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.
(Received July 02 2008)
(Revised October 28 2008)
(Accepted November 18 2008)
(Online publication January 21 2009)