An event-related potential and behavioral study of impaired inhibitory control in children with autism spectrum disorder

Autism spectrum disorders (ASD) are characterized by a deficit of dorsal visual stream processing as well as the impairment of inhibitory control capability. However, the cognitive processing mechanisms of executive dysfunction have not been addressed. In the present study, the endogenous Posner paradigm task was administered to 15 children with ASD and 16 typically developing (TD) children to simultaneously investigate and compare the behavioral performance and event-related potentials (ERPs) measures. Children with ASD showed slower reaction time in the incongruent condition but did not significantly differ in the overall conditions and in response accuracy as compared to TD children. The ASD group also exhibited significant impairment on measures of inhibitory control. In terms of ERPs regarding early and late inhibition, there were no significant differences found with regard to N2 latency, N2 amplitude, and P3 amplitude in children with ASD relative to TD children, but the ASD group manifested prolonged latency on the P3 component to target stimuli, especially in the incongruent condition, which is indicative of slow and inefficient stimulus classification speed as compared to TD children. (C) 2010 Elsevier Ltd. All rights reserved.