Impaired inhibitory control is associated with higher-order repetitive behaviors in autism spectrum disorders

Abstract
Background: Impairments in executive cognitive control, including a reduced ability to inhibit prepotent responses, have been reported in autism spectrum disorders (ASD). These deficits may underlie patterns of repetitive behaviors associated with the disorder.Method: Eighteen individuals with ASD and 15 age- and IQ-matched healthy individuals performed an antisaccade task and a visually guided saccade control task, each with gap and overlap conditions. Measures of repetitive behaviors were obtained using the Autism Diagnostic Inventory – Revised (ADI-R) and examined in relation to neurocognitive task performance.Results: Individuals with an ASD showed increased rates of prosaccade errors (failures to inhibit prepotent responses) on the antisaccade task regardless of task condition (gap/overlap). Prosaccade error rates were associated with the level of higher-order (e.g. compulsions, preoccupations) but not sensorimotor repetitive behaviors in ASD.Conclusions: Neurocognitive disturbances in voluntary behavioral control suggest that alterations in frontostriatal systems contribute to higher-order repetitive behaviors in ASD.