HFA and ADHD: a direct comparison on state regulation and response inhibition.

This study examined whether children with high-functioning autism (HFA) are easily overaroused/activated and whether children with attention-deficit/hyperactivity disorder (ADHD) are easily underaroused/activated. This double dissociation was tested using a go/no-go paradigm with computer-paced fast and slow conditions and a self-paced condition. In the HFA group, a performance decline in the fast condition and slow performance in the self-paced condition were expected. In the ADHD group, a performance decline in the slow condition and fast performance in the self-paced condition were expected. No difference was found between groups for state regulation and response inhibition. Findings are discussed in the light of development, comorbidity, and subtypes.