| The present study focused on children (n = 319) recruited from the community for presence or absence of attention problems and divided with respect to Attention-Deficit Hyperactivity Disorder (ADHD; Not ADHD, Inattentive, Combined), Oppositional-Defiant Disorder (ODD), and Learning Disorder (reading [RD], math [MD], both [RD + MD], or neither). The research dealt with differences among these diagnostic groups on error-related components of event-related potentials (error-related negativity [ERN] and positivity [Pe]) and slowing of reaction time. These measures were assessed in two types of discrimination tasks: one involving a rare target and one involving an equiprobable target.; There were no differences associated with ODD for performance or electrophysiological measures. These results are consistent with much past work indicating the ODD children are not cognitively impaired.; Children with ADHD did not differ from Not-ADHD participants with respect to the pattern of slowing of reaction time following an error (E + 1) across conditions. However, E + 1 slowing varied inconsistently with task and stimulus, so comparisons of diagnostic groups on this measure cannot be easily interpreted.; Children with ADHD had comparable accuracy and reaction time to their Not ADHD counterparts. However, children with ADHD, particularly the Combined Type, had larger ERN amplitude on error trials than children without an ADHD diagnosis. In contrast, children with ADHD did not differ from those without ADHD on ERN amplitude on correct trials or Pe amplitude. Contrary to hypotheses, the results suggest that children with ADHD may be more vigilant self-monitors, possibly in order to achieve average performance.; Children without learning disorder performed considerably better than those with any form of learning disability; there were few differences, in contrast, among these disabled groups. Children with MD or RD + MD displayed greater ERN amplitude on correct trials than did Not LD subjects. In addition, RD + MD subjects displayed significantly smaller Pe amplitude on both error and correct trials when compared to subjects without Learning Disorder. These findings suggest that children with RD + MD are less efficient at monitoring their errors. |
