1. Barneveld PS, de Sonneville L, van Rijn S, van Engeland H, Swaab H. {{Impaired Response Inhibition in Autism Spectrum Disorders, a Marker of Vulnerability to Schizophrenia Spectrum Disorders?}}. {J Int Neuropsychol Soc};2013 (Feb 21):1-10.
In this study, we addressed the relation between specific deficits in cognitive control and schizotypal symptomatology in adolescents with autism spectrum disorders (ASD) diagnosed in childhood. We aimed to identify cognitive control deficits as markers of vulnerability to the development of schizophrenia spectrum pathology in ASD. Symptoms of autism and the risk for schizotypal symptomatology were assessed in 29 high-functioning adolescents with ASD, and compared with 40 typically developing adolescents. Cognitive control (response inhibition, mental flexibility, visuo-motor control, interference control, and perseveration) was evaluated for specific association with schizotypal symptomatology. Impaired response inhibition appeared to be strongly and specifically associated with schizotypal symptomatology in adolescents with ASD, especially those with positive and disorganized symptoms. Response inhibition problems could indicate vulnerability to the development of schizotypal symptomatology in ASD. (JINS, 2013, 19, 1-10).
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2. Brock J, Bzishvili S. {{Deconstructing Frith and Snowling’s homograph-reading task: Implications for autism spectrum disorders}}. {Q J Exp Psychol (Hove)};2013 (Feb 21)
The poor performance of autistic individuals on a test of homograph reading is widely interpreted as evidence for a reduction in sensitivity to context termed « weak central coherence ». To better understand the cognitive processes involved in completing the homograph-reading task, we monitored the eye movements of nonautistic adults as they completed the task. Using single trial analysis, we determined that the time between fixating and producing the homograph (eye-to-voice span) increased significantly across the experiment and predicted accuracy of homograph pronunciation, suggesting that participants adapted their reading strategy to minimize pronunciation errors. Additionally, we found evidence for interference from previous trials involving the same homograph. This progressively reduced the initial advantage for dominant homograph pronunciations as the experiment progressed. Our results identify several additional factors that contribute to performance on the homograph reading task and may help to reconcile the findings of poor performance on the test with contradictory findings from other studies using different measures of context sensitivity in autism. The results also undermine some of the broader theoretical inferences that have been drawn from studies of autism using the homograph task. Finally, we suggest that this approach to task deconstruction might have wider applications in experimental psychology.
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3. Carter M, Scherer S. {{Autism spectrum disorder in the genetics clinic: a review}}. {Clin Genet};2013 (Feb 21)
Autism spectrum disorders (ASDs) are a heterogeneous group of neurodevelopmental disorders affecting social communication, language and behavior. The underlying cause(s) in a given individual is often elusive, with the exception of clinically recognizable genetic syndromes with readily available molecular diagnosis, such as fragile X syndrome. Clinical geneticists approach patients with ASDs by ruling out known genetic and genomic syndromes, leaving more than 80% of families without a definitive diagnosis and an uncertain risk of recurrence. Advances in microarray technology and next-generation sequencing are revealing rare variants in genes with important roles in synapse formation, function and maintenance. This review will focus on the clinical approach to ASDs, given the current state of knowledge about their complex genetic architecture.
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4. Coskun MA, Loveland KA, Pearson DA, Papanicolaou AC, Sheth BR. {{Functional Assays of Local Connectivity in the Somatosensory Cortex of Individuals with Autism}}. {Autism Res};2013 (Feb 20)
Emerging evidence for differences between individuals with autism spectrum disorder (ASD) and neurotypical (NT) individuals in somatic processing and brain response to touch suggests somatosensory cortex as a promising substrate for elucidating differences in functional brain connectivity between individuals with and without autism. Signals from adjacent digits project to neighboring locations or representations in somatosensory cortex. When a digit is stimulated, i.e. touched, its representation in cortex is directly activated; local intracortical connections indirectly activate nonprimary cortical representations corresponding to adjacent digits. The response of the nonprimary cortical representations is thus a proxy for connection strength. Local overconnectivity in autism implies that the nonprimary/primary response ratios of the ASD group will be higher than those of the NT group. D1 and D2 of the dominant hand of the participant were individually stimulated while we recorded neural responses using magnetoencephalography. The cortical representations of D1 and D2 (somatosensory-evoked fields) were computed from the ensemble-averaged data using (a) dipole model fits and (b) singular value decomposition. Individual adjacent/primary response ratios were measured, and group response ratio data were fitted with straight lines. Local overconnectivity in autism implies steeper ASD vs. NT group slopes. Our findings did not support local overconnectivity. Slopes were found to be significantly shallower for the ASD group than the NT group. Our findings support the idea of local underconnectivity in the somatosensory cortex of the brains of individuals with ASD. Autism Res 2013, : -. (c) 2013 International Society for Autism Research, Wiley Periodicals, Inc.
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5. Grubb MA, Behrmann M, Egan R, Minshew NJ, Carrasco M, Heeger DJ. {{Endogenous Spatial Attention: Evidence for Intact Functioning in Adults With Autism}}. {Autism Res};2013 (Feb 20)
Rapid manipulation of the attention field (i.e. the location and spread of visual spatial attention) is a critical aspect of human cognition, and previous research on spatial attention in individuals with autism spectrum disorders (ASD) has produced inconsistent results. In a series of three psychophysical experiments, we evaluated claims in the literature that individuals with ASD exhibit a deficit in voluntarily controlling the deployment and size of the spatial attention field. We measured the spatial distribution of performance accuracies and reaction times to quantify the sizes and locations of the attention field, with and without spatial uncertainty (i.e. the lack of predictability concerning the spatial position of the upcoming stimulus). We found that high-functioning adults with autism exhibited slower reaction times overall with spatial uncertainty, but the effects of attention on performance accuracies and reaction times were indistinguishable between individuals with autism and typically developing individuals in all three experiments. These results provide evidence of intact endogenous spatial attention function in high-functioning adults with ASD, suggesting that atypical endogenous attention cannot be a latent characteristic of autism in general. Autism Res 2013, : -. (c) 2013 International Society for Autism Research, Wiley Periodicals, Inc.
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6. Sasson NJ, Lam KS, Childress D, Parlier M, Daniels JL, Piven J. {{The Broad Autism Phenotype Questionnaire: Prevalence and Diagnostic Classification}}. {Autism Res};2013 (Feb 20)
The Broad Autism Phenotype Questionnaire (BAPQ) was administered to a large community-based sample of biological parents of children with autism (PCAs) and comparison parents (CPs) (n = 1,692). Exploratory factor analysis and internal consistency parameters confirmed a robust three-factor structure of the BAPQ, corresponding to the proposed aloof, pragmatic language and rigidity subscales. Based upon the distribution of Broad Autism Phenotype (BAP) features in the general population, new normative cutoff values for BAPQ subscales were established that provide increased specificity relative to those previously reported, and thus enhance the utility of the BAPQ for diagnostically classifying the BAP. These cutoffs were also used to estimate prevalence of the BAP and its three components, with rates ranging between 14-23% for PCAs and between 5-9% for CPs. Analysis of patterns of BAP characteristics within family members revealed that BAP features were more likely to co-occur in PCAs relative to CPs. Collectively, these findings extend the utility of the BAPQ and provide additional evidence that it is an efficient and reliable tool for disaggregating the heterogeneity of autism through the identification of meaningful subgroups of parents. Autism Res 2013, : -. (c) 2013 International Society for Autism Research, Wiley Periodicals, Inc.
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7. Schupp CW, Simon D, Corbett BA. {{Cortisol Responsivity Differences in Children with Autism Spectrum Disorders During Free and Cooperative Play}}. {J Autism Dev Disord};2013 (Feb 22)
Children with autism spectrum disorder (ASD) demonstrate significant heterogeneity in their profiles of social interaction and stress responsivity. We evaluated behavior and stress response in 52 male children ages 8-12 in a naturalistic playground interaction paradigm involving a child with ASD, a typically developing peer, and a same-age confederate. Younger children in the ASD group engaged in 5.8 times more approach behavior and showed a lower cortisol response than their older peers. Those that verbally initiated with their peers also showed a higher cortisol response. Older children with ASD exhibited the highest stress responsivity, while younger children with ASD showed more willingness to approach others without apparent stress. Intervening early and often may contribute to improvements in social engagement in youth with ASD.
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8. Tager-Flusberg H. {{International society for autism research news}}. {Autism Res};2013 (Feb);6(1):67.
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9. Tyszka JM, Kennedy DP, Paul LK, Adolphs R. {{Largely Typical Patterns of Resting-State Functional Connectivity in High-Functioning Adults with Autism}}. {Cereb Cortex};2013 (Feb 20)
A leading hypothesis for the neural basis of autism postulates globally abnormal brain connectivity, yet the majority of studies report effects that are either very weak, inconsistent across studies, or explain results incompletely. Here we apply multiple analytical approaches to resting-state BOLD-fMRI data at the whole-brain level. Neurotypical and high-functioning adults with autism displayed very similar patterns and strengths of resting-state connectivity. We found only limited evidence in autism for abnormal resting-state connectivity at the regional level and no evidence for altered connectivity at the whole-brain level. Regional abnormalities in functional connectivity in autism spectrum disorder were primarily in the frontal and temporal cortices. Within these regions, functional connectivity with other brain regions was almost exclusively lower in the autism group. Further examination showed that even small amounts of head motion during scanning have large effects on functional connectivity measures and must be controlled carefully. Consequently, we suggest caution in the interpretation of apparent positive findings until all possible confounding effects can be ruled out. Additionally, we do not rule out the possibility that abnormal connectivity in autism is evident at the microstructural synaptic level, which may not be reflected sensitively in hemodynamic changes measured with BOLD-fMRI.
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10. Wainer AL, Block N, Donnellan MB, Ingersoll B. {{The Broader Autism Phenotype and Friendships in Non-clinical Dyads}}. {J Autism Dev Disord};2013 (Feb 22)
The broader autism phenotype (BAP) is a set of subclinical traits qualitatively similar to those observed in autism spectrum disorders. The current study sought to elucidate the association between self- and informant-reports of the BAP and friendships, in a non-clinical sample of college student dyads. Self-informant agreement of the BAP and friendship similarity was evaluated, and the Actor-Partner Interdependence Model was used to test how both friends’ BAP characteristics jointly and uniquely contribute to the experiences of friendships. Results suggest self-informant agreement about the BAP, friendship closeness, quality, and conflict. Actor effects were observed for the BAP and friendship values, quality, conflict, and loneliness. Findings suggest that the BAP relates in meaningful ways to self-perceptions of friendship variables in the general population.
