Autosomal dominant mannose-binding lectin deficiency is associated with worse neurodevelopmental outcomes after cardiac surgery in infants

OBJECTIVES

The MBL2 gene is the major genetic determinant of mannose-binding lectin (MBL)-an acute phase reactant. Low MBL levels have been associated with adverse outcomes in preterm infants. The MBL2_Gly54Asp missense variant causes autosomal dominant MBL deficiency. We tested the hypothesis that MBL2_Gly54Asp is associated with worse neurodevelopmental outcomes after cardiac surgery in neonates.

METHODS

This is an analysis of a previously described cohort of patients with nonsyndromic congenital heart disease who underwent cardiac surgery with cardiopulmonary bypass before age 6 months (n = 295). Four-year neurodevelopment was assessed in 3 domains: Full-Scale Intellectual Quotient, the Visual Motor Integration development test, and the Child Behavior Checklist to assess behavior problems. The Child Behavior Checklist measured total behavior problems, pervasive developmental problems, and internalizing/externalizing problems. A multivariable linear regression model, adjusting for confounders, was fit.

RESULTS

MBL2_Gly54Asp was associated with a significantly increased covariate-adjusted pervasive developmental problem score (β = 3.98; P = .0025). Sensitivity analyses of the interaction between age at first surgery and MBL genotype suggested effect modification for the patients with MBL2_Gly54Asp (P_interaction = .039), with the poorest neurodevelopment outcomes occurring in children who had surgery earlier in life.

CONCLUSIONS

We report the novel finding that carriers of MBL2_Gly54Asp causing autosomal dominant MBL deficiency have increased childhood pervasive developmental problems after cardiac surgery, independent of other covariates. Sensitivity analyses suggest that this effect may be larger in children who underwent surgery at earlier ages. These data support the role of nonsyndromic genetic variation in determining postsurgical neurodevelopment-related outcomes in children with congenital heart disease.

A group of very preterm children characterized by atypical gaze patterns

OBJECTIVE

Very preterm (VP) children are at risk for social difficulties, including autism spectrum disorder (ASD). This study used eye tracking to determine viewing behaviors that may reflect these difficulties.

DESIGN

The gaze patterns of 47 VP (mean gestational age: 28weeks, mean birth weight: 948g, and mean chronological age: 49months) were assessed while viewing dynamic social scenes and compared with those of 25 typically developing (TD) and 25 children with ASD. The temporo-spatial gaze patterns were summarized on a two-dimensional plane using multidimensional scaling (MDS) and the median of the TD children was used to characterize the gazes of the VP children. Time spent viewing the face was also compared.

RESULTS

The VP children formed two clusters: one had a mean MDS distance comparable to that of TD group (n=32; VP-small), and the other had a larger mean distance comparable to that of ASD group (n=15; VP-large). The VP-large were similar to the ASD group by spending significantly less time viewing the face. Their performance was comparable to the TD during the initial 1s, but they could not remain focused on the face thereafter.

CONCLUSIONS

The VP children were objectively classified into two groups based on gaze behaviors. One group was comparable to TD children, whereas the other had difficulty maintaining attention and exhibited atypical viewing behaviors similar to those of the ASD group. Our method may be useful in identifying VP children at higher risk for experiencing social difficulties.

Hemispheric Processing of Idioms and Irony in Adults With and Without Pervasive Developmental Disorder

Previous studies on individuals with pervasive developmental disorders (PDD) have pointed to difficulties in comprehension of figurative language. Using the divided visual field paradigm, the present study examined hemispheric processing of idioms and irony in 23 adults with PDD and in 24 typically developing (TD) adults. The results show that adults with PDD were relatively unimpaired in understanding figurative language. While the TD group demonstrated a right hemisphere advantage in processing the non-salient meanings of idioms as well as the ironic endings of paragraphs, the PDD group processed these stimuli bilaterally. Our findings suggest that brain lateralization is atypical in adults with PDD. Successful performance along with bilateral brain activation suggests that the PDD group uses a compensation mechanism.

Alpha asymmetry in infants at risk for autism spectrum disorders

An emerging focus of research on autism spectrum disorder (ASD) targets the identification of early-developing ASD endophenotypes using infant siblings of affected children. One potential neural endophenotype is resting frontal electroencephalogram (EEG) alpha asymmetry, a metric of hemispheric organization. Here, we examined the development of frontal EEG alpha asymmetry in ASD high-risk and low-risk infant populations. Our findings demonstrate that low and high-risk infants show different patterns of alpha asymmetry at 6 months of age and opposite growth trajectories in asymmetry over the following 12 months. These results support the candidacy of alpha asymmetry as an early neural ASD endophenotype.

Eyeblink conditioning: a non-invasive biomarker for neurodevelopmental disorders

Eyeblink conditioning (EBC) is a classical conditioning paradigm typically used to study the underlying neural processes of learning and memory. EBC has a well-defined neural circuitry, is non-invasive, and can be employed in human infants shortly after birth making it an ideal tool to use in both developing and special populations. In addition, abnormalities in the cerebellum, a region of the brain highly involved in EBC, have been implicated in a number of neurodevelopmental disorders including autism spectrum disorders (ASDs). In the current paper, we review studies that have employed EBC as a biomarker for several neurodevelopmental disorders including fetal alcohol syndrome, Down syndrome, fragile X syndrome, attention deficit/hyperactivity disorder, dyslexia, specific language impairment, and schizophrenia. In addition, we discuss the benefits of using such a tool in individuals with ASD.

Nutritional status of children with autism spectrum disorders (ASDs): a case-control study

Children with autism spectrum disorder (ASD) have problems of food selectivity, implying risks of nutritional deficiencies. The aim was to compare intakes of macro and micronutrients and body mass index in ASD and typically developing (TD) children. In a case-control study, 3-day food diaries and anthropometric measurements were completed for ASD (n = 40) and TD (n = 113) children (aged 6-10 years) living in the same area. Body mass indices were below the 5th percentile in 20 % of ASD versus 8.85% of TD children. We found intakes were lower for fluoride (p = 0.017) and higher for vitamin E (p = 0.001). There was limited food variety and inadequacy of some intakes suggests that routine monitoring of ASD children should include assessment of their dietary habits, as well as anthropometric measurements.

Impairments to visual disengagement in autism spectrum disorder: a review of experimental studies from infancy to adulthood

Impairments in visual disengagement are a current focus of research in autism spectrum disorders (ASD) and may play a key role in the early expression of social-emotional deficits associated with the disorder. This review summarizes current knowledge of visual disengagement and orienting in ASD. Convergent reports from infancy to adulthood indicate that (1) impairments to visual disengagement are apparent on Gap-Overlap tasks, spatial orienting tasks, and tasks involving social stimuli; and (2) these impairments emerge in the first year of life and continue into adulthood. The relationships between visual disengagement, orienting, joint attention, emotional regulation, and IQ are discussed in relation to ASD.

Neuroimaging endophenotypes in autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that has a strong genetic basis, and is heterogeneous in its etiopathogenesis and clinical presentation. Neuroimaging studies, in concert with neuropathological and clinical research, have been instrumental in delineating trajectories of development in children with ASD. Structural neuroimaging has revealed ASD to be a disorder with general and regional brain enlargement, especially in the frontotemporal cortices, while functional neuroimaging studies have highlighted diminished connectivity, especially between frontal-posterior regions. The diverse and specific neuroimaging findings may represent potential neuroendophenotypes, and may offer opportunities to further understand the etiopathogenesis of ASD, predict treatment response, and lead to the development of new therapies.

Using hyperbaric oxygen for autism treatment: A review and discussion of literature

PURPOSE

To determine whether hyperbaric oxygen (HBO2) therapy should be used for the treatment of autism spectrum disorders (ASD).

METHODS

A literature search was performed on PubMed, Cochrane Library and DynaMed for studies evaluating the use of HBO2 for ASD treatment. The studies were then reviewed for the highest quality evidence.

RESULTS

The evidence is weak for the use of HBO2 in ASD, with only one, likely flawed, randomized control study showing treatment benefit.

CONCLUSIONS

HBO2 should not be recommended for ASD treatment until more conclusive favorable results and long-term outcomes are demonstrated from well-designed controlled trials.

Sex differences in autism spectrum disorder based on DSM-5 criteria: evidence from clinician and teacher reporting

In the absence of intellectual impairment autism spectrum disorder (ASD) is diagnosed both less and later in females. This study used clinician and teacher report to explore sex differences in the behavioural presentation of 69 girls and 69 boys all diagnosed with high-functioning ASD. Evidence from DSM-IV-TR and DSM-5 are presented. Sex differences in teacher concerns were also explored. While no sex differences were found in the broad social criteria presented in the DSM-IV-TR or DSM-5, numerous differences were evident in how boys and girls came to meet each criterion. For example, girls were more likely to show an ability to integrate non-verbal and verbal behaviours, maintain a reciprocal conversation, and be able to initiate, but not maintain friendships. Moreover, girls presented with both less and different restricted interests. Teachers also reported substantially fewer concerns for girls than boys, including for externalising behaviours and social skills. Results suggest girls with ASD may present with a surface-level 'look' different from the 'classic' presentation of ASD, and present as less impaired when in a school setting. Consequently, results provide insight in to why the disorder may be more difficult to detect in cognitively-able girls.

Abnormal brain activity in social reward learning in children with autism spectrum disorder: an fMRI study

PURPOSE

We aimed to determine whether Autism Spectrum Disorder (ASD) would show neural abnormality of the social reward system using functional MRI (fMRI).

MATERIALS AND METHODS

27 ASDs and 12 typically developing controls (TDCs) participated in this study. The social reward task was developed, and all participants performed the task during fMRI scanning.

RESULTS

ASDs and TDCs with a social reward learning effect were selected on the basis of behavior data. We found significant differences in brain activation between the ASDs and TDCs showing a social reward learning effect. Compared with the TDCs, the ASDs showed reduced activity in the right dorsolateral prefrontal cortex, right orbitofrontal cortex, right parietal lobe, and occipital lobe; however, they showed increased activity in the right parahippocampal gyrus and superior temporal gyrus.

CONCLUSION

These findings suggest that there might be neural abnormality of the social reward learning system of ASDs. Although this study has several potential limitations, it presents novel findings in the different neural mechanisms of social reward learning in children with ASD and a possible useful biomarker of high-functioning ASDs.

[General and Specific Mechanisms of Visual Cognitive Function Impairment in People with FMRP Deficit]

The purpose of this article is to provide the overview of visual cognitive development in subjects with FMRP deficit. Description of fragile X mental retardation syndrome is presented in the article, that is the most common cause of inherited intellectual disability and one of the most prevalent genetic causes of autism spectrum disorder. The syndrome is associated with deficit of fragile X mental retardation protein following FMR1-gene mutation. Researches of static and dynamic object perception, face perception and oculomotor control are discussed in the article. The results obtained by subjects with FX syndrome are compared with ASD data, syndrome with closed behavioral phenotype. Several factors that underlie visual cognitive deficit are discussed in the article.

Concerns expressed by parents of children with pervasive developmental disorders for different time periods of the day: a case-control study

Background/Aim

The Questionnaire: Children with Difficulties (QCD) is a parent-assessed questionnaire designed to evaluate child’s difficulties in functioning during specific periods of the day. This study aimed to evaluate difficulties in daily functioning of children and adolescents with pervasive developmental disorder (PDD) using the QCD. Results were compared with those for a community sample.

Methods

A case–control design was used. The cases comprised elementary school students (182 males, 51 females) and junior high school students (100 males, 39 females) with PDD, whereas a community sample of elementary school students (568 males, 579 females) and junior high school students (180 males, 183 females) was enrolled as controls. Their behavior was assessed using the QCD, the Tokyo Autistic Behavior Scale (TABS), the ADHD-rating scale (ADHD-RS), and the Oppositional Defiant Behavior Inventory (ODBI) for elementary and junior high school students, respectively. Effects of gender and diagnosis on the QCD scores were analyzed. Correlation coefficients between QCD and TABS, ADHD-RS, and ODBI scores were analyzed.

Results

The QCD scores for the children with PDD were significantly lower compared with those from the community sample (P < 0.001). Significantly strong correlations were observed in more areas of the ADHD-RS and ODBI scores compared with the TABS scores.

Conclusions

Children with PDD experienced greater difficulties in completing basic daily activities; moreover, their QCD scores revealed stronger associations with their ADHD-RS and ODBI scores in comparison with their TABS scores. The difficulties of PDD, ADHD and OBDI symptoms combined in children makes it necessary to assess all diagnoses before any therapy for PDD is initiated in order to be able to evaluate its results properly.

Zinc in gut-brain interaction in autism and neurological disorders

A growing amount of research indicates that abnormalities in the gastrointestinal (GI) system during development might be a common factor in multiple neurological disorders and might be responsible for some of the shared comorbidities seen among these diseases. For example, many patients with Autism Spectrum Disorder (ASD) have symptoms associated with GI disorders. Maternal zinc status may be an important factor given the multifaceted effect of zinc on gut development and morphology in the offspring. Zinc status influences and is influenced by multiple factors and an interdependence of prenatal and early life stress, immune system abnormalities, impaired GI functions, and zinc deficiency can be hypothesized. In line with this, systemic inflammatory events and prenatal stress have been reported to increase the risk for ASD. Thus, here, we will review the current literature on the role of zinc in gut formation, a possible link between gut and brain development in ASD and other neurological disorders with shared comorbidities, and tie in possible effects on the immune system. Based on these data, we present a novel model outlining how alterations in the maternal zinc status might pathologically impact the offspring leading to impairments in brain functions later in life.

A comparative study of sensory processing in children with and without Autism Spectrum Disorder in the home and classroom environments

Sensory processing and higher integrative functions impairments are highly prevalent in children with ASD. Context should be considered in analyzing the sensory profile and higher integrative functions. The main objective of this study is to compare sensory processing, social participation and praxis in a group of 79 children (65 males and 14 females) from 5 to 8 years of age (M=6.09) divided into two groups: ASD Group (n=41) and Comparison Group (n=38). The Sensory Processing Measure (SPM) was used to evaluate the sensory profile of the children: parents reported information about their children's characteristics in the home environment, and teachers reported information about the same characteristics in the classroom environment. The ASD Group obtained scores that indicate higher levels of dysfunction on all the assessed measures in both environments, with the greatest differences obtained on the social participation and praxis variables. The most affected sensory modalities in the ASD Group were hearing and touch. Only in the ASD Group were significant differences found between the information reported by parents and what was reported by teachers: specifically, the teachers reported greater dysfunction than the parents in social participation (p=.000), touch (p=.003) and praxis (p=.010). These results suggest that the context-specific qualities found in children with ASD point out the need to receive information from both parents and teachers during the sensory profile assessment process, and use context-specific assessments.

Oculomotor performance in children with high-functioning Autism Spectrum Disorders

Sensorimotor issues are of increasing focus in the assessment and treatment of Autism Spectrum Disorders (ASD). The oculomotor system is a sensorimotor network that can provide insights into functional neurobiology and has well-established methodologies for investigation. In this study, we assessed oculomotor performance among children with high functioning ASD and typically developing children, ages 6-12 years. Children with ASD exhibited greater horizontal saccade latency and greater phase lag during vertical smooth pursuit. Saccades and smooth pursuit are mediated by spatially distant brain regions and the long-fiber tracts connecting them, many of which are implicated in ASD. Training paradigms for oculomotor deficits have shown positive outcomes in other clinical populations, and deficits described here may provide useful targets for interventions.

Additive effects of social and non-social attention during infancy relate to later autism spectrum disorder

Emerging findings from studies with infants at familial high risk for autism spectrum disorder (ASD), owing to an older sibling with a diagnosis, suggest that those who go on to develop ASD show early impairments in the processing of stimuli with both social and non-social content. Although ASD is defined by social-communication impairments and restricted and repetitive behaviours, the majority of cognitive theories of ASD posit a single underlying factor, which over development has secondary effects across domains. This is the first high-risk study to statistically differentiate theoretical models of the development of ASD in high-risk siblings using multiple risk factors. We examined the prediction of ASD outcome by attention to social and non-social stimuli: gaze following and attentional disengagement assessed at 13 months in low-risk controls and high-risk ASD infants (who were subsequently diagnosed with ASD at 3 years). When included in the same regression model, these 13-month measures independently predicted ASD outcome at 3 years of age. The data were best described by an additive model, suggesting that non-social attention, disengagement, and social attention as evidenced by gaze following, have a cumulative impact on ASD risk. These data argue against cognitive theories of ASD which propose that a single underlying factor has cascading effects across early development leading to an ASD outcome, and support multiple impairment models of ASD that are more consistent with recent genetic and neurobiological evidence.

Association between pupillary light reflex and sensory behaviors in children with autism spectrum disorders

Atypical pupillary light reflexes (PLR) has been observed in children with autism spectrum disorders (ASD), which suggests potential autonomic nervous system (ANS) dysfunction in ASD. ANS is also involved in modulating sensory processing and sensory dysfunction has been widely reported in children with ASD. However, the potential association between physiological measurements of PLR and behavioral observations (e.g. sensory behaviors) has not been examined extensively in literature. In this study, we investigated the potential correlation between PLR and frequently observed sensory behaviors in children with ASD. We found a significant association between PLR constriction amplitude and a set of sensory behaviors in the ASD group but not in typically developing children. Children with ASD who showed more atypical sensory behaviors also had smaller PLR constriction amplitudes. A smaller PLR constriction amplitude suggests lower parasympathetic modulation. This observation implies that some atypical sensory behaviors in children with ASD could be associated with decreased parasympathetic modulation.

NMDA receptor dysfunction in autism spectrum disorders

Abnormalities and imbalances in neuronal excitatory and inhibitory synapses have been implicated in diverse neuropsychiatric disorders including autism spectrum disorders (ASDs). Increasing evidence indicates that dysfunction of NMDA receptors (NMDARs) at excitatory synapses is associated with ASDs. In support of this, human ASD-associated genetic variations are found in genes encoding NMDAR subunits. Pharmacological enhancement or suppression of NMDAR function ameliorates ASD symptoms in humans. Animal models of ASD display bidirectional NMDAR dysfunction, and correcting this deficit rescues ASD-like behaviors. These findings suggest that deviation of NMDAR function in either direction contributes to the development of ASDs, and that correcting NMDAR dysfunction has therapeutic potential for ASDs.

A technological approach to studying motor planning ability in children at high risk for ASD

In this work we propose a new method to study the development of motor planning abilities in children and, in particular, in children at high risk for ASD. Although several modified motor signs have been found in children with ASD, no specific markers enabling the early assessment of risk have been found yet. In this work, we discuss the problem posed by objective and quantitative behavioral analysis in non-structured environment. After an initial description of the main constraints imposed by the ecological approach, a technological and methodological solution to these issues is presented. Preliminary results on 12 children are reported and briefly discussed.

Neurophysiological indices of atypical auditory processing and multisensory integration are associated with symptom severity in autism

Atypical processing and integration of sensory inputs are hypothesized to play a role in unusual sensory reactions and social-cognitive deficits in autism spectrum disorder (ASD). Reports on the relationship between objective metrics of sensory processing and clinical symptoms, however, are surprisingly sparse. Here we examined the relationship between neurophysiological assays of sensory processing and (1) autism severity and (2) sensory sensitivities, in individuals with ASD aged 6-17. Multiple linear regression indicated significant associations between neural markers of auditory processing and multisensory integration, and autism severity. No such relationships were apparent for clinical measures of visual/auditory sensitivities. These data support that aberrant early sensory processing contributes to autism symptoms, and reveal the potential of electrophysiology to objectively subtype autism.

Caregiver strain and sensory features in children with autism spectrum disorder and other developmental disabilities

Caring for children with disabilities contributes to increased levels of parent stress or caregiver strain. However, the potential relationship of sensory features to strain among caregivers of children with autism spectrum disorder (ASD) and other developmental disabilities (DD) is unknown. Sensory features include overreactions, underreactions, and unusual interests in sensations, which may negatively impact family functioning. This descriptive study confirmed three caregiver strain types (i.e., objective, subjective internalized, subjective externalized) and explored differences among ASD (n  =  71) and DD (n  =  36) groups, with the ASD group reporting higher levels. Furthermore, this study explored the contribution of sensory features to caregiver strain, finding differential contributions to strain in the ASD group and covariate contributions (i.e., child cognition, mother's education) in the DD group.

Parents' first concerns about toddlers with autism spectrum disorder: effect of sibling status

Symptoms of autism spectrum disorders may appear as early as 6 months, but parent concern, which can precipitate evaluation, often lags significantly. The presence of typical or atypical older siblings can change parents' sensitivity to departures from typical development. This study investigated type and age of parent's first concerns in toddlers with autism spectrum disorder, prior to diagnosis. Participants had (1) at least one older sibling with autism spectrum disorder (Sibs-ASD); (2) only typically developing older siblings (Sibs-TD), or (3) were only/oldest (No-Sibs). Specific autism spectrum disorder diagnoses and symptom severity were similar among groups. Developmentally, No-Sibs showed the largest delays, followed by Sibs-TD, followed by Sibs-ASD. Mean age of first concern was 16 months for No-Sibs, 14 months for Sibs-TD, and 10 months for Sibs-ASD. Age of first concern differed significantly by group, even after controlling for mother's age and education. Concern about language was prevalent in all groups. Thus, the presence of an older child with typical or, especially, atypical development was associated with earlier concerns for the affected child, despite milder developmental delays. These findings underscore the importance of encouraging parents to report concerns to pediatricians, routine standardized screening for autism spectrum disorder, and the need for pediatrician vigilance, especially for only or oldest children.

Neural targets in the study and treatment of social cognition in autism spectrum disorder

The purpose of this chapter is to present results from recent research on social cognition in autism spectrum disorder (ASD). The clinical phenomenology and neuroanatomical circuitry of ASD are first briefly described. The neuropharmacology of social cognition in animal models of ASD and humans is then addressed. Next, preclinical and clinical research on the neurohormone oxytocin is reviewed. This is followed by a presentation of results from preclinical and clinical studies on the excitatory amino acid glutamate. Finally, the role of neuroinflammation in ASD is addressed from the perspectives of preclinical neuroscience and research involving humans with ASD.

Incidence and behavioral correlates of epileptiform abnormalities in autism spectrum disorders

Autism spectrum disorders (ASD) are associated with an increased incidence of epilepsy and of epileptiform discharges on electroencephalograms. It is unknown whether epileptiform discharges correlate with symptoms of ASD. We completed a retrospective chart review of 101 patients with ASD who had overnight electroencephalograms. We looked for a relationship between epileptiform abnormalities and diagnosis, history of regression, communication skills, and other features associated with ASD. There was a higher incidence of epileptiform activity in children with stereotypies and aggressive behavior. The incidence of epileptiform abnormalities was significantly lower in Asperger's compared with more severe forms of autism. Results suggest that increasing severity of autistic symptoms may be associated with higher likelihood of epileptiform abnormalities. Whether treatment alters outcome is unknown.

Anxiety, hyperactivity and stereotypy in a zebrafish model of fragile X syndrome and autism spectrum disorder

Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and is caused by a loss of function of the fragile X mental retardation (fmr1) gene. Animal fmr1-knockout (KO) models are not only of interest for the study of FXS, but have also important implications for our understanding of autism spectrum disorder (ASD). Here we report the behavioral changes in fmr1-knockout zebrafish in an open field with two white and two transparent walls. The neophobic responses that in wild-type (WT) zebrafish normally occur during the first 5-10 min in an unfamiliar environment (such as freezing, hypo-activity and preferences for the bottom and opaque walls of the tank), were weakened in fmr1 mutants, suggesting a reduction of novelty-induced anxiety. The fmr1-KO zebrafish showed somewhat increased vertical activity beyond the 'neophobic phase', but no overall hyperactivity. The mutants demonstrated a clear habituation-independent preference for the transparent walls. Whether this was attributable to altered spatial information processing or to reduced avoidance of open spaces is discussed. Finally, since restrictive repetitive (or stereotypical) behaviors are frequently present in FXS and ASD patients, we analyzed relative turning angles, directional and preferential turning ratios and performed frequency-domain analysis. However, no indications of abnormal movement patterning were detected. The possible reasons for the absence of stereotypical behaviors are discussed in terms of behavioral endpoint selection and of eliciting conditions. Overall, our findings are consistent with those reported in fmr1-KO mice and suggest that further analysis of the fmr1-KO zebrafish model has potential to deepen our understanding of FXS and ASD.

Abstract analogical reasoning in high-functioning children with autism spectrum disorders

Children with autism spectrum disorders (ASD) exhibit a deficit in spontaneously recognizing abstract similarities that are crucial for generalizing learning to new situations. This may contribute to deficits in the development of appropriate schemas for navigating novel situations, including social interactions. Analogical reasoning is the central cognitive mechanism that enables typically developing children to understand abstract similarities between different situations. Intriguingly, studies of high-functioning children with ASD point to a relative cognitive strength in basic, nonabstract forms of analogical reasoning. If this analogical reasoning ability extends to abstract analogical reasoning (i.e., between superficially dissimilar situations), it may provide a bridge between a cognitive capability and core ASD deficits in areas such as generalization and categorization. This study tested whether preserved analogical reasoning abilities in ASD can be extended to abstract analogical reasoning, using photographs of real-world items and situations. Abstractness of the analogies was determined via a quantitative measure of semantic distance derived from latent semantic analysis. Children with ASD performed as well as typically developing children at identifying abstract analogical similarities when explicitly instructed to apply analogical reasoning. Individual differences in abstract analogical reasoning ability predicted individual differences in a measure of social function in the ASD group. Preliminary analyses indicated that children with ASD, but not typically developing children, showed an effect of age on abstract analogical reasoning. These results provide new evidence that children with ASD are capable of identifying abstract similarities through analogical reasoning, pointing to abstract analogical reasoning as a potential lever for improving generalization skills and social function in ASD.

Neuromodulation integrating rTMS and neurofeedback for the treatment of autism spectrum disorder: an exploratory study

Autism spectrum disorder (ASD) is a pervasive developmental disorder characterized by deficits in social interaction, language, stereotyped behaviors, and restricted range of interests. In previous studies low frequency repetitive transcranial magnetic stimulation (rTMS) has been used, with positive behavioral and electrophysiological results, for the experimental treatment in ASD. In this study we combined prefrontal rTMS sessions with electroencephalographic (EEG) neurofeedback (NFB) to prolong and reinforce TMS-induced EEG changes. The pilot trial recruited 42 children with ASD (~14.5 years). Outcome measures included behavioral evaluations and reaction time test with event-related potential (ERP) recording. For the main goal of this exploratory study we used rTMS-neurofeedback combination (TMS-NFB, N = 20) and waitlist (WTL, N = 22) groups to examine effects of 18 sessions of integrated rTMS-NFB treatment or wait period) on behavioral responses, stimulus and response-locked ERPs, and other functional and clinical outcomes. The underlying hypothesis was that combined TMS-NFB will improve executive functions in autistic patients as compared to the WTL group. Behavioral and ERP outcomes were collected in pre- and post-treatment tests in both groups. Results of the study supported our hypothesis by demonstration of positive effects of combined TMS-NFB neurotherapy in active treatment group as compared to control WTL group, as the TMS-NFB group showed significant improvements in behavioral and functional outcomes as compared to the WTL group.

Socialization and nonverbal communication in atypically developing infants and toddlers

Emphasis on early identification of atypical development has increased as evidence supporting the efficacy of intervention has grown. These increases have also directly affected the availability of funding and providers of early intervention services. A majority of research has focused on interventions specific to an individual's primary diagnoses. For example, interventions for those with cerebral palsy (CP) have traditionally focused on physiological symptoms, while intervention for individuals with Autism Spectrum Disorder (ASD) focus on socialization, communication, and restricted interests and repetitive behaviors. However deficits in areas other than those related to their primary diagnoses (e.g., communication, adaptive behaviors, and social skills) are prevalent in atypically developing populations and are significant predictors of quality of life. Therefore, the purpose of the current study was to examine impairments in socialization and nonverbal communication in individuals with Down's syndrome (DS), CP, and those with CP and comorbid ASD. Individuals with comorbid CP and ASD exhibited significantly greater impairments than any diagnostic group alone. However, individuals with CP also exhibited significantly greater impairments than those with DS. The implications of these results are discussed.

Using the Autism Detection in Early Childhood (ADEC) and Childhood Autism Rating Scales (CARS) to predict long term outcomes in children with autism spectrum disorders

This study evaluated the predictive validity of the Autism Detection in Early Childhood (ADEC; Young, Autism detection in early childhood: ADEC. Australian Council of Educational Research, Camberwell, VIC 2007) and a well-established screening tool, the Childhood Autism Rating Scale (CARS; Schopler et al. The childhood autism rating scale (CARS). Western Psychological Services, Los Angeles 1988), for long term outcomes of children with ASD engaged in an early intervention program. Participants were 55 children (44 male, 11 female) aged 19–42 months (M = 33.5, SD = 5.6) at initial assessment who were followed up 2 and 6 years after their initial assessment. The ADEC and the CARS performed similarly when predicting long term outcomes such as clinical diagnostic outcome and overall adaptive functioning level. However, only the ADEC score was significantly correlated with ASD symptom severity at the 6-year follow up. Although these findings need to be replicated with additional and larger samples, this study extends our understanding of the psychometric properties of both the ADEC and the CARS.

A systematic review of interventions used to treat catatonic symptoms in people with autistic spectrum disorders

A systematic review was conducted to examine the efficacy of a range of treatments for autistic catatonia. The review identified 22 relevant papers, reporting a total of 28 cases including both adult and paediatric patients. Treatment methods included electroconvulsive therapy (ECT), medication, behavioural and sensory interventions. Quality assessment found the standard of the existing literature to be generally poor, with particular limitations in treatment description and outcome measurement. There is some limited evidence to support the use of ECT, high dose lorazepam and behavioural interventions for people with autistic catatonia. However, there is a need for controlled, high-quality trials. Reporting of side effects and adverse events should also be improved, in order to better evaluate the safety of these treatments.

Early language profiles in infants at high-risk for autism spectrum disorders

Many preschoolers with autism spectrum disorders (ASD) present relative lack of receptive advantage over concurrent expressive language. Such profile emergence was investigated longitudinally in 54 infants at high-risk (HR) for ASD and 50 low-risk controls, with three language measures taken across four visits (around 7, 14, 24, 38 months). HR infants presented three outcome subgroups: ASD, other atypicality, and typical development. Reduced receptive vocabulary advantage was observed in HR infants by 14 months, but was maintained to 24 months only in ASD/other atypicality outcome subgroups while typically-developing HR infants regained a more normative profile. Few group differences appeared on a direct assessment of language and parent-reported functional communication. Processes of early development toward ASD outcome and in intermediate phenotypes are discussed.

'Reading the Mind in the Eyes': an fMRI study of adolescents with autism and their siblings

BACKGROUND

Mentalizing deficits are a hallmark of the autism spectrum condition (ASC) and a potential endophenotype for atypical social cognition in ASC. Differences in performance and neural activation on the 'Reading the Mind in the Eyes' task (the Eyes task) have been identified in individuals with ASC in previous studies.

METHOD

Performance on the Eyes task along with the associated neural activation was examined in adolescents with ASC (n = 50), their unaffected siblings (n = 40) and typically developing controls (n = 40). Based on prior literature that males and females with ASC display different cognitive and associated neural characteristics, analyses were stratified by sex. Three strategies were applied to test for endophenotypes at the level of neural activation: (1) identifying and locating conjunctions of ASC-control and sibling-control differences; (2) examining whether the sibling group is comparable to the ASC or intermediate between the ASC and control groups; and (3) examining spatial overlaps between ASC-control and sibling-control differences across multiple thresholds.

RESULTS

Impaired behavioural performance on the Eyes task was observed in males with ASC compared to controls, but only at trend level in females; and no difference in performance was identified between sibling and same-sex control groups in both sexes. Neural activation showed a substantial endophenotype effect in the female groups but this was only modest in the male groups.

CONCLUSIONS

Behavioural impairment on complex emotion recognition associated with mental state attribution is a phenotypic, rather than an endophenotypic, marker of ASC. However, the neural response during the Eyes task is a potential endophenotypic marker for ASC, particularly in females.

Interaction of participant characteristics and type of AAC with individuals with ASD: a meta-analysis

Individuals with autism spectrum disorders (ASD) and complex communication needs often rely on augmentative and alternative communication (AAC) as a means of functional communication. This meta-analysis investigated how individual characteristics moderate effectiveness of three types of aided AAC: the Picture Exchange Communication System (PECS), speech-generating devices (SGDs), and other picture-based AAC. Effectiveness was measured via the Improvement Rate Difference. Results indicated that AAC has small to moderate effects on speech outcomes, and that SGDs appear to be most effective when considering any outcome measure with individuals with ASD without comorbid intellectual/developmental disorders (IDD). PECS appears to be most effective when considering any outcome measure with individuals with ASD and IDD. SGDs and PECS were the most effective type of AAC for preschoolers, when aggregating across outcome measures. No difference was found between systems for elementary-aged and older individuals.

[Autism spectrum disorder. Contemporary experimental researches review]

Autism, like schizophrenia, are heterogeneous diseases, which are directed by both genetic factors and external influences in the early stages of development. Knowledge about the similarities and differences of these disorders can help early diagnosis and treatment. Patients with autism have specific cognitive difficulties in social relations. They are characterized by impairment of social interaction, communication and behavioral flexibility. The severity of the delay the development of autistic children, clinical and psychological indicators is correlated with an increase in the high frequency of spontaneous EEG activity. Cognitive task in autistic children, unlike normal persons, does not lead to a significant restructuring of high-frequency EEG activity, which may be a violation of the reaction mechanism to external stimuli and behavioral disorders. Abnormality in high-frequency components of EEG reactivity on cognitive task, the perception of human faces and visual illusions as well as the inadequate system of mirror neurons, can be considered common mechanisms underlying disorders of autism and schizophrenia. These general mechanisms may be considered as related to violation of the inhibition-exitation balance, controlled via GABA-transmission and NMDA-receptors. A multidimensional study of patterns of disontogenesis in autism, in addition to detailing the clinical picture of disease and rehabilitation activities, allows us to clear the fundamental understanding of the brain.

Limited fine motor and grasping skills in 6-month-old infants at high risk for autism

Atypical motor behaviors are common among children with autism spectrum disorders (ASD). However, little is known about onset and functional implications of differences in early motor development among infants later diagnosed with ASD. Two prospective experiments were conducted to investigate motor skills among 6-month-olds at increased risk (high risk) for ASD (N1  = 129; N2  = 46). Infants were assessed using the Mullen Scales of Early Learning (MSEL) and during toy play. Across both experiments, high-risk infants exhibited less mature object manipulation in a highly structured (MSEL) context and reduced grasping activity in an unstructured (free-play) context than infants with no family history of ASD. Longitudinal assessments suggest that between 6 and 10 months, grasping activity increases in high-risk infants.

Multimodal imaging in autism: an early review of comprehensive neural circuit characterization

There is accumulating evidence that the neurobiology of autism spectrum disorders (ASD) is linked to atypical neural communication and connectivity. This body of work emphasizes the need to characterize the function of multiple regions that comprise neural circuits rather than focusing on singular regions as contributing to deficits in ASD. Multimodal neuroimaging - the formal combination of multiple functional and structural measures of the brain - is extremely promising as an approach to understanding neural deficits in ASD. This review provides an overview of the multimodal imaging approach, and then provides a snapshot of how multimodal imaging has been applied in the study of ASD to date. This body of work is separated into two categories: one concerning whole brain connectomics and the other focused on characterizing neural circuits implicated as altered in ASD. We end this review by highlighting emerging themes from the existing body of literature, and new resources that will likely influence future multimodal imaging studies.

Right temporoparietal gray matter predicts accuracy of social perception in the autism spectrum

Individuals with an autism spectrum disorder (ASD) show hallmark deficits in social perception. These difficulties might also reflect fundamental deficits in integrating visual signals. We contrasted predictions of a social perception and a spatial-temporal integration deficit account. Participants with ASD and matched controls performed two tasks: the first required spatiotemporal integration of global motion signals without social meaning, the second required processing of socially relevant local motion. The ASD group only showed differences to controls in social motion evaluation. In addition, gray matter volume in the temporal-parietal junction correlated positively with accuracy in social motion perception in the ASD group. Our findings suggest that social-perceptual difficulties in ASD cannot be reduced to deficits in spatial-temporal integration.

Developmental pathways of language and social communication problems in 9-11 year olds: unpicking the heterogeneity

This paper addressed relations between language, social communication and behaviour, and their trajectories, in a sample of 9-11-year-olds (n=91) who had been referred to clinical services with concerns about language as pre-schoolers. Children were first assessed at 2½-4 years, and again 18 months later. Results revealed increasing differentiation of profiles across time. By 9-11 years, 11% of the sample had social communication deficits, 27% language impairment, 20% both, and 42% neither. The size of group differences on key language and social communication measures was striking (2-3 standard deviations). Social communication deficits included autistic mannerisms and were associated with social, emotional and behavioural difficulties (SEBDs); in contrast, language impairment was associated with hyperactivity only. Children with both language and social communication problems had the most severe difficulties on all measures. These distinct school-age profiles emerged gradually. Investigation of developmental trajectories revealed that the three impaired groups did not differ significantly on language or SEBD measures when the children were first seen. Only low performance on the Early Sociocognitive Battery, a new measure of social responsiveness, joint attention and symbolic understanding, differentiated the children with and without social communication problems at 9-11 years. These findings suggest that some children who first present with language delay or difficulties have undetected Autism Spectrum Disorders which may or may not be accompanied by language impairment in the longer term. This new evidence of developmental trajectories starting in the preschool years throws further light on the nature of social communication and language problems in school-age children, relations between language impairment and SEBDs, and on the nature of early language development.

Constructing fictional stories: a study of story narratives by children with autistic spectrum disorder

Children with autistic spectrum disorder (ASD) are reported to have difficulties with narrative language but little is known about how this affects their production of fictional stories. In this study, we aimed to establish whether fictional narratives of children with ASD differed from those of typically developing children and if performance was commensurate with levels of oral language. Fictional stories produced by 27 high functioning children with ASD, aged 11-14 yrs, were compared with those of language and age matched groups of typically developing children. Differences were found between the children with ASD and comparison groups in structural, evaluative and global features of their stories indicating specific difficulties with this form of narrative. Stories of the ASD group were shorter and contained fewer causal statements than those of both comparison groups and sentences were less grammatically complex than those of the age match but not the language match group. In global measures, the stories of the ASD group were impoverished relative to both comparison groups. The results are discussed in relation to cognitive theories of autism and language development.

Oxytocin and vasopressin systems in genetic syndromes and neurodevelopmental disorders

Oxytocin (OT) and arginine vasopressin (AVP) are two small, related neuropeptide hormones found in many mammalian species, including humans. Dysregulation of these neuropeptides have been associated with changes in behavior, especially social interactions. We review how the OT and AVP systems have been investigated in Autism Spectrum Disorder (ASD), Prader-Willi Syndrome (PWS), Williams Syndrome (WS) and Fragile X syndrome (FXS). All of these neurodevelopmental disorders (NDD) are marked by social deficits. While PWS, WS and FXS have identified genetic mutations, ASD stems from multiple genes with complex interactions. Animal models of NDD are invaluable for studying the role and relatedness of OT and AVP in the developing brain. We present data from a FXS mouse model affecting the fragile X mental retardation 1 (Fmr1) gene, resulting in decreased OT and AVP staining cells in some brain regions. Reviewing the research about OT and AVP in these NDD suggests that altered OT pathways may be downstream from different etiological factors and perturbations in development. This has implications for ongoing studies of the therapeutic application of OT in NDD. This article is part of a Special Issue entitled Oxytocin and Social Behav.

Effect of familiarity on reward anticipation in children with and without autism spectrum disorders

BACKGROUND

Previous research on the reward system in autism spectrum disorders (ASD) suggests that children with ASD anticipate and process social rewards differently than typically developing (TD) children--but has focused on the reward value of unfamiliar face stimuli. Children with ASD process faces differently than their TD peers. Previous research has focused on face processing of unfamiliar faces, but less is known about how children with ASD process familiar faces. The current study investigated how children with ASD anticipate rewards accompanied by familiar versus unfamiliar faces.

METHODS

The stimulus preceding negativity (SPN) of the event-related potential (ERP) was utilized to measure reward anticipation. Participants were 6- to 10-year-olds with (N = 14) and without (N = 14) ASD. Children were presented with rewards accompanied by incidental face or non-face stimuli that were either familiar (caregivers) or unfamiliar. All non-face stimuli were composed of scrambled face elements in the shape of arrows, controlling for visual properties.

RESULTS

No significant differences between familiar versus unfamiliar faces were found for either group. When collapsing across familiarity, TD children showed larger reward anticipation to face versus non-face stimuli, whereas children with ASD did not show differential responses to these stimulus types. Magnitude of reward anticipation to faces was significantly correlated with behavioral measures of social impairment in the ASD group.

CONCLUSIONS

The findings do not provide evidence for differential reward anticipation for familiar versus unfamiliar face stimuli in children with or without ASD. These findings replicate previous work suggesting that TD children anticipate rewards accompanied by social stimuli more than rewards accompanied by non-social stimuli. The results do not support the idea that familiarity normalizes reward anticipation in children with ASD. Our findings also suggest that magnitude of reward anticipation to faces is correlated with levels of social impairment for children with ASD.

Abnormalities in the zinc-metalloprotease-BDNF axis may contribute to megalencephaly and cortical hyperconnectivity in young autism spectrum disorder patients

Whereas aberrant brain connectivity is likely the core pathology of autism-spectrum disorder (ASD), studies do not agree as to whether hypo- or hyper-connectivity is the main underlying problem. Recent functional imaging studies have shown that, in most young ASD patients, cerebral cortical regions appear hyperconnected, and cortical thickness/brain size is increased. Collectively, these findings indicate that developing ASD brains may exist in an altered neurotrophic milieu. Consistently, some ASD patients, as well as some animal models of ASD, show increased levels of brain-derived neurotrophic factor (BDNF). However, how BDNF is upregulated in ASD is unknown. To address this question, we propose the novel hypothesis that a putative zinc-metalloprotease-BDNF (ZMB) axis in the forebrain plays a pivotal role in the development of hyperconnectivity and megalencephaly in ASD. We have previously demonstrated that extracellular zinc at micromolar concentrations can rapidly increase BDNF levels and phosphorylate the receptor tyrosine kinase TrkB via the activation of metalloproteases. The role of metalloproteases in ASD is still uncertain, but in fragile X syndrome, a monogenic disease with an autistic phenotype, the levels of MMP are increased. Early exposure to lipopolysaccharides (LPS) and other MMP activators such as organic mercurials also have been implicated in ASD pathogenesis. The resultant increases in BDNF levels at synapses, especially those involved in the zinc-containing, associative glutamatergic system may produce abnormal brain circuit development. Various genetic mutations that lead to ASD are also known to affect BDNF signaling: some down-regulate, and others up-regulate it. We hypothesize that, although both up- and down-regulation of BDNF may induce autism symptoms, only BDNF up-regulation is associated with the hyperconnectivity and large brain size observed in most young idiopathic ASD patients. To test this hypothesis, we propose to examine the ZMB axis in animal models of ASD. Synaptic zinc can be examined by fluorescence zinc staining. MMP activation can be measured by in situ zymography and Western blot analysis. Finally, regional levels of BDNF can be measured. Validating this hypothesis may shed light on the central pathogenic mechanism of ASD and aid in the identification of useful biomarkers and the development of preventive/therapeutic strategies.

In utero exposure to valproic acid changes sleep in juvenile rats: a model for sleep disturbances in autism

STUDY OBJECTIVES

To determine whether sleep disturbances are found in the valproic acid model of autism spectrum disorders (ASD).

DESIGN

Comparative study for sleep behavior, sleep architecture, electroencephalogram (EEG) spectral analysis, and glutamic acid decarboxylase (GAD) 65/67 protein expression in juvenile rats exposed to valproic acid (VPA), sodium salt, or saline in utero.

SETTING

N/A.

PARTICIPANTS

Juvenile (postnatal day 32) male and female Sprague-Dawley rats.

INTERVENTIONS

In utero exposure to either saline or 400 mg/kg VPA administered intraperitoneally to the dams on gestational day 12.5. On postnatal days 22-24, all rats were implanted with transmitters to record EEG and electromyogram (EMG) activity.

MEASUREMENTS AND RESULTS

During the light phase, when nocturnal animals are typically quiescent, the VPA-exposed animals spent significantly more time in wake (∼35 min) and significantly less time in non-rapid eye movement (NREM) sleep (∼26 min) compared to the saline controls. Furthermore, spectral analysis of the EEG revelled that VPA-exposed animals exhibited increased high-frequency activity during wake and rapid eye movement (REM) sleep and reduced theta power across all vigilance states. Interestingly, the gamma-aminobutyric acid (GABA)-ergic system, which modulates the induction and maintenance of sleep states, was also disrupted, with reduced levels of both GAD 65 and GAD67 in the cortical tissue of VPA-exposed animals compared to saline controls.

CONCLUSIONS

To date, the current animal models of ASD have been underutilized in the investigation of associated sleep disturbances. The VPA animal model recapitulates aspects of sleep disruptions reported clinically, providing a tool to investigate cellular and molecular dysregulation contributing to sleep disruptions in ASD.

Neural substrates of numerosity estimation in autism

Visual skills, including numerosity estimation are reported to be superior in autism spectrum disorders (ASD). This phenomenon is attributed to individuals with ASD processing local features, rather than the Gestalt. We examined the neural correlates of numerosity estimation in adults with and without ASD, to disentangle perceptual atypicalities from numerosity processing. Fourteen adults with ASD and matched typically developed (TD) controls estimated the number of dots (80-150) arranged either randomly (local information) or in meaningful patterns (global information) while brain activity was recorded with magnetoencephalography (MEG). Behavioral results showed no significant group difference in the errors of estimation. However, numerical estimation in ASD was more variable across numerosities than TD and was not affected by the global arrangement of the dots. At 80-120 ms, MEG analyses revealed early significant differences (TD > ASD) in source amplitudes in visual areas, followed from 120 to 400 ms by group differences in temporal, and then parietal regions. After 400 ms, a source was found in the superior frontal gyrus in TD only. Activation in temporal areas was differently sensitive to the global arrangement of dots in TD and ASD. MEG data show that individuals with autism exhibit widespread functional abnormalities. Differences in temporal regions could be linked to atypical global perception. Occipital followed by parietal and frontal differences might be driven by abnormalities in the processing and conversion of visual input into a number-selective neural code and complex cognitive decisional stages. These results suggest overlapping atypicalities in sensory, perceptual and number-related processing during numerosity estimation in ASD.

Neural mechanisms of savant calendar calculating in autism: an MEG-study of few single cases

This study contrasted the neurological correlates of calendar calculating (CC) between those individuals with autism spectrum disorder (ASD) and typically developing individuals. CC is the ability to correctly and quickly state the day of the week of a given date. Using magnetoencephalography (MEG), we presented 126 calendar tasks with dates of the present, past, and future. Event-related magnetic fields (ERF) of 3000ms duration and brain activation patterns were compared in three savant calendar calculators with ASD (ASDCC) and three typically developing calendar calculators (TYPCC). ASDCC outperformed TYPCC in correct responses, but not in answering speed. Comparing amplitudes of their ERFs, there was a main effect of group between 1000 and 3000ms, but no further effects of hemisphere or sensor location. We conducted CLARA source analysis across the entire CC period in each individual. Both ASDCC and TYPCC exhibited activation maxima in prefrontal areas including the insulae and the left superior temporal gyrus. This is in accordance with verbal fact retrieval and working memory as well as monitoring and coordination processes. In ASDCC, additional activation sites at the right superior occipital gyrus, the right precuneus, and the right putamen point to visual-spatial strategies and are in line with the preference of autistic individuals for engaging posterior regions relatively more strongly in various reasoning and problem solving tasks.

Pathophysiology of autism spectrum disorders: Revisiting gastrointestinal involvement and immune imbalance

Autism spectrum disorders (ASD) comprise a group of neurodevelopmental abnormalities that begin in early childhood and are characterized by impairment of social communication and behavioral problems including restricted interests and repetitive behaviors. Several genes have been implicated in the pathogenesis of ASD, most of them are involved in neuronal synaptogenesis. A number of environmental factors and associated conditions such as gastrointestinal (GI) abnormalities and immune imbalance have been linked to the pathophysiology of ASD. According to the March 2012 report released by United States Centers for Disease Control and Prevention, the prevalence of ASD has sharply increased during the recent years and one out of 88 children suffers now from ASD symptoms. Although there is a strong genetic base for the disease, several associated factors could have a direct link to the pathogenesis of ASD or act as modifiers of the genes thus aggravating the initial problem. Many children suffering from ASD have GI problems such as abdominal pain, chronic diarrhea, constipation, vomiting, gastroesophageal reflux, and intestinal infections. A number of studies focusing on the intestinal mucosa, its permeability, abnormal gut development, leaky gut, and other GI problem raised many questions but studies were somehow inconclusive and an expert panel of American Academy of Pediatrics has strongly recommended further investigation in these areas. GI tract has a direct connection with the immune system and an imbalanced immune response is usually seen in ASD children. Maternal infection or autoimmune diseases have been suspected. Activation of the immune system during early development may have deleterious effect on various organs including the nervous system. In this review we revisited briefly the GI and immune system abnormalities and neuropeptide imbalance and their role in the pathophysiology of ASD and discussed some future research directions.

Biobehavioral profiles of arousal and social motivation in autism spectrum disorders

BACKGROUND

Children with autism spectrum disorder (ASD) are impaired in social communication and interaction with peers, which may reflect diminished social motivation. Many children with ASD show enhanced stress when playing with other children. This study investigated social and stress profiles of children with ASD during play.

METHODS

We utilized a peer interaction paradigm in a natural playground setting with 66 unmedicated, prepubertal, children aged 8-12 years [38 with ASD, 28 with typical development (TD)]. Salivary cortisol was collected before and after a 20-min playground interaction that was divided into periods of free and solicited play facilitated by a confederate child. Statistical analyses included Wilcoxon rank-sum tests, mixed effects models, and Spearman correlations to assess the between-group differences in social and stress functioning, identify stress responders, and explore associations between variables, respectively.

RESULTS

There were no differences between the groups during unsolicited free play; however, during solicited play by the confederate, significant differences emerged such that children with ASD engaged in fewer verbal interactions and more self-play than the TD group. Regarding physiological arousal, children with ASD as a group showed relatively higher cortisol in response to social play; however, there was a broad range of responses. Moreover, those with the highest cortisol levels engaged in less social communication.

CONCLUSIONS

The social interaction of children with ASD can be facilitated by peer solicitation; however, it may be accompanied by increased stress. The children with ASD that have the highest level of cortisol show less social motivation; yet, it is unclear if it reflects an underlying state of heightened arousal or enhanced reactivity to social engagement, or both.