Executive function deficits in children with autism

A group of 8-year-old children with autism was compared to a group of typically-developing 4-year-olds (approximately matched for verbal mental age) and to a group of typically- developing 8-year-olds (matched for chronological age) on a computerized version of the dimensional change card sort task. This task requires children to classify a set of stimuli first by one dimension (pre-switch phase) and then to reclassify the same stimuli by another contrasting dimension (post-switch phase). There were four conditions that differed in the nature of the rule used to sort the stimuli and the processing demands required by the post-switch phase. Children with autism were both quantitatively and qualitatively different from the other children in the post-switch phase. They obtained the lowest scores across the four conditions and were the only group to experience difficulty in the simplest condition in which only a single perceptual feature was used to sort the stimuli. Nonetheless, the children with autism solved the most difficult condition based on a conceptual classification better than the typically-developing year-olds, once vocabulary level was controlled. The results are discussed in terms of the role of inhibition in the executive functioning of children with autism.