Executive functioning in individuals with intellectual disabilities and autism spectrum disorders

Item does not contain fulltextBACKGROUND: Executive functioning (EF) is important for adequate behavioural functioning and crucial for explaining symptoms of autism spectrum disorders (ASD) in individuals with normal intelligence, but is scarcely studied in individuals with ASD and intellectual disabilities (ID). We therefore study EF in an ID population by comparing performances on three frequently studied executive functions (shifting, inhibition and updating) between individuals with ASD and individuals without ASD. When studying ID populations, one should be aware of Spearman's Law of Diminishing Returns (SLODR), as it questions the possibility of measuring separate cognitive functions in ID populations. METHODS: Six EF tasks were administered to 50 individuals with mild to borderline ID, of which half was diagnosed with ASD. In order to investigate the distinctness of the three executive functions in this ID sample, the results on the six EF tasks were subjected to principal components analysis (PCA). Subsequently, a multivariate analysis of variance (MANOVA) was performed to assess differences between the ASD and non-ASD group on shifting, inhibition and updating. RESULTS: The PCA revealed the hypothesised EF trichotomy. MANOVA analysis showed no significant group differences on EF-performance. CONCLUSIONS: Three separate executive functions were measured in this ID population, but despite much evidence that individuals with ASD display more behavioural problems and the proven relevance of EF in behavioural functioning, no significant group difference was found on shifting, inhibition or updating. After this first effort to achieve more insight into EF of individuals with ASD and ID the relation between behavioural problems and EF will require further study

Clinical assessment of ASD in adults using self and other report: psychometric properties and validity of the Adult Social Behavior Questionnaire (ASBQ)

The aim of this study was to develop and validate the Adult Social Behavior Questionnaire (ASBQ), a multidimensional Autism Spectrum Disorder (ASD) questionnaire that contains both a self report version and a version to be completed by someone close. Psychometric qualities, convergence between self report and other report ratings, and scores in a group diagnosed with ASD and multiple comparison groups were examined. Principal Component Analyses yielded a structure with six dimensions (reduced contact, reduced empathy, reduced interpersonal insight, violation of social conventions, insistence on sameness, and sensory stimulation/motor stereotypies) for both self- and other-report versions. Reliability estimates and correlations between self- and other-ratings were good and the score profile on the 44-item ASBQ differentiated a group with ASD from a non clinical group and patients with depression, schizophrenia and ADHD. We conclude that the ASBQ is a short and easy to apply questionnaire that captures the heterogeneous nature of ASD. It yields a score profile among six ASD problem domains both from the perspective of the patient and from a significant other. (C) 2016 Elsevier Ltd. All rights reserved

Familiarity and face processing

The results of three experiments explore the role of familiarity in face processing. Using the complete-over-part advantage (Experiment 1) and the chimeric faces task (Experiment 2), the results revealed evidence for what may be termed ‘holistic processing’ of unfamiliar, newly-learned, and famous faces. Notably, the extent of holistic processing on both tasks was not moderated by the familiarity of the stimuli. Experiment 3 replicated this pattern using a simultaneous chimeric task to rule out a simple explanation through memory demands. Taken together, these three experiments provide robust and convergent evidence to suggest that all faces regardless of familiarity can be processed in a holistic fashion. On the basis of these results, discussion is presented regarding the value of considering different ‘types’ of facial processing over and above a more simple consideration of task difficulty