical locations based on the average MRI and individual MRI; suggesting that individual structural MRIs give some advantage to cortical identification.


Finally, these methods may be used for participants for whom the 3-D spatial locations are known, by registering the spatial locations of the optodes to the participant's own MRI, to an age-appropriate average MRI, or a MRI from a 'library' of infant MRIs.

Xie, W., & Richards, J.E. (2014). The effects of interstimulus intervals on infant attention and face perception: An event-related potentials study. Poster presented at the International Conference on Infant Studies, Berlin, Germany, July 2014.conferenceDownload2014

Introduction. Sustained attention is one type of the endogenous attentional function that affects infant cognitive processes. Faces are socially significant and ubiquitous in humans’ daily lives. Both Infant sustained attention and face perception develop dramatically in the period of 3 to 6 months. Electroencephalograph (EEG) and Event-related Potentials (ERPs) have been used as measurements of cortical responses in both infant attention and face perception studies (e.g., the Nc, N290, P400). Interstimulus Interval (ISI) is the time period between the offset of one stimulus presentation and the onset of the next stimulus presentation. The effect of ISIs on infant sustained attention is still unknown. The relationship between infant attention development and face perception development has not been examined either. This study examined the effects of various ISIs on infant sustained attention and face perception. Infant face perception development and its relation to infant attention development were also investigated.

Methods. Three types of ISIs were employed in this study. They were 400 -600 ms, 600 -1000 ms, and 1500 ms to 2000 ms. Three types of stimuli including female faces, infant faces, and objects will be used in this study. Infants at 3, 4.5, and 6 months of age will be recruited in the present study (N = 8). Electrocardiogram (ECG) and EEG data were recorded in this study. A high-density, 128-channel EEG recording system produced by the Electrical Geodesics Incorporated (EGI, Eugene, OR) was used for EEG recording. The The ERPs data were obtained from the EEG recordings, and three ERPs components are measured: Nc (attention), N290 and P400 (face processing).

Results. Infants have larger N290 and P400 responses to faces than toys (Figure 1). Figure 1 also indicates that three months show similar N290 responses to faces and toys but have larger P400 responses with shorter latency to faces than toys. By contrast, six months show clear larger N290 and P400 responses to faces than toys. Figure 2 shows that infants have different cortical responses to faces in different attentional phases defined by their heart rate data. Specifically, the N290 and P400 response to faces is smaller in amplitude and slower in latency when infants are paying attention. In the three types of ISIs conditions infant have different N290 responses to stimuli: N290 responses to stimuli (faces and toys) increase as the ISIs increase (Figure 2). In addition, faces and objects presented within the short ISI condition did not elicit clear different N290 and P400 responses for 3-month-olds; however, faces and toys in the short ISI condition did cause clear different ERP responses for 6-month-olds.

Discussion. Face-sensitive ERPs components (N290, P400) exhibit young infant distinct cortical responses to faces than objects. To our knowledge, this is the first study that possibly show larger P400 responses to faces than objects in 3- to 6-months infants. The findings of the N290 are consistent with previous research (e.g., Halit et al., 2003, 2004). Comparison of these ERPs between 3 and 6 months also indicates the development of infant face processing. Different patterns of ERPs responses in different attentional phases might suggest that infant attention has impact on their face processing. However, they might also due to unequal trials in different attentional phases. Another interesting finding is that short ISIs might be used in ERPs experiments with older infants; however, for young infants (e.g., 3 months), high rate presentations might not give them enough time to fully process target information.

Zieber, N., Richards, J.E., Tonnsen, B., Roberts, J.E. (2014). Neural correlates of face processing in infants at risk for Autism and infants with Fragile X Syndrome. Poster presented at the International Conference on Infant Studies, Berlin, Germany, July 2014.conferenceDownload2014Distinct differences in the neural activation to faces have been documented in adults with autism spectrum disorders (ASD). Specifically, this group exhibits significantly longer latencies of the N170 component (a right-lateralized ERP component over lateral posterior regions of the scalp occurring 170ms after stimulus onset) in response to faces than those exhibited by typical controls. Adults with ASD also fail to demonstrate a right hemisphere advantage for faces. In typically developing infants, two ERP components (N290, P400) have been found to be modulated by faces in a similar manner to the adult N170. Yet little research has examined whether this is the case in infants at high risk for developing autism spectrum disorders, and even fewer studies have compared face processing in ASIBs to other groups at high genetic risk for autism, such as infants with fragile X syndrome (the leading known heritable cause of autism). The current study sought to compare early differences in face perception between typically developing (TD) infants, high-risk infant siblings of children with ASD (ASIBS), and infants with Fragile X (FX) syndrome through the recording of event-related potentials (ERPs) to objects and faces at 12 months of age.

The current study is the first to compare face-sensitive ERP components in FXS children. As a group these children are at high-risk for ASD outcome. We found the N290 component to be similar in typically developing, children with an older sibling diagnosed with ASD, and children with FXS/premutations. There were some laterality differences in the three groups, with the TDD infants showing a left face/toy distinction, and theother groups showing smaller laterality effects. The P400 seemed to be larger in the two at-risk groups. This may relflect an object-based preference for processing occurring at the P400 latencies. A compelling finding was that FXS children assessed at 12 months with the AOSI as showing multiple risk signs showed a larger Nc to the stranger than to the mother face, whereas both TDD and ASIB groups showed enhanced Nc response to the mother face. This could mean the early component (N290) more automatic components might not be strongly influenced by the risk factors, whereas the later component is response to processes of attention and cognitive processing.
Lloyd-Fox, S., Richards, J.E., Blasi, A., Murphy, D., Elwell, C.E., & Johnson, M.H. (in press). Co-registering NIRS with underlying cortical areas in infants. Neurophotonics.journalDownload2014Functional Near Infrared Spectroscopy (fNIRS) can localize functional responses to a greater degree than electroenchephalography (EEG), however it cannot provide information about underlying anatomy. Recently researchers have investigated the efficacy of channel placement, conducting spatial registration of NIRS channels to cortical anatomy in adults. The current work, investigated this issue with infants by co-registering NIRS and MRI data from 55 individuals. Our findings suggest that NIRS channels can be reliably co-registered with regions of interest in the frontal and temporal cortex of infants from 4 – 7months of age without the need for individual infant MRIs. We have generated a standardized scalp surface map of fNIRS channel locators to reliably locate cortical regions for NIRS developmental researchers. This map can be used to identify the inferior frontal gyrus (IFG), superior temporal sulcus (STS) region (which includes the superior and middle temporal gyri (MTG) nearest to the STS), MTG and temporal-parietal regions of 4-7 month infants. Future work will model data for the whole head, taking into account properties of light transport in tissue, for infants from 0 – 2 years of age.
Zieber, N., & Richards, J.E. (2014). The developmental origins in infants’ ERP responses to faces and objects. Poster presented at the International Conference on Infant Studies, Berlin, Germany, July 2014.conferenceDownload2014Specialized processing of faces begins early in life, yet we are just beginning to understand the neural underpinnings of the development of face expertise in infancy. Adults exhibit differential neural responses to faces as opposed to other classes of objects, evidenced by a larger N170 amplitude for faces than for objects. The N170 is a negative event-related potential (ERP) component occurring about 170ms post-stimulus onset, and research with infants has found two components that may be precursors to the adult N170. One of these components, the N290, is a negative deflection over posterior regions peaking at 290ms that is greater in amplitude for faces than visual noise (Halit, Csibra, Volein, & Johnson, 2004). In the first year of life, as infants acquire extensive exposure to faces, the N290 begins to differ in response to upright (as opposed to inverted) faces and to human (as opposed to monkey) faces (de Haan, Pascalis, & Johnson, 2002). However, few studies have examined whether changes occur in the morphology of the N290 that correspond to emerging expertise with faces as opposed to other objects. In the current study, infants’ ERPs were recorded while infants of three different ages (4.5, 6, and 8 months) passively viewed faces and objects (toys). We also tested 9- and 12-month-olds (N = 8, 20, respectively).
Thirty-eight infants (14 4.5- month-olds, 12 6-month-olds, and 12 8-month-olds) participated in the study. Infants viewed a series of brief stimulus presentations (500 ms) of images of their own mother, another infant’s mother, their own toy, or another infant’s toy randomly interspersed across trials. High-density EEGs were recorded using an EGI 128-channel Geodesic Sensor Net. The EEG data was analyzed for groups of electrodes over occipito-temporal regions (e.g., around T5, T6, O1, O2, Oz) based upon previous infant studies that have found the N290 to be most prominent over these areas (de Haan et al., 2002). For each participant, ERP grand averages were computed for the time of the target onset, and the peak amplitude was derived using individualized time windows to capture each subject’s N290
The dependent measure was the mean amplitude of the N290 component. A main effect of age was found [F(2, 88)= 5.81; p < .005*], and the increase in the amplitude of the N290 from 4.5 to 7.5 months can be clearly seen in Figure 1. There was also a marginally significant effect of trial type [F(1,88)=3.26; p < .07], as the amplitude was larger for faces than for toys (but the interaction was not significant). Thus, the N290 amplitude was larger for faces than for toys (see Fig. 1), and increased in amplitude across the age groups.
The current study documents a developmental change in the face-sensitive N290 corresponding to a time period when infants are developing expertise with faces. These studies suggest that, like adults, infants demonstrate special processing of faces compared to other objects, and that the N290 is similar to the N170 in that its amplitude is greater to faces than other objects.
McDonald, J. J., Green, J. J., Jannati, A., & Di Lollo, V. (in press). On the electrophysiological evidence for the capture of visual attention. Journal of Experimental Psychology: Human Perception and Performance.journalDownload2014The presence of a salient distractor interferes with visual search. According to the salience-driven selection hypothesis, this interference is because of an initial deployment of attention to the distractor. Three event-related potential (ERP) findings have been regarded as evidence for this hypothesis: (a) salient distractors were found to elicit an ERP component called N2pc, which reflects attentional selection; (b) with target and distractor on opposite sides, a distractor N2pc was reported to precede the target N2pc (N2pc flip); (c) the distractor N2pc on slow-response trials was reported to occur particularly early, suggesting that the fastest shifts of attention were driven by salience. This evidence is equivocal, however, because the ERPs were noisy (b, c) and were averaged across all trials, thereby making it difficult to know whether attention was deployed directly to the target on some trials (a, b). We reevaluated this evidence using a larger sample size to reduce noise and by analyzing ERPs separately for fast- and slow-response trials. On fast-response trials, the distractor elicited a contralateral positivity (PD)—an index of attentional suppression—instead of an N2pc. There was no N2pc flip or early distractor N2pc. As it stands, then, there is no ERP evidence for the salience-driven selection hypothesis.
Emberson, L, Richards, J.E., Aslin, R. (2014). The infant occipital cortex responds to a predictive cross-modal stimulus. Paper presented at the International fNIRS conference, Toronto, CA October, 2014conferenceDownload2014
Xie, W., Richards, J.E., Lei, D., Lee, K., & Gong, Q. (2014). Structural MRI of Chinese brain development and comparison of the brain development trajectory between Chinese and U.S. children and adolescents. Frontiers in Systems Neuroscience. 8:. 10.3389/fnsys.2014.00249journalDownload2014This current study investigated brain development for Chinese and American children and adolescents aged 8 to 16 years using structural magnetic resonance imaging (MRI) techniques. Direct comparisons between Chinese and US children brain/head MR images were performed in order to explore similarities and differences in brain development trajectory between these two groups. Our results revealed both regional and age differences in both brain/head morphological and tissue level development between Chinese and US children. Chinese children brain and head were shorter, wider, and higher than US children. There were significant differences in the gray matter (GM) and white matter (WM) intensity between the two nationalities. Development trajectories for cerebral volume, GM, and certain brain structures were also distinct between these two populations.
Richards, J.E. Boswell, C., Stevens, M., & Vendemia, J.M.C. (2015). Evaluating methods for constructing average high-density electrode positions. Brain Topography, 28, 70-86, doi 10.1007/s01548-014-0400-8journalDownload2014Accurate analysis of scalp-recorded electrical activity requires the identification of electrode locations in 3D space. For example, source analysis of EEG/ERP (electroencephalogram, EEG; event-related-potentials, ERP) with realistic head models requires the identification of electrode locations on the head model derived from structural MRI recordings. Electrode systems must cover the entire scalp in sufficient density to discriminate EEG activity on the scalp and to complete accurate source analysis. The current study compares techniques for averaging electrode locations from 86 participants with the 128 channel “Geodesic Sensor Net” (GSN; EGI, Inc.), 38 participants with the 128 channel “Hydrocel Geodesic Sensor Net” (HGSN; EGI, Inc.), and 174 participants with the 81 channels in the 10-10 configurations. A point-set registration between the participants and an average MRI template resulted in an average configuration showing small standard errors, which could be transformed back accurately into the participants’ original electrode space. Average electrode locations are available for the GSN (86 participants), Hydrocel-GSN (38 participants), and 10-10 and 10-5 systems (174 participants)
Lee, K., Ding, X.P, Richards, J.E., Xie, W., & Fu, G. (2014). Neural correlates of own and other race recognition in preschoolers: A functional near infrared spectocopy (fNIRS) study. Paper presented at the International fNIRS conference, Toronto, CA October, 2014.conference2014
Richards, J.E., and Stevens, M. (submitted). Central stimulus comprehensibility and distractibility in young children’s television viewing.journal2014
Hunter, S.K., & Richards, J.E. (submitted). Development of eye movements in young infants in response to complex dynamic stimuli.journal2014
Henderson, J.M., Luke, S.G., Schmidt, J., and Richards, J.E. (2013). Co-registration of eye movements and event-related potentioals in connected-text paragraph reading. Frontiers in Neuroscience, 7:28. 7:28. doi: 10.3389/fnsys.2013.00028journalDownload2013Eyetracking during reading has provided a critical source of on-line behavioral data informing basic theory in language processing. Similarly, event-related potentials have provided an important on-line measure of the neural correlates of language processing. Recently there has been strong interest in co-registering eyetracking and ERPs from simultaneous recording to capitalize on the strengths of both techniques, but a challenge has been devising approaches for controlling artifacts produced by eye movements in the EEG waveform. In this paper we describe our approach to correcting for eye movements in EEG and demonstrate its applicability to reading. The method is based on independent components analysis, and uses three criteria for identifying components tied to saccades: (1) component loadings on the surface of the head are consistent with eye movements; (2) source analysis localizes component activity to the eyes, and (3) the temporal activation of the component occurred at the time of the eye movement and differed for right and left eye movements We demonstrate this method’s applicability to reading by comparing ERPs time-locked to fixation onset in two reading conditions. In the text-reading condition, participants read paragraphs of connected text. In the pseudo-reading control condition, participants moved their eyes through spatially similar pseudo-text that preserved word locations, word shapes, and paragraph spatial structure, but eliminated meaning. The corrected EEG, time-locked to fixation onsets, showed effects of reading condition in early ERP components. The results indicate that co-registration of eyetracking and EEG in connected-text paragraph reading is possible, and has the potential to become an important tool for investigating the cognitive and neural bases of on-line language processing in reading.
Richards, J.E. (2013). Cortical sources of ERP I the prosaccade and antisaccade task using realistic source models. Poster presented at the Society for Psychophysiological Research, Firenze, Italy, October 2013.conferenceDownload2013The cortical sources of event-related-potentials (ERP) using realistic source models were examined in a prosaccade and antisaccade task. College-age participants were presented with a preparatory interval and a target that indicated the direction of the eye movement that was to be made. In some blocks a cue was given in the peripheral location where the target was to be presented and in other blocks no cue was given. In Experiment 1 the prosaccade and antisaccade trials were presented randomly within a block; in Experiment 2 procedures were compared in which either prosaccade and antisaccade trials were mixed in the same block, or trials were presented in separate blocks with only one type of eye movement. There was a central negative slow wave occurring prior to the target, a slow positive wave over the parietal scalp prior to the saccade, and a parietal spike potential immediately prior to saccade onset. Cortical source analysis of these ERP components showed a common set of sources in the ventral anterior cingulate and orbital frontal gyrus for the presaccadic positive slow wave and the spike potential. In Experiment 2 the same cued- and non-cued blocks were used, but prosaccade and antisaccade trials were presented in separate blocks. This resulted in a smaller difference in reaction time between prosaccade and antisaccade trials. Unlike the first experiment, the central negative slow wave was larger on antisaccade than on prosaccade trials, and this effect on the ERP component had its cortical source primarily in the parietal and mid-central cortical areas contralateral to the direction of the eye movement. These results suggest that blocked prosaccade and antisaccade trials results in preparatory or set effects that decreases reaction time, eliminates some cueing effects, and is based on contralateral parietal-central brain areas.
Xie, W., Richards, J.E., Lee, K., Gong, Q., and Lei, D. (2013). The construction of MRI brain templates for Chinese children and adolescents from 8 years to 16 years of age. Paper presented at the SYNAPSE & SENC conference, Columbia, SC, March, 2013.conferenceDownload2013A MRI brain template is a representation of human brain including anatomical information and provides a standard reference for assessment of brain structure and function (Ashburner & Friston, 1999). Brain templates are generated from the average of a group of subjects. Studies have shown that both developmental age and race have effects on brain morphology and structural variation (e.g., Gogtay et al., 2004; Lenroot & Giedd, 2006; Lee at al., 2005; Tang et al., 2010). For example, Tang et al. (2010) found that Chinese adults’ brains are generally wider, shorter, and rounder in shape than American adults’ brains. Thus, population-specific brain templates that provide finer brain information are beneficial to both structural and functional neuroscience studies. To date, age-specific templates have not been constructed for Chinese infants, children, or adolescents. In this study, we developed brain templates for 8, 10, 12, 14, and 16 year old Chinese children and adolescents using high quality magnetic resonance imaging (MRI) and well-validated image analysis techniques.
Richards, J.E. (2013). Cortical sources of ERP in the prosaccade and antisaccade eye movements using realistic source models. Frontiers in Systems Neuroscience, 7:27. doi: 10.3389/fnsys.2013.00027journalDownload2013The cortical sources of event-related-potentials (ERP) using realistic source models were examined in a prosaccade and antisaccade procedure. College-age participants were presented with a preparatory interval and a target that indicated the direction of the eye movement that was to be made. In some blocks a cue was given in the peripheral location where the target was to be presented and in other blocks no cue was given. In Experiment 1 the prosaccade and antisaccade trials were presented randomly within a block; in Experiment 2 procedures were compared in which either prosaccade and antisaccade trials were mixed in the same block, or trials were presented in separate blocks with only one type of eye movement. There was a central negative slow wave occurring prior to the target, a slow positive wave over the parietal scalp prior to the saccade, and a parietal spike potential immediately prior to saccade onset. Cortical source analysis of these ERP components showed a common set of sources in the ventral anterior cingulate and orbital frontal gyrus for the presaccadic positive slow wave and the spike potential. In Experiment 2 the same cued- and non-cued blocks were used, but prosaccade and antisaccade trials were presented in separate blocks. This resulted in a smaller difference in reaction time between prosaccade and antisaccade trials. Unlike the first experiment, the central negative slow wave was larger on antisaccade than on prosaccade trials, and this effect on the ERP component had its cortical source primarily in the parietal and mid-central cortical areas contralateral to the direction of the eye movement. These results suggest that blocked prosaccade and antisaccade trials results in preparatory or set effects that decreases reaction time, eliminates some cueing effects, and is based on contralateral parietal-central brain areas.
Craig, A., Komarova, Y., Wood, S., & Vendemia, J. (2013). Suspicious Minds: An fMRI Investigation of Deception Detection Processes in the Marketplace, Journal of Marketing Research, 49(1), 361-372.journal2013
Schmidt, J., Henderson, J.M., Luke, S.G., & Richards, J.E. (2013). Co-registration of eye movements and event-related-potentials in reading. Poster presented at the Society for Psychophysiological Research, Firenze, Italy, October 2013.conferenceDownload2013Eye-tracking has become a nearly ubiquitous tool that provides an online measure of information processing across a variety of tasks. Likewise, event-related potentials (ERPs) provide an online measure of neural processing. Recent work has attempted to combine these techniques and co-register the eye movement record with the electroencephalography (EEG) waveform, allowing for the analysis of ERPs time locked to fixation onset. However, an impediment has been eye-movement-related EEG artifacts(e.g. Dimigen, Sommer, Hohlfield, Jacobs, & Kliegl, 2011). Our method for co-registration uses Independent Components Analysis (ICA) to identify and remove the components resulting from eye movement activity. After removal, the residual EEG activity was reconstructed and analyzed for fixation related ERPs. The eye movement components were identified using three criteria: (1) the component loadings on the surface of the head were consistent with an eye movement; (2) source analysis localized the component to the eyes, and (3) the temporal activation of the component occurred at the time of the electrooculogram activity in the eye and differs for right and left eye movements. This method was tested in the context of a connected text reading paradigm in which observers read paragraphs of normal text or pseudo-text. In the normal text condition subjects read paragraphs, whereas in the pseudo-text control condition observers “read” through a font in which each letter was replaced by a geometric shape that preserved word location and word shapes but eliminated meaning (see Henderson & Luke, 2012). The corrected EEG waveform was aligned to word fixation onset and early results suggest P1 and N1 differences between text and pseudo-text conditions as well as trends towards frequency effects in the text condition. These results suggest that the co-registration of eye movements and ERPs can be successfully combined to investigate a wide variety of tasks.
Tonnsen, B.L., Zieber, N., Roberts, J.E., & Richards, J.E. (2013). Visual preferences in infants at high-risk for autism: Behavioral and psychophysiological cross-group comparisons. Poster presented at the Society for Research in Child Development, Seattle, WA April, 2013conferenceDownload2013Introduction. Studies of infant siblings of children with autism (ASIBs) suggest atypical responses to faces (e.g. McCleery et al., 2009) and atypical patterns of face versus object preferences (e.g. Bhat et al., 2010). However, no published studies have compared visual processing in ASIBs to other groups at high genetic risk for autism, including infants with fragile X syndrome (FXS), the leading known heritable cause of autism. The present study examined behavioral and psychophysiological response to novel and familiar faces and toys across infants with FXS, ASIBs, and typically developing (TD) controls using a paired-comparison paradigm.

Methods. Twenty-two infants (6 TD, 10 ASIB, 6 FXS) were tested at 12 months of age as part of an ongoing study. Infants viewed paired comparison trials of simultaneously-presented faces (mother, stranger) or toys (participant’s toy, unfamiliar toy). Preference scores were calculated as the proportion of looking time toward the unfamiliar stimulus. Infants also viewed brief presentations (500ms) of each stimulus for the purpose of measuring stimulus-onset event related potentials (ERPs) implicated in novelty (Nc) and face processing (N290, P400).

Results. Behavioral data were analyzed using repeated measure analyses of variance (Figure 1). Within face trials, preference toward the stranger differed by group, F(2, 19)=6.80, p=.001, with FXS and ASIB groups showing less stranger preference than controls. Preference toward unfamiliar toys also differed by group, F(2, 19)=12.04, p<.001, with the FXS group showing less novelty preference than both TD and ASIB groups. Together, these behavioral data suggest a face-specific reduction in novelty preference in ASIBs and a more general reduction in novelty preference to both faces and toys in FXS.

Visual inspection of ERP grand averages suggests atypical Nc patterns in both high risk groups (Figure 2). Both FXS and ASIB groups produced larger Nc components than controls, with the greatest amplitudes in the FXS group. All groups showed greater frontal Nc amplitude toward familiar versus unfamiliar toys. Although the control group produced a slightly greater central Nc amplitude toward the stranger versus mother, this pattern was reversed in high risk groups in which slightly greater responses were observed toward mothers versus strangers. The peaks of the Nc and N290 occurred later in response to faces in ASIBs, whereas peaks occurred later in response to objects for FXS (Nc) and TD (Nc and N290) groups. These findings may suggest a developmental lag in shifting preferential attention toward strangers versus mothers in ASIBs and FXS, as well as atypical Nc and N290 latencies associated with processing faces in ASIBs.

Discussion. Atypical face processing is well-documented in autism and may be related to the socio-communicative deficits inherent to the disorder. Our data indicate both shared patterns of atypical face and object processing across ASIBs and FXS, as well as several face-specific patterns unique to ASIBs. Studying early markers of atypical visual processing across multiple high-risk groups may inform the latent heterogeneity of indicators, potentially contributing to early detection and intervention of efforts

Richards, J.E. (2013). Cortical sources of ERP in the prosaccade and antisaccade eye movements using realistic source models (Supplemental Information). Frontiers in Systems Neuroscience, 7:27. doi: 10.3389/fnsys.2013.00027journalDownload2013The cortical sources of event-related-potentials (ERP) using realistic source models were examined in a prosaccade and antisaccade procedure. College-age participants were presented with a preparatory interval and a target that indicated the direction of the eye movement that was to be made. In some blocks a cue was given in the peripheral location where the target was to be presented and in other blocks no cue was given. In Experiment 1 the prosaccade and antisaccade trials were presented randomly within a block; in Experiment 2 procedures were compared in which either prosaccade and antisaccade trials were mixed in the same block, or trials were presented in separate blocks with only one type of eye movement. There was a central negative slow wave occurring prior to the target, a slow positive wave over the parietal scalp prior to the saccade, and a parietal spike potential immediately prior to saccade onset. Cortical source analysis of these ERP components showed a common set of sources in the ventral anterior cingulate and orbital frontal gyrus for the presaccadic positive slow wave and the spike potential. In Experiment 2 the same cued- and non-cued blocks were used, but prosaccade and antisaccade trials were presented in separate blocks. This resulted in a smaller difference in reaction time between prosaccade and antisaccade trials. Unlike the first experiment, the central negative slow wave was larger on antisaccade than on prosaccade trials, and this effect on the ERP component had its cortical source primarily in the parietal and mid-central cortical areas contralateral to the direction of the eye movement. These results suggest that blocked prosaccade and antisaccade trials results in preparatory or set effects that decreases reaction time, eliminates some cueing effects, and is based on contralateral parietal-central brain areas.
Emberson, L., Palmeri, H., Cannon, G., Richards, J.E., and Aslin, R.N (2013). Differences in repetition suppression across sensory systems in 6-month-olds: Using NIRS to compare infant and adult neural functio. Poster presented at the Cognitive Neuroscience Society, San Francisco, April 2013..conferenceDownload2013
Cortical source analysis of infant spatial cueing. Hearing Interest Group, Medical University of South Carolina, Charleston, SC. March, 2013presentation2013
Tonnsen, B. L., Richards, J.E. & Roberts, J. E. (2013). Heart activity and visual attention in infants at risk for autism. Symposium presentation at the 46th Annual Gatlinburg Conference on Research in Developmental Disabilities, San Antonio, TX, March, 2013. conference2013
We know "What's inside a baby's head". Department of Psychology, University of Tennessed, March, 2013presentation2013
Lloyd-Fox, S., Wu, R., Richards J.E., Elwell, C.E., & Johnson, M.H. (2013). Cortical activation to action perception is associated with action production abilities in young infants. Cerebral Cortex.journal2013The extent to which perception and action share common neural processes is much debated in cognitive neuroscience. Taking a developmental approach to this issue allows us to assess whether perceptual processing develops in close association with the emergence of related action skills within the same individual. The current study used functional near infrared spectroscopy (fNIRS) to investigate the perception of human action in four to six month old human infants. In addition the infants’ manual dexterity was assessed. Results show that the degree of cortical activation, within the temporo-parietal junction (TPJ) region, to the perception of manual actions in individual infants correlates with their own level of fine motor skills. This association was not fully explained by either measures of attention or general developmental stage. We suggest that this striking concordance between the emergence of motor skills and related perceptual processing within individuals is consistent with experience-related cortical specialisation in the developing brain.
Phillips, M.C.,Richards, J.E., Stevens, M., & Connington, A. (2013). A stereotaxic MRI brain atlas for infant participants. Poster presented at the Society for Research in Child Development, Seattle, WA April, 2013conferenceDownload2013The study of infant brain development is hampered by the lack of tools for doing brain structural analysis with MRI. Adult neuroimaging work uses average MRI templates and stereotaxic atlases to identify brain anatomical locations. There are adult stereotaxic atlas MRI volumes that are used for automatic labeling of individual participant and group average brain areas, e.g., Talairach, Harvard-Oxford, “AAL”, LONI PBA40. Recent work has resulted in a neurodevelopmental MRI database of average MRI templates of average templates and segmented priors from 2 weeks through adulthood (citations omitted). The current study produced a stereotaxic atlas for each template age in the preschool range (2 weeks through 4 years) and compared the automatic registration/transformation of the average to individuals with manually identified brain areas.

The ages came from the neurodevelopmental MRI average brain templates (3, 4.5, 6, 7.5, 9, 12, 15, 18, 24, 30, 36, 48 months). A stereotaxic atlas distributed with the FSL computer program, the MNI atlas, was used. This atlas identifies the major cortical lobes, cerebellum, and some subcortical regions. The atlas was modified to fit an average brain template based on 20-24 year olds with high-resolution 3T scans (T1W, 3T, 3D, 1x1x1mm resolution). This was done by affine registering the MNI average brain template to the 20-24 year old average brain template, then warping the atlas from the MNI to the 20-24 year old and manually modifying the atlas to fit the average template. The 20-24 year brain template was registered to infant age brain templates, and the atlas was warped to the brain templates for ages 3, 4.5, 6, 7.5, 9, and 12 months (templates based on T1W, 3D, 1x1x1mm resolution, N = 10 at each age). The transformed atlas was manually edited to fit precisely on the average template for each age. The resulting atlas has the cortical lobes (frontal, parietal, occipital, temporal, insula), two gyri (fusiform, cingulate), cerebellum, brainstem, thalamus, striatum, corpus callosum, and ventricles. Atlases were constructed with a “majority fit procedure” from 3 month atlas to 2 week template, and from 12 month atlas to 15, 18, 24, 30, 36, and 48 months.

The atlases were tested by examining 4 individuals at each age with five manually identified areas (frontal, occipital, temporal, cerebellum, thalamus). The manually drawn areas were compared to registered/warped areas for the age-appropriate atlas, atlases from older infant ages, and adult atlases. There was a close fit between the manually identified and automatically labeled regions for the age-appropriate atlas (e.g., 3 mo individuals with 3 mo avg, DICE coefficient > .95; 12 mo individuals with 12 mo average, DICE coefficient > .97). The fit systematically decreased for older age atlases, and there was an expected poor fit with adult atlases (e.g., 3 or 6 mo with 20-24 year average, ~.85).

These atlases allow the automatic identification of anatomical areas in infant MRI studies. They may be used to guide the development of more detailed stereotaxic atlases (e.g., “Harvard-Oxford” gryal and sulcal identification; “AAL” stereotaxic atlas; LONI PBA40 atlas).

Zieber, N., & Richards, J.E. (2013). Developmental changes in the infant N290 in response to faces and toys. Poster presented at the Society for Research in Child Development, Seattle, WA April, 2013.conferenceDownload2013>

Specialized processing of faces begins early in life, yet we are just beginning to understand the neural underpinnings of the development of face expertise in infancy. Adults exhibit differential neural responses to faces as opposed to other classes of objects, evidenced by a larger N170 amplitude for faces than for objects. The N170 is a negative event-related potential (ERP) component occurring about 170ms post-stimulus onset, and research with infants has found two components that may be precursors to the adult N170. One of these components, the N290, is a negative deflection over posterior regions peaking at 290ms that is greater in amplitude for faces than visual noise (Halit, Csibra, Volein, & Johnson, 2004). In the first year of life, as infants acquire extensive exposure to faces, the N290 begins to differ in response to upright (as opposed to inverted) faces and to human (as opposed to monkey) faces (de Haan, Pascalis, & Johnson, 2002). However, few studies have examined whether changes occur in the morphology of the N290 that correspond to emerging expertise with faces as opposed to other objects. In the current study, infants’ ERPs were recorded while infants of three different ages (4.5, 6, and 8 months) passively viewed faces and objects (toys).

Thirty-eight infants (14 4.5- month-olds, 12 6-month-olds, and 12 8-month-olds) participated in the study. Infants viewed a series of brief stimulus presentations (500ms) of images of their own mother, another infant’s mother, their own toy, or another infant’s toy randomly interspersed across trials. High-density EEGs were recorded using an EGI 128-channel Geodesic Sensor Net. The EEG data was analyzed for groups of electrodes over occipito-temporal regions (e.g., around T5, T6, O1, O2, Oz) based upon previous infant studies that have found the N290 to be most prominent over these areas (de Haan et al., 2002). For each participant, ERP grand averages were computed for the time of the target onset, and the peak amplitude was derived using individualized time windows to capture each subject’s N290.

The dependent measure was the mean amplitude of the N290 component. A main effect of age was found [F(2, 88)= 5.81; p < .005*], and the increase in the amplitude of the N290 from 4.5 to 7.5 months can be clearly seen in Figure 1. There was also a marginally significant effect of trial type [F(1,88)=3.26; p < .07], as the amplitude was larger for faces than for toys (but the interaction was not significant). Thus, the N290 amplitude was larger for faces than for toys (see Fig. 1), and increased in amplitude across the age groups.

The current study documents a developmental change in the face-sensitive N290 corresponding to a time period when infants are developing expertise with faces. These studies suggest that, like adults, infants demonstrate special processing of faces compared to other objects, and that the N290 is similar to the N170 in that its amplitude is greater to faces than other objects.

Cortical source analysis of infant spatial cueing. University of Tennessee, March, 2013presentation2013
Richards, J.E. (2013). Cortical source analysis of ERP in infant spatial cueing. Poster presented at the Society for Research in Child Development, Seattle, WA April, 2013conferenceDownload2013Infants show covert orienting in a “spatial cueing” procedure, including facilitation and inhibition of return of RT, and enhancement of the P1 component of the ERP to target onset for the validly cued trials (P1 validity effect). Infant orienting to peripheral targets may be elicited covertly with pre-target spatial cueing, resulting in enhanced P1 event-related-potentials (ERP) and decreased reaction time to a peripheral target. The enhanced P1 has been attributed to generator sources in the lateral occipital / fusiform gyrus. This poster examines the effect of predictive cueing on these sources with fully predictive peripheral cues (covert “orienting”), cues predicting contralateral targets (covert “attention”), and non-predictive cues.

Infants of 14 or 20 weeks of age were tested in a spatial cueing procedure. A central stimulus was presented until the infant fixated it, a cue was presented in the periphery for 300 ms, and then a “target” was presented on the same side as the cue (“valid”), on the opposite side of the cue (“invalid”), or a target was presented without a prior cue (“neutral”), and at short- or long- stimulus onset asychrony. Heart rate deceleration and the return of heart rate to a prestimulus level were used to define periods of attentiveness and inattentiveness. ERP averages were computed around the time of the target onset. A neurodevelopmental MRI database and “Finite Element Model” (FEM) head models were used for a realistic head model for source analysis. About half of the participants had a structural MRI, and the MRI from the participant or from an age-appropriate average MRI template was used for the head model. The cortical sources of the P1 validity effect was examined with current density reconstruction methods using sLORETA. Several posterior brain areas have been hypothesized to control the P1 validity effect in adults (e.g., lateral occipital cortex, fusiform gyrus, inferior-posterior temporal cortex). These and surrounding control areas (central occipital pole, superior parietal cortex, superior-posterior temporal cortex) were used with a “region of interest” (ROI) analysis to quantify current density in these regions as a function of experimental variables.

ERP analyses showed an enhanced P1 on valid trials over invalid and neutral trials. This P1 component was enhanced if the infant was attentive, and primarily on short SOA trials. The enhanced P1 was larger for short SOAs, suggesting this was spatially-cued orienting rather than endogenous attention. The current density reconstruction analysis was used with the hypothesized posterior brain regions to quantify cortical current sources. The P1 facilitation occurred both in the in the lateral occipital cortex and the inferior temporal cortex. However, attention modulated the P1 validity effect for the current density only in the lateral occipital cortex. Surrounding areas and control areas did not show the current density as a function of these experimental variables. These results suggest that the lateral occipital cortex and the inferior temporal cortex are involved in the modulation of the P1 validity effect by attention. This study demonstrates the use of realistic head models for cortical source analysis of infant spatial attention.

Richards, J.E. (2013). Discussant for paper symposium, Getting more out of EEG: New inroads to the developing brain. Presented at the Society for Research in Child Development, Seattle, WA April, 2013conference2013
Schmidt, J., Henderson, J.M., Luke, S.G., & Richards, J.E. (2013). Co-registration of eye movements and event-related-potentials in reading. Poster presented at the Vision Science Society, Naples, FL May, 2013.conference2013Eye-tracking has become a nearly ubiquitous tool that provides an online measure of information processing across a variety of tasks. Likewise, event-related potentials (ERPs) provide an online measure of neural processing. Recent work has attempted to combine these techniques and co-register the eye movement record with the electroencephalography (EEG) waveform, allowing for the analysis of ERPs time locked to fixation onset. However, an impediment has been eye-movement-related EEG artifacts(e.g. Dimigen, Sommer, Hohlfield, Jacobs, & Kliegl, 2011). Our method for co-registration uses Independent Components Analysis (ICA) to identify and remove the components resulting from eye movement activity. After removal, the residual EEG activity was reconstructed and analyzed for fixation related ERPs. The eye movement components were identified using three criteria: (1) the component loadings on the surface of the head were consistent with an eye movement; (2) source analysis localized the component to the eyes, and (3) the temporal activation of the component occurred at the time of the electrooculogram activity in the eye and differs for right and left eye movements. This method was tested in the context of a connected text reading paradigm in which observers read paragraphs of normal text or pseudo-text. In the normal text condition subjects read paragraphs, whereas in the pseudo-text control condition observers “read” through a font in which each letter was replaced by a geometric shape that preserved word location and word shapes but eliminated meaning (see Henderson & Luke, 2012). The corrected EEG waveform was aligned to word fixation onset and early results suggest P1 and N1 differences between text and pseudo-text conditions as well as trends towards frequency effects in the text condition. These results suggest that the co-registration of eye movements and ERPs can be successfully combined to investigate a wide variety of tasks.
Meek, S.W., Phillips, M.C., Boswell, C.P., Vendemia, J.M.C. (2013). Deception and the Misinformation Effect: An event-related potential study, International Journal of Psychophysiology, 87(1), 81-87.journal2013
Development of sustained attention in infants. Institute for Mind and Brain, University of South Carolina, April, 2013presentation2013
Henderson, J.M., Luke, S.G., Schmidt, J., & Richards, J.E. (2012). Co-registration of eye movements and ERPs in normal and mindless reading. Poster presented at the Society for the Neurobiology of Language, San Sebastian, Spain. October, 2012.conference2012
McCleery, J.P., & Richards, J.E. (2012). Comparing realistic head models for cortical source locationization of infant event-related potentials. Poster presented at the 3rd UK Paediatric Neuropsychology Symposium, University College London Institute for Child Health, London, England. April, 2012.conference2012Event-related potentials (ERPs) are highly useful for identifying and characterising neural mechanisms associated with different temporal stages of processing in infant participants. However, ERPs are currently limited in their ability to provide meaningful information regarding the neuroanatomical sources of these mechanisms. The major limiting factor in infant EEG/ERP source estimation has been the absence of realistic models of the intervening tissue (e.g., scalp, skull, cerebrospinal fluid) and brain structure.

Here, we employ a unique database of infant head and brain models (Reference deleted) to examine the effects of variability in head/brain structure on cortical source estimation. We compare source analyses based on Magnetic Resonance Image (MRI) head and brain models that are either 1) the infant’s own; 2) an infant close in age with a similar size head; 3) an infant close in age with the most different size head; or 4) an arbitrarily chosen infant of a different age. We also assess average head/brain models for 1) infants the same age as the infant; 2) 12-month-olds; 3) 2-year olds; 4) 12-year olds; 5) 20- to 24-year olds; and 6) the Montreal Neurological Institute adult average (MNI-105). These MRI templates vary considerably in their degree of similarity to the participants’ actual head and skull at multiple levels, including the actual shape and location of the cortical structures.

sLORETA current density reconstruction was used for all models, with sources restricted to the grey matter, using CURRY and EMSE computer programs. Finite Element Model (FEM), Boundary Element Model (BEM), and 3-shell spherical models were tested for all head/brain types. The optimal model was defined as the FEM model based on the infant’s own MRI. Region of Interest proportion analysis methods based upon identifiable sub-regions (e.g., medial-basal prefrontal cortex, ventral anterior cingulate cortex) were employed in order to quantify and compare the accuracy of each model to this optimal model.

Sources for a commonly studied infant ERP component, the Nc, were analysed in two infants (4.5-month-old, 6-month-old), and sources for saccadic and pre-saccadic eye movements were analysed in three additional participants (4.6, 6.0, 7.5 mo). Overall, the models based on an MRI from an infant of the same age with the same head size, and models based on an average MRI from infants of the same age, produced the closest source estimate fits to the optimal model. Source estimates based on models of infants of the same age but with a very different sized head, or based on the average of infants of different ages, were much less accurate. Three-shell spherical models also produced generally unreliable results, whereas BEM and FEM models generally produced similar source estimates. Qualitative evaluation further supports the qualitative findings in that the use of MRIs of infants of different ages, or of infants of the same age with different head sizes, produced unreliable and sometimes spurious source estimations. These spurious estimates would have significant negative impact upon the interpretation of neural mechanisms. This study has clear implications for acceptable and optimal procedures for infant EEG/ERP source analysis.
Richards, J.E. (2012). Cortical source analysis of ERP in infant spatial cueing. Poster presented at the International Conference on Infant Studies, Minneapolis, MN. June, 2012.conference2012
Richards, J.E., Stevens, M., & Connington, A. (2012). A stereotaxic MRI brain atlas for infant participants. Poster presented at the 3rd UK Paediatric Neuropsychology Symposium, University College London Institute for Child Health, London, England. April, 2012.conference2012
Richards, J.E., Stevens, M., & Connington, A. (2012). A stereotaxic MRI brain atlas for infant participants. Poster presented at the International Conference on Infant Studies, Minneapolis, MN. June, 2012.conference2012
Green, J. J. & Woldorff, M. G. (2012). Arrow-elicited cueing effects at short intervals: Rapid attentional orienting or cue-target stimulus conflict? Cognition, 122(1), 96-101.journalDownload2012The observation of cueing effects (faster responses for cued than uncued targets) rapidly following centrally-presented arrows has led to the suggestion that arrows trigger rapid automatic shifts of spatial attention. However, these effects have primarily been observed during easy target-detection tasks when both cue and target remain on the screen until the behavioral response. We manipulated stimulus duration and task difficulty in an attention-cueing experiment to explore non-attentional explanations for rapid cueing effects. Contrary to attention-based predictions, short-interval cueing effects were observed only for long-duration cue and target stimuli, occurred even when the cue and target were presented simultaneously, and were driven by slowing of the uncued-target responses, rather than any facilitation for cued targets. We propose that, under these long-duration, short-interval conditions, the processing of the cue and target interact more extensively in the brain, and that when the cue and target convey incongruent spatial information (i.e., on invalidly cued trials) it leads to conflict-related slowing of responses.
Richards. J.E. (2012). Structural and functional neuroimaging in infants. Invited symposium, International Conference on Infant Studies, Minneapolis, MN. June 2012.conference2012
Tonnsen, B.K., Richards, J.E., & Roberts, J.E. (2012). Experimental and parent-reported self-regulation in infants at high- and low-risk for autism. Poster presented at the 3rd UK Paediatric Neuropsychology Symposium, University College London Institute for Child Health, London, England. April, 2012.conference2012
Tonnsen, B.K., Richards, J.E., & Roberts, J.E. (2012). Experimental and parent-reported self-regulation in infants at high- and low-risk for autism. Developmental Medicine and Child Neurology, 54, Supplement 2, 19. (abstract)journal2012
Tawanda M. Greer, T.M., Vendemia, J.M.C., & Stancil, M. (2012). Neural correlates of racial mistrust in African-Americans: An fMRI Study, Neuropsychology, 26(6), 704-712.journal2012
Adlof, S.M. & Perfetti, C.A. (2012). Word-to-text semantic integration in children: An auditory ERP study. Symposium on Research in Child Language Disorders: Madison, Wisconsin. June, 2012.conference2012
McCleery, J.P., & Richards, J.E. (2012). Comparing realistic head models for cortical source locationization of infant event-related potentials. Poster presented at the International Conference on Infant Studies, Minneapolis, MN. June, 2012.conference2012Event-related potentials (ERPs) are highly useful for identifying and characterising neural mechanisms associated with different temporal stages of processing in infant participants. However, ERPs are currently limited in their ability to provide meaningful information regarding the neuroanatomical sources of these mechanisms. The major limiting factor in infant EEG/ERP source estimation has been the absence of realistic models of the intervening tissue (e.g., scalp, skull, cerebrospinal fluid) and brain structure.

Here, we employ a unique database of infant head and brain models (Reference deleted) to examine the effects of variability in head/brain structure on cortical source estimation. We compare source analyses based on Magnetic Resonance Image (MRI) head and brain models that are either 1) the infant’s own; 2) an infant close in age with a similar size head; 3) an infant close in age with the most different size head; or 4) an arbitrarily chosen infant of a different age. We also assess average head/brain models for 1) infants the same age as the infant; 2) 12-month-olds; 3) 2-year olds; 4) 12-year olds; 5) 20- to 24-year olds; and 6) the Montreal Neurological Institute adult average (MNI-105). These MRI templates vary considerably in their degree of similarity to the participants’ actual head and skull at multiple levels, including the actual shape and location of the cortical structures.

sLORETA current density reconstruction was used for all models, with sources restricted to the grey matter, using CURRY and EMSE computer programs. Finite Element Model (FEM), Boundary Element Model (BEM), and 3-shell spherical models were tested for all head/brain types. The optimal model was defined as the FEM model based on the infant’s own MRI. Region of Interest proportion analysis methods based upon identifiable sub-regions (e.g., medial-basal prefrontal cortex, ventral anterior cingulate cortex) were employed in order to quantify and compare the accuracy of each model to this optimal model.

Sources for a commonly studied infant ERP component, the Nc, were analysed in two infants (4.5-month-old, 6-month-old), and sources for saccadic and pre-saccadic eye movements were analysed in three additional participants (4.6, 6.0, 7.5 mo). Overall, the models based on an MRI from an infant of the same age with the same head size, and models based on an average MRI from infants of the same age, produced the closest source estimate fits to the optimal model. Source estimates based on models of infants of the same age but with a very different sized head, or based on the average of infants of different ages, were much less accurate. Three-shell spherical models also produced generally unreliable results, whereas BEM and FEM models generally produced similar source estimates. Qualitative evaluation further supports the qualitative findings in that the use of MRIs of infants of different ages, or of infants of the same age with different head sizes, produced unreliable and sometimes spurious source estimations. These spurious estimates would have significant negative impact upon the interpretation of neural mechanisms. This study has clear implications for acceptable and optimal procedures for infant EEG/ERP source analysis.
Phillips, M.C., Richards, J.E., & Sanchez, C. (2012). Age specific MRI brain and head templates for healthy adults form 20 through 89 years of age. Presented at the Hard Data Café, Department of Psychology, University of South Carolina, Spring, 2012.conferenceDownload2012
Richards, J.E., Stevens, M., & Connington, A. (2012). A stereotaxic MRI brain atlas for infant participants. Developmental Medicine and Child Neurology, 54, Supplement 2, 9-10;. (abstract)journal2012
McCleery, J.P., & Richards, J.E. (2012). Comparing realistic head models for cortical source locationization of infant event-related potentials. Developmental Medicine and Child Neurology, 54, Supplement 2, 10.. (abstract)journal2012
Mallin, B.A., & Richards, J.E. (2012). Peripheral stimulus localization by infants of moving stimuli on complex backgrounds. Infancy, 17, 692-714.journalDownload2012This study examined the effect of attention in young infants on the saccadic localization of dynamic peripheral stimuli presented on complex and interesting backgrounds. Infants at 14, 20, and 26 weeks of age were presented with scenes from a “Sesame Street” movie until fixation on a moving character occurred, and then presented with scenes in which the character movement occurred in a new location. Localization of the moving character in the new location was faster when the infant was engaged in attention than when inattentive, for scenes in which the character moved from one location to another, or scenes in which the character stopped moving and characters in new locations began moving. Alternatively, localization of the character was slower during attention when the first character disappeared and a different character appeared in a new location. We also found a decrease in the linear component of the main sequence in the saccade characteristics over the three testing ages, and attention affected the main sequence for infants at the two oldest ages. These results partially replicate prior findings showing that attention to a focal stimulus affects localization of peripheral stimuli, but suggest that the nature of the stimuli being localized modifies the role of attention in affecting eye movements to peripheral stimuli.
Tonnsen, B.L., Richards, J.E., Robinson, A.R., Deal, S. & Roberts, J. E. (2012). Visual attention in infants at high risk for autism: Comparing fragile X to autism siblings. Symposium presentation at the 13th International Fragile X Conference, Miami, FL, July, 2012.conference2012
Papademetriou, M.D., Richards, J.E., Correira, T., Blasi, A., Lloyd-fox S., Johnson, M., & Elwell, C.E. (2012). Cortical mapping of 3D optical topography in infants. Advances in Experimental Medicine and Biology, 985.journal2012
Brains for all the ages. 27th Annual Winter Conference on Current Issues in Developmental Psychobiology, Honolulu, Hawaii, Janurary, 2012.presentation2012
Cortical source analysis of ERP in infant recognition and face/object perception. Marie Curie Visiting Professor program, Center for Brain and Cognitive Development, Birckbeck College, University of London, March, 2012.presentation2012
Infant attention to “realistic” video stimuli. 27th Annual Winter Conference on Current Issues in Developmental Psychobiology, Honolulu, Hawaii, Janurary, 2012.presentation2012
Structural and functional neuroimaging in infants. Invited symposium, International Conference on Infant Studies, Minneapolis, MN. June 2012.presentation2012
Sanchez, C.E., Richards, J.E., & Almli, C.R. (2012). Age-specific MRI brain templates for pediatric neuroimaging. Developmental Neuropsychology, 37, 379-399.journalDownload2012The goal of this work was to create a database of pediatric, age-specific MRI brain and head templates for use by researchers for neuroimaging work with children. The participants included children from 4.5 through 24 years of age. The templates were done in 6 month intervals through 19.5 years, and consist of average T1W and T2W scans for the head and brain, and segmenting priors for GM, WM, and T2W-derived CSF. This database is available for use by other investigators and clinicians for their MRI studies, as well as other types of neuroimaging and electrophysiological research (http://jerlab.psych.sc.edu/neurodevelopmentalmri).
Neural basis of infant familiarity preferences (and novelty preferences). 26th Annual Winter Conference on Current Issues in Developmental Psychobiology, Herradura, Costa Rica, January, 2011.presentation2011
Sanchez, C.E., Richards, J.E., Schatz, J., & White, D. (2011). Age-Specific Pediatric Templates for Normalization and Segmentation of MRIs: An Example of Their Utility in a Pediatric PKU Sample. Society for Research in Child Development, April, 2011.conference2011
Green, J. J., Doesburg, S. M., Ward, L. M., & McDonald, J. J. (2011). Electrical neuroimaging of voluntary audio-spatial attention: Evidence for a supramodal attention control network. Journal of Neuroscience, 31(10), 3560-3564.journalDownload2011Previous attempts to investigate the supramodal nature of attentional control have focused primarily on identifying neuroanatomical overlap in the frontoparietal systems activated during voluntary shifts of spatial attention in different sensory modalities. However, the activation of the same neural structures is insufficient evidence for a supramodal system, as the same brain regions could interact with one another in very different ways during shifts of attention in different modalities. Thus, to explore the similarity of the functional networks, it is necessary to identify the neural structures involved and to examine the timing and sequence of activities within the network. To this end, we used an electrical neuroimaging technique to localize the neural sources of electroencephalographic signals recorded from human subjects during audiospatial shifts of attention and to examine the timing and sequence of activities within several regions of interest. We then compared the results to an analogous study of visuospatial attention shifts. Similar frontal and parietal regions were activated during visual and auditory shifts of attention, and the timing of activities within these regions was nearly identical. Following this modality-independent sequence of attention-control activity, activity in the relevant sensory cortex was enhanced in anticipation of the response-relevant target. These results are consistent with the hypothesis that a single supramodal network of frontal and parietal regions mediates voluntary shifts of spatial attention and controls the flow of sensory information in modality-specific sensory pathways.
Richards, J.E. (2011). Tools for Cortical Source Analysis of EEG and ERP for Infants and Young Children. Society for Research in Child Development, April, 2011.conference2011
Reynolds, G.D., & Richards. J.E. (2011). Processing of Repeated and Non-Repeated Visual Stimuli in Infancy: Visual Preferences and Event-Related Potentials. Society for Research in Child Development, April, 2011.conference2011
McCleery, J.P. Surtees, A., Graham, K.A., Richards, J.E., & Apperly, I.A. (2011). The neural and cognitive time-course of theory of mind. Journal of Neuroscience, 31, 12849-12854.journal2011
McCleery, J. P., Graham, K. A., Richards, J. E., Allen, H. A., Ceponiene, R., & Nielsen, D.  (2011).  Neural mechanisms of pre-lexical speech processing:  A view through repetition suppression.  Poster presented in session Language: Auditory, Comprehension, and Gene Studies, at the 41st Annual Meeting of the Society for Neuroscience.  Washington, D.C. November, 2011.conference2011
Sanchez, C.E., Richards, J.E., & Almli, C.R. (2011). Neurodevelopmental MRI brain templates for children from 2 weeks to 4 years of age. Developmental Psychobiology. Doi:10. 1-02/dev20579; 57, 77-91.journalDownload2011
McDonald, J. J., Green, J. J., Stoermer, V. S., & Hillyard, S. A. (2011). Cross-modal spatial cueing of attention influences visual perception. In M. M. Murray & M. T. Wallace (Eds.), Frontiers in the neural basis of multisensory processes. CRC Press: Boca Raton, FL.chapter2011
What’s inside a baby’s head? Structural and functional brain development in infants. University of Brmingham, Birmingham, England, UK. April, 2011.presentation2011
McIlreavy, M., & Richards, J.E. (2011). Internal and External Attention in Infancy: Heart Rate Defined Classifications and Gamma Band Activity. Society for Research in Child Development, April, 2011.conference2011
McIlreavy, M., & Richards, J.E. (2011). High-Density EEG in Infancy: Heart Rate Defined Sustained Attention and Inattention. Society for Research in Child Development, April, 2011.conference2011
Phillips, M. C., Meek, S. W., & Vendemia, J. M. C. (2011). Understanding the underlying structure of deceptive behaviors, Personality and Individual Differences, 50(6), 783-789.journal2011
Apperly, I., McCleery, J., Surtees, A., Graham, K., & Richards, J.E. (2011). The cognitive basis and neural time-course of very simple visual perspective-taking. British Psychological Society, May, 2011.conference2011
Reynolds, G.D., Courage, M.L., & Richards, J.E. (2010). Infant attention and visual preferences: Converging evidence from behavior, Event-Related Potentials, and cortical source localization. Developmental Psychology, 46, 886-904.journalDownload2010
Neural basis of infant familiarity preferences (and novelty preferences). McDonnell Research Group on Infant Cognitive Development, Barcelona Spain, December, 2010.presentation2010
What’s inside a baby’s head? Structural and functional brain development in infants. International Conference on Infant Studies, Baltimore, MD, March, 2010.conference2010
Richards, J.E. (2010). Infant attention, arousal, and the brain. In Oaks, L.M., Cashon, C.H., Casaola, M., & Rakison, D.H. (Eds). Infant Perception and Cognition: Recent advances, emerging theories, and future directions. NY: Oxford University Press.chapterDownload2010
Richards, J.E. (2010). The development of attention to simple and complex visual stimuli in infants: Behavioral and psychophysiological measures. Developmental Review, 30, 203-219.journalDownload2010
A neurodevelopmental MRI database for infants. C.E. Sanchez, J.E. Richards, R. Almli, International Conference on Infant Studies, Baltimore, MD, March, 2010.conference2010
Pimpek, T.A., Kikorian, H.L., Richards, J.E., Anderson, D.R., Lund, A.R., & Stevens, M. (2010). Video comprehensibility and attention in very young children. Developmental Psychology, 46, 1283-1293.journalDownload2010
Green, J. J. & McDonald, J. J. (2010). The role of temporal predictability in the anticipatory biasing of sensory cortex during visuospatial shifts of attention. Psychophysiology, 47(6), 1057-1065.journalDownload2010The presentation of an attention-directing cue elicits a lateralized ERP deflection called the late directing attention positivity (LDAP) and lateralized changes in alpha-band elelctroencephalogram oscillations. Both of these electrophysiological responses have been independently linked to biasing of visual cortex in anticipation of an impending target. However, the LDAP is not always observed, and the link between the ERP and alpha-band modulations remains unclear. Here, we examined the effect of advance knowledge of the time of target onset on the ERP and alpha-band responses to cues. The LDAP was present only when the attention-directing cues accurately indicated the time of target appearance, whereas two sequential attention-related alpha-band modulations were observed regardless of the temporal information provided by the cues. Thus, alpha-band activity may be a more reliable index of pretarget biasing of visual cortical activity than lateralized ERP effects.
Reynolds, G.D., Courage, M.L., & Richards, J.E. (2010). The development of attention. Oxford Handbook of Cognitive Psychology. NY: Oxford University Press.chapter2010
What’s inside a baby’s head? Structural and functional brain development in infants. (invited plenary address). International Conference on Infant Studies, Baltimore, MD, March, 2010.presentation2010
Richards, J.E., Reynolds, G.D., & Courage, M.I. (2010). The neural bases of infant attendion. Current Directions in Psychological Science, 19, 41-16.journalDownload2010
Doesburg, S. M., Green, J. J., McDonald, J. J., & Ward, L. M. (2009). Rhythms of consciousness: Binocular rivalry reveals large-scale oscillatory network dynamics mediating visual perception. PLoS One, 4(7), e6142.journalDownload2009The observation of cueing effects (faster responses for cued than uncued targets) rapidly following centrally-presented arrows has led to the suggestion that arrows trigger rapid automatic shifts of spatial attention. However, these effects have primarily been observed during easy target-detection tasks when both cue and target remain on the screen until the behavioral response. We manipulated stimulus duration and task difficulty in an attention-cueing experiment to explore non-attentional explanations for rapid cueing effects. Contrary to attention-based predictions, short-interval cueing effects were observed only for long-duration cue and target stimuli, occurred even when the cue and target were presented simultaneously, and were driven by slowing of the uncued-target responses, rather than any facilitation for cued targets. We propose that, under these long-duration, short-interval conditions, the processing of the cue and target interact more extensively in the brain, and that when the cue and target convey incongruent spatial information (i.e., on invalidly cued trials) it leads to conflict-related slowing of responses.
Sanchez, C.E., Basilakos, A.A., & Richards, J.E. (2009) Different ages, different stages: A neurodevelopmental age-based database of normal brain development for MRI. . Psychophysiology, 46, S81 (abstract).journal2009
Reynolds, G.D., Courage, M., & Richards, J.E. (2009) Cortical sources of infant visual preferences. Psychophysiology, 46, S81 (abstract).journal2009
Different ages, different stages: A neurodevelopmental age-based database of normal brain development for MRI. C.E. Sanchez, A.A. Basilakos, J.E. Richards, Society for Psychophysiological Research, Berlin, October 2009conference2009
Cortical sources of infant visual preferences. G.D. Reynolds, M.L. Courage, & J.E. Richards. Cognitive Neurosciences Society, San Francisco, March, 2009.conference2009
Doesburg, S. M., Green, J. J., McDonald, J. J., & Ward, L. M. (2009). From local inhibition to long-range integration: A functional dissociation of alpha-band synchronization across cortical scales in visuospatial attention. Brain Research, 1303, 97-110.journalDownload2009Voluntarily shifting attention to a location of the visual field improves the perception of events that occur there. Regions of frontal cortex are thought to provide the top-down control signal that initiates a shift of attention, but because of the temporal limitations of functional brain imaging, the timing and sequence of attentional-control operations remain unknown. We used a new analytical technique (beamformer spatial filtering) to reconstruct the anatomical sources of low-frequency brain waves in humans associated with attentional control across time. Following a signal to shift attention, control activity was seen in parietal cortex 100–200 ms before activity was seen in frontal cortex. Parietal cortex was then reactivated prior to anticipatory biasing of activity in occipital cortex. The magnitudes of early parietal activations were strongly predictive of the degree of attentional improvement in perceptual performance. These results show that parietal cortex, not frontal cortex, provides the initial signals to shift attention and indicate that top-down attentional control is not purely top down.
Cortical sources of infant visual preferences. G.D. Reynolds, M.L. Courage, & J.E. Richards. Society for Psychophysiological Research, Berlin, October 2009.conference2009
Different ages, different stages: A neurodevelopmental age-based database of normal brain development for MRI. C.E. Sanchez, A.A. Basilakos, J.E. Richards, Cognitive Neurosciences Society, San Francisco, March, 2009;conference2009
Different ages, different stages: A neurodevelopmental age-based database of normal brain development for MRI. C.E. Sanchez, A.A. Basilakos, J.E. Richards, Society for Research in Child Development, Denver, March, 2009;conference2009
A neurodevelopmental database / stereotaxic atlas for MR imaging of infants and children. 24th Annual Winter Conference on Current Issues in Developmental Psychobiology, St Croix, Virgin Islands, January, 2009.presentation2009
Reynolds, G.D, & Richards, J.E. (2009). Cortical source analysis of infant cognition. Developmental Neuropsychology, 3, 312-329.journalDownload2009Neuroimaging techniques such as positron emission topography (PET) and functional magnetic resonance imaging (fMRI) have been utilized with older children and adults to identify cortical sources of perceptual and cognitive processes. However, due to practical and ethical concerns, these techniques cannot be routinely applied to infant participants. An alternative to such neuroimaging techniques appropriate for use with infant participants is high-density EEG recording and cortical source localization techniques. The current paper provides an overview of a method developed for such analyses. The method consists of four steps: 1) recording high-density (e.g., 128-channel) EEG. 2) Analysis of individual participant raw segmented data with independent component analysis (ICA). 3) Estimation of equivalent current dipoles (ECDs) that represent cortical sources for the observed ICA component clusters. 4) Calculation of component activations in relation to experimental factors. We discuss an example of research applying this technique to investigate the development of visual attention and recognition memory. We also describe the application of “realistic head modeling” to address some of the current limitations of infant cortical source localization.
Richards, J.E. (2009). Attention in the brain and early infancy. In S.P. Johnson (Ed.), Neoconstructism: The new science of cognitive development. chapterDownload2009The attention system of the young infant shows rapid development. This development has been hypothesized to be strongly influenced by changes in brain areas controlling attention processes. This chapter reviews some infant attention systems and shows how brain development affects the development of infant attention. An important advance in this research is the ability of researchers to measure brain activity with noninvasive methods in infant participants. Activity in the infant’s brain can be measured as the infant engages in attention, and development in brain and attention can be related. A goal of research in this area is to show the link between measures of infant brain development and measures of attention development.
Cortical sources of infant visual preferences. G.D. Reynolds, M.L. Courage, & J.E. Richards. Society for Research in Child Development, Denver, March, 2009;conference2009
Green, J. J.& McDonald, J. J. (2008). Electrical neuroimaging reveals timing of attentional control activity in human brain. PLoS Biology, 6(4), e81. doi:10.1371/journal.pbio.0060081journalDownload2008Voluntarily shifting attention to a location of the visual field improves the perception of events that occur there. Regions of frontal cortex are thought to provide the top-down control signal that initiates a shift of attention, but because of the temporal limitations of functional brain imaging, the timing and sequence of attentional-control operations remain unknown. We used a new analytical technique (beamformer spatial filtering) to reconstruct the anatomical sources of low-frequency brain waves in humans associated with attentional control across time. Following a signal to shift attention, control activity was seen in parietal cortex 100–200 ms before activity was seen in frontal cortex. Parietal cortex was then reactivated prior to anticipatory biasing of activity in occipital cortex. The magnitudes of early parietal activations were strongly predictive of the degree of attentional improvement in perceptual performance. These results show that parietal cortex, not frontal cortex, provides the initial signals to shift attention and indicate that top-down attentional control is not purely top down.
Richards, J.E. (2008). Developmental cognitive neuroscience of infant attention: Les Cohen festschrift. International Conference on Infant Studies, Vancouver. (PDF)conferenceDownload2008This is a review of work reflecting similar trends in attention and DCN of attention vis-a-vis Leslie Cohen.
Richards, J.E. (2008). What's inside a baby's head?. International Conference on Infant Studies, Vancouver. (PDF)conferenceDownload2008Developmental psychologists studying infant cognitive development often use brain development as an explanation for cognitive development. Until recently it has been impossible to "look inside the baby's head" to determine brain developmental status. Neuroimaging techniques (MRI, PET) were limited to infants with medical indications, and a picture of the brain of the normally developing infant was not possible. Recently normally developing infants and children have had brain imaging with MRI. This includes early scattered reports of functional MRI (fMRI), the NIH MRI study of normal brain development, and my own use of 3T structural MRIs. These studies have resulted in very revealing findings about the nature of the infant brain and its relation to cognitive development,The current presentation will describe an approach to studying the brain-cognitive relation in infant development with realistic cortical source models of EEG/ERP. High-density EEG is recorded while infants participate in cognitive psychophysiological tasks (e.g., recognition memory; spatial cueing; hidden objects). These infants also have a structural (anatomical) MRI. A realistic model of the spatial topography of the materials in the baby's head is constructed. Equivalent current dipole models of the event-related potentials taken in the psychophysiological tasks give the location of the brain activity during the task; presumably these are tied to the psychological processes involved in the tasks. This neuroimaging technique gives location of the source of the activity, the time-course of the neural activity, and the relationship of the brain activity to the psychological processes involved in the task. The use of this technique with infants has shown several characteristics of infant's head and brain that are strikingly different from adults and older children (myelination; skull thickness; brain material impedances; relation between skull landmarks and underlying brain lobes). This technique also has proven beneficial in locating the brain correlates of psychological processes in the young infant.  
Richards, J.E. (2008). Infant sustained attention affects brain areas controlling covert orienting. International Conference on Infant Studies, Vancouver. (PDF)conferenceDownload2008 Infants covertly move attention around in space without moving fixation. This is shown in the “spatial cueing” procedure in which a cue indicates the side of an upcoming target or is contralateral to the target (“valid” and “invalid”). Infants localize the target more quickly on valid trials than on invalid trials (“facilitation”), though at certain stimulus-onset-asychrony durations target localization may be delayed (“inhibition of return”). Several prior studies of infant participants with scalp-recorded event-related-potentials (ERP) find an enhancement of the first positive component (P1 component?) to target onset for the validly cued trials (P1 validity effect) and the cortical source for this component is the contralateral extrastriate occipital cortex and fusiform gyrus. The current study used heart-rate-defined attention phases to examine this effect under conditions of attention and inattention. The infants in this study were 14 or 20 weeks of age. A continuous spatial cueing procedure was used in which a stimulus was presented until the infant fixated it, a cue was presented in the periphery for 300 ms, and then a “target” was presented on the same side as the cue (“valid”), on the opposite side of the cue (“invalid”), or a target was presented without a prior cue (“neutral”). Heart rate was recorded continuously and heart rate slowing and the return of heart rate to a prestimulus level were used to define periods of attentiveness and inattentiveness. The EEG was recorded using 124 scalp channels and two eye movement channels. ERP averages were computed around the time of the target onset and immediately preceding the saccade towards the target. Cortical source analysis was used to identify the location and activation of the places in the cortex responsible for generating the P1 validity effect. Traditional ERP analyses showed a “validity effect” in which there was an enhanced P1 on valid trials over invalid and neutral trials. This P1 component was enhanced if the infant was attentive, and primarily on short SOA trials. Cortical source analysis was used to identify the cortical areas involved in this ERP effect. Two cortical sources could be identified that accounted for ERP activity occurring about 100 to 130 ms following target onset. The current sources were located in the extrastriate occipital cortex (BA 18, 19) and fusiform gyrus contralateral to the cue. This area was activated most highly for validly cued targets relative to either neutral trials (no cue) or invalidly cued targets (contralateral cue). The activity in these cortical locations was larger when the infant was attentive than when inattentive, and the activity level in these areas during attention was negatively correlated with reaction time (high amplitude cortical activation, short reaction time, facilitation of responding). These results suggest that the “P1 validity effect” in infants is due to short-latency enhancement of the secondary visual areas (“covert orienting”) rather than to feedback from higher cortical areas (“covert attention”).
Courage, M.L, & Richards, J.E. (2008). Attention. In M.M. Haith and J.B. Benson (Eds.), Encyclopedia of infant and early childhood development (pps 106-117). Oxford, UK: Elsevier.chapter2008
Pempekl, T.A., Kirkorian, H.L, Stevens. M., Lundl, A.F., Richards, J.E., & Anderson, D.R.(2008). Video comprehensibility and attention in very young children. . International Conference on Infant Studies, Vancouver. (PDF)conferenceDownload2008Infants have increasingly become a target audience of digital media products. Yet, little is know about the extent to which very young children understand video. This study sought to determine the youngest ages at which infants discriminate between comprehensible and incomprehensible television content. Analysis of look length revealed that by 24 months of age, infants make this discrimination, looking longer at comprehensible video. Measures of heart rate support this finding insofar as heart rate deceleration (indicicative of engagement) was associated with look length. Thus, very young infants appear to be insensitive to language and even sequences presented via video.
Brain (and head) steretotaxic atlas for infants and children: Application to EEG / ERP cortical source analysis. Sloan-Kettering Vision Institute, San Francisco, CA. April, 2008.presentation2008
What’s inside a baby’s head? . (invited presentation) J.E. Richards, International Conference on Infant Studies, Vancouver, B.C., Canada, April, 2008.presentation2008
What’s inside a baby’s head? . (invited presentation) J.E. Richards, National Science Foundation, Washington DC, April, 2008.presentation2008
What’s inside a baby’s head? Attention processes revealed by source analysis of EEG. 23rd Annual Winter Conference on Current Issues in Developmental Psychobiology, Cozumel, Mexico, January 2008.presentation2008
What’s inside a baby’s head? Attention processes revealed by source analysis of EEG. . (invited presentation) Duke University, September, 2008.presentation2008
Video comprehensibility and attention in very young children. T. A. Pempek, D. Anderson, M. Stevens, & J.E. Richards, International Conference on Infant Studies, Vancouver, B.C., Canada, April, 2008.conference2008
Richards, J.E. (2008). Attention in young infants: A developmental psychophysiological perspective. In C.A. Nelson & M. Luciana (Eds.), Handbook of developmental cognitive neuroscience. Cambridge, MA, US: MIT Press.chapterDownload2008Attention changes dramatically in the period of infancy. Attention is selective and involves the focusing of cognitive processing on specific objects or tasks. Attention also has an arousal aspect, reflecting ehanced processing when attention is engaged. It is commonly thought that the development of attention is based heavily on the age-related changes in brain structures responsible for attention control. The present chapter will do three things. First, two types of brain systems that may be involved in attention and which show development will be reviewed. Second, psychophysiological measures that have been useful in the study of brain-attention relation development in infants will be presented. Finally, several studies will be examined that studied the development of infant attention with these psychophysiological methods. These experiments will be related to changes occurring in the neural systems underlying attention.
Infant sustained attention affects brain areas controlling covert orienting. J.E. Richards, International Conference on Infant Studies, Vancouver, B.C., Canada, April, 2008.conference2008
What’s inside a baby’s head? J.E. Richards, International Conference on Infant Studies, Vancouver, B.C., Canada, April, 2008.conference2008
Reynolds, G.D., & Richards, J.E. (2008). Attention and early brain development. In Tremblay, R.E., Barr, R.G., Peters, R.DeV., & Boifin, M. (Eds.). Encyclopedia on Early Childhood Development (pps 1-5). http://www.child-encyclopedia.com/documents/Reynolds-RichardsANGxp.pdfchapter2008
What’s inside a baby’s head? Sloan-Ketterling Eye Institute, San Francisco, CA, September, 2007.presentation2007
Development of infant attention to multimodal stimuli: Relation between arousal and specific attention processes. Indiana University, January, 2007.presentation2007
Infant sustained attention affects brain areas controlling covert orienting. J.E. Richards, Society for Research in Child Development, Boston, April, 2007.conference2007
Richards, J.E. (2007). Realistic head models for cortical source analysis in infant participants. Society for Research in Child Development, Boston. (PDF) conferenceDownload2007Cortical source analysis can identify cortical areas that are active during infant cognitive processing. This analysis uses high-density EEG recording and quantitative models that identify dipole sources inside the head to account for the EEG data. These sources can be related to the EEG activity in the time domain, to the experimental procedures, and to the cognitive processes occurring during the task. Cortical source analysis with infant participants has used adult models for the electrical and spatial characteristics of the head. The current poster will overview a method for using infant MRIs to develop realistic head models for infant participants for cortical source analysis. The method consists of several steps: 1) the MRI of a representative infant or the infant in the psychophysiological experiment must be obtained; 2) the head must be “segmented” with computer programs that analyze the MRI recording; 3) values for impedance for skull, scalp, CSF, and brain for infant participants must be estimated; 4) sufficient number of electrodes must be recorded; 5) realistic “forward” models using the spatial topography of the MRI must be computed. These steps allow the use of “realistic models” in computer programs that do cortical source analysis (e.g., “equivalent current dipole” analysis in BESA, or Source-Signal EMSE programs). This technique has been applied to cortical sources involve in infant spatial cueing, infant visual recognition memory, the response of infants to mother’s and stranger’s face, and EEG during object disappearance and appearance. The result of using realistic head models is illustrated in four findings. First, infant skull and scalp impedances (conductivity; resistance) are much lower than adults, so that using appropriate infant values results in cortical sources closer to the surface. Second, the number of recording channels affects cortical source analysis, with less than ~50 electrodes resulting in models that fit poorly and that mislocate the cortical source. Third, using realistic head models for areas of current leakage in the skull (sutures / seams between skull bones, partially closed fontenal) or for varying head characteristics (varying skull thickness, placement of brain with respect to skull landmarks) result in better fits and more appropriate locations of cortical sources. Finally, this is illustrated with a “representative MRI” approach in which a single MRI is used for all participants, and with an “individual MRI” approach in which the infant has both an anatomical MRI and participates in the psychophysiological experiment.
Realistic head models for cortical source analysis in infant participants. J.E. Richards, Society for Research in Child Development, Boston, April, 2007.conference2007
Richards, J.E. (2007). Infant sustained attention affects brain areas controlling covert orienting. Society for Research in Child Development, Boston. (PDF)conferenceDownload2007 Infants covertly move attention around in space without moving fixation. This is shown in the “spatial cueing” procedure in which a cue indicates the side of an upcoming target or is contralateral to the target (“valid” and “invalid”). Infants localize the target more quickly on valid trials than on invalid trials (“facilitation”), though at certain stimulus-onset-asychrony durations target localization may be delayed (“inhibition of return”). Several prior studies of infant participants with scalp-recorded event-related-potentials (ERP) find an enhancement of the first positive component (P1 component?) to target onset for the validly cued trials (P1 validity effect) and the cortical source for this component is the contralateral extrastriate occipital cortex and fusiform gyrus. The current study used heart-rate-defined attention phases to examine this effect under conditions of attention and inattention. The infants in this study were 14 or 20 weeks of age. A continuous spatial cueing procedure was used in which a stimulus was presented until the infant fixated it, a cue was presented in the periphery for 300 ms, and then a “target” was presented on the same side as the cue (“valid”), on the opposite side of the cue (“invalid”), or a target was presented without a prior cue (“neutral”). Heart rate was recorded continuously and heart rate slowing and the return of heart rate to a prestimulus level were used to define periods of attentiveness and inattentiveness. The EEG was recorded using 124 scalp channels and two eye movement channels. ERP averages were computed around the time of the target onset and immediately preceding the saccade towards the target. Cortical source analysis was used to identify the location and activation of the places in the cortex responsible for generating the P1 validity effect. Traditional ERP analyses showed a “validity effect” in which there was an enhanced P1 on valid trials over invalid and neutral trials. This P1 component was enhanced if the infant was attentive, and primarily on short SOA trials. Cortical source analysis was used to identify the cortical areas involved in this ERP effect. Two cortical sources could be identified that accounted for ERP activity occurring about 100 to 130 ms following target onset. The current sources were located in the extrastriate occipital cortex (BA 18, 19) and fusiform gyrus contralateral to the cue. This area was activated most highly for validly cued targets relative to either neutral trials (no cue) or invalidly cued targets (contralateral cue). The activity in these cortical locations was larger when the infant was attentive than when inattentive, and the activity level in these areas during attention was negatively correlated with reaction time (high amplitude cortical activation, short reaction time, facilitation of responding). These results suggest that the “P1 validity effect” in infants is due to short-latency enhancement of the secondary visual areas (“covert orienting”) rather than to feedback from higher cortical areas (“covert attention”).
Reynolds, G.D., & Richards, J.E. (2007). Infant heart rate: A developmental psychophysiological perspective. In L.A. Schmidt & S.J. Segalowitz (Eds.), Developmental Psychophysiology (pps 173-210). Cambridge, UK: Cambridge Press.chapterDownload2007Psychophysiology is the study of the relation between psychological events and biological processes in human subjects. The electrocardiogram (ECG) and heart rate (HR) have been commonly used measures throughout the history of psychophysiological research. Early studies found that stimuli eliciting differing emotional responses in adults also elicited HR responses differing in magnitude and direction of change from baseline (e.g., Darrow, 1929; Graham & Clifton, 1966; Lacey, 1959). Vast improvements in methods of measuring ECG and knowledge regarding the relationship between HR and cognitive activity have occurred. Heart rate has been particularly useful in developmental psychophysiological research. Researchers interested in early cognitive and perceptual development have utilized HR as a window into cognitive activity for infants before they are capable of demonstrating complex behaviors or providing verbal responses. Also, the relation between brain control of HR and the behavior of HR during psychological activity has helped work in developmental cognitive neuroscience. In this chapter, we address the use of the ECG and HR in research on human infants. We review research utilizing three ways in which HR has been used in this work: HR changes, attention phases defined by HR, and HR variability (particularly respiratory sinus arrhythmia). Topics we will focus on are: the areas of the brain that are indexed with these measures, developmental changes associated with these measures, and the relationship of these measures to psychological processes. Before covering research with infants, we will briefly review background information on the heart, the ECG and HR, and its relation to psychophysiology.
Does it matter that the infant’s mind is in its brain? And the brain is in a body? York University, November, 2007.presentation2007
Infant visual preferences within the modified-oddball ERP paradigm. G.D. Reynolds, M.Courage, & J.E. Richards, International Conference on Infant Studies, Kyoto, Japan, June, 2006.conference2006
Why are infants in-distractible during visual attention? First Hayward Endowment Annual Lecture, Department of Psychology, East Tennessee State University, April, 2006.presentation2006
Infant visual preference, recognition memory, attention and the brain. Virginal Polytechnic University, October, 2006.presentation2006
Reynolds, G.D., Courage, M., & Richards, J.E. (2006). Infant visual preferences within the modified-oddball ERP paradigm. International Conference on Infant Studies, Kyoto, Japan. (PDF) conferenceDownload2006The modified-oddball paradigm has been used to measure ERP components associated with attention and recognition memory in infancy.  Infants are familiarized with 2 stimuli and then exposed to brief presentations of three types of memory stimuli: frequent familiar, infrequent familiar, and infrequent novel.  Recognition memory is inferred based on differential cortical responding to each of the memory stimulus types.  A middle-latency negative ERP component over central leads labeled Negative Central (Nc) is assumed to reflect a general orienting response associated with attention.  The Nc has been found to be greater in amplitude following novel stimulus presentations. Late slow waves proposed to reflect recognition memory include the negative slow wave (associated with novelty detection), and the positive slow wave (associated with an updating of recognition memory).  A commonly used behavioral measure of recognition memory is the visual paired-comparison choice trial.  Paired-comparison trials involve simultaneous presentation of a familiar and a novel stimulus.  Recognition memory for the familiar stimulus is inferred when infants spend a greater proportion of time looking at the novel stimulus (i.e., demonstrate a novelty preference). No study to date has measured ERPs during paired-comparison trials because of the eye-movement artifacts produced during shifts between stimuli.  One goal of the present study was to examine infant ERPs during paired-comparison trials by utilizing independent components analysis to identify and remove eye-movement components from the EEG data. A second goal was to examine the consistency between ERP components and behavioral correlates of attention and recognition memory by embedding paired-comparison trials within the modified-oddball paradigm.  Infants 20, 26, and 32 weeks of age served as participants.  Infants were familiarized with two stimuli prior to testing. Participants were then exposed to alternating blocks of paired-comparison trials and brief stimulus presentations.  The paired-comparison trials and blocks of brief stimulus presentations were alternated in order to measure the infants’ visual preferences as the study progressed. Look durations during the paired-comparison trials were scored off-line to obtain novelty preference scores. Electroencephalographic recordings were made with a 126-channel system and ERP averages were made from -50 ms to 2000 ms around stimulus onset for brief stimulus exposures, and for the duration of the paired-comparison trials. Our ERP analysis focused on the Nc component. There was a significant effect of age on visual preference.  The 26- and 32-week-olds preferred novel stimuli, whereas the 20-week-olds preferred familiar stimuli. In the ERP analysis of paired-comparison trials, greater amplitude Nc was found to the non-preferred stimulus.  When infants demonstrated a novelty preference, Nc was greater in amplitude to the familiar stimulus (and vice versa). Results of the ERP analysis of brief stimulus presentations replicated past studies with greater amplitude Nc following novel stimulus presentations. These findings indicate that behavioral measures can be successfully integrated into ERP studies of infant cognitive development, although ERP and behavioral findings may not be entirely consistent. While infants demonstrated greater amplitude Nc to novel stimuli following brief stimulus presentations, greater amplitude Nc was found to familiar stimuli when look duration was indicative of a novelty preference.
Stevens, M. & Richards, J.E. (2006). Television program comprehensibility and distractibity in 6- to 24-month-old children. International Conference on Infant Studies, Kyoto, Japan. (PDF) conference2006Distractibility during television viewing has been an important topic for those interested in children’s attention development. It has been hypothesized that extended looking during television viewing is controlled by a mechanism called “attentional inertia”. If attention is engaged by the television program, there is an increasing cognitive engagement that holds fixation toward the television for extended periods. The comprehensibility of the television program is an important determinant of whether cognitive engagement occurs. The present study examined the effect of the television program language comprehensibility in 6 to 24 month old children with a distraction procedure.
Television program comprehensibility and distractibity in 6- to 24-month-old children. M. Stevens & J.E. Richards, International Conference on Infant Studies, Kyoto, Japan, June, 2006.conference2006
Infant visual preference, recognition memory, attention and the brain. Pennsylvania State University, October, 2006.presentation2006
Richards, J.E. (2006). Realistic Head Models for Cortical Source Analysis in Infant Participants. Society for Researh in Child Development, Atlanta GA. (PDF)conferenceDownload2006Cortical source analysis can identify cortical areas that are active during infant cognitive processing. This analysis uses high-density EEG recording and quantitative models that identify dipole sources inside the head to account for the EEG data. These sources can be related to the EEG activity in the time domain, to the experimental procedures, and to the cognitive processes occurring during the task. Cortical source analysis with infant participants has used adult models for the electrical and spatial characteristics of the head. The current poster will overview a method for using infant MRIs to develop realistic head models for infant participants for cortical source analysis. The method consists of several steps: 1) the MRI of a representative infant or the infant in the psychophysiological experiment must be obtained; 2) the head must be “segmented” with computer programs that analyze the MRI recording; 3) values for impedance for skull, scalp, CSF, and brain for infant participants must be estimated; 4) sufficient number of electrodes must be recorded; 5) realistic “forward” models using the spatial topography of the MRI must be computed. These steps allow the use of “realistic models” in computer programs that do cortical source analysis (e.g., “equivalent current dipole” analysis in BESA, or Source-Signal EMSE programs). This technique has been applied to cortical sources involve in infant spatial cueing, infant visual recognition memory, the response of infants to mother’s and stranger’s face, and EEG during object disappearance and appearance. The result of using realistic head models is illustrated in four findings. First, infant skull and scalp impedances (conductivity; resistance) are much lower than adults, so that using appropriate infant values results in cortical sources closer to the surface. Second, the number of recording channels affects cortical source analysis, with less than ~50 electrodes resulting in models that fit poorly and that mislocate the cortical source. Third, using realistic head models for areas of current leakage in the skull (sutures / seams between skull bones, partially closed fontenal) or for varying head characteristics (varying skull thickness, placement of brain with respect to skull landmarks) result in better fits and more appropriate locations of cortical sources. Finally, this is illustrated with a “representative MRI” approach in which a single MRI is used for all participants, and with an “individual MRI” approach in which the infant has both an anatomical MRI and participates in the psychophysiological experiment.
Infant visual preferences within the modified-oddball ERP paradigm. G.D. Reynolds, M.Courage, & J.E. Richards, Cognitive Neurosciences Society, San Francisco, April, 2006.conference2006
Courage, M.L., Reynolds, G.D., & Richards, J.E. (2006). Infants' visual attention to patterned stimuli: Developmental change and individual differences from 3- to 12-months of age. Child Development, 77, 680-695.journalDownload2006To examine the developmental course of look duration as a function of age and stimulus type, infants aged 14-, 20-, 26-, 39-, and 52 weeks were shown static and dynamic versions of achromatic geometric stimuli, faces, and Sesame Street material for 20 seconds of accumulated looking.  As duration of a look does not reflect a unitary attentional process but can be parsed according to corresponding heart-rate defined phases (i.e., stimulus orienting, sustained attention, attention termination), infants’ HR change was also measured.  Analysis of the look duration data indicated that prior to 26 weeks, infants’ looks decreases linearly for all stimuli.  For the older infants, look durations continued to decline for the geometric patterns but increased for the Sesame Street and face stimuli.  On-line measures of heart-rate confirmed this greater engagement with the more complex stimulus types.  Individual differences in look duration and baseline heart rate variability were independently related to stimulus type.  Infants with short look durations and those with high heart rate variability showed larger HR decelerations in sustained attention to Sesame Street and face stimuli than to the achromatic geometric patterns.  Infants with long look durations did not differ in their deceleration to the stimulus types and also spent more time in the phase of attention termination relative to phases of orienting and sustained attention.  The results suggested that short lookers and those with high HRV showed greater engagement with complex stimuli that did long lookers and those with low HRV. 
Realistic head models for cortical source analysis in infant participants. J.E. Richards, International Conference on Infant Studies, Kyoto, Japan, June, 2006.conference2006
EEG and ERP analysis using EGI. (one-day teaching workshop) Pennsylvania State University, April, 2005.presentation2005
Johnson, M.H., Griffin, R., Csibra, G., Halit, H., Farroni, T., de Haan, M., Baron-Cohen, S., & Richards, J.E. (2005). The emergence of the social brain network: Evidence from typical and atypical development. Development and Psychopathology, 17, 599-619.journalDownload2005Several research groups have identified a network of regions of the adult cortex that are activated during social perception and cognition tasks.  In this paper we focus on the development of this social brain network during early childhood and test aspects of a particular viewpoint on human functional brain development:  “Interactive Specialisation”.  Specifically, we apply new data analysis techniques to a previously published data set of event-related potential studies involving infants of 3, 4 and 12 months infants viewing faces of different orientation and direction of eye gaze.  Using source separation and localisation methods, several likely generators of scalp recorded ERP are identified, and we describe how they are modulated by stimulus characteristics.  We then review the results of a series of experiments concerned with perceiving and acting on eye gaze, before reporting on a new experiment involving young children with autism.  Finally, we discuss predictions based on the atypical emergence of the social brain network.
Richards, J.E. (2005). Localizing cortical sources of event-related potentials in infants’ covert orienting. Developmental Science, 8, 255-278.journalDownload2005This study used cortical source analysis to localize the cortical sources of event-related-potentials (ERP) during covert orienting in infants aged 14 and 20 weeks. The infants were tested in a spatial cueing procedure. The reaction time to localize the target showed response facilitation for valid trials relative to invalid or neutral trials. High-density EEG (126 channels) was recorded during the task, and independent component analysis and equivalent current dipole analysis was used to locate the cortical sources of the EEG during the task. There was a larger P1 ERP component on the valid trials than the other trials (P1 validity effect), and this occurred due to activity in Brodmann’s areas 18 and 19. A presaccadic ERP component occurred over the frontal cortex (-65 ms) and was larger to a target in a cued location than in uncued locations. This effect was localized to the superior frontal gyrus on the inferior portion of the prefrontal cortex. Increases from 14 to 20 weeks in amplitude of the P1 validity effect and the presaccadic ERP could be modeled by an increase in activation in the corresponding cortical areas.
Richards, J.E. (2005). Attention. Entry in The Cambridge Encyclopedia of Child Development (282-286).. Cambridge Press. (PDF)chapterDownload2005Attention may be defined as the selective enhancement of some behavior at the expense of other behavior. Writings on attention often cites William James, Principles of Psychology (1890), “…everyone know what attention is”. This is because we all have a commonsense notion of what attention is and that it is ubiquitous across all types of behavior (e.g., attention to objects, joint attention with others, social attention, motor skills).  Attention is defined both as a specific psychological mechanism and as a characteristic of individual psychological behavior.  Thus, in the developmental perspective there may be a separate cognitive process called “attention” that develops independent of other psychological behavior as well as attention development specific to behavior. Attention development is often linked to the development of brain areas that are involved in attention.
What babies look at: Developmental trends and individual differences in infants’ attention to pattern. M. Courage, G.D. Reynolds, & J.E. Richards, Society for Research in Child Development, Atlanta, GA. April 2005.conference2005
Television program comprehensibility and distractibity in 1- and 2-year-old children. J.E. Richards, Society for Research in Child Development, Atlanta, GA. April, 2005.conference2005
Infant visual preferences within the modified-oddball ERP paragirm. G.D. Reynolds, M.Courage, & J.E. Richards, Society for Psychophysiological Research, Lisbon, Portugal, October, 2005.conference2005
Infant visual preferences within the modified-oddball ERP paradigm. G.D. Reynolds, M.Courage, & J.E. Richards, Society for Research in Child Development, Atlanta, GA. April, 2005.conference2005
Reynolds, G.D., Courage, M., & Richards, J.E. (2005) Infant visual preferences within the modified-oddball ERP paradigm. Psychophysiology, 42, S60 (abstract).journal2005
Spatial orienting and arousal in infant: Brain bases and development. Pennsylvania State University, April, 2005.presentation2005
Developmental cognitive neuroscience of sustained attention in infants. Department of Psychology, Emory University, February, 2004.presentation2004
Converging measures of infant attention. The John Merck Fund Summer Institute on the Biology of Developmental Disabilities. Princeton University, July, 2004.presentation2004
Richards, J.E., & Anderson, D.R. (2004). Attentional inertia in children’s extended looking at television. Advances in Child Development and Behavior, 32, 163-212..journalDownload2004In this chapter we consider sustained visual attention in children and adults. We focus on children’s looking at television, but we also consider sustained play with toys. Our work indicates that sustained looking at television or during play reveals attentional processes that have not been apparent in standard experimental studies of attention to static visual displays. In the child’s typical environment, attention is drawn to interesting, informative, and important aspects of the real world. The sensory and cognitive properties of such objects are often meaningful to the child and incorporate movement and change over time. We believe that often television programs and movies, and probably play with toys, mimic these types of stimuli and reveal patterns of attention that are not typically found in laboratory studies. In the present chapter, we focus on a phenomenon we call attentional inertia. Attentional inertia is a progressive increase in the attentional engagement as a look is sustained. In this chapter, we are primarily concerned with what happens once a look is initiated; why are looks subsequently sustained or terminated? We will review past work that shows attentional inertia during television and toy play, examine changes in the distribution of looks to television using data from a wide range of ages, and examine two quantitative models that account for extended looking during television viewing.
Richards, J.E. (2004). Recovering dipole sources from scalp-recorded event-related-potentials using component analysis: Principal component analysis and independent component analysis. International Journal of Psychophysiology, 54, 201-220.journalDownload2004Principal components analysis (PCA) and independent component analysis (ICA) were examined in their ability to recover cortical sources from simulated data. Datasets of EEG segments were generated that contained cortical sources that were temporally overlapping or non-overlapping, and cortical sources with varying degree of spatial orthogonality. For temporal overlapping cortical sources, both PCA and ICA resulted in components that required multiple-source equivalent current dipole models. The spatially overlapping cortical sources affected the PCA method more than ICA, resulting in single PCA components in which all nonorthogonal cortical sources were represented. For both PCA and ICA, dipole models with fixed-location dipoles successfully accounted for most of the variance in the component weights, even when the spatial or temporal overlap of the generating sources required multiple-dipole models.
Richards, J.E. (2004). Attention. The Cambridge Encyclopedia of Child Development (282-286). Cambridge Press.chapter2004
Richards, J.E. (2004). Development of covert orienting in young infants. In L. Itti, G. Rees, & J. Tsotsos (Eds.), Neurobiology of attention (Chapter 14, pp. 82-88). Academic Press / Elsevier.journalDownload2004Adults can shift attention to different regions of space without moving the eyes, i.e., covert orienting of attention. Covert orienting implies that information processing may occur for stimuli in peripheral locations. The purpose of the present chapter is to review evidence that infants in the first six months of life are able to shift attention throughout space covertly. These studies show that there is an increasing efficiency from birth to six months with which infant shift spatial attention. Some cortical areas that may be involved in the development of spatial attention will be suggested.
Richards, J.E. (2004). The development of sustained attention in infants. In M.I. Posner (Ed.), Cognitive neuroscience of attention (Chapter 25, pp 342-356). Guilford Press..chapterDownload2004Attention may be characterized by its selectivity and intensity. The selective aspect of attention narrows the focus of information processing from a wide range of available stimuli, thoughts, and responses, to a single aspect of the environment, or a selected set of stimulus-response activities. The intensity aspect of attention improves the quality of information processing once the information processing focus is narrowed. This results in improvements in the quality of the cognitive activities involved in the attentive behavior. This latter aspect of attention is often called sustained attention. Infants show increases in sustained attention over the first year of life. In this chapter some research will be reviewed that illustrates the development of sustained attention in young infants.
Why are infants in-distractible during visual attention? Department of Psychology, Emory University, February, 2004.presentation2004
The convergence of electroencephalographic and heart rate measures of attention in infancy. G.D. Reynolds & J.E. Richards, International Society for Infancy Studies, Chicago, IL. April, 2004.conference2004
Richards, J.E. (2004). A quantitative method to use high-density EEG recordings to localize cortical sources of infant cognitive activity. International Society for Infancy Studies, Chicago, IL. conference2004Many models of infant cognitive development hypothesize that changes in cognition (attention, memory, face processing, language) are based upon the development of specific neural systems. Such cognitive neuroscience models have been tested in adults and older children with neuroimaging techniques such as PET and fMRI. However, the application of such techniques to infant participants is either unethical (e.g., PET) or impractical (e.g., fMRI). An alternative to such neuroimaging techniques is the use of high-density EEG recording and cortical source analysis. The current poster will overview a method being developed for such analyses with infant participants. The method consists of four steps: 1) recording of EEG activity with high-density (64- or 128-channel) EEG system. The use of the high-density EEG / ERP gives the resolution necessary to localize cortical sources of ERP activity. 2) analysis of individual participant raw segmented data with independent components analysis (ICA) or principal components analysis (PCA). The raw segmented data is analyzed rather than ERP averages, allowing the separation of cortical sources by experimental factors later in the analysis. The component analysis results in loadings that represent topographically-organized scalp sources. These scalp sources, particularly those from ICA, contain any single-source components generating the EEG. 3) identification of clusters of components with similar topographical loadings; 4) estimation of equivalent current dipole (ECD), i.e., cortical location. The ECD estimation is done on the components coming from individual participants, and are seeded by an ECD from the grand average of the cluster groups. 5) calculation of component activations in relation to experimental factors. whose loadings may be used to acquire single-source ECD models. The activations of the clustered component groups shows the experimental validity of the cortical sources identified in the ICA. This technique has been applied to cortical sources involved in infant spatial cueing, infant visual recognition memory, and the responses of young infants to face-stimuli. For example, the cortical source of the P1 validity effect in young infants during a spatial cueing task was shown to be located in the extrastriate occipital cortex and ventral fusiform gyrus. The “Nc” component occurring in response to the presentation of a brief visual stimulus had its cortical source in the prefrontal cortex, including the anterior cingulate. These results show that scalp-recorded EEG/ERP may help identify brain areas involved in infants’ cognitive development. The application of the high-density EEG recording and the methods for cortical source localization give researchers a tool to verify neurodevelopmental models of infant development.
Recognition memory and attention in infants. 5th Annual Frontiers in Neuroscience Research Day, Medical University of South Carolina, March, 2004.presentation2004
Reynolds, G.D. & Richards, J.E. (2004). Cortical source localization of infant visual attention and recognition memory. International Society for Infancy Studies, Chicago, IL. conference2004Early studies of the development of recognition memory in infants demonstrated a negative component over central leads (Nc) with greater amplitude in event-related potentials following presentations of a novel stimulus than presentations of a familiar stimulus. In contrast, subsequent investigations utilizing a familiarization phase prior to stimulus exposure found that Nc amplitudes do not vary significantly following novel versus familiar stimulus presentations. Recent research has demonstrated that attention affects ERPs associated with recognition memory. The present study investigated the effects of familiarization and attention on electrophysiological correlates of recognition memory in infants. Seventy infants in the following three age groups were used as participants: 20, 26, and 32 weeks of age. Two familiarization groups were utilized: familiarization and familiarization control. Infants in the familiarization group were familiarized with two stimuli that were used during testing, infants in the familiarization control group were familiarized with two stimuli that were not used in subsequent testing. Following the familiarization phase, infants were exposed to a modified-oddball paradigm with presentations of three types of memory stimuli: frequent familiar, infrequent familiar, and infrequent novel. Electroencephalographic recordings were made with a 124-channel system and ERP averages were made from -50 ms to 2000 ms around stimulus onset. The ERP were quantified with spatial independent components analysis, and equivalent current dipoles" were estimated to locate cortical sources of the ERP components. Heart rate was measured as an index of attention. A negative component (Nc) was found to occur about 500 ms after stimulus onset. The cortical source of this component was located in areas of frontal cortex including the middle frontal gyrus inferior frontal gyrus and anterior cingulate cortex. Infants in the familiarization group demonstrated greater amplitude Nc components following novel stimulus presentations than familiar stimulus presentations. The familiarization control group did not display differences in the amplitude of Nc for stimulus type. Nc amplitude was greater during periods of attention than during periods of inattention. Age differences were found in late slow wave components for memory stimulus type. These findings suggest that familiarization attention and stimulus type impact ERPs associated with recognition memory in infants.
Perspectives on infants’ visual attention: Developmental change and individual differences. J.E. Richards, International Society for Infancy Studies, Chicago, IL. April 2004.conference2004
Looking at and interacting with comprehensible and incomprehensible Teletubbies. A. Frankenfield, J.E. Richards, T.A. Pempek, H.L. Kirkorian, & D.R. Anderson, International Society for Infancy Studies, Chicago, IL. April 2004.conference2004
Infant visual attention: Peripheral localization of life-like video stimuli. C.R. Crane, B.A. Mallin, & J.E. Richards, Arizona Psychological Association, Tuscon, AZ. October, 2004.conference2004
Infant peripheral stimulus localization of dynamic stimuli. B.A. McKinney & J.E. Richards, International Society for Infancy Studies, Chicago, IL. April 2004.conference2004
Infant localization of visual and dynamic peripheral stimuli. J.L. Moore, J.F. Stephens, B.A. McKinney, & John E. Richards, Southeastern Psychological Association, Atlanta, GA. March, 2004.conference2004
Frankenfield, A., Richards, J.E., Pempek, T.A., Kirkorian, H.L., & Anderson, D.L. (2004) Looking at and interacting with comprehensible and incomprehensible Teletubbies. International Society for Infancy Studies, Chicago, IL.conference2004Attention to television by preschool children is related to program comprehensibility. Comprehension, in turn, is dependent on two important cognitive abilities - understanding of language and understanding of event sequences. There is no question that by age 3 children comprehend TV made for them, but increasingly, TV programs and videos are being made for children 2 and under. This experiment uses a procedure developed by Anderson et al. (1981) to determine whether very young children discriminate comprehensible from incomprehensible versions of Teletubbies. At this time, data have been collected and analyzed for 24-month-olds. We are collecting data from 18-month-olds, 12-month-olds, and 6-month-olds. Participants were 25, 24-month-old children. Each infant viewed one of two 40-minute videos of Teletubbies containing normal segments of the show, as well as distortions of the same segments. Twelve of the subjects viewed backward speech distortions, while thirteen viewed distortions created through random rearrangement of camera shots. Each child sat on his/her parent's lap approximately 30" from the television screen. The children were free to play with toys, watch the television, or interact with their parent. Videotapes of the sessions were coded for looks at the television and interactions with the show. A mixed-model ANOVA indicated that children looked at normal more than distorted segments, but the effect was smaller and only marginal for backward speech. The results for random edit were complicated by strong order effects, with children receiving the normal segment first watching normal more than distorted, and those receiving distorted first paying low but equal amounts of attention. A between-subjects analysis of the first trial data of mean look length and mean percent looking indicated that subjects viewing the normal segments had greater attention than those subjects viewing the distorted segments. Analysis of interactions supported the effect of comprehensibility with children interacting more during normal segments. There was a surprising negative relationship between prior experience with Teletubbies and attention to the show. Children who had not previously viewed Teletubbies paid more attention to normal segments than to distorted versions. However, if children had prior experience with the show, they paid equal (but lower) attention to both the normal and distorted segments. 24-month-olds behaviorally discriminated comprehensible from incomprehensible Teletubbies, but only if they hadn't seen the program before. For this age group, familiarity may overwhelm the importance of comprehensibility. It is an open question at this time whether younger children will discriminate comprehensibility at all.
Developmental and individual differences in infants’ attention as a function of stimulus characteristics. M. Courage, G.D. Reynolds, & J.E. Richards, International Society for Infancy Studies, Chicago, IL. April 2004.conference2004
Courage, M., Reynolds, G.D., & Richards, J.E. (2004). Developmental and individual differences in infants' attention as a function of stimulus characteristics. International Society for Infancy Studies, Chicago, IL. conference2004There is evidence that the duration of infants' looks (e.g., mean or peak look length) during habituation and other familiarization procedures decreases with age across the first year of life. This has generally been attributed to increased speed and/or efficiency in information processing with age. Moreover, individual differences in these same look-duration measures within age have been observed in several research labs (e.g., Colombo and colleagues; Rose and colleagues). These data indicate that "short" lookers compared to "long" lookers encode information more quickly (i.e., with briefer, more broadly distributed fixations), show higher novelty preferences (i.e., better recognition) on immediate and delayed tests, require less time to shift from processing global to local pattern information, disengage fixation from a stimulus more quickly, and show higher performance on tests of language and cognition in childhood. Longer look duration is ostensibly less mature and is typical of very young infants, as well as those who are at risk for developmental delay (e.g., preterm infants, infants with Down syndrome). However, most of these data have been based in infants' attention to static, two-dimensional, black and white patterned stimuli. In contrast, research in which infants' attention to dynamic, colorful, and complex stimuli (e.g., television material, novel toys) has been observed indicates that look duration often increases with age (e.g., Richards and colleagues; Ruff, Oakes and colleagues). This is especially likely when infants' heart rate and/or facial _expression and manual examination indicate that they are engaged in sustained or focused attention. One goal of the study reported here was to examine developmental and individual differences in infants' look duration to stimuli that vary in their configuration, complexity, and movement characteristics. Five groups of infants aged 14, 20, 26, 39, and 52 weeks were the participants. The infants were presented with 8 stimuli for 20 seconds of accumulated looking to each one. The stimuli were: a still frame of a woman's face, the same face in conversation (no sound), static and dynamic versions of a black and white matrix of dots, static and dynamic versions of a black and white geometric pattern, a single still frame from a Sesame Street video and a dynamic clip from the same video. The series of stimuli were presented twice. Each infant's heart rate was assessed during a 2 minute baseline periods immediately before the first and second series of stimulus presentations. Heart rate was also measured throughout the stimulus presentations. The results showed that for all stimulus types there was a significant decrease in look duration (peak look, mean look) from 14 to 26 weeks followed by one of two general patterns of look duration from 39 to 52 months (a) a continued decrease or a plateau -- for the achromatic geometric and the face stimuli or (b) a significant increase -- for the Sesame Street stimuli. This latter pattern is inconsistent with the traditional model of a linear decrease in look duration across the first postnatal year but is consistent with models of infant attention in which measures of look duration have been shown to increase with age sometime after 6 months. Patterns of individual differences in look duration and heart rate variability were complexly interrelated with these general developmental trends. In conclusion, the results of this study support the view that the development of infants' attention to visual stimuli is not a unitary process but may follow a multiphasic course (e.g., Colombo et al., 1999) in which look duration reflects the maturation of different cognitive and attentional processes over time.
Cortical source localization of infant visual attention and recognition memory. G.D. Reynolds & J.E. Richards, International Society for Infancy Studies, Chicago, IL. April 2004.conference2004
A quantitative method to use high-density EEG recordings to localize cortical sources of infant cognitive activity. J.E. Richards, International Society for Infancy Studies, Chicago, IL. April 2004.conference2004
Reynolds, G.D. & Richards, J.E. (2004). The convergence of electroencephalographic and heart reat measures of attention in infancy. International Society for Infancy Studies, Chicago, IL. conference2004In two recent studies conducted in our laboratory, we have utilized heart rate (HR) and electroencephalographic (EEG/ERP) measures simultaneously with infant participants. These studies examined the effects of attention (measured with visual fixation and HR) on electrophysiological correlates of attention and recognition memory. In both studies, infants at ages 4.5, 6, and 7.5 months were presented with a “Sesame Street” movie that elicited periods of attention and inattention, and computer-generated stimuli were presented overlaid on the movie for 500 ms. Infants were familiarized with two stimuli that were used during testing. Following familiarization, infants were exposed to a modified oddball paradigm with presentations of three types of memory stimuli: frequent familiar (FF), infrequent familiar (IF), and infrequent novel (IN). ERP averages were made from -50 ms to 2000 ms around stimulus onset, and the heart rate data was parsed into HR-defined attention phases. This design resulted in three experimental conditions: age (4.5, 6, and 7.5 months), stimulus type (FF, IF, and IN), and attention (stimulus orienting, sustained attention, and attention termination). In the first study, the EEG was recorded from twenty locations. Topographical ERP scalp potential maps were calculated. An ERP component labeled the “Nc” (Negative Central, about 450 - 550 ms after stimulus onset) was larger during attention than inattention and increased in magnitude over the three testing ages during attention. Late slow waves in the ERP (from 1000 to 2000 ms post-stimulus onset) consisted of a positive slow wave in response to the infrequent familiar stimulus at all three testing ages. The late slow wave in response to the infrequent novel stimulus during attention was a positive slow wave for the 4.5 month old infants, to a positive-negative slow wave for the 6 month old infants, and a negative slow wave for the 7.5 month old infants. These results show attention facilitates the brain response during infant recognition memory and show that developmental changes in recognition memory are closely related to changes in attention. In the second study, two familiarization groups were utilized: familiarization and familiarization control. Infants in the familiarization group were familiarized with two stimuli that were used during testing, infants in the familiarization control group were familiarized with two stimuli that were not used in subsequent testing. EEG recordings were made with a 124-channel system. The ERP were quantified with spatial independent component analysis, and "equivalent current dipoles" were estimated to locate cortical sources of the ERP components. A negative component (Nc) was found to occur about 500 ms after stimulus onset. The cortical source of this component was located in the anterior cingulate gyrus. Differences in amplitude of Nc were found across groups during attentive states but not during periods of inattention. Late slow wave components were demonstrated that varied in temporal and spatial morphology with stimulus type. These findings suggest that familiarization, attention, and stimulus type impact ERPs associated with recognition memory in infants. Furthermore, the use of HR as a means of controlling for attentiveness in infants during stimulus presentation may serve to increase effect sizes found in studies utilizing EEG recordings.
Hunter, S.K., & Richards, J.E. (2003). Peripheral stimulus localization by 5- to 14-week-old infants during phases of attention. Infancy, 4,1-25.journalDownload2003This study examined the effect of attention in young infants on the saccadic localization of peripheral stimuli. Infants ranging in age from 5 to 14 weeks were tested using a peripheral stimulus detection paradigm. The presence of a central fixation stimulus decreased detection probability, particularly if attention was engaged with the central stimulus. Peripheral stimulus localization usually was accomplished with a single eye movement. When localization was accomplished by multiple eye movements, corrective saccades occurred most frequently, and fixed-amplitude hypometric saccades occurred less frequently. A change in the "main sequence" was found from 5 to 11 weeks of age, and this decrease was independent of attention.
Infant attention and cortical sources of ERP for recognition of briefly presented visual stimuli. J.E. Richards, Society for Research in Child Development, Tampa, FL. April, 2003.conference2003
Richards, J.E. (2003). Cortical sources of event-related-potentials in the prosaccade and antisaccade task. Psychophysiology, 40, 878-894.journalDownload2003The cortical sources of event-related-potentials (ERP) were examined in the prosaccade and antisaccade task in college-age participants. Participants were presented with an antisaccade or prosaccade task with a cue that indicated the spatial location of the target, a cue that indicated the type of eye movement, or no cue. A principal component analysis of the target-related ERP showed a contingent negative variation, parietal activity, and extrastriate occipital activity. An overt spatial cue resulted in extrastriate activity localized in Brodmann’s area 19 whereas a covert cue results in activity in area 19 or 37. The presaccadic ERP activity primarily consisted of a contralateral positive potential and ipsilateral negative potential, which appears to be a result of activity in Brodmann’s areas 8, 10, and 11. These analyses suggest that several areas of the cortex and multiple psychological processes are involved in the control of eye movements in the antisaccade and prosaccade task.
Richards, J.E. (2003). Attention affects the recognition of briefly presented visual stimuli in infants: An ERP study. Developmental Science, 6, 312-328.journalDownload2003This study examined the effect of attention in infants on the ERP changes occurring during the recognition of briefly presented visual stimuli. Infants at ages 4.5, 6, and 7.5 months were presented with a “Sesame Street” movie that elicited periods of attention and inattention, and computer-generated stimuli were presented overlaid on the movie for 500 ms. One stimulus was familiar to the infants and was presented frequently, a second stimulus was familiar but presented infrequently, and a set of 14 novel stimuli were presented infrequently. An ERP component labeled the “Nc” (Negative Central, about 450 - 550 ms after stimulus onset) was larger during attention than inattention and increased in magnitude over the three testing ages during attention. Late slow waves in the ERP (from 1000 to 2000 ms post-stimulus onset) consisted of a positive slow wave in response to the infrequent familiar stimulus at all three testing ages. The late slow wave in response to the infrequent novel stimulus during attention was a positive slow wave for the 4.5 month old infants, to a positive-negative slow wave for the 6 month old infants, and a negative slow wave for the 7.5 month old infants. These results show attention facilitates the brain response during infant recognition memory and show that developmental changes in recognition memory are closely related to changes in attention.
Richards, J.E. (2003). Development of attentional systems. In M. De Haan & M.H. Johnson (Eds.), The cognitive neuroscience of development (pp 73-98). East Sussex, UK: Psychology PresschapterDownload2003The development of visual attention depends on developmental changes in the brain areas controlling attention. Some models are reviewed that hypothesize parallel developmental changes in visual attention and the brain, particularly in human infants. The applicability of these models is examined with experiments using psychophysiological measures (electroencephalogram (EEG), event-related potentials (ERP), heart rate) that are controlled by the hypothesized brain areas. This chapter emphasizes the need for using relatively direct measures of brain activity in addition to behavioral measures in the empirical examination of neurodevelopmental models of visual attention.
The impact of familiarization on elecrtrophysiological correlates of recognition memory in infants. G. Reynolds & J.E. Richards, Cognitive Neuroscience Society, New York, NY. March, 2003.conference2003
Recovering cortical dipole sources from scalp-recorded event-related-potentials using component analysis: Principal component analysis and independent component analysis. J.E. Richards, Cognitive Neuroscience Society, New York, NY. March, 2003.conference2003
Differential heart-rate activity in infants to uni- and multimodal events. R.P. Cooper & J.E. Richards, Society for Research in Child Development, Tampa, FL. April, 2003.conference2003
Why are infants in-distractible during visual attention? Department of Psychology, Washington University, January, 2002.presentation2002
Principal components analysis of event-related-potentials for cortical source analysis. Birbeck College, University of London, London, England, September 2002.presentation2002
Neuroimaging in infants using ERP. Birbeck College, University of London, London, England, September, 2002.presentation2002
Cortical source analysis of ERP of individual participants in psychophysiological experiments. J.E. Richards, Society for Psychophysiological Research, Washington, D.C. October, 2002.conference2002
Cortical sources of ERP for infants' recognition of briefly presented visual stimuli. J.E. Richards, Society for Psychophysiological Research, Washington D.C.. October, 2002.conference2002
Cortical sources of the P1 / N1 validity effect in spatial cueing in young infants. J.E. Richards, International Society for Infancy Studies, Toronto, CA. April, 2002.conference2002
Developmental changes in the main sequence using interesting visual stimuli. B. McKinney, E. Lewis, V. Wills, & J.E. Richards, International Society for Infancy Studies, Toronto, CA. April, 2002.conference2002
Differential heart-rate activity in infants to uni- and multimodal events. R.P. Cooper & J.E. Richards, Society for Psychophysiological Research, Washington, D.C. October, 2002.conference2002
Getting distracted from the main task: Infants and preschoolers watching TV! J.E. Richards, International Society for Infancy Studies, Toronto, CA. April, 2002.conference2002
McKinney, B., Lewis, E., Wills, V., & Richards, J.E. (2002). Developmental changes in the main sequence using interesting visual stimuli. International Society for Infancy Studies, Toronto, CA..conference2002This study examined the quantitative characteristics of infant saccadic eye movements in infants from 17 to 26 weeks of age. The “main sequence” is a linear relation between saccade velocity and amplitude. The main sequence relation is generated by the brainstem areas that control oculomotor nerves. In this study the main sequence was examined when infants made a saccade from an initial stimulus to a distractor stimulus in the display. Change in heart rate, which is an index of attention, and the experimentally defined stimuli were examined together.   Infants ranging in age from 17 to 26 weeks (total N = 12) were presented with experimentally defined stimuli in a Sesame Street movie. The segmented scenes consisted of random scenes shown as filler and one of five scene changes: calibration, movement combinations, location switch, location/character switch, and additions. The scene changes were initiated by a button press by the experimenter when the infant was looking at the correct location. Once the infant attended to the initial stimulus, a button was pressed which presented the second scene. This was followed by another button press once the infant attended to the second stimulus. This occurred for 55 s trial lengths. The electrooculogram was used to measure saccadic eye movements and the electrocardiogram was used to measure heart rate and heart rate phases. The fastest velocity of the saccade and the total amplitude of the saccade were quantified.   The main sequence relation between saccade velocity and amplitude was found in this study. That is, the velocity of the saccade was positively correlated with the amplitude of the saccade. The effect of attention on the main sequence relation was also examined. The decreased main sequence slopes for all ages during sustained attention were significantly different from the slopes during stimulus orienting and attention termination. There was not a significant difference between the slopes for the heart rate phase types, stimulus onset and attention termination. During sustained attention, the main sequence slopes show that there is a difference between the oldest age group (26 weeks) and the younger ages (17 and 20 weeks). However, the slopes for 17 and 20 week olds were not significantly different during this phase type. Finally there were no real differences in main sequence slopes among the age groups during attention termination. These changes in main sequence slopes across phase types for the three age groups support the theory that the visual system continues to develop postnatally. These findings suggest that attention promotes the main sequence relation in infants.
Richards, J.E. (2002). Cortical source analysis of ERP of individual participants in psychophysiological experiments. Society for Psychophysiological Research, Washington, D.C.conference2002The identification of cortical sources of event-related potentials (ERP) can be used to study psychologically-related brain activity with non-intrusive measures in traditional psychophysiological tasks. These analyses usually are done on measures averaged over a group of many participants. This presentation will show some of the techniques necessary for analyzing this in individual participants. Its use will be illustrated in a study of antisaccade-related presaccadic-ERP in children and adults, and identification of cortical sources in infant participants. There are four steps necessary for analyzing cortical sources for individual participants. First, knowledge of individual's head structure is necessary to correlate scalp-recorded ERP with brain structure. This may be accomplished via structural MRIs of individuals, or by "warping" external head measurements on individuals to representative brain topographies (representative or "average" MRI, stereotaxic atlas). Second, numerical techniques quantify the ERP for the individual. This may be participant-based grand averages. The methods include spatial component analysis (independent component analysis, principal component analysis), which can result in measures of component activation for a single participant or single trials. Third, a variety of source techniques exist that may be used to locate the cortical source of the scalp-recorded ERP. These include numerical methods and commercial computer packages. Finally, the locations found in the source analysis must be related to the cortical structures for that individual.
Richards, J.E. (2002). Cortical sources of the P1 / N1 validity effect in spatial cueing in young infants. International Society for Infancy Studies, Toronto, CA.conference2002Infants have been shown to covertly move attention around in space without moving fixation. This is shown in the “spatial cueing” procedure in which a cue indicates the side of an upcoming target (“valid trial”), or is contralateral to the target (“invalid trial’). Infants localize the target more quickly if the cue and target are in the same location than when not (“facilitation”), though at certain stimulus-onset-asychrony durations target localization may be delayed (“inhibition of return”). Two prior studies have shown with scalp-recorded event-related-potentials (ERP) that there is an enhancement of the first positive component to target onset for the validly cued target. However, these studies were done with relative few electrodes (e.g., 10-20 system) and can not be used to infer the cortical sources for these ERP effects. The present study identifies cortical activity related to spatial cueing using 128-channel EEG recording. The infants in this study were 14 or 20 weeks of age.  A spatial cueing procedure was used in which a central stimulus was presented for two seconds and a “cue” stimulus was then presented in the periphery for 300 ms. Subsequently, a “target” stimulus was presented on the same side of the cue or the opposite side of the cue. Control trials were included in which a target was presented without a previous cue. The EEG was recorded with a “high-density” system using 124 scalp channels and two eye movement channels. The EEG was used to make event-related-potential averages around the time of the target onset and immediately preceding the saccade towards the target. Traditional ERP analyses showed a “validity effect” in which there was an enhanced P1 ERP component to the target on the same side as the cue, compared to the P1 amplitude on the contralateral side or on control trials.  “Brain electrical source analysis” (BESA, cortical source analysis) was used to identify the cortical areas involved in this ERP effect. Cortical areas were identified that were hypothesized to be involved in this effect, an electrical current source was hypothesized at that location, an electrical scalp distribution based on that cortical current source was generated, and the hypothesized and actual electrical distributions were compared. Two cortical sources could be identified that accounted for ERP activity occurring about 100 to 130 ms following target onset. First, there was a current source located around the calcarine fissure, in the primary visual cortex (Brodmann area 17). This activity was unrelated to the validity of the target and occurred whenever a target appeared.  Second, there was a current source located in the fusiform gyrus (Brodmann area 19). This area was activated most highly for validly cued targets relative to either control trials (no cue) or invalidly cued targets (contralateral cue). This result suggests that the “P1 validity effect” in infants may be due to the enhancement of the “ventral stream” for processing objects rather than a function of “spatial attention”.
Richards, J.E. (2002). Getting distracted from the main task:  Infants and preschoolers watching TV!  International Society for Infancy Studies, Toronto, CA.conference2002The “distractibility” phenomenon is characterized as a competition between a central task and a competing secondary task. Several studies have shown that when young children are watching interesting TV programs that they engage in extended looking indicating increasing attention engagement. This looking is accompanied by increased memory for scenes, relative indistractiblity from looking away from the TV, heart rate changes indicating progressive attention engagement, and increased comprehension of TV content. Watching TV is a “primary task” to which attention is directed and irrelevant secondary events are ignored. Recently, it was shown that infants and young preschoolers, ages 6 to 26 months, are harder to distract from a children’s movie (“Follow that Bird”) when looking and heart rate measures indicated attention is directed to the television. There were two findings. First, the longer a look was in progress, the longer the distraction latency and the less likelihood that the distractor was localized. Second, the heart rate changes occurring at the time of distractor onset moderated this influence.  The period immediately before distractor onset had a larger sustained lowered heart rate for the trials on which the children continued looking at the center TV monitor than for the trials on which the children looked to the distractor.  There were some effects in that study that suggested the older age children (18, 24 months) also were less distractible during “comprehensible” movies than during “incomprehensible” computer-generated patterns. Alternatively, 6 and 12 month old infants were equally attentive to movie and computer-generated patterns. Currently, the effect of TV program comprehensibility on distractibility is being examined with two kinds of stimuli. First, normal movie-like presentations (e.g., “Follow that Bird”) are presented or movies with scrambled sequences are shown. It is hypothesized that infants from 6 to 24 months will not distinguish these sequences because of an inability to follow the thematic elements of the movie. Alternatively, normal movies with backward speech, foreign language, scrambled speech, or scrambled intrascene sequences should be less comprehensible than either normal sequenced or scrambled sequence movies for older infants for whom language comprehension is advanced enough to appreciate the language elements of the presentation. The level of attention to the movie is examined by recording heart rate changes and determining if infants and young preschoolers are distracted by stimuli presented on peripheral TV monitors. Three general conclusions come from these studies.  First, the basic patterns of distraction from the “main task” are established early in life, as early as 6 months of age. This is shown by the regular relation between visual attention engagement and distraction, and patterns of heart rate change and distraction. Second, the underlying distraction processes are modified by elements external to distractibility. These two studies show that the comprehensibility of the stimuli affects distraction parameters.  Finally, these studies show the applicability of the distraction procedure and recording of heart rate changes in the study of attention in the early preschool period.
Localizing cortical areas involved in cognitive function in infants: Perspectives from spatial cueing. Duke University, October, 2002.presentation2002
Cooper, R.P, & Richards, J.E. (2002). Differential heart-rate activity in infants to uni- and multimodal events. Society for Psychophysiological Research, Washington, D.C. (PDF).presentationDownload2002This investigation compared visual and heart-rate defined attention in infants to multimodal displays.  To date, 37 infants (14 to 26-weeks-old) saw and/or heard 9 events (twice, for a total of 18 trials) in a semi-random sequence: (1) visual only (geometric form, adult-directed face, infant-directed face), (2) auditory only (music, AD voice, ID voice), and (3) visual+auditory (geometric form+music, AD face+voice, ID face+voice).  ECG was recorded using Ag-AgCl electrodes and digitized at 1 KHz. Interbeat intervals were calculated during prestimulus and poststimulus periods (for each trial).  Trial duration was determined by two successive periods of HR deceleration/acceleration, or 60 seconds (whichever came first).  There was a significant effect of event type on percent HR deceleration/trial length (F(8, 566)=2.09, p<.04), with the longest decelerations on ID face+voice trials (M =.65,SD=.23).  This measure was < .60 for the other stimulus events.  Also, a significant main effect of event type on percent visual attention/trial length was found (F(8,652)=11.81,p<.001), with the largest amount of looking on geometric+music trials (38%) and ID face+voice trials (36%) compared to all other stimulus events.  Although infants looked the least on auditory alone trials (all < 20%), they were as attentive (defined by HR deceleration) on these trials as to visual alone.  These results suggest that visual and auditory events are not equal in their ability to direct and maintain infants’ attention, with most attention generated by female ID multimodal interactions.
Richards, J.E. (2002). Cortical sources of ERP for infants' recognition of briefly presented visual stimuli. Psychophysiology, 37, S70 (abstract).journal2002
Richards, J.E. (2002). Cortical sources of ERP for infants' recognition of briefly presented visual stimuli. Society for Psychophysiological Research, Washington D.C. (PDF)conferenceDownload2002Young infants show ERP component responses to briefly presented visual stimuli dependent on stimulus familiarity and probability. Some components (e.g., "Nc") represent simple orienting to the stimulus, whereas other components (late slow wave) are affected by recognition memory. This study examined these ERP components in infants from 20 to 32 weeks using high-density EEG recording to quantify cortical sources of these components. Twenty infants were presented with a Sesame Street recording that was replaced with a familiar stimulus presented frequently ("FF"; 60% probability) or infrequently ("IF"; 20% probablity), and novel stimuli presented infrequently ("IN"; 20% probablity). Heart rate was used to assess the infant's attention to the Sesame Street recording at the time of the brief stimulus presentation (attentive or inattentive). EEG was recorded with a 124-channel system (EGI) and ERP averages were made from -50 ms to 2000 ms around stimulus onset. The ERP were quantified for each participant with spatial principal component (PC) analysis, clustered with other participant's PCs, and "equivalent current dipoles" were estimated for averaged PC loadings and individual participant loadings to locate cortical sources of the ERP components. There were three findings. First, a spatial PC representing broad frontal-central negativity was active at about 500 ms following the brief stimulus presentation ("Nc" component). This activity was larger if the infant was in an attentive state. The size of the Nc component did not differ for the IN, IF, and FF stimuli. The cortical source of this component was located in the anterior cingulate gyrus (Brodmann area 33). Second, a PC reflecting scalp activity over the parietal scalp showed late slow wave activity (750 to 1600 ms). This cortical activity did not occur for the FF stimuli, was negatively activated for the IN stimuli and positively activated for the IF stimuli. It was present primarily on presentations in which the infant was attentive, but did occur to a lesser degree when the infant was inattentive but still fixating toward the monitor. The cortical source of this activity was the superior parietal lobe (Brodmann area 7). Third, at about the same time as the second component, there was a activation of a PC broadly spaced over central and parietal-central leads (800 to 1500 ms). This activity occurred only for the IN stimuli, and was unaffected by attention. Its cortical source was located in the posterior portion of the cingulate gyrus (Brodmann area 23). These results identify cortical sources of recognition memory activity in young infants. They suggest that the affect of attention is to enhance the cortical areas involved in "stimulus orienting" and those involved in recognition memory.
Brain bases of attention-directed eye movements in infants. James S. McDonnell Foundation, Workshops on Infant Cognition, Venice, Italy, March, 2002.presentation2002
Richards, J.E. (2002). Cortical source analysis of ERP of individual participants in psychophysiological experiments. Psychophysiology, 37, S69 (abstract).journal2002
Richards, J.E., & Hunter, S.K. (2002). Testing neural models of the development of infant visual attention. Developmental Psychobiology, 40, 226-236.journalDownload2002There have been several models of the development of infant visual attention that have used information about neural development. Most of these models have been based on non-human animal studies and have relied on indirect measures of neural development in human infants. This paper discusses methods for studying a “neurodevelopmental” model of infant visual attention using indirect and direct measures of cortical activity. We concentrate on the effect of attention on eye movement control and show how animal-based models, indirect measurement in human infants, and direct measurement of brain activity inform this model.
Frick, J., & Richards, J.E. (2001). Individual differences in recognition of briefly presented visual stimuli. Infancy, 2, 331-352.journalDownload2001Infants' recognition memory has been shown to be related to individual differences in look duration and level of heart period variability. This study examined the effect of individual differences in these two measures on infants' recognition of briefly presented visual stimuli using a paired-comparison recognition-memory paradigm. A sample of 35 full-term infants was studied longitudinally at 14, 20, and 26 weeks of age. Recognition memory for briefly presented stimuli was tested in six experimental conditions, with delays corresponding to different heart rate-defined phases of attention. The 20- and 26-week-old infants, and infants with high levels of heart period variability, generally showed more recognition memory for briefly presented visual stimuli. Further, greater amounts of recognition memory were demonstrated when stimuli were presented during sustained attention. The results do not provide support for broad individual differences in recognition memory for briefly presented visual stimuli. The results do indicate that stimulus and procedural factors may be more important for the study of individual differences in infant visual attention than has previously been suggested.
Richards, J.E. (2001). Cortical indices of saccade planning following covert orienting in 20-week-old infants. Infancy, 2, 135-157journalDownload2001This study examined scalp-recorded "event-related-potential" (ERP) indices of saccade planning in 20-week-old infants. A spatial cueing procedure was used in which the infants were presented with a central fixation stimulus and a peripheral cue. A peripheral target followed the cue on the ipsilateral or contralateral side of the cue. The procedure resulted in covert orienting of attention in these participants, reflected in behavioral (e.g., response facilitation or inhibition of return depending on cue-target stimulus-onset-asynchrony) and ERP (P1 facilitation to ipsilateral target) indices of covert orienting of attention. A presaccadic ERP potential occurred over the frontal cortex about 50 ms before the saccade onset that was largest when the saccade was to a target in a cued location. A presaccadic ERP potential occurred about 300 ms before the saccade onset that was largest for the saccades toward the cued location whether the target was present or not. These results suggest that saccade planning occurs in infants at this age and that this saccadic planning is controlled by cortical systems.
Richards, J.E. (2001). Attention in young infants: A developmental psychophysiological perspective. In C.A. Nelson & M. Luciana (Eds.), Developmental cognitive neuroscience (pp. 321-338) Cambridge, MA, US: MIT Press.chapterDownload2001Attention changes dramatically in the period of infancy. Attention is selective and involves the focusing of cognitive processing on specific objects or tasks. Attention also has an arousal aspect, reflecting ehanced processing when attention is engaged. It is commonly thought that the development of attention is based heavily on the age-related changes in brain structures responsible for attention control. The present chapter will do three things. First, two types of brain systems that may be involved in attention and which show development will be reviewed. Second, psychophysiological measures that have been useful in the study of brain-attention relation development in infants will be presented. Finally, several studies will be examined that studied the development of infant attention with these psychophysiological methods. These experiments will be related to changes occurring in the neural systems underlying attention.
Richards, J.E. (2001). Cortical indices of saccade planning in infants. Infancy, 2, 123-133journalDownload2001This paper briefly reviews the development of cortical involvement in saccadic eye movement in young infants. A distinction between reflexive and voluntary saccadic eye movements is made and developmental changes in the neural systems controlling these eye movements are discussed. Cortical indices of saccade planning in adults have been measured using scalp-recorded "event-related-potential" (ERP). Event-related-potential measurement may provide a manner in which reflexive and voluntary saccadic eye movements may be distinguished in infants. Three studies are introduced that used ERP measures to infer saccade planning in young infants, and two short papers comment on these studies.
Extended visual fixation and distractibility during television viewing in the early preschool years. J.E. Richards, Society for Research in Child Development, Minneapolis, MN, April, 2001.conference2001
Using high-density EEG recording to localize cortical sources of infant attention.. J.E. Richards, Society for Research in Child Development, Minneapolis, MN, April, 2001.conference2001
Richards, J.E., and Turner, E.D. (2001). Distractibility during extended viewing of television in the early preschool years. Child Development, 72, 963-972.journalDownload2001Distractibility during extended visual fixations in children from 6 months to 2 years of age was examined. A children's movie ("Sesame Street" movie, "Follow that Bird") was presented for a minimum of 20 min while fixation was videotaped and heart rate was recorded. Distractors (computer-generated patterns or another “Sesame Street” movie) were presented on an adjacent TV screen. Consistent with prior research with older preschool aged children, the latency to turn toward the distractor was a function of the length of the look occurring before the distractor onset. The heart rate at the time immediately before distractor onset had a larger sustained lowered heart rate for the trials on which the children continued looking at the center TV monitor than for the trials on which the children looked to the distractor. This pattern of distractibility suggests attention increases over the course of a look toward the television and that heart rate changes reflect this increase in attention..
Lansink, J.M., Mintz, S., & Richards, J. E.. (2000). The distribution of infant attention during object examination. Developmental Science. 3, 163-170.journalDownload2000The distribution of attention during toy play was studied in 6-, 9-, and 12-month old infants. Heart rate and behavioral measures of attention were collected as the infants interacted with either a single object or multiple objects. The first look often consisted of a sequence of casual inspection (casual attention), active examination of the toy (focused attention), casual inspection, and then a look away; fixations were initiated with casual attention and terminated during casual attention. Subsequent fixations consisted of such sequences, or a single episode of casual inspection (casual attention). On some episodes the infants would cycle between casual and focused attention several times before looking away. Heart rate-defined sustained attention occurred more frequently at the transition from the first casual attention to focused attention and during the cycling between casual and focused attention. The proportion of time spent in sustained attention during this cycling was found to increase across the three testing ages. A look away from the object was usually preceded by a behavioral judgement of casual attention accompanied by heart-rate-defined inattention.
The effect of attention on the recognition of brief visual stimuli in infants: An ERP study. J.E. Richards, Society for Psychophysiological Research, San Diego, CA, October, 2000.conference2000
Richards, J.E., & Cronise, K. (2000). Extended visual fixation in the early preschool years: look duration, heart rate changes, and attentional inertia. Child Development, 72, 602-620journalDownload2000Visual fixation in infants from 6 months to 2 years of age was examined for its fit to the theory of "attentional inertia". A children's movie ("Sesame Street" movie, "Follow that Bird") or an extended audiovisual stimulus (computer-generated patterns) was presented for a minimum of 20 min while fixation was videotaped and heart rate (HR) was recorded. Consistent with attentional inertia theory, fixations toward the stimuli had a lognormal distribution, HR decreased over the course of a look, and HR returned to prestimulus levels immediately prior to look offset. Older children (18 months, 24 months) showed a distinction in the parameters describing the lognormal distribution for the "Sesame Street" movie and the audiovisual patterns, whereas younger children (6 months, 12 months) responded similarly to the two stimulus types. Fixation patterns of children in this age range suggest attention increases over the course of a look, and parameters consistent with attentional inertia theory differentially develop in this age range..
The effect of attention on the recognition of brief visual stimuli: An ERP study. J.E. Richards, International Conference for Infancy Studies, Brighton, England, July 2000.conference2000
The development of covert attention to peripheral targets and its relation to attention to central visual stimuli. J.E. Richards, International Conference for Infancy Studies, Brighton, England, July 2000.conference2000
Richards, J.E. (2000). The effect of cueing on presaccadic ERP for pro- and anti-saccades. Psychophysiology, 37. (abstract).journal2000
Richards, J.E. (2000). The effect of attention on the recognition of brief visual stimuli in infants: An ERP study. Psychophysiology, 37. (abstract).journal2000
Saccade planning in adults and infants: Brain control of voluntary movement. Department of Psychology, Virginia Polytechnic University, March, 2000.presentation2000
Richards, J.E. (2000). Localizing the development of covert attention in infants using scalp event-related-potentials. Developmental Psychology, 36, 91-108.journalDownload2000This study examined covert shifts of attention in infants aged 14, 20, and 26 weeks of age, using scalp-recorded event-related-potentials (ERP). The infants were presented with a central fixation stimulus, and a peripheral cue stimulus was presented. A target followed the cue on the ipsilateral or contralateral side of the cue. The ERP was calculated from a 10-20 recording montage. The reaction time to localize the target showed covert attention shifts (e.g., response facilitation or inhibition of return depending on cue-target stimulus-onset-asynchrony). There was a larger P1 ERP component when the cue was presented on the ipsilateral side than when it was presented on the contralateral side, or on control trials. Presaccadic ERP potentials were larger to the target when it was in the cued location than when it was in uncued locations, suggesting that infants expected the target in that location. There were increases from 14- to 26-weeks of age in the amount of inhibition of return, post target onset P1 effect, and in the presaccadic ERP potentials. These results suggest that cortical development is related to the development of covert orienting of attention and saccade planning in infants in this age range.
Studying the mind by examining the brain. Department of Psychology, University of South Carolina, Columbia, SC, February, 2000.presentation2000
Richards, J.E. (2000). Development of multimodal attention in young infants: Modification of the startle reflex by attention. Psychophysiology, 37, 65-75.journalDownload2000This study examined the effect of level of attention engagement to compound auditory-visual stimuli on the modification of the startle blink reflex in young infants. Infants at 8, 14, 20, or 26 weeks of age were presented with interesting stimuli that had both audio and visual components. After stimulus onset, at delays defined by heart rate changes known to be associated with sustained attention or attention disengagement, blink reflexes were elicited by visual or auditory stimuli. Blink amplitude was enhanced when the infants were engaged in attention to the foreground auditory-visual stimuli relative to control trials with no foreground patterns. This enhancement of the blink amplitude increased from 8 to 26 weeks of age. There was no significant difference in the attention-enhancement effect between the visual and auditory blink stimuli. In distinction to selective modality enhancement when single modality stimuli are presented, these results show that these multimodal stimuli engage both visual and auditory attention systems in this age range..
Development of attention in young infants: Some “arousing” studies. Sackler Institute Meeting, New Orleans, LA, February, 2000.presentation2000
Developmental changes in the “main sequence” relation in infant saccades. S.K. Hunter & J.E. Richards, International Society for Infancy Studies, Brighton, England, July, 2000.conference2000
The effect of cueing on presaccadic ERP for pro- and anti-saccades. J.E. Richards, Society for Psychophysiological Research, San Diego, CA, October, 2000.conference2000
Los indices cortezas del los saccades planeados despues de “Covert Orienting” in los infantes que tengan 20 semanas. J.E. Richards, Congreso Latinamericano Neuropsychologica, Varadero, Cuba, October, 1999.conference1999
Cortical indices of saccade planning following covert orienting in 20-week-old infants. J.E. Richards, Society for Psychophysiological Research, Granada, Spain, October, 1999.conference1999
Development of attention in young infants: Some “arousing” studies. International Society of Developmental Psychobiology, Miami, FL, October, 1999.presentation1999
Richards, J.E. (1999). Cortical indices of saccade planning following covert orienting in 20-week-old infants. Psychophysiology, 36, S95 (abstract).journal1999
Richards, J.E. (1999). Development of multimodal attention in young infants: Modification of the startle reflex by attention. Psychophysiology, 36, S95 (abstract).journal1999
Richards, J.E., & Holley, F.B. (1999). Infant attention and the development of smooth pursuit tracking. Developmental Psychology, 35, 856-867. journalDownload1999The effect of attention on smooth pursuit and saccadic tracking was studied in infants at 8, 14, 20, and 26 weeks of age. The infants were presented with a small rectangle moving in a sinusoidal pattern at speeds ranging from 4 to 24 deg/sec in either the horizontal or vertical direction. Attention level was distinguished with a recording of heart rate changes known to be related to sustained attention or inattentiveness. There was an increase across these four ages in overall stimulus tracking, the gain of the smooth pursuit eye movements over the stimulus movement, and in the amplitude of compensatory saccades at faster tracking speeds. One age change was an increase in the preservation of smooth pursuit tracking ability as stimulus speed increased. A second developmental change was the increasing tendency during attentive tracking for infants to shift from smooth pursuit to saccadic tracking when the stimulus speed increased to the highest velocities. This study shows that attention has a large effect on eye movements used during stimulus tracking in young infants and that the development of smooth pursuit and targeted saccadic eye movements is closely related to the development of sustained attention in this age range.
Development of extended visual fixation in early childhood. J.E. Richards, Society for Research in Child Development, Albuquerque, NM, April, 1999.conference1999
Development of multimodal attention in young infants: Modification of the startle reflex by attention. J.E. Richards, Society for Psychophysiological Research, Granada, Spain, October, 1999.conference1999
Richards, J. E., & Holley, F.B. (1999) Infant attention and the development of smooth pursuit tracking. Developmental Psychology,35, 856-867. journal1999
Richards, J.E. (1998). Development of selective attention in young infants: Enhancement and attenuation of blink startle reflex by attention. Developmental Science,1, 45-51journalDownload1998This study examined the effect of level of attention engagement on the modification of the blink reflex in young infants. Infants at 8, 14, 20, or 26 weeks of age were presented with interesting visual or auditory stimuli. At delays defined by changes in heart rate known to be associated with sustained attention or attention disengagement, blink reflexes were elicited by visual or auditory blink reflex stimuli. Blink amplitude varied according to the level of attention, and the match between the foreground and blink reflex stimulus. If the infant was attending to the foreground stimulus, a blink reflex stimulus in the same modality resulted in enhanced blink reflex magnitude. A blink reflex stimulus the other modality resulted in an attenuated blink reflex magnitude. If attention was not engaged with the foreground stimulus, this modulation of the blink reflex did not occur. This selective modality effect showed an increasing tendency to occur between 8 and 26 weeks of age. These results show that selective attention to modalities increases over this age range.
Kelly, S.J., & Richards, J.E. (1998). Heart rate orienting and respiratory sinus arrhythmia development in rats exposed to alcohol or hypoxia. Neurotoxicology and Teratology, 20, 193-202.journalDownload1998The effect of alcohol exposure and hypoxia on the heart rate orienting response and RSA development was studied in preweanling rats. Rats were artificially reared from postnatal days 4 through 12 and either exposed to alcohol (5 g/kg/day) or hypoxia (two 15-min episodes/day) from postnatal days 4 to 10. Control groups consisted of artificially reared and normally reared rats not exposed to alcohol or hypoxia. The heart rate and respiration was recorded at baseline and during repeated exposures to auditory and visual stimuli every other day from postnatal day 13 through 21. The hypoxia group showed an enhanced heart rate orienting response to the auditory stimuli on postnatal days 17 and 19 compared to the other three groups, which did not differ from each other. The baseline interbeat interval increased over this period of time and there was a large increase in respiratory sinus arrhythmia from postnatal day 15 to 21. The alcohol and hypoxia rats showed significantly less of an increase in respiratory sinus arrhythmia on postnatal days 19 and 21. All rats showed a greater response to the auditory stimuli than to the visual stimuli on postnatal days 17 and 19 and all groups showed equivalent habituation to both stimuli within a session. The results suggest that respiratory sinus arrhythmia and the heart rate response to stimuli may not be strongly related during this developmental stage in the rat and that hypoxia but not alcohol exposure alters attentional processes for auditory stimuli as measured by the heart rate orienting response.
Richards, J.E. (1998). Focusing on visual attention. Early Development and Parenting, 7, 153-158. journalDownload1998This article reviews Chapter 3 concerning visual attention in Mark Johnson's Developmental Cognitive Neuroscience book. The book covers the field of visual attention with an illustrative approach to how brain development influences the development of visual attention in infants. There are some limitations of this chapter. One limitation is the limited range of topics and depth of studies that are covered, probably due to space limitations. It also is apparent from this chapter that direct manipulations of infant brain systems during development are lacking in this field, and direct measures of brain activity in infants would be helpful in the study of attention. This chapter, and the book in general, provides a useful introduction to this newly emerging field of cognitive developmental neuroscience.
Frick, J.E., & Richards, J.E. (1998). Individual differences in infants' recognition of briefly presented visual stimuli. Infant Behavior and Development, 21. (abstract).journal1998
Richards, J.E., & Lansink, J.M. (1998). Distractibility during visual fixation in young infants: The selectivity of attention. In C. Rovee-Collier, L. Lipsitt, & H. Hayne (Eds.), Advances in Infancy Research (Volume 13, pp. 407-444). Norwood, NJ: Ablex Publishing Co.chapter1998Attention is a cognitive process with which we focus information processing activity on specific objects and exclude other objects from consideration. The selective aspect of attention enhances the intensity of cognitive processing on the object or location to which attention is directed. The selectivity of visual attention often involves spatial selectivity. Fixation is directed to one portion of the visual field and attention is directed to objects in that part of the visual field. Alternatively, some objects in the visual field of fixation may be selected and others ignored. The "selective" and "intensity" aspects of attention have been discussed in recent reviews of infant attention development (Berg & Richards, 1997; Richards & Hunter, 1998; Ruff & Rothbart, 1996). In infants, the selectivity and intensity aspects of attention have been measured with distraction paradigms. If the infant is actively attending to a specific object in a part of the visual field (selectivity), and intense cognitive processing is occurring (intensity), then the infant should not be distractible by events occurring in other parts of the visual field. Richards (1987) did the first systematic manipulation using this paradigm. Three- to six-month-old infants were presented with a visual pattern on a TV screen that elicited large heart rate changes. The heart rate changes were presumed to indicate that stimulus orienting or active attention engagement was occurring. A visual stimulus was presented in the periphery, and the latency to direct fixation towards the stimulus was measured. The latency to be distracted by the peripheral stimulus was longer if the heart rate changes were still occurring (attention engaged) than if heart rate had returned to its prestimulus level (attention disengaged). Thus, infant distractibility is inversely related to attentive engagement. This chapter will do three things. First, we will summarize briefly three models of attention that have emphasized attention's selectivity. In this section we will present a model based on the neurophysiological development in infants that reflects one aspect of distractibility research. Second, we will review some research using distractibility as a measure of infant attention. We also will emphasize the methods that have been used to measure distractibility during engaged attentive activity in young infants. Third, we will present recent findings from our own work showing the locus of attention's selectivity, and the generality of selectivity.
Theoretical implications of infant distractiblity in selective attention. J.M. Lansink & J.E. Richards, International Society for Infancy Studies, Atlanta, GA, April, 1998.conference1998
Hicks, J.M., & Richards, J.E. (1998). The effects of stimulus movement and attention on peripheral stimulus localization by 8- to 26-week-old-infants. Infant Behavior and Development, 21, 571-589.journalDownload1998Peripheral stimulus localization in infants occurs infrequently during sustained attention to a focal stimulus, and occurs more frequently when no focal stimulus is present, or if a focal stimulus is present but is unattended. This study examined the effect of stimulus movement on localization probability and latency during attention and inattention. Forty infants, 10 each at 8, 14, 20, and 26 weeks of age were presented with a central stimulus. Then, a peripheral stimulus was presented (static or dynamic checkerboard) during attention or inattention to the central stimulus. Stimulus movement did not affect localization probability. Infants localized the dynamic peripheral stimulus more quickly than the static peripheral stimulus, particularly when there was no focal stimulus. Signal detection analysis showed that sensitivity to the peripheral stimulus increased over this age range along with a decrease in the bias against responding. The effects of attention were on response bias, and sensitivity to stimulus movement was independent of attention phase. These results are consistent with a model of attention affecting the localization response to the peripheral stimulus but not affecting the sensitivity of the sensory and perceptual pathways for peripheral stimuli.
Localizing the development of covert attention in infants using scalp event-related-potentials. J.E. Richards, International Society for Infancy Studies, Atlanta, GA, April, 1998.conference1998
Richards, J.E., & Hunter, S.K. (1998). Attention and eye movement in young infants: Neural control and development. In J.E. Richards (Ed.), Cognitive neuroscience of attention: A developmental perspective (pp. 131-162). Hillsdale, NJ: Lawrence Erlbaum Associates.chapterDownload1998Infant attention shows rapid development from 2 to 6 months of age. In particular, attention seems to change from exogenous controlled fixation to individual voluntary control of sustained attention. At the same time, several eye movement systems are showing rapid development. These include the smooth pursuit system, having a "functional" origin at 2 months and dramatic improvement through six months, "visual capture" at 2 months to endogenous control fixation by six months. These changes in eye movement, controlled by developing neural systems, intersect the development in sustained attention. In this chapter I will discuss how the parallel development of the eye movement control systems and attention systems leads to attention-influenced eye movement patterns in the first six months.
Richards, J.E. (1998). Localizing the development of covert attention in infants using scalp event-related-potentials. Infant Behavior and Development, 21. (abstract).journal1998
Richards, J.E. (1998). Focusing on visual attention. Early Development and Parenting, 7, 153-158.journal1998
Lansink, J.M, & Richards, J.E. (1998). Theoretical implications of infant distractibility in selective attention. Infant Behavior and Development, 21. (abstract).journal1998
Hunter, S.K., & Richards, J.E. (1998). Peripheral stimulus localization during visual attention in 5, 8, 11, and 14-week old infants. Infant Behavior and Development, 21. (abstract).journal1998
Peripheral stimulus localization during visual attention in 5-, 8-, 11-, and 14-week old infants. S.K.Hunter & J.E. Richards, International Society for Infancy Studies, Atlanta, GA, April, 1998.conference1998
Richards, J.E. (1998). Cognitive neuroscience of attention: A developmental perspective. Hillsdale, NJ: Lawrence Erlbaum Associates.book1998Introduction The book will cover physiological bases of attention, including research on primates, theoretical models of brain systems that control guided eye movements during attention, a neuropsychological approach to attention and pre-attentive processes, and object-based attention. The book will also present developmental cognitive neuroscience models of attention. These developmental models will include both infant and child models, will include infant peripheral stimulus localization, object-segregation, object concept and attention, and covert attention.
Individual differences in infants' recognition of briefly presented visual stimuli. J.E. Frick & J.E. Richards, International Society for Infancy Studies, Atlanta, GA, April, 1998.conference1998
Lansink, J.M., & Richards, J.E. (1997). Heart rate and behavioral measures of attention in 6-, 9-, and 12-month-old infants during object exploration. Child Development, 68, 610-620.journalDownload1997This study examined the effect of heart rate and behavioral measures of attention on distractibility of 6-, 9-, and 12-month old infants. The infants were presented with a toy, and a distractor was presented while they attended to the toy. The distractor was presented during heart rate changes indicating sustained attention or attention termination, or during periods of time when behavioral ratings indicated the infant was in focused or casual attention. There were longer distraction latencies during attentional engagement as defined by heart rate changes or behavioral ratings than for periods of inattention. Infants had the longest distraction latencies when heart rate and behavior measures were congruent with respect to attention engagement (heart rate deceleration and focused attention). Conversely, latencies were shortest for congruent values of inattention (heart rate acceleration and casual attention). Infant information processing may be greatest when a heart rate deceleration occurs simultaneously with an episode of focused attention.
Richards, J.E., & Gibson, T.L. (1997). Extended visual fixation in young infants: Look distributions, heart rate changes, and attention. Child Development. 68, 1041-1056.journalDownload1997Visual fixation in infants from 3 to 6 months of age was examined for its fit to the theory of "attentional inertia". This theory posits that during the progression of a look there is increasing attention toward the stimulus and an "inertia" to continue fixation. An extended audiovisual stimulus was presented for 20 min to infants while fixation was videotaped and heart rate (HR) was recorded. Consistent with the attentional inertia theory, fixations toward the stimulus had a lognormal distribution. Hazard functions describing these distributions showed a decreasing conditional probability of looking away with increases in fixation duration. Fixation onset and stimulus changes occurring within a fixation were accompanied by HR deceleration. The average HR level continued to decrease over the duration of a fixation and returned to prestimulus level immediately prior to the fixation offset. Infant fixation has characteristics similar to fixation in children and adults, and attention appears to increase over the course of a look in young infants.
The development of sustained attention in infants. Department of Psychology, University of Alabama at Birmingham, March, 1997.presentation1997
Kelly, S.J., & Richards, J.E. (1997). Development of heart inter-beat interval variability in preweanling rats: Effects of exposure to alcohol and hypoxia. Physiology and Behavior, 61, 231-241. journalDownload1997The effect of alcohol exposure and hypoxia on the development of heart rate and heart inter-beat interval (IBI) variability was studied in preweanling rats. Rats were artificially reared from postnatal day (PD) 4 through 12 and either exposed to alcohol (5 g/kg/day) or hypoxia (two 15 min episodes/day) from PD 4 to 10. Control groups consisted of artificially reared and normally reared rats not exposed to alcohol or hypoxia. The heart rate and respiration was recorded for 20 min sessions every other day from PD 5 through 21. Inter-beat intervals and measures of their variability caused by respiratory sinus arrhythmia (RSA) were computed from the recordings. There was a steady decline in average IBI across this age range. There was little change in RSA from PD 5 to 15, followed by a large increase in RSA level from PD 15 to 21. The alcohol and hypoxia rats showed significantly less of an increase in RSA level on PD 19 and 21. Large bradycardias in heart rate occurred in all groups on PD 5, 9, and 17, and were more prevalent in rats exposed to alcohol or hypoxia. These data suggest that neural control of the chronotropic functions of the heart undergoes major changes in the late preweanling stage and the changes in neural control are slowed by hypoxia or alcohol exposure during the early postnatal period.
Localizing infant covert attention with scalp ERP's. J.E. Richards, Society for Psychophysiological Research, Cape Cod, MA. October, 1997.conference1997
Localizing infant covert attention with scalp ERP's. J.E. Richards, Cognitive Neurosciences Society, Boston, MA. April, 1997.conference1997
Heart rate and behavioral measures of infant attention during toy play. J. Lansink, J.E. Richards, and S. Mintz, Society for Research in Child Development, Washington, D.C. April, 1997.conference1997
Richards, J.E. (1997). Effects of attention on infants' preference for briefly exposed visual stimuli in the paired-comparison recognition-memory paradigm. Developmental Psychology, 33, 22-31.chapterDownload1997The effects of attention on 3 to 6 month old infants' responses to briefly exposed visual stimuli were examined in two studies. In Study 1, infants were exposed to stimuli ranging in duration from 2.5 to 20 s. Stimuli presented at 2.5 or 5.0 s resulted in a "familiarity preference" in a subsequent paired-comparison procedure, whereas a "novelty preference" was found with 10 or 20 s exposure durations. In Study 2, a recording of a Sesame Street movie was used to elicit heart rate defined attention phases. Stimuli replaced Sesame Street for 2.5 or 5.0 s, during heart-rate defined sustained attention, attention termination, or 5 s following attention termination. For 20 and 26 week old infants, stimuli presented for 5.0 s during sustained attention resulted in shortened fixation times on the previously exposed stimulus and a "novelty preference" effect similar to that found when the exposure time was 20 s in length. The duration of stimulus exposure occurring during sustained attention in the familiarization phase was positively correlated with the preference for the novel stimulus in the paired-comparison procedure. Stimuli presented during attention termination resulted in familiarity preference in a subsequent paired-comparison procedure. Thus, processing of briefly presented visual stimuli is markedly different depending on the type of attention in which the infant is currently engaged. Some mechanisms for infants' acquisition of stimulus information are suggested.
Richards, J. E. (1997). "Effects of attention on infants' preference for briefly exposed visual stimuli in the paired-comparison recognition-memory paradigm." Dev Psychol 33(1): 22-31.journal1997his study examined the effect of attention on 3- to 6-month-olds responses to briefly exposed visual stimuli. In Study I, stimuli presented at 2.5 or 5.0 s resulted in a familiarity preference in a subsequent paired-comparison procedure. A novelty preference was found with 10.0- or 20.0-s exposure durations. In Study 2, a Sesame Street movie elicited heart-rate-defined attention phases and stimuli replaced Sesame Street during sustained attention, attention termination, or 5.0 s following attention termination. For 20 and 26-week-olds. Stimuli presented for 5.0 s during sustained attention resulted in a novelty preference similar to that found when exposure time was 20.0 s. The duration of stimulus exposure during sustained attention in the familiarization phase was positively correlated with the preference for the novel stimulus in the paired-comparison procedure. Thus, processing of briefly presented visual stimuli differs depending on the type of attention in which the infant is currently engaged.
Berg, W.K, & Richards, J.E. (1997). Attention across time in infant development. In P.J. Lang, R.F. Simons, and M.T. Balaban (Eds), Attention and orienting: Sensory and motivational processes (pp. 347-368). Mahway, NJ: Erlbaum.journalDownload1997The process of reacting to the events transpiring in our environment is a complex one involving many steps. The type of attention response to make at any one time - orienting versus defensive responses, selective versus nonselective, for example - must first be determined. This determination is made in conjunction with the modulation and sequencing of a set of responses over time, often with later responses being altered as a result of information gathered in the initial analysis. The evidence is growing that infants demonstrate such contingently programmed sequences of analysis, but that these behaviors undergo developmental changes in the first months of life. It is this chapter's purpose to illustrate these results, particularly as they are evidenced in the relation between cardiac activity and cognitive development.
Richards, J.E., & Hunter, S.K. (1997). Peripheral stimulus localization by infants with eye and head movements during visual attention. Vision Research. 37, 3021-3035journalDownload1997The effect of attention to a focal stimulus on 14, 20 and 26-week-old infant's peripheral stimulus localization with eye and head movements was examined in this study. Fixation was engaged on a stimulus in the central visual field and a stimulus was presented in the periphery immediately or after a delay. Peripheral stimulus localization occurred less frequently near the beginning of fixation and when a significant heart rate deceleration had occurred (sustained attention), compared with when no focal stimulus was present or after heart rate had returned to prestimulus level (attention termination). Localization was accompanied by head movements on more than twothirds of the trials, and the likelihood of head movements was positively associated with stimulus eccentricity. The saccades to localize the peripheral stimulus had unusually high velocities in the attention conditions for the two older aged groups relative to their saccades in inattentive conditions. There were unusual "localizing head movements" in the attention conditions in the absence of loc~lizing saccades or changes in fixation for the two older age groups. Infant attention modulates eye movement characteristics of infants. These data also support the hypothesis that eye and head mow.~ment systems are relatively independent in the infant, and that eye-head relations during infant attention may be different from during inattention.
Richards, J.E. (1997). Localization of peripheral stimuli by infants: Age, attention and individual differences in heart rate variability. Journal of Experimental Psychology: Human Perception and Performance, 23, 667-680.journalDownload1997The effect of attention to a focal stimulus on 3 to 6 month old infants’ peripheral stimulus localization was examined in this study. Fixation was engaged on a central visual stimulus and a stimulus was presented in the periphery after discrete time intervals (0 to 12 s) or until changes in heart rate (HR) occurred. Peripheral stimulus localization occurred less frequently when a significant HR deceleration had occurred (sustained attention) than when HR had returned to its prestimulus level (attention termination). Infants with high HR variability levels were less likely to be distracted by the peripheral stimulus during sustained attention than low HR variability infants. A signal detection analysis showed that response bias was altered by attention, and that during inattention high HR variability infants were more likely to shift fixation away from the central stimulus independent of the peripheral stimulus presence. These data suggest that infant attention affects decision processes for continuing focal stimulus fixation rather than affecting peripheral stimulus discriminability.
Richards, J.E. (1997). Localizing infant covert attention with scalp ERP's. Psychophysiology, 34. (abstract).journal1997
Attentional inertia in infants and preschool aged children. K. Cronise, M.R. Sylvia, & J.E. Richards, Society for Research in Child Development, Washington, D.C. April, 1997.conference1997
Attentional inertia in 14, 20, and 26 week infants. J.E. Richards & T.L. Gibson, International Society for Infancy Studies, Providence, RI. April, 1996.conference1996
Stimulus movement and peripheral stimulus localization by 20- and 26-week-old infants. J. Hicks & J.E. Richards, International Society for Infancy Studies, Providence, RI. April, 1996.conference1996
Stimulus movement and peripheral stimulus localization by 20- and 26-week-old infants. J. Hicks & J.E. Richards, Society for Psychophysiological Research, Vancouver, BC, Canada. October, 1996.conference1996
Physiological and behavioral measures of attention in 6-, 9-, and 12-month-old infants during toy play. J. Lansink & J.E. Richards, International Society for Infancy Studies, Providence, RI. April, 1996.conference1996
Invited Symposium: Infant attention development: Perspectives from cognitive neuroscience. J.E. Richards, International Society for Infancy Studies, Providence, RI. April, 1996.conference1996
Attentional inertia in 14, 20, and 26 week infants. J.E. Richards & T.L. Gibson, Society for Psychophysiological Research, Vancouver, BC, Canada. October, 1996.conference1996
Why don't infants look at peripheral stimuli? Infancy Group, Human Frontiers Science Program, Kings College, Cambridge University, Cambridge, England, September, 1996.presentation1996
The development of sustained attention in infants. Department of Psychology, Virginia Polytechnic University, October, 1996.presentation1996
Sustained attention in the infant's first year. Cognitive Development Unit, Medical Research Council, University College, London, England, September, 1996.presentation1996
Richards, J.E., & Holley, F. (1996). Smooth pursuit and saccadic tracking eye movements are affected by attention in the young infant. Infant Behavior and Development, 19. (abstract).journal1996
Richards, J.E., & Gibson, T.L. (1996). Attentional inertia in 14, 20, and 26 week old infants. Psychophysiology, 33. (abstract).journal1996
Richards, J.E., & Gibson, T.L. (1996). Attentional inertia in 14, 20, and 26 week old infants. Infant Behavior and Development, 19. (abstract).journal1996
Richards, J.E. (1996). Infant attention development: Perspectives from cognitive neuroscience. Infant Behavior and Development, 19. (abstract).journal1996
Lansink, J., & Richards, J.E. (1996). Physiological and behavioral measures of attention in 6-, 9-, and 12-month-old infants during toy play. Psychophysiology, 33. (abstract).journal1996
Lansink, J., & Richards, J.E. (1996). Physiological and behavioral measures of attention in 6-, 9-, and 12-month-old infants during toy play. Infant Behavior and Development, 19. (abstract).journal1996
Hicks, J., & Richards, J.E. (1996). Stimulus movement and peripheral stimulus localization by 20- and 26-week-old infants. Psychophysiology, 33. (abstract).journal1996
Hicks, J., & Richards, J.E. (1996). Stimulus movement and peripheral stimulus localization by 20- and 26-week-old infants. Infant Behavior and Development, 19. (abstract).journal1996
Smooth pursuit and saccadic tracking eye movements are affected by attention in young infants. J.E. Richards & F. Holley, International Society for Infancy Studies, Providence, RI. April, 1996.conference1996
Physiological and behavioral measures of attention in 6-, 9-, and 12-month-old infants during toy play. J. Lansink & J.E. Richards, Society for Psychophysiological Research, Vancouver, BC, Canada. October, 1996.conference1996
Richards, J.E. (1995). Reliability of respiratory sinus arrhythmia, in 14, 20, and 26 week old infants. Infant Behavior and Development, 18, 155-161. journalDownload1995Measures of respiratory sinus arrhythmia (RSA) in R-R intervals were calculated from a five minute recording of 3 to 6 month old full-term infants. The reliability of the measures was estimated with Cronbach's a for sampling durations of 5, 15, 25, or 60 seconds, for single or multiple samples from each of the five baseline periods. Reliability of RSA was good (> .8) for samples of 25 seconds or greater, but decreased with smaller sampling durations. The sensitivity of the measures in detecting an age effect between 14, 20, and 26 week old infants correlated positively with the reliability of the measure. This study suggests that reliability of RSA measures in young infants is acceptable.
Smooth pursuit and saccadic tracking eye movements are affected by attention in young infants. J.E. Richards & F. Holley, Society for Psychophysiological Research, Toronto, Ontario, Canada. October, 1995.conference1995
Sustained attention in infants. Midlands Technical College, Psychology Seminar Series, March, 1995.presentation1995
Richards, J.E., & Kelly, S.J. (1995). Development of heart rate, RSA, and heart rate orienting in rat pups: A model for Fetal Alcohol Syndrome and Respiratory Distress Syndrome? Psychophysiology, 32, S62. (abstract) journal1995
Richards, J.E., & Holley, F. (1995). Smooth pursuit and saccadic tracking eye movements are affected by attention in young infants. Psychophysiology, 32, S63. (abstract).journal1995
Richards, J.E. (1995). Reliability of respiratory sinus arrhythmia, in 14, 20, and 26 week old infants. Infant Behavior and Development, 18, 155-161.journal1995
Richards, J.E. (1995). Infant cognitive psychophysiology: Normal development and implications for abnormal developmental outcomes. In T.H. Ollendick & R.J. Prinz (Eds.), Advances in Clinical Child Psychology (Vol 17, pps 77-107). New York: Plenum Press.chapterDownload1995Psychophysiology may be defined as "the study of relations between psychological manipulations and resulting physiological responses, measured in the living organism, to promote understanding of the relation between mental and bodily processes" (Andreassi, 1989). The main impetus of psychophysiology is to relate psychological behavior to underlying physiological systems. Psychophysiology is also the study of parallel relations between psychological behavior and physiological systems. Psychophysiological research typically uses non-invasive recording methods and human subjects. Cognitive psychology is the study of behavior such as attention, memory, information processing, thinking, and language. Cognitive psychophysiology uses physiological functions to study these functions. The present chapter reviews some studies of infant cognitive development that have used psychophysiological models. The focus will be on those research models in which the infant's cognitive development is thought to be inextricably related to the development of the physiological system.
Development of heart rate, RSA, and heart rate orienting in rat pups: A model for Fetal Alcohol Syndrome and Respiratory Distress Syndrome? J.E. Richards & S.J. Kelley, Society for Psychophysiological Research, Toronto, Ontario, Canada. October, 1995.conference1995
Richards, J.E. (1994). Baseline respiratory sinus arrhythmia and heart rate responses during sustained visual attention in preterm infants from 3 to 6 months of age. Psychophysiology, 31, 235-243. journalDownload1994Three groups of preterm infants were studied longitudinally at 14, 20, and 26 weeks of age (corrected for gestational age). The groups included infants with no perinatal medical complications, those with mild respiratory problems requiring ventilatory assistance, and those with respiratory distress syndrome. Baseline heart rate and respiratory sinus arrhythmia (RSA) were recorded for 5 min, and heart rate was also recorded while the infants engaged in sustained visual attention to stimuli presented on video monitors. The heart rate response during stimulus orienting and sustained attention was smaller in those infants with respiratory distress syndrome than in the other preterm infants and in comparison with the response seen in full-term infants in previous research. Magnitude of RSA was positively correlated with the attention responses irrespective of the preterm group assignment. There was greater stability in baseline heart rate and RSA for the preterm infants than has been found with fullterm infants. These data suggest that the cardiorespiratory functioning of the preterm infant indexes a stable individual difference characteristic that is correlated with heart responses during sustained attention, and heart rate attention systems may be damaged in the high-risk preterm infant. Descriptors: Infant heart rate, Respiratory sinus arrhythmia, Preterm infants, Respiratory distress syndrome, Sustained attention
Infants' recognition of briefly presented visual stimuli as a function of attention status. John E. Richards, International Society for Infant Studies, Paris, France. June, 1994.conference1994
Richards, J.E. (1994). Baseline respiratory sinus arrhythmia and heart rate responses during sustained visual attention in preterm infants from 3 to 6 months of age. Psychophysiology, 31, 235-243.journal1994
Development of selective attention in infants from 8 to 26 weeks of age: Evidence from central-peripheral attention systems. Society for Psychophysiological Research, Atlanta, GA. October, 1994.conference1994
Richards, J.E. (1994). Infants' recognition of briefly presented visual stimuli as a function of attention status. Infant Behavior and Development, 17 (May), 895. (abstract)journal1994
Development of selective attention in infants from 8 to 26 weeks of age: Evidence from central-peripheral attention systems. Workshop honoring Frances Graham, Society for Psychophysiological Research, October, 1994.presentation1994
Development of attention in young infants to television and objects. Children's Televisions Workshop, New York, NY. March, 1994.presentation1994
Infant blink reflexes as a function of visual attention status. J.E. Richards, Society for Psychophysiological Research, Munich, Germany. October, 1993.conference1993
Infant blink reflexes as a function of visual attention status. J.E. Richards, Society for Research in Child Development, New Orleans, LA, March, 1993.conference1993
Theoretical issues in psychophysiological research: Cognitive and perceptual development. Conference on Psychophysiology as a Theoretical Science, National Institute of Mental Health, Washington, D.C., March, 1993.presentation1993
Infant selective attention development....In the blink of an eye! Wake Forest University, Winston-Salem, NC. September, 1993.presentation1993
Developmental cognitive neuroscience with human infants. School of Medicine, University of South Carolina, Columbia, SC. August, 1993.presentation1993
Richards, J.E. (1993). Infant blink reflexes as a function of visual attention status. Psychophysiology, 30. (abstract).journal1993
Individual differences in infant visual attention and cardio-respiratory indices of "vagal tone". J.E. Richards, Society for Psychophysiological Research, San Diego, CA. October, 1992.conference1992
Development of the relation between attention systems in early infancy. J.E. Richards, Society for Psychophysiological Research, San Diego, CA. October, 1992.conference1992
Richards, J.E. (1992). The development of the relation between attention systems in early infancy. Infant Behavior and Development, 15 (May), 121. (abstract)journal1992
The development of the relation between attention systems in early infancy. John E. Richards, International Society for Infant Studies, Miami, FL. May, 1992.conference1992
Richards, J.E. (1992). Infant peripheral visual stimulus localization as a function of central attention status. Infant Behavior and Development, 15 (May), 651. (abstract)journal1992
Richards, J.E., & Casey, B.J. (1992). Development of sustained visual attention in the human infant. In B.A. Campbell, H. Hayne, & R. Richardson (Eds.), Attention and information processing in infants and adults: Perspectives from human and animal research (pps. 30-60). Hillsdale, NJ: Erlbaum.chapterDownload1992Many investigators have posited that infant attention consists of multiple components or processes (Cohen, 1972, 1973; Richards, 1987; Ruff, 1986a). The components of infant attention occur sequentially. Cognitive activity differs during these components, and during each component the infant processes stimulus information differently. The idea of attention phases, or components of attention, occurs in the literature on adult cognition. Many researchers examining adult cognition (e.g., Posner & Boies, 1971; Posner & Cohen, 1982; Robinson & Peterson, 1986) have postulated distinct components of attention in adult cognitive activity. The theoretical models of attention components posit that attention phases may be distinguished by their utilization of cognitive processing resources. Behavioral measures or physiological arousal can be used to assess resource utilization. An example of a behavioral measure is the "dual-task" procedure (see Siddle & Spinks, this volume). Performance Or) a "primary" task and a "secondary" task (often a probe) may require the same processing resources. Allocating resources to either the primary or secondary task reduces the level of resources available for the other task. The degradation of performance on the other task is a measure of the level of resource allocation to the original task. Active cognitive processing also affects physiological systems. The amount of cognitive resources allocated is thought to be proportional to the extent of physiological responses Oennings, 1986; Kahneman, 1973). Many physiological systems (e.g., heart rate, pupil dilation, respiration, skin conductance response) correlate with resource allocation Oennings, 1986). This chapter reviews research showing that infant attention consists of multiple components, emphasizing individual and developmental differences in sustained attention. Two concerns are emphasized. First, behavioral measures can be used to distinguish components of infant attention. Second, heart rate (100m.) changes during visual fixation closely parallel the behavioral measures. The distinction of attention components in infants relies on a multioperational definition using both behavior and HR.
Richards, J.E. (1992). Individual differences in infant visual attention and cardio-respiratory indices of "vagal tone". Psychophysiology, 29, S59. (abstract)journal1992
Richards, J.E. (1992). Development of the relation between attention systems in early infancy. Psychophysiology, 29, S13. (abstract) journal1992
Infant peripheral visual stimulus localization as a function of central attention status. John E. Richards, International Society for Infant Studies, Miami, FL. May, 1992.conference1992
Richards, J.E. (1991). Infant eye movements during peripheral visual stimulus localization as a function of central stimulus attention status. Psychophysiology, 28, S4. (abstract)journal1991
Richards, J.E. (1991). Peripheral visual stimulus localization as a fucntion of central stimulus attention status in young infants. Psychophysiology, 28, S46. (abstract)journal1991
Development of sustained attention and distractibility in early infancy. Albert Einstein College of Medicine, Bronx, NY. November, 1991.presentation1991
The conceptualization and measurement of attention in infant and young children (conversation hour). Chair: Holly Ruff. Society for Research in Child Development. Seattle, WA. April, 1991.conference1991
Sustained visual attention in preterm infants from 3 to 6 months of age. J.E. Richards, Society for Research in Child Development. Seattle, WA. April, 1991.conference1991
Peripheral visual stimulus localization as a function of central stimulus attention status in young infants. J.E. Richards, Society for Psychophysiological Research., Chicago IL. October, 1991.conference1991
Infant eye movements during peripheral visual stimulus localization as a function of central stimulus attention status. J.E. Richards, Society for Psychophysiological Research., Chicago IL. October, 1991.conference1991
The development of visual attention in young infants. Russell Research Award Lecture Series, University of South Carolina, Columbia, SC. September, 1991.presentation1991
The development of sustained attention in young infants. Graduate Center of the City University of New York, New York, NY. November, 1991.presentation1991
Richards, J.E., & Casey, B.J. (1991). Heart rate variability during attention phases in young infants. Psychophysiology, 28, 43-53. journalDownload1991Heart rate variability during visual attention was studied in infants who were tested crosssectionally at 14, 20, or 26 weeks of age. They were presented with a recording of a Sesame Street program on a TV screen. After heart rate had decelerated below the prestimulus level and then returned to prestimulus level, a computer-generated pattern replaced the Sesame Street display. Heart rate variability changed throughout attention. The change consisted of a decrease in variability during attention and a return to prestimulus levels approximately five seconds following attention termination. The heart rate and variability responses are consistent with a model of parasympathetic vagal influence on the heart in which vagal firing is increased during sustained attention and is inhibited during attention termination. DESCRIPTORS: Heart rate variability, Visual attention, Infants, Vagal influence.
Casey, B.J., & Richards, J.E. (1991). A refractory period for the heart rate response in infant visual attention. Developmental Psychobiology, 24, 327-340.journal1991A refractory period for the heart rate (HR) response of 14-,20-, and 26-week-old infants to second stimulus onset and primary stimulus offset during termination of visual attention was investigated. A stimulus that elicited a significant HR deceleration was presented. Following the return of HR to prestimulus level, a second stimulus occurred or the first stimulus ended at time delays of 0, 3, 6, and 9 s. If the second stimulus occurred at 0 or 3 s after HR returned to its prestimulus level, the HR response was smaller than the initial HR orienting response (OR). A usual HR OR resulted by waiting 6-9 s after the return of HR to prestimulus level. A significant offset response occurred only for the 6-sec delay. Active inhibition of vagal cardiac activity during attention termination may cause the observed refractory period in the HR response, which appears to last from 3-6 s following sustained attention.
Richards, J.E., & Casey, B.J. (1991). Heart rate variability during attention phases in young infants. Psychophysiology, 28, 43-53.journal1991
Infant visual recognition memory performance as a function of heart rate defined phases of attention. J.E. Richards & B.J. Casey, Society for Psychophysiological Research, Boston, MA. October, 1990.conference1990
Richards, J.E., & Casey, B.J. (1990). Infant visual recognition memory performance as a function of heart rate defined phases of attention. Psychophysiology, 27, S58. (abstract)journal1990
Sustained visual attention in preterm infants from 3 to 6 months of age. J.E. Richards, Society for Psychophysiological Research, Boston, MA. October, 1990.conference1990
Richards, J.E. (1990). Sustained visual attention in preterm infants from 3 to 6 months of age. Psychophysiology, 27, S57. (abstract)journal1990
Infant visual recognition memory performance as a function of heart rate defined phases of attention. J.E. Richards & B.J. Casey, International Conference on Infant Studies, Montreal, Canada, April, 1990.conference1990
Development of visual sustained attention in infants. J.E. Richards, Fifth International Congress of Psychophysiology, Budapest, Hungary. July, 1990.conference1990
Heart rate defined phases of infant visual information processing. Langfield Lecture Series, Princeton University, June, 1990.presentation1990
Modulating heart rate changes in older infants. Fifth International Congress of Psychophysiology, Budapest, Hungary. July, 1990.presentation1990
The effects of attention on infant behavior in the paired-comparison paradigm. Albert Einstein College of Medicine, Bronx, NY. June, 1990.presentation1990
Richards, J.E., & Casey, B.J. (1990). Infant visual recognition memory performance as a function of heart rate defined phases of attention. Infant Behavior and Development, 13, 585. (abstract)journal1990
Casey, B.J., & Richards, J.E. (1989). Heart rate and reaction time as indices of automatic and controlled processing in children. Psychophysiology, 26, S18. (abstract).journal1989
Richards, J.E. (1989). OS/2, multi-tasking, and psychophysiological experimentation. Psychophysiology, 26, S50. (abstract)journal1989
Richards, J.E. (1989). Short-term reliability of measures of R-R interval variability in healthy, full-term 14, 20, and 26 week old infants. Psychophysiology, 26, S51. (abstract).journal1989
Discussant, Conference on Physiological Basis of Higher Mental Functions, National Institutes of Child Health and Human Development, Philadelphia, PA. May, 1989.presentation1989
Short-term reliability of measures of R-R interval variability in healthy, full-term 14, 20, and 26 week old infants. J.E. Richards, Society for Psychophysiological Research, New Orleans, LA, October, 1989.conference1989
OS/2, multi-tasking, and psychophysiological experimentation. J.E. Richards, Society for Psychophysiological Research, New Orleans, LA, October, 1989.conference1989
Richards, J.E., & Cameron, D. (1989). Infant heart rate variability and behavioral-developmental status. Infant Behavior and Development, 12, 45-58.journalDownload1989Physiological recordings of heart rate (HR)and HRvariability were taken in a baseline recording of infants at 14, 20, and 26 weeks of age. The measures included HRmean,HR standard deviatian, and respiratory sinus arrhythmia (RSA). The Bayley Developmental Examwas given at 26 weeks of age for one group and at 26 and 52 weeks of age for a second group. Parental report of temperament was obtained with the Infant Temperament Questionnaire at 26 weeks of age. The Bayley Mental Development Index (MDI) was significantly correlated with concurrently recorded HRlevel and standard deviation of HR. The approach subscale of the temperament rating was consistently positively carrelated with RSA at each of the baseline recording ages, whereas the other temperament measures were inconsistently associated with physiological measures. Stability of the HRvariability measures was associated with concurrent developmental level, as well as good developmental outcome at 12 months. These results support the position that variability in HR may be indexing important physiological phenomena which are strongly associated with the developmental status of the young infant.
Richards, J.E. (1989). Development and stability in heart-rate-defined, visual sustained attention in 14, 20, and 26 week old infants. Psychophysiology, 26. 422-430.journalDownload1989Infants were studied at 14, 20, and 26 weeks of age in a longitudinal design. They were presented with varying and complex patterns on a TV screen. Two-thirds of the presentations were accompanied by a stimulus in the periphery delayed in time from the onset of fixation on the central stimulus. As in previous research, the infants were not as easily distracted by the interrupting stimulus when the presentation occurred at the point of maximal heart rate deceleration as when the presentation occurred at the end of the heart rate response. Infants with large amounts of respiratory sinus arrhythmia (i.e., heart rate variability) in a baseline recording were less distractible during the deceleration-defined trials than were infants with low amounts of respiratory sinus arrhythmia. Intra-individual patterns of development in respiratory sinus arrhythmia over the testing ages were closely paralleled by patterns of heart rate responding during sustained attention. Individual differences in baseline levels of heart rate and respiratory sinus arrhythmia were more stable than individual differences in sustained attention. The stability of attention responses over age may be mediated by the stability of the physiological system (e.g., heart rate, respiratory sinus arrhythmia, etc.), and by the within-age relation of attention to heart rate variability. DESCRIPTORS: Attention, Heart rate, Infants, Respiratory sinus arrhythmia.
Heart rate and reaction time as indices of automatic and controlled processing in children, B.J. Casey & J.E. Richards, Society for Psychophysiological Research, New Orleans, LA, October, 1989.conference1989
A refractory period for the heart rate response in infant visual attention. B.J. Casey & J.E. Richards, Society for Research in Child Development, Kansas City, April, 1989.conference1989
Richards, J.E. (1989). Sustained visual attention in 8-week-old infants. Infant Behavior and Development, 12, 425-436.journalDownload1989Sustained visual attention was studied in 8-week-old infants. The infants were presented with varying and complex patterns on a TV monitor. At a delay from the onset of fixation on this stimulus, a similar pattern was presented on an adjacent TV monitor within the infant's field of vision. This secondary stimulus was presented when heart rate slowed significantly below prestimulus level, when the heart rate returned to prestimulus level, or at 3 or 7 s following the onset of the first stimulus. The infants were less easily distracted by the secondary stimulus when heart rate was lower than prestimulus level than when it had returned to prestimulus levels. The amount of heart rate slowing on the heart rate deceleration trials was significantly correlated with baseline amplitude of respiratory sinus arrhythmia (Le., heart rate variability). Distraction time was positively correlated with heart rate variability on heart rate deceleration and heart rate acceleration trials. These results replicate the measurement of sustained attention in older infants and extend the study of the development of sustained attention earlier in life. However, there may be a dissociation between behavioral and physiological indices of sustained attention which become more closely associated in the next 2 to 3 months.
Casey, B.J., & Richards, J.E. (1988). A refractory period for the heart rate response in infant visual attention. Psychophysiology, 25, 439. (abstract)journal1988
Casey, B. J., & Richards, J. E. (1988). Sustained visual attention in young infants measured with an adapted version of the visual preference paradigm. Child Development, 59, 1515-1521.journalDownload1988Phases of infant visual attention were studied using a visual preference procedure that was modified to be similar to a "dual-task," interrupted stimulus procedure. Infants were tested in a cross-sectional design at 14, 20, or 26 weeks of age. The infants were presented with varying and complex TV patterns on a TV monitor. At a delay from the onset of fixation on this stimulus, a similar pattern was presented on an adjacent TV monitor within the infant's field of vision. This secondary stimulus was presented either when heart rate (HR) decelerated significantly below prestimulus level or when the HR returned to prestimulus level. These 2 conditions correspond to sustained attention and attention termination when phases of visual attention. The infants were less easily distracted by the secondary stimulus when HR was lower than prestimilus level then when it had returned to prestimulus levels. The amount of HR slowing on the HR deceleration trials increased over this age range, suggesting a developmental increase in sustained attention across this age range. The HR response at the time the infant looked at the secondary stimulus was different for the 2 delay conditions and differed from the HR response at primary stimulus onset. These results confirm the existence of distinct phases of attention during the visual preference procedure and suggest a refinement of the use of simple fixation time as a measure of infant attention with this procedure.
Assessment of respiratory sinus arrhythmia and developmental psychophysiology. Western Psychiatric Institute and Clinic, University of Pittsburgh, Pittsburgh, PA. June, 1988.presentation1988
Development of sustained attention in 3 to 6 month olds. Department of Psychology, University of Pittsburgh, Pittsburgh, PA. May, 1988.presentation1988
Heart rate variability during attention phases in young infants: A model of vagal parasympathetic changes during attention. J.E. Richards & B.J. Casey, Society for Psychophysiological Research, San Francisco, CA, October, 1988.conference1988
Richards, J.E., & Casey, B.J. (1988). Heart rate variability during attention phases in young infants: A model of vagal parasympathetic changes during attention. Psychophysiology, 25, 427-429. (abstract)journal1988
Casey, B.J., & Richards, J.E. (1988). Development and stability in visual sustained attention in young infants. Infant Behavior and Development, 11. (abstract)journal1988
Symposium: The use of respiratory sinus arrhythmia as a psychophysiological measure of vagal parasympathetic cardiac control. J.E. Richards, Society for Psychophysiological Research, San Francisco, CA, October, 1988.conference1988
HR-defined phases of visual information processing in infants. J.E. Richards, & B.J. Casey, International Conference on Infancy Studies, Washington, D.C., April, 1988.conference1988
Richards, J.E. (1988). Heart rate offset responses to visual stimuli in infants from 14 to 26 weeks of age. Psychophysiology, 25, 278-291.journalDownload1988Heart rate offset responses to visual stimuli were studied in infants tested cross-sectionally at 14,20, and 26 weeks of age. In Experiments 1 and 2, offset responses were measured in each infant following visual stimuli presented with three procedures. The fixed interval method consisted of stimulus presentations of 7 s in duration. The infant control method consisted of stimulus presentations which were terminated when the infant looked away from them. The interrupted stimulus method consisted of stimulus presentations which were terminated when the infant looked away toward an interrupting, secondary stimulus. In Experiment 3 these procedures were compared with two procedures in which stimulus termination occurred at the point of heart rate deceleration or the return of heart rate toward prestimulus level. The stimuli in Experiment 1 were checkerboard patterns, in Experiment 2 were complex and varying stimuli, and in Experiment 3 were either TV stimuli or an overhead light. The offset responses were similar for the fixed interval and infant control methods, and consisted of brief heart rate decelerations. The magnitude of the heart rate response was generally small (1.5 to 2 bpm), with the largest heart rate response being 4 bpm. The pre-offset heart rate response was similar for the infant control and interrupted stimulus and heart rate acceleration trials, with heart rate showing a return to prestimulus levels immediately preceding subject-controlled fixation termination. Infants with high levels of respiratory sinus arrhythmia (RSA) measured during a 5- min baseline showed larger heart rate offset responses than did lowRSA infants. These results call into question the interpretation of heart rate offset responses in the context of Sokolov's model of the orienting response. However, the offset paradigm is useful in the study of subject-controlled attention processes. DESCRIPTORS: Infancy, Heart rate, Offset response, Respiratory sinus arrhythmia, Visual attention.
Richards, J.E. (1988). Heart rate changes and heart rate rhythms, and infant visual sustained attention. In P.K. Ackles, J.R. Jennings, and M.G.H. Coles (Eds.), Advances in psychophysiology (Vol. 3, pp. 189-221). Greenwich, CT: JAI Press.chapterDownload1988Pay attention to me! A recalcitrant child in the "terrible twos" often hears this admonishment from her parents. This admonishment shows that parents assume that children at young ages can direct their attention in a voluntary fashion and respond to verbal instructions. But what about getting a much younger child to "pay attention"? When do children first begin to attend to the sights and sounds of their world? When can a child direct its attention voluntarily to interesting stimuli? Parents often use special methods to elicit attention in young infants, e.g., cooing, making faces, playing, and even talking to infants. This parental behavior implicitly assumes that the infant is able to direct her attention to specific stimuli at a very early age. When does an infant start attending to environmental stimulation? How does one attract the attention of an infant? What types of things do they prefer to look at, and for how long? These are questions that psychologists have asked for several years about the attentional processes of infants. Moreover, attention to a stimulus is one indicator that the infant can discriminate the stimulus from its surroundings or from previous stimuli. Therefore, various measures of attention have been used as dependent variables in studies of psychological processes in the infant. Psychophysiologists have contributed to the study of infant attention in several Ways. Most notably, however, was the discovery by psychophysiologists that heart rate (HR) is closely associated with attention in infants. Thus, many studies of infant attention have used HR responses in behavioral tasks as a measure of ongoing attention.
Development and stability in visual sustained attention in young infants. J.E. Richards, International Conference on Infancy Studies, Washington, D.C., April, 1988.conference1988
A refractory period for the heart rate response in infant visual attention. B.J. Casey & J.E. Richards, Society for Psychophysiological Research, San Francisco, CA, October, 1988.conference1988
Richards, J.E., & Casey, B.J. (1988). HR-defined phases of visual information processing in infants. Infant Behavior and Development, 11. (abstract)journal1988
Richards, J.E. (1987). Development and stability in visual sustained attention in young infants. Psychophysiology, 24, 608. (abstract)journal1987
HR-defined phases of visual information processing in infants. J.E. Richards, & B.J. Casey, Society for Psychophysiological Research, Amsterdam, The Netherlands, October, 1987.conference1987
Sustained visual attention in young infants measured with an adapted version of the visual preference paradigm. B.J. Casey & J.E. Richards, Society for Psychophysiological Research, Amsterdam, The Netherlands, October, 1987.conference1987
Casey, B.J., & Richards, J.E. (1987). Sustained visual attention in young infants measured with an adapted version of the visual preference paradigm. Psychophysiology, 24, 583. (abstract)journal1987
Richards, J.E., & Casey, B.J. (1987). HR-defined phases of visual information processing in infants. Psychophysiology, 24, 608. (abstract)journal1987
Richards, J.E. (1987). Infant visual sustained attention and respiratory sinus arrhythmia. Child Development, 58, 488-496. journalDownload1987Infants were studied cross-sectionally at 14, 20, and 26 weeks of age. They were presented with varying and complex patterns on a TV screen. Two-thirds of the presentations were accompanied by an "interrupting stimulus" in the periphery delayed in time from the onset of fixation on the central stimulus. The infants were not easily distracted from looking at the central stimulus when the presentation of the interrupting stimulus occurred at the point of maximal heart rate (HR) deceleration. However, if the presentation occured at the end of the HR response, the infants were easily distracted. Infants with large amounts of respiratory sinus arrhythmia (RSA; i.e. HR variability) in a baseline recording were less distractible during the deceleration-defined trials than were infants with low amounts of RSA. High-RSA infants also showed larger HR deceleration on these trials than did the low-RSA infants. These results are consistent with a model positing that sustained HR lowering during visual fixation is an index of active attention and that RSA is an index of voluntary, sustained attention in infants.
Development and stability in visual sustained attention in young infants. J.E. Richards, Society for Psychophysiological Research, Amsterdam, The Netherlands, October, 1987.conference1987
Richards, J.E. (1986). Power spectral analysis quantification of respiratory sinus arrhythmia. Psychophysiology, 23, 414. (abstract)journal1986
Richards, J.E. (1986). Infants are not distractible during physiologically defined periods of sustained attention. Infant Behavior and Development, 9, 300. (abstract)journal1986
Infant developmental status and heart rate and heart rate variability. J.E. Richards & D. Cameron, Society for Psychophysiological Research, Montreal, Canada, October, 1986.conference1986
Symposium: Quantitative methods for assessing respiratory sinus arrhythmia. J.E. Richards, Society for Psychophysiological Research, Montreal, Canada, October, 1986.conference1986
Infants are not distractible during physiologically defined periods of sustained attention. J.E. Richards, International Conference on Infant Studies, Los Angeles, CA., April, 1986.conference1986
Richards, J.E., & Cameron, D. (1986). Infant developmental status and heart rate and heart rate variability. Psychophysiology, 23, 455-456. (abstract)journal1986
Richards, J.E., Parmelee, A.H., & Beckwith, L. (1986). Spectral analysis of infant EEG and behavioral outcome at age five. Electroencephalography and Clinical Neurophysiology, 64, 1-11.journalDownload1986Power spectral and discriminant analysis techniques were used to compare EEG records obtained at term and at 3 months past term from 5 groups of varying risk and developmental outcome. The groups were: (1) healthy full-terms; (2) healthy pre-terms with normal outcomes; (3) sick pre-terms with normal outcomes; (4) sick pre-terms with delayed development; (5) sick pre-terms with later neurological problems. The EEG samples recorded at term were identified as belonging to the correct subject group at 52-70% accuracy, 20% being chance for 5 groups. The accuracy varied with the 4 classes of EEG patterns used. The individual subjects were also classified into their correct groups with few exceptions. Similar success was obtained with EEG samples selected from recording at 3 months past term. The predominant power spectral discriminating features were changes in intra- and inter-hemispheric coherence, and increased power, particularly in the middle and higher frequency range. Thus, computer analyses of EEG samples, using features not readily identified visually, differentiated risk from non-risk infants and also differentiated infants with substantial neonatal medical complications who have good or poor developmental outcomes. Keywords: EEG, High-risk Infants, Preterm Infants, Power Spectral Analysis
Power spectral analysis quantification of respiratory sinus arrhythmia. J.E. Richards, Society for Psychophysiological Research, Montreal, Canada, October, 1986.conference1986
Heart rate offset response to visual stimuli in young infants. J.E. Richards, Society for Psychophysiological Research, Houston, TX., October, 1985.conference1985
Infants are not distractible during physiologically defined periods of sustained attention. J.E. Richards, Society for Psychophysiological Research, Houston, TX., October, 1985.conference1985
Richards, J.E. (1985). The development of sustained visual attention in infants from 14 to 26 weeks of age. Psychophysiology, 22, 409-416.journalDownload1985The development of sustained visual allention was examined in Infants cross-seclionally at 14, 20, and 26 weeks of age. lIearl rate, hearl rate variablllt)., and respiralory sinus arrhythmia were measured in a S-min baseline period. Two methods for measuring ,'isual altention "'Cre used. The "infanl conlrol" method consisted of checkerboard presentations which were terminated when Ihe infanllooked awa)' from Ihem. The "interrupled slimulus" method consisted of a blinking panel in addition 10 the checkerboard palterns in order to altempt to actively terminate the lixation. The visual and cardiac responses during the inlerrupled stimulus method "'ere more highly correia led ".lth baseline respiratory sillus arrhylhmia than were the responses during the infant conlrol trials. The long latenc)' hearl rale responses during Ihe inlerrupled stimulus Irials showed a developmenlal change toward more mature response pallerns from 141026 weeks of age. It ma)' be concluded that: I) sllstained allenlion, measured with Ihe inlerrupled slimulus method, increases from 14 to 26 ,,'eeks of age; and 2) haseline respiralory sinus arrhylhmia is correlated with suslained allenlion respllnses and Iheir developmenl. DESCRIPTORS: Infancy, I leart rale, Resplralory sinus arrhylhmia, Visual allenlion, Suslained allention.
Richards, J.E. (1985). Infants are not distractible during physiologically defined periods of sustained attention. Psychophysiology, 22, 572. (abstract)journal1985
Richards, J.E. (1985). Respiratory sinus arrhythmia predicts heart rate and visual responses during visual attention in 14 and 20 week old infants. Psychophysiology, 22, 101-109.journalDownload1985The prediction oCcardiac attentional responses by respiratory sinus arrhythmia was tested in inCants at 14 and at 20 weeks oCage. Heart rate, heart rate variability, and respiratory sinus arrhythmia were measured in a 5-min baseline period. Respiration and heart rate responses were recorded during the habituation oCinfant visual attention. The level oCrespiratory sinus arrhythmia in the baseline was significantly correlated with the cardiac deceleration, especially in the 20-weekold inCants. The relationship between cardiac and respiratory responses during attention was stronger in the 20-week-olds, paralleling the increase in respiratory sinus arrhythmia at this age. Visual fixation durations were also significantly correlated with measures oCheart rate variability Cromthe baseline. These results imply that cardiac variability not only predicts the level oCcardiac attentional responsivity, but may be useCulin the indexing oCindividual differences in the responsivity oCmore general attentional systems. DESCRIPTORS: Heart rate, Respiratory sinus arrhythmia, Visual attention, InCants.
Richards, J.E. (1985). Heart rate offset response to visual stimuli in young infants. Psychophysiology, 22, 610. (abstract)journal1985
Respiratory sinus arrhythmia and infant attention. J.E. Richards & M.L. Turner, Society for Research in Child Development, Toronto, Ontario, Canada, April, 1985.conference1985
The development of sustained visual attention in infants from 14 to 26 weeks of age. J.E. Richards, Southeastern Conference in Human Development, Athens, GA., April, 1984.conference1984
Richards, J.E., & Turner, M.L. (1984). Structural models of infant heart rate and respiration and their relationship to visual and heart rate responses during attention. Psychophysiology, 21, 595. (abstract)journal1984
Richards, J.E. (1984). The interrupted stimulus method for measuring sustained attention in infants from 14 to 26 weeks of age. Psychophysiology, 21, 594-595. (abstract)journal1984
The interrupted stimulus method for measuring sustained attention in infants from 14 to 26 weeks of age. J.E. Richards, Society for Psychophysiological Research, Milwaulkee, WI., October, 1984.conference1984
Structural models of infant heart rate and respiration and their relationship to visual and heart rate responses during attention. J.E. Richards & M.L. Turner, Society for Psychophysiological Research, Milwaulkee, WI., October, 1984.conference1984
Respiration and respiratory sinus arrhythmia predict cardiac and visual responses during visual attention in 14 to 20 week olds. J.E. Richards, Society for Psychophysiological Research, Asilomar, CA., September, 1983.conference1983
Classifying risk-outcome groups with spectral analysis of infant EEG patterns. J.E. Richards and A.H. Parmelee, Society for Research in Child Development, Detroit, MI., April, 1983.conference1983
Richards, J.E. (1983). Respiration and respiratory sinus arrhythmia predict cardiac and visual responses during visual attention in 14 to 20 week olds. Psychophysiology, 20, 464. (abstract)journal1983
The role of respiration in cardiac and visual attention responses in 14 and 20 week olds. J.E. Richards, Society for Research in Child Development, Detroit, MI., April, 1983.conference1983
Richards, J.E., & Rader, N. (1983). Affective, behavioral, and avoidance responses on the visual cliff: Effect of crawling onset age, crawling experience, and testing age. Psychophysiology, 20, 633-642.journalDownload1983Two visual cliff experiments with human infants are reported that were designed to determine relationships among cardiac responses, avoidance and other behavioral responses, and developmental factors. The developmental factors considered were age at crawling onset, age at testing, and amount of crawling experience. In Experiment 1, infants were given either 30 or 60 days of crawling experience following crawling onset. In Experiment 2, infants were tested at either 9 or 12 months of age and crawling onset age was recorded. Infants were tested using a crawling avoidance procedure and the placing procedure that has been established for heart rate responses. Crawling onset age was the best predictor of avoidance behavior. Heart rate response was also a significant predictor of visual cliff avoidance, and was found to be related to testing age, especially for late crawlers. Looking down behavior was also found to distinguish crawling avoidance and crossing of the deep side of the cliff apparatus. These results, it is argued, suggest that fear is not the primary determinant of avoidance behavior on the visual cliff, but does contribute to avoidance at later ages. DESCRIPTORS: Infants, Visual cliff, Heart rate, Development.
Discriminating children of differing perinatal risk and five year behavioral outcome with spectral analysis of infant EEG patterns. J.E. Richards and A.H. Parmelee, Society for Psychophysiological Research, Minneapolis, MINN., October, 1982.conference1982
Richards, J.E., Reeves, J., & Shapiro, D. (1982). Prediction of individual differences in a blood pressure biofeedback task with spectral analysis of baseline physiological measures. Psychophysiology, 19, 300-301. (abstract)journal1982
Richards, J.E. (1982). A comparison of heart rate and heart period with real-time units in time-series spectral analysis. Psychophysiology, 19, 343. (abstract)journal1982
Richards, J.E., & Parmelee, A.H. (1982). Discriminating children of differing perinatal risk and five year behavioral outcome with spectral analysis of infant EEG patterns. Psychophysiology, 19, 581. (abstract)journal1982
Prediction of individual differences in a blood pressure biofeedback task with spectral analysis of baseline physiological measures. J.E. Richards, J. Reeves, and D. Shapiro, Society for Psychophysiological Research, Washington, D.C., October, 1981.conference1981
Richards, J.E., & Rader, N. (1981). Behavioral and cardiac response on the visual cliff in human infants. Psychophysiology, 18, 164. (abstract)journal1981
Richards, J.E. (1981). Analyzing repeated physiological measures with multivariate ANOVA. Psychophysiology, 18, 148. (abstract)journal1981
Infants use of a bridge to cross a visual cliff. N. Rader, D. Spiro, and J.E. Richards, Western Psychological Association, Los Angeles, CA., April, 1981.conference1981
Richards, J.E., & Rader, N. (1981). Crawling onset age predicts visual cliff crossing in human infants. Journal of Experimental Psychology: Human Perception and Performance, 7, 382-387.journalDownload1981Two experiments are reported that tested the effects of crawling-onset age, the amount of crawling experience, and testing age on avoidance of the deep side of a visual cliff apparatus by human infants. In Experiment 1, 49 infants ranging in age from 7 to 13 mo. were tested on the visual cliff after I or 2 mo. of crawling experience. Discriminant analysis revealed that crawling-onset age, and not crawling experience., discriminated between those infants who crossed and those infants who avoided the apparent drop-off. Infants who crossed the deep side were infants with an early crawling-onset age. In Experiment 2, 40 infants were tested on a visual cliff apparatus, half at 9 and half at 12 mo. of age. Discriminant analysis again found that crawling-onset age discriminated between infants who crossed and infants who would not cross the deep side, whereas testing age alone did not. These res\llts call into question the idea that experience crawling is critical in inducing visually guided avoidance behavior in infants. It is argued that the crawling-onset age effect occurs because crawling during the tactile phase of infancy interferes with later visual control of locomotion.
A comparison of heart rate and heart period with real-time units in time-series spectral analysis. J.E. Richards, Society for Psychophysiological Research, Washington, D.C., October, 1981.conference1981
Crawling onset age predicts visual cliff crossing in human infants. J.E. Richards and N. Rader, International Conference on Infant Studies, New Haven, CONN., April, 1980.conference1980
Rader, N., Bausano, M., & Richards, J.E. (1980). On the nature of the visual-cliff-avoidance response in human infants. Child Development, 51, 61-68. journal1980
Richards, J.E. (1980). The statistical analysis of heart rate data: A review emphasizing infancy data. Psychophysiology, 17, 153-166.journalDownload1980Heart rate is a dependent variable used widely in psychological and psychophysiological research. Several statistical problems arise in the analysis of heart rate data, many of them specific to inCancy research. The present paper discusses the problems of a statistically appropriate cardiac measure, the Law of Initial Values, the problem of differential variability in heart rate scores, and the use oCmultivariate statistical methods in analyzing heart rate data. Special attention is given to those problems and solutions which have potential application to the analysis of infant heart rate data. A ftowchart is presented which may guide the researcher in the appropriate use oCthe several statistical techniques reviewed in this paper. DESCRIPTORS: Heart rate, Heart rate statistical analysis, Infant heart rate, Statistical analysis, Infancy.
Analyzing repeated physiological measures with multivariate ANOVA. J.E. Richards, Society for Psychophysiological Research, Vancouver, B.C., Canada, October, 1980.conference1980
Behavioral and cardiac response on the visual cliff in human infants. J.E. Richards and N. Rader, Society for Psychophysiological Research, Vancouver, B.C., Canada, October, 1980.conference1980
Crawling onset age predicts visual cliff crossing in human infants. J.E. Richards and N. Rader, Western Psychological Association, Honolulu, HA., May, 1980.conference1980
Effects of modeled response novelty and social reinforcement on infant imitation. J.E. Richards and W.R. Smith, Western Psychological Association, San Diego, April, 1979.conference1979
On the nature of the visual cliff response in human infants. N. Rader, M. Bausano, J. Richards, and U. Viswanathan, Society for Research in Child Development, San Francisco, CA., March, 1979.conference1979
Participant in symposia: The meaning of infant behavior: A re-examination. Western Psychological Association, San Diego, CA., April, 1979.conference1979