John Herrington | University of Pennsylvania (original) (raw)

Papers by John Herrington

Background: Respiratory sinus arrhythmia (RSA), a measure of heart rate variability, reflects the... more Background: Respiratory sinus arrhythmia (RSA), a measure of heart rate variability, reflects the action of the parasympathetic nervous system on heart rate. A higher RSA is associated with better physical and emotional health, and a more adaptive response to changing environmental demands. Recent studies have used RSA to better understand the anxiety symptoms and social deficits in ASD. Social impairment is a defining feature of ASD, and anxiety is a commonly occurring comorbid condition with rates at approximately 40%. To our knowledge no studies have yet compared RSA for individuals with ASD with and without anxiety to individuals with an anxiety disorder alone. Objectives: The aim of this study was to compare RSA during a relaxing task across four groups of participants who were well-characterized using gold standard measures for ASD (i.e., the ADOS) and Anxiety (i.e., the ADIS). It was hypothesized that individuals with ASD regardless of their anxiety status would have a lower ...

Autism : the international journal of research and practice, Jan 29, 2015

This study investigated the accuracy of brief anxiety scales for non-treatment-seeking youth with... more This study investigated the accuracy of brief anxiety scales for non-treatment-seeking youth with autism spectrum disorder. In all, 54 youth (7-17 years; IQ: 67-158) with autism spectrum disorder and their parents completed (a) an expanded version of the Anxiety Disorders Interview Schedule-Child/Parent designed to capture typical and atypical fears and (b) brief scales of anxiety symptoms (Behavior Assessment Schedule for Children, Second Edition; Screen for Child Anxiety and Related Emotional Disorders; Negative Affective Self-Statement Questionnaire; Pediatric Anxiety Rating Scale). The results indicate that measures lacked adequate sensitivity and specificity, and the detection of atypical fears was particularly poor. Revised cut scores are offered, but refined and/or revised instruments are likely needed for research on youth with autism spectrum disorder.

Journal of Vision, 2010

Paradigms that provide independent input to each eye (eg binocular rivalry) have been used to tes... more Paradigms that provide independent input to each eye (eg binocular rivalry) have been used to test the role of subcortical visual processing streams and establish the boundaries of visual awareness. These methods have advantages over backward masking, which is ...

The high dimensionality of connectivity networks necessitates the development of methods identify... more The high dimensionality of connectivity networks necessitates the development of methods identifying the connectivity building blocks that not only characterize the patterns of brain pathology but also reveal representative population patterns. In this paper, we present a non-negative component analysis framework for learning localized and sparse sub-network patterns of connectivity matrices by decomposing them into two sets of discriminative and reconstructive bases. In order to obtain components that are designed towards extracting population differences, we exploit the geometry of the population by using a graphtheoretical scheme that imposes locality-preserving properties as well as maintaining the underlying distance between distant nodes in the original and the projected space. The effectiveness of the proposed framework is demonstrated by applying it to two clinical studies using connectivity matrices derived from DTI to study a population of subjects with ASD, as well as a developmental study of structural brain connectivity that extracts gender differences.

Journal of Autism and Developmental Disorders, 2014

This study examines whether deficits in visual information processing in autism-spectrum disorder... more This study examines whether deficits in visual information processing in autism-spectrum disorder (ASD) can be offset by the recruitment of brain structures involved in selective attention. During functional MRI, 12 children with ASD and 19 control participants completed a selective attention one-back task in which images of faces and houses were superimposed. When attending to faces, the ASD group showed increased activation relative to control participants within multiple prefrontal cortex areas, including dorsolateral prefrontal cortex (DLPFC). DLPFC activation in ASD was associated with increased response times for faces. These data suggest that prefrontal cortex activation may represent a compensatory mechanism for diminished visual information processing abilities in ASD.

NeuroImage, 2011

Decades of research have documented the specialization of fusiform gyrus (FG) for facial informat... more Decades of research have documented the specialization of fusiform gyrus (FG) for facial information processes. Recent theories indicate that FG activity is shaped by input from amygdala, but effective connectivity from amygdala to FG remains undocumented. In this fMRI study, 39 participants completed a face recognition task. 11 participants underwent the same experiment approximately four months later. Robust face-selective activation of FG, amygdala, and lateral occipital cortex were observed. Dynamic causal modeling and Bayesian Model Selection (BMS) were used to test the intrinsic connections between these structures, and their modulation by face perception. BMS results strongly favored a dynamic causal model with bidirectional, facemodulated amygdala-FG connections. However, the right hemisphere connections diminished at time 2, with the face modulation parameter no longer surviving Bonferroni correction. These findings suggest that amygdala strongly influences FG function during face perception, and that this influence is shaped by experience and stimulus salience.

Clinical Journal of the American Society of Nephrology, 2013

CKD has been linked with cognitive deficits and affective disorders in multiple studies. Analysis... more CKD has been linked with cognitive deficits and affective disorders in multiple studies. Analysis of structural and functional neuroimaging in adults and children with kidney disease may provide additional important insights into the pathobiology of this relationship. This paper comprehensively reviews neuroimaging studies in both children and adults. Major databases (PsychLit, MEDLINE, WorldCat, ArticleFirst, PubMed, Ovid MEDLINE) were searched using consistent search terms, and studies published between 1975 and 2012 were included if their samples focused on CKD as the primary disease process. Exclusion criteria included case reports, chapters, and review articles. This systematic process yielded 43 studies for inclusion (30 in adults, 13 in children). Findings from this review identified several clear trends: (1) presence of cerebral atrophy and cerebral density changes in patients with CKD; (2) cerebral vascular disease, including deep white matter hyperintensities, white matter lesions, cerebral microbleeds, silent cerebral infarction, and cortical infarction, in patients with CKD; and (3) similarities in regional cerebral blood flow between patients with CKD and those with affective disorders. These findings document the importance of neuroimaging procedures in understanding the effect of CKD on brain structure, function, and associated behaviors. Results provide a developmental linkage between childhood and adulthood, with respect to the effect of CKD on brain functioning across the lifespan, with strong implications for a cerebrovascular mechanism contributing to this developmental linkage. Use of neuroimaging methods to corroborate manifest neuropsychological deficits or perhaps to indicate preventive actions may prove useful to individuals with CKD.

Journal of autism and developmental disorders, 2014

We assessed anxiety consistent (i.e., "traditional") and inconsistent (i.e., "atyp... more We assessed anxiety consistent (i.e., "traditional") and inconsistent (i.e., "atypical") with diagnostic and statistical manual (DSM) definitions in autism spectrum disorder (ASD). Differential relationships between traditional anxiety, atypical anxiety, child characteristics, anxiety predictors and ASD-symptomology were explored. Fifty-nine participants (7-17 years, M(age) = 10.48 years; IQ > 60) with ASD and parents completed semi-structured interviews, self- and parent-reports. Seventeen percent of youth presented with traditional anxiety, 15 % with atypical anxiety, and 31 % with both. Language ability, anxious cognitions and hypersensitivity predicted traditional anxiety, whereas traditional anxiety and ASD symptoms predicted atypical anxiety. Findings suggest youth with ASD express anxiety in ways similar and dissimilar to DSM definitions. Similarities support the presence of comorbid anxiety disorders in ASD. Whether dissimilarities are unique to ASD re...

Brain and Cognition, 2011

Numerous studies implicate superior temporal sulcus (STS) in the perception of human movement. Mo... more Numerous studies implicate superior temporal sulcus (STS) in the perception of human movement. More recent theories hold that STS is also involved in the understanding of human movement. However, almost no studies to date have associated STS function with observable variability in action understanding. The present study directly associated STS activity with performance on a challenging task requiring the interpretation of human movement. During functional MRI scanning, fourteen adults were asked to identify the direction (left or right) in which either a point-light walking figure or spinning wheel were moving. The task was made challenging by perturbing the dot trajectories to a level (determined via pretesting) where each participant achieved 72% accuracy. The walking figure condition was associated with increased activity in a constellation of social information processing and biological motion areas, including STS, MT+/V5, right pars opercularis (inferior frontal gyrus), fusiform gyrus, and amygdala. Correctly answered walking figure trials were uniquely associated with increased activity in two right hemisphere STS clusters and right amygdala. Present findings provide some of the strongest evidence to date that STS plays a critical role in the successful interpretation of human movement.

Social Cognitive and Affective Neuroscience, 2014

Data from developmental psychology suggests a link between the growth of socio-emotional competen... more Data from developmental psychology suggests a link between the growth of socio-emotional competences and the infant's sensitivity to the salience of social stimuli. The aim of the present study was to find evidence for this relationship in healthy adults. Thirty-five participants were recruited based on their score above the 85th or below the 15th percentile of the empathy quotient questionnaire (EQ, . Functional magnetic resonance imaging (fMRI) was used to compare neural responses to cues of social and non-social (monetary) reward. When compared to the high-EQ group, the low-EQ group showed reduced activity of the brain s reward system, specifically the right nucleus accumbens, in response to cues predictive of social reward (videos showing gestures of approval)but increased activation in this area for monetary incentives. Our data provide evidence for a link between self-reported deficits in social proficiency and reduced sensitivity to the motivational salience of positive social stimuli.

Neuropsychologia, 2013

Human social motivation is characterized by the pursuit of social reward and the avoidance of soc... more Human social motivation is characterized by the pursuit of social reward and the avoidance of social punishment. The ventral striatum/nucleus accumbens (VS/Nacc), in particular, has been implicated in the reward component of social motivation, i.e., the 'wanting' of social incentives like approval. However, it is unclear to what extent the VS/Nacc is involved in avoiding social punishment like disapproval, an intrinsically pleasant outcome. Thus, we conducted an event-related functional magnetic resonance imaging (fMRI) study using a social incentive delay task with dynamic video stimuli instead of static pictures as social incentives in order to examine participants' motivation for social reward gain and social punishment avoidance. As predicted, the anticipation of avoidable social punishment (i.e., disapproval) recruited the VS/Nacc in a manner that was similar to VS/Nacc activation observed during the anticipation of social reward gain (i.e., approval). Stronger VS/Nacc activity was accompanied by faster reaction times of the participants to obtain those desired outcomes. This data support the assumption that dynamic social incentives elicit robust VS/Nacc activity, which likely reflects motivation to obtain social reward and to avoid social punishment. Clinical implications regarding the involvement of the VS/ Nacc in social motivation dysfunction in autism and social phobia are discussed.

Journal of Autism and Developmental Disorders, 2014

Alpha circuits (8-12 Hz), necessary for basic and complex brain processes, are abnormal in autism... more Alpha circuits (8-12 Hz), necessary for basic and complex brain processes, are abnormal in autism spectrum disorder (ASD). The present study obtained estimates of resting-state (RS) alpha activity in children with ASD and examined associations between alpha activity, age, and clinical symptoms. Given that the thalamus modulates cortical RS alpha rhythms, associations between thalamic structure and alpha activity were examined. RS magnetoencephalography was obtained from 47 typically-developing children (TDC) and 41 children with ASD. RS alpha activity was measured using distributed source localization. Left and right thalamic volume measurements were also obtained. In both groups, the strongest alpha activity was observed in Calcarine Sulcus regions. In Calcarine regions, only TDC showed the expected association between age and alpha peak frequency. ASD had more alpha activity than TDC in regions bordering the Central Sulcus as well as parietal association cortices. In ASD, whereas greater left Central Sulcus relative alpha activity was associated with higher Social Responsiveness Scale (SRS) scores, greater Calcarine region relative alpha activity was associated with lower SRS scores. Although thalamic volume group differences were not observed, relationships between thalamic volume and Calcarine alpha power were unique to TDC. The present study also identified a failure to shift peak alpha frequency as a function of age in primary alpha-generating areas in children with ASD. Findings suggested that increased RS alpha activity in primary motor and somatosensory as well as parietal multimodal areas-with increased alpha thought to reflect greater inhibition-might impair the ability to identify or interpret social cues. Finally, to our knowledge, this is the first study to report associations between thalamic volume and alpha power, an association observed only in TDC. The lack of thalamic and alpha associations in ASD suggests thalamic contributions to RS alpha abnormalities in ASD.

Autism research : official journal of the International Society for Autism Research, Jan 10, 2015

Autism Spectrum Disorder (ASD) is characterized by social impairments that have been related to d... more Autism Spectrum Disorder (ASD) is characterized by social impairments that have been related to deficits in social attention, including diminished gaze to faces. Eye-tracking studies are commonly used to examine social attention and social motivation in ASD, but they vary in sensitivity. In this study, we hypothesized that the ecological nature of the social stimuli would affect participants' social attention, with gaze behavior during more naturalistic scenes being most predictive of ASD vs. typical development. Eighty-one children with and without ASD participated in three eye-tracking tasks that differed in the ecological relevance of the social stimuli. In the "Static Visual Exploration" task, static images of objects and people were presented; in the "Dynamic Visual Exploration" task, video clips of individual faces and objects were presented side-by-side; in the "Interactive Visual Exploration" task, video clips of children playing with object...

Autism and Child Psychopathology Series, 2014

BMC Nephrology, 2015

Background: Chronic kidney disease is strongly linked to neurocognitive deficits in adults and ch... more Background: Chronic kidney disease is strongly linked to neurocognitive deficits in adults and children, but the pathophysiologic processes leading to these deficits remain poorly understood. The NiCK study (Neurocognitive Assessment and Magnetic Resonance Imaging Analysis of Children and Young Adults with Chronic Kidney Disease) seeks to address critical gaps in our understanding of the biological basis for neurologic abnormalities in chronic kidney disease. In this report, we describe the objectives, design, and methods of the NiCK study.

A growing literature indicates that visual cortex areas viewed as primarily responsive to exogeno... more A growing literature indicates that visual cortex areas viewed as primarily responsive to exogenous stimuli are susceptible to top-down modulation by selective attention. The present study examines whether brain areas involved in biological motion perception are among these areas-particularly with respect to selective attention towards human movement goals. Fifteen participants completed a point-light biological motion study following a two-by-two factorial design, with one factor representing an exogenous manipulation of human movement goals (goal-directed versus random movement), and the other an endogenous manipulation (a goal identification task versus an ancillary color-change task). Both manipulations yielded increased activation in the human homologue of motion-sensitive area MT+ (hMT+) as well as the extrastriate body area (EBA). The endogenous manipulation was associated with increased right posterior superior temporal sulcus (STS) activation, whereas the exogenous manipulation was associated with increased activation in left posterior STS. Selective attention towards goals activated a portion of left hMT+/EBA only during the perception of purposeful movement-consistent with emerging theories associating this area with the matching of visual motion input to known goal-directed actions. The overall pattern of results indicates that attention towards the goals of human movement activates biological motion areas. Ultimately, selective attention may explain why some studies examining biological motion show activation in hMT+ and EBA, even when using control stimuli with comparable motion properties.

Emotion (Washington, D.C.), 2005

Functional MRI (fMRI) was used to examine the relationship between processing of pleasant and unp... more Functional MRI (fMRI) was used to examine the relationship between processing of pleasant and unpleasant stimuli and activity in prefrontal cortex. Twenty volunteers identified the colors in which pleasant, neutral, and unpleasant words were printed. Pleasant words prompted more activity bilaterally in dorsolateral prefrontal cortex (DLPFC) than did unpleasant words. In addition, pleasant words prompted more activity in left than in right DLPFC. Response speed to pleasant words was correlated with DLPFC activity. These data directly link positive affect, enhanced performance, and prefrontal activity, providing some of the first fMRI evidence supporting models of emotional valence and frontal brain asymmetry based on electroencephalography (EEG).

Journal of the American Academy of Child & Adolescent Psychiatry, 2013

Autism spectrum disorder (ASD) is associated with amplified emotional responses and poor emotiona... more Autism spectrum disorder (ASD) is associated with amplified emotional responses and poor emotional control, but little is known about the underlying mechanisms. This article provides a conceptual and methodologic framework for understanding compromised emotion regulation (ER) in ASD. After defining ER and related constructs, methods to study ER were reviewed with special consideration on how to apply these approaches to ASD. Against the backdrop of cognitive characteristics in ASD and existing ER theories, available research was examined to identify likely contributors to emotional dysregulation in ASD. Little is currently known about ER in youth with ASD. Some mechanisms that contribute to poor ER in ASD may be shared with other clinical populations (e.g., physiologic arousal, degree of negative and positive affect, alterations in the amygdala and prefrontal cortex), whereas other mechanisms may be more unique to ASD (e.g., differences in information processing/perception, cognitive factors [e.g., rigidity], less goal-directed behavior and more disorganized emotion in ASD). Although assignment of concomitant psychiatric diagnoses is warranted in some cases, poor ER may be inherent in ASD and may provide a more parsimonious conceptualization for the many associated socioemotional and behavioral problems in this population. Further study of ER in youth with ASD may identify meaningful subgroups of patients and lead to more effective individualized treatments.

Background: Respiratory sinus arrhythmia (RSA), a measure of heart rate variability, reflects the... more Background: Respiratory sinus arrhythmia (RSA), a measure of heart rate variability, reflects the action of the parasympathetic nervous system on heart rate. A higher RSA is associated with better physical and emotional health, and a more adaptive response to changing environmental demands. Recent studies have used RSA to better understand the anxiety symptoms and social deficits in ASD. Social impairment is a defining feature of ASD, and anxiety is a commonly occurring comorbid condition with rates at approximately 40%. To our knowledge no studies have yet compared RSA for individuals with ASD with and without anxiety to individuals with an anxiety disorder alone. Objectives: The aim of this study was to compare RSA during a relaxing task across four groups of participants who were well-characterized using gold standard measures for ASD (i.e., the ADOS) and Anxiety (i.e., the ADIS). It was hypothesized that individuals with ASD regardless of their anxiety status would have a lower ...

Autism : the international journal of research and practice, Jan 29, 2015

This study investigated the accuracy of brief anxiety scales for non-treatment-seeking youth with... more This study investigated the accuracy of brief anxiety scales for non-treatment-seeking youth with autism spectrum disorder. In all, 54 youth (7-17 years; IQ: 67-158) with autism spectrum disorder and their parents completed (a) an expanded version of the Anxiety Disorders Interview Schedule-Child/Parent designed to capture typical and atypical fears and (b) brief scales of anxiety symptoms (Behavior Assessment Schedule for Children, Second Edition; Screen for Child Anxiety and Related Emotional Disorders; Negative Affective Self-Statement Questionnaire; Pediatric Anxiety Rating Scale). The results indicate that measures lacked adequate sensitivity and specificity, and the detection of atypical fears was particularly poor. Revised cut scores are offered, but refined and/or revised instruments are likely needed for research on youth with autism spectrum disorder.

Journal of Vision, 2010

Paradigms that provide independent input to each eye (eg binocular rivalry) have been used to tes... more Paradigms that provide independent input to each eye (eg binocular rivalry) have been used to test the role of subcortical visual processing streams and establish the boundaries of visual awareness. These methods have advantages over backward masking, which is ...

The high dimensionality of connectivity networks necessitates the development of methods identify... more The high dimensionality of connectivity networks necessitates the development of methods identifying the connectivity building blocks that not only characterize the patterns of brain pathology but also reveal representative population patterns. In this paper, we present a non-negative component analysis framework for learning localized and sparse sub-network patterns of connectivity matrices by decomposing them into two sets of discriminative and reconstructive bases. In order to obtain components that are designed towards extracting population differences, we exploit the geometry of the population by using a graphtheoretical scheme that imposes locality-preserving properties as well as maintaining the underlying distance between distant nodes in the original and the projected space. The effectiveness of the proposed framework is demonstrated by applying it to two clinical studies using connectivity matrices derived from DTI to study a population of subjects with ASD, as well as a developmental study of structural brain connectivity that extracts gender differences.

Journal of Autism and Developmental Disorders, 2014

This study examines whether deficits in visual information processing in autism-spectrum disorder... more This study examines whether deficits in visual information processing in autism-spectrum disorder (ASD) can be offset by the recruitment of brain structures involved in selective attention. During functional MRI, 12 children with ASD and 19 control participants completed a selective attention one-back task in which images of faces and houses were superimposed. When attending to faces, the ASD group showed increased activation relative to control participants within multiple prefrontal cortex areas, including dorsolateral prefrontal cortex (DLPFC). DLPFC activation in ASD was associated with increased response times for faces. These data suggest that prefrontal cortex activation may represent a compensatory mechanism for diminished visual information processing abilities in ASD.

NeuroImage, 2011

Decades of research have documented the specialization of fusiform gyrus (FG) for facial informat... more Decades of research have documented the specialization of fusiform gyrus (FG) for facial information processes. Recent theories indicate that FG activity is shaped by input from amygdala, but effective connectivity from amygdala to FG remains undocumented. In this fMRI study, 39 participants completed a face recognition task. 11 participants underwent the same experiment approximately four months later. Robust face-selective activation of FG, amygdala, and lateral occipital cortex were observed. Dynamic causal modeling and Bayesian Model Selection (BMS) were used to test the intrinsic connections between these structures, and their modulation by face perception. BMS results strongly favored a dynamic causal model with bidirectional, facemodulated amygdala-FG connections. However, the right hemisphere connections diminished at time 2, with the face modulation parameter no longer surviving Bonferroni correction. These findings suggest that amygdala strongly influences FG function during face perception, and that this influence is shaped by experience and stimulus salience.

Clinical Journal of the American Society of Nephrology, 2013

CKD has been linked with cognitive deficits and affective disorders in multiple studies. Analysis... more CKD has been linked with cognitive deficits and affective disorders in multiple studies. Analysis of structural and functional neuroimaging in adults and children with kidney disease may provide additional important insights into the pathobiology of this relationship. This paper comprehensively reviews neuroimaging studies in both children and adults. Major databases (PsychLit, MEDLINE, WorldCat, ArticleFirst, PubMed, Ovid MEDLINE) were searched using consistent search terms, and studies published between 1975 and 2012 were included if their samples focused on CKD as the primary disease process. Exclusion criteria included case reports, chapters, and review articles. This systematic process yielded 43 studies for inclusion (30 in adults, 13 in children). Findings from this review identified several clear trends: (1) presence of cerebral atrophy and cerebral density changes in patients with CKD; (2) cerebral vascular disease, including deep white matter hyperintensities, white matter lesions, cerebral microbleeds, silent cerebral infarction, and cortical infarction, in patients with CKD; and (3) similarities in regional cerebral blood flow between patients with CKD and those with affective disorders. These findings document the importance of neuroimaging procedures in understanding the effect of CKD on brain structure, function, and associated behaviors. Results provide a developmental linkage between childhood and adulthood, with respect to the effect of CKD on brain functioning across the lifespan, with strong implications for a cerebrovascular mechanism contributing to this developmental linkage. Use of neuroimaging methods to corroborate manifest neuropsychological deficits or perhaps to indicate preventive actions may prove useful to individuals with CKD.

Journal of autism and developmental disorders, 2014

We assessed anxiety consistent (i.e., "traditional") and inconsistent (i.e., "atyp... more We assessed anxiety consistent (i.e., "traditional") and inconsistent (i.e., "atypical") with diagnostic and statistical manual (DSM) definitions in autism spectrum disorder (ASD). Differential relationships between traditional anxiety, atypical anxiety, child characteristics, anxiety predictors and ASD-symptomology were explored. Fifty-nine participants (7-17 years, M(age) = 10.48 years; IQ > 60) with ASD and parents completed semi-structured interviews, self- and parent-reports. Seventeen percent of youth presented with traditional anxiety, 15 % with atypical anxiety, and 31 % with both. Language ability, anxious cognitions and hypersensitivity predicted traditional anxiety, whereas traditional anxiety and ASD symptoms predicted atypical anxiety. Findings suggest youth with ASD express anxiety in ways similar and dissimilar to DSM definitions. Similarities support the presence of comorbid anxiety disorders in ASD. Whether dissimilarities are unique to ASD re...

Brain and Cognition, 2011

Numerous studies implicate superior temporal sulcus (STS) in the perception of human movement. Mo... more Numerous studies implicate superior temporal sulcus (STS) in the perception of human movement. More recent theories hold that STS is also involved in the understanding of human movement. However, almost no studies to date have associated STS function with observable variability in action understanding. The present study directly associated STS activity with performance on a challenging task requiring the interpretation of human movement. During functional MRI scanning, fourteen adults were asked to identify the direction (left or right) in which either a point-light walking figure or spinning wheel were moving. The task was made challenging by perturbing the dot trajectories to a level (determined via pretesting) where each participant achieved 72% accuracy. The walking figure condition was associated with increased activity in a constellation of social information processing and biological motion areas, including STS, MT+/V5, right pars opercularis (inferior frontal gyrus), fusiform gyrus, and amygdala. Correctly answered walking figure trials were uniquely associated with increased activity in two right hemisphere STS clusters and right amygdala. Present findings provide some of the strongest evidence to date that STS plays a critical role in the successful interpretation of human movement.

Social Cognitive and Affective Neuroscience, 2014

Data from developmental psychology suggests a link between the growth of socio-emotional competen... more Data from developmental psychology suggests a link between the growth of socio-emotional competences and the infant's sensitivity to the salience of social stimuli. The aim of the present study was to find evidence for this relationship in healthy adults. Thirty-five participants were recruited based on their score above the 85th or below the 15th percentile of the empathy quotient questionnaire (EQ, . Functional magnetic resonance imaging (fMRI) was used to compare neural responses to cues of social and non-social (monetary) reward. When compared to the high-EQ group, the low-EQ group showed reduced activity of the brain s reward system, specifically the right nucleus accumbens, in response to cues predictive of social reward (videos showing gestures of approval)but increased activation in this area for monetary incentives. Our data provide evidence for a link between self-reported deficits in social proficiency and reduced sensitivity to the motivational salience of positive social stimuli.

Neuropsychologia, 2013

Human social motivation is characterized by the pursuit of social reward and the avoidance of soc... more Human social motivation is characterized by the pursuit of social reward and the avoidance of social punishment. The ventral striatum/nucleus accumbens (VS/Nacc), in particular, has been implicated in the reward component of social motivation, i.e., the 'wanting' of social incentives like approval. However, it is unclear to what extent the VS/Nacc is involved in avoiding social punishment like disapproval, an intrinsically pleasant outcome. Thus, we conducted an event-related functional magnetic resonance imaging (fMRI) study using a social incentive delay task with dynamic video stimuli instead of static pictures as social incentives in order to examine participants' motivation for social reward gain and social punishment avoidance. As predicted, the anticipation of avoidable social punishment (i.e., disapproval) recruited the VS/Nacc in a manner that was similar to VS/Nacc activation observed during the anticipation of social reward gain (i.e., approval). Stronger VS/Nacc activity was accompanied by faster reaction times of the participants to obtain those desired outcomes. This data support the assumption that dynamic social incentives elicit robust VS/Nacc activity, which likely reflects motivation to obtain social reward and to avoid social punishment. Clinical implications regarding the involvement of the VS/ Nacc in social motivation dysfunction in autism and social phobia are discussed.

Journal of Autism and Developmental Disorders, 2014

Alpha circuits (8-12 Hz), necessary for basic and complex brain processes, are abnormal in autism... more Alpha circuits (8-12 Hz), necessary for basic and complex brain processes, are abnormal in autism spectrum disorder (ASD). The present study obtained estimates of resting-state (RS) alpha activity in children with ASD and examined associations between alpha activity, age, and clinical symptoms. Given that the thalamus modulates cortical RS alpha rhythms, associations between thalamic structure and alpha activity were examined. RS magnetoencephalography was obtained from 47 typically-developing children (TDC) and 41 children with ASD. RS alpha activity was measured using distributed source localization. Left and right thalamic volume measurements were also obtained. In both groups, the strongest alpha activity was observed in Calcarine Sulcus regions. In Calcarine regions, only TDC showed the expected association between age and alpha peak frequency. ASD had more alpha activity than TDC in regions bordering the Central Sulcus as well as parietal association cortices. In ASD, whereas greater left Central Sulcus relative alpha activity was associated with higher Social Responsiveness Scale (SRS) scores, greater Calcarine region relative alpha activity was associated with lower SRS scores. Although thalamic volume group differences were not observed, relationships between thalamic volume and Calcarine alpha power were unique to TDC. The present study also identified a failure to shift peak alpha frequency as a function of age in primary alpha-generating areas in children with ASD. Findings suggested that increased RS alpha activity in primary motor and somatosensory as well as parietal multimodal areas-with increased alpha thought to reflect greater inhibition-might impair the ability to identify or interpret social cues. Finally, to our knowledge, this is the first study to report associations between thalamic volume and alpha power, an association observed only in TDC. The lack of thalamic and alpha associations in ASD suggests thalamic contributions to RS alpha abnormalities in ASD.

Autism research : official journal of the International Society for Autism Research, Jan 10, 2015

Autism Spectrum Disorder (ASD) is characterized by social impairments that have been related to d... more Autism Spectrum Disorder (ASD) is characterized by social impairments that have been related to deficits in social attention, including diminished gaze to faces. Eye-tracking studies are commonly used to examine social attention and social motivation in ASD, but they vary in sensitivity. In this study, we hypothesized that the ecological nature of the social stimuli would affect participants' social attention, with gaze behavior during more naturalistic scenes being most predictive of ASD vs. typical development. Eighty-one children with and without ASD participated in three eye-tracking tasks that differed in the ecological relevance of the social stimuli. In the "Static Visual Exploration" task, static images of objects and people were presented; in the "Dynamic Visual Exploration" task, video clips of individual faces and objects were presented side-by-side; in the "Interactive Visual Exploration" task, video clips of children playing with object...

Autism and Child Psychopathology Series, 2014

BMC Nephrology, 2015

Background: Chronic kidney disease is strongly linked to neurocognitive deficits in adults and ch... more Background: Chronic kidney disease is strongly linked to neurocognitive deficits in adults and children, but the pathophysiologic processes leading to these deficits remain poorly understood. The NiCK study (Neurocognitive Assessment and Magnetic Resonance Imaging Analysis of Children and Young Adults with Chronic Kidney Disease) seeks to address critical gaps in our understanding of the biological basis for neurologic abnormalities in chronic kidney disease. In this report, we describe the objectives, design, and methods of the NiCK study.

A growing literature indicates that visual cortex areas viewed as primarily responsive to exogeno... more A growing literature indicates that visual cortex areas viewed as primarily responsive to exogenous stimuli are susceptible to top-down modulation by selective attention. The present study examines whether brain areas involved in biological motion perception are among these areas-particularly with respect to selective attention towards human movement goals. Fifteen participants completed a point-light biological motion study following a two-by-two factorial design, with one factor representing an exogenous manipulation of human movement goals (goal-directed versus random movement), and the other an endogenous manipulation (a goal identification task versus an ancillary color-change task). Both manipulations yielded increased activation in the human homologue of motion-sensitive area MT+ (hMT+) as well as the extrastriate body area (EBA). The endogenous manipulation was associated with increased right posterior superior temporal sulcus (STS) activation, whereas the exogenous manipulation was associated with increased activation in left posterior STS. Selective attention towards goals activated a portion of left hMT+/EBA only during the perception of purposeful movement-consistent with emerging theories associating this area with the matching of visual motion input to known goal-directed actions. The overall pattern of results indicates that attention towards the goals of human movement activates biological motion areas. Ultimately, selective attention may explain why some studies examining biological motion show activation in hMT+ and EBA, even when using control stimuli with comparable motion properties.

Emotion (Washington, D.C.), 2005

Functional MRI (fMRI) was used to examine the relationship between processing of pleasant and unp... more Functional MRI (fMRI) was used to examine the relationship between processing of pleasant and unpleasant stimuli and activity in prefrontal cortex. Twenty volunteers identified the colors in which pleasant, neutral, and unpleasant words were printed. Pleasant words prompted more activity bilaterally in dorsolateral prefrontal cortex (DLPFC) than did unpleasant words. In addition, pleasant words prompted more activity in left than in right DLPFC. Response speed to pleasant words was correlated with DLPFC activity. These data directly link positive affect, enhanced performance, and prefrontal activity, providing some of the first fMRI evidence supporting models of emotional valence and frontal brain asymmetry based on electroencephalography (EEG).

Journal of the American Academy of Child & Adolescent Psychiatry, 2013

Autism spectrum disorder (ASD) is associated with amplified emotional responses and poor emotiona... more Autism spectrum disorder (ASD) is associated with amplified emotional responses and poor emotional control, but little is known about the underlying mechanisms. This article provides a conceptual and methodologic framework for understanding compromised emotion regulation (ER) in ASD. After defining ER and related constructs, methods to study ER were reviewed with special consideration on how to apply these approaches to ASD. Against the backdrop of cognitive characteristics in ASD and existing ER theories, available research was examined to identify likely contributors to emotional dysregulation in ASD. Little is currently known about ER in youth with ASD. Some mechanisms that contribute to poor ER in ASD may be shared with other clinical populations (e.g., physiologic arousal, degree of negative and positive affect, alterations in the amygdala and prefrontal cortex), whereas other mechanisms may be more unique to ASD (e.g., differences in information processing/perception, cognitive factors [e.g., rigidity], less goal-directed behavior and more disorganized emotion in ASD). Although assignment of concomitant psychiatric diagnoses is warranted in some cases, poor ER may be inherent in ASD and may provide a more parsimonious conceptualization for the many associated socioemotional and behavioral problems in this population. Further study of ER in youth with ASD may identify meaningful subgroups of patients and lead to more effective individualized treatments.