Neurocognitive Concussion Test Performance for Student Athletes on the Autism Spectrum

OBJECTIVE

To examine baseline neurocognitive functioning among adolescent athletes on the autism spectrum based on self-reported level of academic performance.

METHOD

Participants in this cross-sectional, observational study were 6,441 adolescent athletes with a self-reported diagnosis of autism who completed pre-season neurocognitive testing using Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT); 4,742 reported a co-occurring learning disorder (LD), and 6,612 individuals without autism or LD were included as a control group. The majority (57%) self-reported Average Academic Performance, 39% Above Average, and 4% Below Average performance.

RESULTS

Athletes with self-reported autism (with or without LD; 12.2%) were 2.74x (95% CI: 2.17-2.82) more likely to fall below cutoffs for ImPACT Embedded Invalidity Indicators (EVIs), with a significant interaction between self-reported Diagnosis and Academic Performance; individuals with co-occurring autism and LD who reported Below Average Academic Performance had the greatest likelihood of scoring below cutoffs (22%), followed by ASD without LD (14.8%) and Controls (14.6%) with Below Average Academic Performance. Analyses of variance (ANOVAs) revealed main effects of Diagnosis and Academic Performance on neurocognitive performance, with interactions on all ImPACT Composite Scores except Processing Speed.

CONCLUSION

Athletes with self-reported ASD are more likely to fall below ImPACT EVIs and score worse on ImPACT, with greater likelihood/worse performance related to level of academic functioning. Academic performance should be considered when interpreting neurocognitive testing data, to best index neuropsychological functioning associated with concussion in this population. The current findings highlight the importance of individual participant baseline neuropsychological testing for individuals on the autism spectrum.

A delayed intervention start randomized controlled trial of high- and low-tech communication training approaches for school-age autistic children with co-occurring intellectual disability

The researchers designed a delayed intervention start randomized controlled trial to compare improvements in functional communication following augmentative and alternative communication (AAC) interventions. The study compared outcomes from function-based applied behavior analytic (ABA) and eclectic non-ABA forms of classroom-based communication strategies (waitlist control) as well as from high- and low-tech forms of AAC. High-tech AAC consisted of tablet-based communication, and low-tech AAC used an exchange of picture cards. The community-based sample consisted of 29 autistic children with a co-occurring intellectual disability. Participants were randomized to groups (AAC, waitlist control), and each group received approximately 3 months of communication intervention. Multilevel modeling of learner outcomes indicated that the function-based approach produced greater improvements than the eclectic alternative, but significant differences were not observed between outcomes of high- and low-tech forms of function-based AAC. These results are consistent with earlier investigations and provide supporting evidence that both high- and low-tech forms of function-based intervention are effective for use with autistic children with accompanying intellectual disability. Additional discussion is provided regarding further research into how technology is applied and incorporated into behavior analytic programming.

Sex differences in social and emotional insight in youth with and without autism

Autism was formally recognized by the medical community in the first half of the twentieth century. Almost 100 years later, a small but growing literature has reported sex differences in the behavioral expression of autism. Recent research has also begun to explore the internal experiences of individuals with autism, including social and emotional insight. The current study examines sex differences in language-based markers of social and emotional insight in girls and boys with autism and non-autistic peers during semi-structured clinical interviews. Sixty-four participants aged 5 to 17 years were individually matched on chronological age and full-scale IQ to form four groups: autistic girls, autistic boys, non-autistic girls, and non-autistic boys. Transcribed interviews were scored using four scales that index aspects of social and emotional insight. Results revealed the main effects of diagnosis, such that youth with autism exhibited lower insight than non-autistic youth on scales indexing social cognition and object relations, emotional investment, and social causality. With regards to sex differences, across diagnoses, girls were rated higher than boys on the social cognition and object relations, emotional investment, and social causality scales. Examined within each diagnosis separately, clear sex differences emerged: both autistic and non-autistic girls demonstrated better social cognition and understanding of social causality than boys in their respective diagnostic groups. No within-diagnosis sex differences were found on the emotional insight scales, however. These results suggest that relatively enhanced social cognition and understanding of social causality in girls may be a population-level sex difference that is preserved in autism, despite the core social challenges that characterize this condition. The current findings reveal critical new information about insight into social and emotional thinking and relationships in autistic girls versus boys that have important implications for improving identification and designing effective interventions.

Safety and Feasibility of an Immersive Virtual Reality Intervention Program for Teaching Police Interaction Skills to Adolescents and Adults with Autism

Low-cost, wireless immersive virtual reality (VR) holds significant promise as a flexible and scalable intervention tool to help individuals with autism spectrum disorder (ASD) learn and develop critical practical life skills, including interacting safely and effectively with police officers. Previous research suggests that VR is a motivating intervention platform, but many individuals with ASD also exhibit anxiety and sensory sensitivities which might make it difficult to tolerate VR experiences. Here, we describe the results of a relatively large-scale, National Institutes of Health-funded systematic examination of the safety, feasibility, and usability of an immersive VR training program in adolescents and adults with ASD, aged 12 and older. Sixty verbally fluent individuals with no personal or immediate family history of seizures or migraines participated in either one (n = 30) or three 45-min (n = 30) VR sessions using a lightweight wireless headset, and were monitored for side effects. Participants also reported on system usability, enjoyment, and willingness to engage in further VR sessions. Results confirm that immersive VR is safe, feasible, and highly usable for verbally fluent adolescents and adults with ASD. LAY SUMMARY: Immersive virtual reality (VR) holds promise as a means to provide social skills interventions for individuals with autism spectrum disorder (ASD), but it is unclear whether associated anxiety and sensory symptoms might limit feasibility. Here, we report data that indicate that immersive VR is both safe and feasible for use in verbally fluent adolescents and adults with ASD, for up to three 45-min sessions. Autism Res 2020, 13: 1418-1424. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.

A Lifespan Approach to Patient-Reported Outcomes and Quality of Life for People on the Autism Spectrum

Autistic self-advocates, family members, and community organizations have called for greater emphasis on enhancing quality of life (QoL) for people with autism. Doing this is critical to understand how QoL unfolds across the life course and to clarify whether gender affects QoL, health, and functioning for people with autism. The purpose of this study was to curate and test a lifespan QoL measurement tool using freely available and well-constructed National Institutes of Health Parent-Reported Outcomes Measurement Information System (PROMIS). To develop the PROMIS Autism Battery-Lifespan (PAB-L), we identified PROMIS scales relevant for autism, reviewed each item, consulted with a panel of autism experts, and elicited feedback from autistic people and family members. This battery provides a comprehensive portrait of QoL for children ages 5-13 (through parent proxy), teens 14-17 (parent proxy and self-report), and adults 18-65 (self-report) with autism compared to the general population. Participants and parent informants (N = 912) recruited through a children's hospital and nationwide U.S. autism research registry completed the PAB-L online. Results indicate that compared to general population norms, people with autism of all ages (or their proxies) reported less desirable outcomes and lower QoL across all domains. Women and girls experienced greater challenges in some areas compared to men and boys with autism. The PAB-L appears to be a feasible and acceptable method for assessing patient-reported outcomes and QoL for autistic people across the life course. Autism Res 2020, 13: 970-987. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We developed a survey to measure the quality of life of children, teens, and adults with autism using free National Institutes of Health PROMIS questionnaires. People with autism and family members rated the PROMIS Autism Battery-Lifespan as useful and important. Some reported a good quality of life, while many reported that their lives were not going as well as they wanted. Women and girls reported more challenges in some areas of life than men and boys.

What's in a name? A preliminary event-related potential study of response to name in preschool children with and without autism spectrum disorder

The ability to selectively respond to one’s own name is important for social and language development, and is disrupted in atypically developing populations (e.g., autism spectrum disorder). Research with typically developing samples using event-related potentials (ERPs) has demonstrated that the subject’s own name (SON) is differentiated from other stimuli at both early sensory and later cognitive stages of auditory processing. While neural indices of response to name have been researched extensively in adults, no such studies have been conducted with typically developing preschool children or children with autism spectrum disorder (ASD). The present study investigated ERP response to name in a sample of typically developing (TD) preschoolers (n = 19; mean age = 4.3 years) as well as a small, exploratory comparison group of preschoolers with ASD (n = 13; mean age = 4.4 years). TD preschoolers exhibited significantly greater negativity to SON over frontal regions than to an unfamiliar nonsense name, consistent with the adult SON negativity component. This component was present whether the name was spoken by a parent or an unfamiliar adult, suggesting that it reflects SON-specific processing rather than broad self-relevant information processing. Comparing preschoolers with ASD to the TD children revealed a significant SON negativity component across both groups. The amplitude of the SON negativity response was significantly correlated with social variables in the ASD group, though these correlations did not survive correction for multiple comparisons. This study is the first to demonstrate the presence of the SON component in preschool children with and without ASD.

A pilot community-based randomized comparison of speech generating devices and the picture exchange communication system for children diagnosed with autism spectrum disorder

A pilot community-based randomized controlled trial was conducted to compare the effects of the Picture Exchange Communication System (PECS) to a teaching sequence using a high-tech Speech Generating Device (SGD) to teach social communication behaviors. The two approaches were compared to evaluate the effectiveness of the newer, more high-tech intervention using technology to improve social and communicative behavior of children diagnosed with Autism Spectrum Disorder. A total of 35 school-age children were randomized to either a high-tech (SGD device) or low-tech (PECS cards) form of Augmentative and Alternative Communication (AAC). Study participants received 4 months of communication training delivered in their classrooms, and the primary outcome measures of the trial were several functional communication skills emphasized in the PECS teaching sequence. Results indicated that both high-tech and low-tech AAC approaches resulted in significant improvements in communication, and that these improvements did not differ significantly between the two approaches. These findings support the use of high-tech AAC, and highlight the need for evidence-based guidelines for its use as well as evaluation with individuals with a range impairments and disabilities. Autism Research 2018, 11: 1701-1711. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This study compared the effectiveness of a free and open-source app for teaching social and communicative behavior to children with autism spectrum disorder (ASD) to traditional picture card approaches. Thirty-five children with ASD were randomized to a picture card or app-based intervention and both treatment approaches resulted in significant improvements in social and communicative behavior. These data indicated that both "high-tech" and "low-tech" interventions were effective for improving behavior and that there was not a significant difference between the two approaches.

Diagnosis and management of Cornelia de Lange syndrome: first international consensus statement

Cornelia de Lange syndrome (CdLS) is an archetypical genetic syndrome that is characterized by intellectual disability, well-defined facial features, upper limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in any one of seven genes, all of which have a structural or regulatory function in the cohesin complex. Although recent advances in next-generation sequencing have improved molecular diagnostics, marked heterogeneity exists in clinical and molecular diagnostic approaches and care practices worldwide. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria, both for classic CdLS and non-classic CdLS phenotypes, molecular investigations, long-term management and care planning.

Effects of maternal depression in the Still-Face Paradigm: A meta-analysis

The Still-Face Paradigm (SFP) enables researchers to examine the quality of mother-infant interactions. In typical infants, a classic still-face effect (SFE) has been confirmed whereby infants demonstrate reduced positive affect (PA), reduced gaze (GA), and increased negative affect (NA). Recently, the SFP has been used to examine the effect of maternal depression upon infant behaviour. However, the nature and consistency of the behavioural responses of infants of depressed mothers during the SFP remains unclear. In the current meta-analysis, we examined whether or not infants of depressed mothers demonstrate the classic SFE, as well as whether or not these infants display the same levels of PA, NA, and GA as their counterparts with non-depressed mothers. Results revealed that infants of depressed mothers display the classic SFE like infants of their non-depressed counterparts. However, infants of depressed mothers also demonstrated significantly higher levels of PA during the still-face episode. One potential interpretation of this finding is that infants prior experience of similar, depressed interactions with their mothers, encourages them to amplify their positive attachment signals in order to engage maternal attention and response. Alternatively, or additionally, infants of depressed mothers could be using PA in order to regulate their own NA.

Serotonin 5-HTTLPR Genotype Modulates Reactive Visual Scanning of Social and Non-social Affective Stimuli in Young Children

Previous studies have documented the 5-HTTLPR polymorphisms as genetic variants that are involved in serotonin availability and also associated with emotion regulation and facial emotion processing. In particular, neuroimaging and behavioral studies of healthy populations have produced evidence to suggest that carriers of the Short allele exhibit heightened neurophysiological and behavioral reactivity when processing aversive stimuli, particularly in brain regions involved in fear. However, an additional distinction has emerged in the field, which highlights particular types of fearful information, i.e., aversive information which involves a social component versus non-social aversive stimuli. Although processing of each of these stimulus types (social and non-social) is believed to involve a subcortical neural system which includes the amygdala, evidence also suggests that the amygdala itself may be particularly responsive to socially significant environmental information, potentially due to the critical relevance of social information for humans. Examining individual differences in neurotransmitter systems which operate within this subcortical network, and in particular the serotonin system, may be critically informative for furthering our understanding of the neurobiological mechanisms underlying responses to emotional and affective stimuli. In the present study we examine visual scanning patterns in response to both aversive and positive images of a social or non-social nature in relation to 5-HTTLPR genotypes, in 49 children aged 4–7 years. Results indicate that children with at least one Short 5-HTTLPR allele spent less time fixating the threat-related non-social stimuli, compared with participants with two copies of the Long allele. Interestingly, a separate set of analyses suggests that carriers of two copies of the short 5-HTTLPR allele also spent less time fixating both the negative and positive non-social stimuli. Together, these findings support the hypothesis that genetically mediated differences in serotonin availability mediate behavioral responses to different types of emotional stimuli in young children.

Comment on Technology-Based Intervention Research for Individuals on the Autism Spectrum

The purpose of this letter to the editor is to comment on several review papers recently published in the current Journal of Autism and Developmental Disorders, Special Issue on Technology: Software, Robotics, and Translational Science. These reviews address a variety of aspects relating to technology-aided intervention and instruction for individuals with Autism Spectrum Disorders (ASDs). Here, I comment on and evaluate the overall status of research and development in this area, including reflection on current challenges in this area in the context of previous challenges and resolutions in behavioral intervention research. From these reviews and the current evaluation, I further discuss important next steps for the field which may be critical for guiding progress toward meaningful impacts upon individuals with ASD.

Visual preference for social stimuli in individuals with autism or neurodevelopmental disorders: an eye-tracking study

BACKGROUND

Recent research has identified differences in relative attention to competing social versus non-social video stimuli in individuals with autism spectrum disorder (ASD). Whether attentional allocation is influenced by the potential threat of stimuli has yet to be investigated. This is manipulated in the current study by the extent to which the stimuli are moving towards or moving past the viewer. Furthermore, little is known about whether such differences exist across other neurodevelopmental disorders. This study aims to determine if adolescents with ASD demonstrate differences in attentional allocation to competing pairs of social and non-social video stimuli, where the actor or object either moves towards or moves past the viewer, in comparison to individuals without ASD, and to determine if individuals with three genetic syndromes associated with differing social phenotypes demonstrate differences in attentional allocation to the same stimuli.

METHODS

In study 1, adolescents with ASD and control participants were presented with social and non-social video stimuli in two formats (moving towards or moving past the viewer) whilst their eye movements were recorded. This paradigm was then employed with groups of individuals with fragile X, Cornelia de Lange, and Rubinstein-Taybi syndromes who were matched with one another on chronological age, global adaptive behaviour, and verbal adaptive behaviour (study 2).

RESULTS

Adolescents with ASD demonstrated reduced looking-time to social versus non-social videos only when stimuli were moving towards them. Individuals in the three genetic syndrome groups showed similar looking-time but differences in fixation latency for social stimuli moving towards them. Across both studies, we observed within- and between-group differences in attention to social stimuli that were moving towards versus moving past the viewer.

CONCLUSIONS

Taken together, these results provide strong evidence to suggest differential visual attention to competing social versus non-social video stimuli in populations with clinically relevant, genetically mediated differences in socio-behavioural phenotypes.

Neural mechanisms of the observation of human and non-human object touch in children: An event-related potential study

Previous behavioural research on the development of self-other tactile processing and perception suggests that this system may develop in a somewhat protracted manner relative to other aspects of social development. Neuroimaging research has shown that somatosensory mechanisms are activated when adults observe another person or object being touched. In this study, we measured event-related potentials from 4- to 5-year-old children to investigate the development of the neural correlates of the observation of human and object touch. Participants were presented with video clips of an arm or a cylindrical object being touched. Touch versus non-touch effects were observed in the amplitudes of the LSW component (600-700 ms) measured from electrodes over somatosensory region. Additionally, human versus non-human stimulus effects were reflected in the amplitudes of the parietal-central N100 component, as well as in the latencies of the N170 component recorded from parietal-occipital electrodes in children, as in adults in a previous study using this same paradigm. These findings provide evidence that relatively mature tactile mirroring mechanisms are activated during the observation of touch in children, and further suggest the possibility that these mechanisms are not particularly slow in their development relative to other aspects of social cognition.

Face scanning and spontaneous emotion preference in Cornelia de Lange syndrome and Rubinstein-Taybi syndrome

BACKGROUND

Existing literature suggests differences in face scanning in individuals with different socio-behavioural characteristics. Cornelia de Lange syndrome (CdLS) and Rubinstein-Taybi syndrome (RTS) are two genetically defined neurodevelopmental disorders with unique profiles of social behaviour.

METHODS

Here, we examine eye gaze to the eye and mouth regions of neutrally expressive faces, as well as the spontaneous visual preference for happy and disgusted facial expressions compared to neutral faces, in individuals with CdLS versus RTS.

RESULTS

Results indicate that the amount of time spent looking at the eye and mouth regions of faces was similar in 15 individuals with CdLS and 17 individuals with RTS. Both participant groups also showed a similar pattern of spontaneous visual preference for emotions.

CONCLUSIONS

These results provide insight into two rare, genetically defined neurodevelopmental disorders that have been reported to exhibit contrasting socio-behavioural characteristics and suggest that differences in social behaviour may not be sufficient to predict attention to the eye region of faces. These results also suggest that differences in the social behaviours of these two groups may be cognitively mediated rather than subcortically mediated.

BDNF Val(66)Met and 5-HTTLPR Genotype are Each Associated with Visual Scanning Patterns of Faces in Young Children

Previous studies have documented both neuroplasticity-related BDNF Val(66)Met and emotion regulation-related 5-HTTLPR polymorphisms as genetic variants that contribute to the processing of emotions from faces. More specifically, research has shown the BDNF Met allele and the 5-HTTLPR Short allele to be associated with mechanisms of negative affectivity that relate to susceptibility for psychopathology. We examined visual scanning pathways in response to angry, happy, and neutral faces in relation to BDNF Val(66)Met and 5-HTTLPR genotyping in 49 children aged 4-7 years. Analyses revealed that variations in the visual processing of facial expressions of anger interacted with BDNF Val(66)Met genotype, such that children who carried at least one low neuroplasticity Met allele exhibited a vigilance-avoidance pattern of visual scanning compared to homozygotes for the high neuroplasticity Val allele. In a separate investigation of eye gaze towards the eye versus mouth regions of neutral faces, we observed that short allele 5-HTTLPR carriers exhibited reduced looking at the eye region compared with those with the higher serotonin uptake Long allele. Together, these findings suggest that genetic mechanisms early in life may influence the establishment of patterns of visual scanning of environmental stressors, which in conjunction with other factors such as negative life events, may lead to psychological difficulties and disorders in the later adolescent and adult years.

Implicit Discrimination of Basic Facial Expressions of Positive/Negative Emotion in Fragile X Syndrome and Autism Spectrum Disorder

Fragile X syndrome (FXS) and autism spectrum disorders (ASD) are characterized by impaired social functioning. We examined the spontaneous discrimination of happy and disgusted facial expressions, from neutral faces, in individuals with FXS (n  =  13, Mage  =  19.70) and ASD (n  =  15, Mage  =  11.00) matched on adaptive behavior and verbal abilities measured by the Vineland Adaptive Behavior Scale. Eye gaze to the eyes and mouth of neutral faces was also measured. Results suggest individuals with FXS and ASD distinguish facial expressions spontaneously in the same way. Individuals with FXS looked significantly less at the eye region of neutral faces than individuals with ASD. These results provide insight into similarities and differences in face processing in two neurodevelopmental disorders noted for their similarities in social behavior.

Maternal pre-pregnancy weight and externalising behaviour problems in preschool children: a UK-based twin study

OBJECTIVE

To estimate the heritability of child behaviour problems and investigate the association between maternal pre-pregnancy overweight and child behaviour problems in a genetically sensitive design.

DESIGN

Observational cross-sectional study.

SETTING

The Twins and Multiple Births Association Heritability Study (TAMBAHS) is an online UK-wide volunteer-based study investigating the development of twins from birth until 5 years of age.

PARTICIPANTS

A total of 443 (16% of the initial registered members) mothers answered questions on pre-pregnancy weight and their twins' internalising and externalising problems using the Child Behavior Checklist and correcting for important covariates including gestational age, twins' birth weight, age and sex, mother's educational level and smoking (before, during and after pregnancy).

PRIMARY OUTCOMES

The heritability of behaviour problems and their association with maternal pre-pregnancy weight.

RESULTS

The genetic analysis suggested that genetic and common environmental factors account for most of the variation in externalising disorders (an ACE model was the most parsimonious with genetic factors (A) explaining 46% (95% CI 33% to 60%) of the variance, common environment (C) explaining 42% (95% CI 27% to 54%) and non-shared environmental factors (E) explaining 13% (95% CI 10% to 16%) of the variance. For internalising problems, a CE model was the most parsimonious model with the common environment explaining 51% (95% CI 44% to 58%) of the variance and non-shared environment explaining 49% (95% CI 42% to 56%) of the variance. Moreover, the regression analysis results suggested that children of overweight mothers showed a trend (OR=1.10, 95% CI 0.58% to 2.06) towards being more aggressive and exhibit externalising behaviours compared to children of normal weight mothers.

CONCLUSIONS

Maternal pre-pregnancy weight may play a role in children's aggressive behaviour.

Motor development and motor resonance difficulties in autism: relevance to early intervention for language and communication skills

Research suggests that a sub-set of children with autism experience notable difficulties and delays in motor skills development, and that a large percentage of children with autism experience deficits in motor resonance. These motor-related deficiencies, which evidence suggests are present from a very early age, are likely to negatively affect social-communicative and language development in this population. Here, we review evidence for delayed, impaired, and atypical motor development in infants and children with autism. We then carefully review and examine the current language and communication-based intervention research that is relevant to motor and motor resonance (i.e., neural "mirroring" mechanisms activated when we observe the actions of others) deficits in children with autism. Finally, we describe research needs and future directions and developments for early interventions aimed at addressing the speech/language and social-communication development difficulties in autism from a motor-related perspective.

Atypical social referencing in infant siblings of children with autism spectrum disorders

Social referencing was investigated in 18-month-old siblings of children with autism spectrum disorders (ASD; "high-risk infants"). Infants were exposed to novel toys, which were emotionally tagged via adults' facial and vocal signals. Infants' information seeking (initiation of joint attention with an adult) and their approach/withdrawal behavior toward the toys before versus after the adults' emotional signals was measured. Compared to both typically developing infants and high-risk infants without ASD, infants later diagnosed with ASD engaged in slower information seeking, suggesting that this aspect of referencing may be an early indicator of ASD. High-risk infants, both those who were and those who were not later diagnosed with ASD, exhibited impairments in regulating their behavior based on the adults' emotional signals, suggesting that this aspect of social referencing may reflect an endophenotype for ASD.

Neural time-course of the observation of human and non-human object touch

Recent functional magnetic resonance imaging studies have reported activation of primary and secondary somatosensory cortices when participants observe another person or object being touched. In this study, we used event-related potentials to examine the nature and time-course of the neural mechanisms associated with the observation of humans and non-human objects being touched. Participants were presented with short video clips of a human arm or a non-human cylindrical object being touched by an object, compared with an object moving in front of the arms or cylinders without touching them. Touch vs non-touch effects were observed in the amplitudes of the N100 and N250 components, as well as a late slow wave component (500-600 ms), measured from electrodes over primary somatosensory cortex. Human vs non-human stimulus effects were reflected in the latencies of the N100, P170 and N250 components recorded over somatosensory cortex, as well as the temporal-parietal visual-perceptual N170 and N250 components. These findings suggest that human and non-human touch observation are associated with somatosensory processing at both an early sensory-perceptual stage and a relatively late cognitive stage, both preceding and following the perceptual encoding of the humanness of stimuli that typically occurs in extrastriate visual areas.

Developmental changes in mu suppression to observed and executed actions in autism spectrum disorders

There has been debate over whether disruptions in the mirror neuron system (MNS) play a key role in the core social deficits observed in autism spectrum disorders (ASD). EEG mu suppression during the observation of biological actions is believed to reflect MNS functioning, but understanding of the developmental progression of the MNS and EEG mu rhythm in both typical and atypical development is lacking. To provide a more thorough and direct exploration of the development of mu suppression in individuals with ASD, a sample of 66 individuals with ASD and 51 typically developing individuals of 6-17 years old were pooled from four previously published studies employing similar EEG methodology. We found a significant correlation between age and mu suppression in response to the observation of actions, both for individuals with ASD and typical individuals. This relationship was not seen during the execution of actions. Additionally, the strength of the correlation during the observation of actions did not significantly differ between groups. The results provide evidence against the argument that mirror neuron dysfunction improves with age in individuals with ASD and suggest, instead, that a diagnosis-independent developmental change may be at the root of the correlation of age and mu suppression.

Neural correlates of verbal and nonverbal semantic integration in children with autism spectrum disorders

BACKGROUND

Autism is a pervasive developmental disorder characterized by deficits in social-emotional, social-communicative, and language skills. Behavioral and neuroimaging studies have found that children with autism spectrum disorders (ASD) evidence abnormalities in semantic processing, with particular difficulties in verbal comprehension. However, it is not known whether these semantic deficits are confined to the verbal domain or represent a more general problem with semantic processing. The focus of the current study was to investigate verbal and meaningful nonverbal semantic processing in high-functioning children with autism (mean age = 5.8 years) using event-related potentials (ERPs).

METHOD

ERPs were recorded while children attended to semantically matching and mismatching picture-word and picture-environmental sound pairs.

RESULTS

ERPs of typically developing children exhibited evidence of semantic incongruency detection in both the word and environmental sound conditions, as indexed by elicitation of an N400 effect. In contrast, children with ASD showed an N400 effect in the environmental sound condition but not in the word condition.

CONCLUSIONS

These results provide evidence for a deficiency in the automatic activation of semantic representations in children with ASD, and suggest that this deficit is somewhat more selective to, or more severe in, the verbal than the nonverbal domain.

Atypical face versus object processing and hemispheric asymmetries in 10-month-old infants at risk for autism

BACKGROUND

Previous studies have documented atypicalities in face/object processing in children and adults with autism spectrum disorders (ASDs). To investigate whether such atypicalities may reflect a genetically mediated risk factor present early in development, we measured face/object processing in 10-month-old high-risk infants who carry some of the genes associated with ASD because they have an older sibling diagnosed with the disorder.

METHODS

We employed event-related potentials (ERPs) to measure cortical responses to pictures of faces and objects, the objects being toys. Latencies and amplitudes of four ERP components (P100, N290, P400, and Nc) were compared between 20 high-risk infants and 20 low-risk control subjects (infants with no family history of ASD).

RESULTS

Responses to faces versus objects differed between high- and low-risk infants for the latencies of the N290 and P400. Differences were driven by faster responses to faces than objects in low-risk, but not high-risk, infants (P400) and, conversely, faster responses to objects than faces in high-risk, but not low-risk, infants (N290). Object responses were also faster in high-risk than low-risk infants (both N290 and P400). Left versus right hemisphere responses also differed between high- and low-risk infants for the amplitudes of the P100, N290, and P400; collapsed across faces/objects, low-risk, but not high-risk, infants exhibited hemisphere asymmetries.

CONCLUSIONS

Genetic risk for ASD is associated with atypical face versus object processing and an atypical lack of hemispheric asymmetry early in life. These atypicalities might contribute to development of the disorder.

Effects of gestational length, gender, postnatal age, and birth order on visual contrast sensitivity in infants

To investigate effects of visual experience versus preprogrammed mechanisms on visual development, we used multiple regression analysis to determine the extent to which a variety of variables (that differ in the extent to which they are tied to visual experience) predict luminance and chromatic (red/green) contrast sensitivity (CS), which are mediated by the magnocellular (M) and parvocellular (P) subcortical pathways, respectively. Our variables included gestational length (GL), birth weight (BW), gender, postnatal age (PNA), and birth order (BO). Two-month-olds (n = 60) and 6-month-olds (n = 122) were tested. Results revealed that (1) at 2 months, infants with longer GL have higher luminance CS; (2) at both ages, CS significantly increases over a approximately 21-day range of PNA, but this effect is stronger in 2- than 6-month-olds and stronger for chromatic than luminance CS; (3) at 2 months, boys have higher luminance CS than girls; and (4) at 2 months, firstborn infants have higher CS, while at 6 months, non-firstborn infants have higher CS. The results for PNA/GL are consistent with the possibility that P pathway development is more influenced by variables tied to visual experience (PNA), while M pathway development is more influenced by variables unrelated to visual experience (GL). Other variables, including prenatal environment, are also discussed.

The roles of visual expertise and visual input in the face inversion effect: behavioral and neurocomputational evidence

Research has shown that inverting faces significantly disrupts the processing of configural information, leading to a face inversion effect. We recently used a contextual priming technique to show that the presence or absence of the face inversion effect can be determined via the top-down activation of face versus non-face processing systems [Ge, L., Wang, Z., McCleery, J., & Lee, K. (2006). Activation of face expertise and the inversion effect. Psychological Science, 17(1), 12-16]. In the current study, we replicate these findings using the same technique but under different conditions. We then extend these findings through the application of a neural network model of face and Chinese character expertise systems. Results provide support for the hypothesis that a specialized face expertise system develops through extensive training of the visual system with upright faces, and that top-down mechanisms are capable of influencing when this face expertise system is engaged.

Abnormal magnocellular pathway visual processing in infants at risk for autism

BACKGROUND

A wealth of data has documented impairments in face processing in individuals with autism spectrum disorders (ASD). Recently, the suggestion has been made that these impairments may arise from abnormal development of a subcortical system involved in face processing that originates in the magnocellular pathway of the primate visual system.

METHODS

To test this developmental hypothesis, we obtained visual perceptual data from 6-month-old infants who were at risk for ASD because they had an older sibling diagnosed with the disorder ("high-risk infants"). To measure sensitivity of the magnocellular (M) pathway and, for comparison, of the parvocellular (P) visual pathway, we employed visual stimuli designed to selectively stimulate the two. Sensitivity data from high-risk infants (n = 13) were compared with data from matched control infants (i.e., "low-risk" infants with no family history of ASD, n = 26).

RESULTS

On the P pathway stimulus, high-risk infants exhibited sensitivities that were identical to those of control infants. By contrast, on the M pathway stimulus, high-risk infants exhibited sensitivities nearly twofold greater than those of control infants.

CONCLUSIONS

Given that ASD and its symptoms are known to run in families, these preliminary results suggest that ASD may be associated with abnormal M pathway function early in infancy, which may aid in early diagnosis of the disorder.

Activation of face expertise and the inversion effect

We used a contextual priming paradigm to examine top-down influences on the face-inversion effect. Adult participants were primed with either faces or Chinese characters and then tested on ambiguous figures that could be perceived as either faces or Chinese characters, dependent on the priming condition. The ambiguous figures differed from one another in their configural information, which is crucial for processing faces but not Chinese characters. The inversion effect was observed in the face-priming condition, but not in the character-priming condition. The present results provide the first direct evidence that top-down activation of the face-processing expertise system plays a crucial role in the face-inversion effect.

Consonant production patterns of young severely language-delayed children with autism

While much attention has been given to documenting the language skills of verbal children with autism, the basic speech sound development patterns of severely language-impaired children with autism are unknown. Previous research has shown that certain consonants are generally produced earlier in development than other consonants, both in typically developing children and in children with language-learning impairments. While several large studies indicate that children with autism who have strong verbal skills have intact phonological development, there is some evidence that children with autism who are more severely language impaired may have abnormal phonological production. This study documents the speech sound development of non-verbal and minimally verbal children with autism. Prompts were administered for each individual speech sound while spontaneous and imitated sounds were recorded and scored. Results indicate that children with autism show the same general speech sound production patterns as typically developing and language-learning impaired children.

LEARNING OUTCOMES

Individuals who read this manuscript will obtain information regarding: (1) normal phonological development, (2) a comparison of speech sound production of a group of 14 children with a diagnosis of autism spectrum disorder with the production of a group of 10 typically developing children, and (3) comparisons of imitated and spontaneous sound production of the children diagnosed with autism spectrum disorder.

EEG evidence for mirror neuron dysfunction in autism spectrum disorders

Autism spectrum disorders (ASD) are largely characterized by deficits in imitation, pragmatic language, theory of mind, and empathy. Previous research has suggested that a dysfunctional mirror neuron system may explain the pathology observed in ASD. Because EEG oscillations in the mu frequency (8-13 Hz) over sensorimotor cortex are thought to reflect mirror neuron activity, one method for testing the integrity of this system is to measure mu responsiveness to actual and observed movement. It has been established that mu power is reduced (mu suppression) in typically developing individuals both when they perform actions and when they observe others performing actions, reflecting an observation/execution system which may play a critical role in the ability to understand and imitate others' behaviors. This study investigated whether individuals with ASD show a dysfunction in this system, given their behavioral impairments in understanding and responding appropriately to others' behaviors. Mu wave suppression was measured in ten high-functioning individuals with ASD and ten age- and gender-matched control subjects while watching videos of (1) a moving hand, (2) a bouncing ball, and (3) visual noise, or (4) moving their own hand. Control subjects showed significant mu suppression to both self and observed hand movement. The ASD group showed significant mu suppression to self-performed hand movements but not to observed hand movements. These results support the hypothesis of a dysfunctional mirror neuron system in high-functioning individuals with ASD.