ERP correlates of impaired error monitoring in children with ADHD

Objective: The purpose of the current study was to elaborate on error monitoring in children with Attention Deficit Hyperactivity Disorder (ADHD) using the ERP methodology. Method: Children with ADHD executed a visual Go/No-Go task with 25 percent No-Go trials; and a two stimulus reaction time task wherein a neutral warning signal (S1) was presented to inform the child to prepare for an imperative stimulus (S2). Results: In both tasks, children with ADHD responded as fast as controls but made twice as many errors. In addition, they failed to adjust their speed of responding after making an error. Exploring the error-related potentials revealed that the error-related negativity (ERN) was the same for the two groups, but that children with ADHD showed a diminished error positivity (Pe). Conclusions: Based on these findings, we conclude that children with ADHD are normal in early error monitoring processes related to error detection, but show abnormal response strategy adjustments and are deviant in later error monitoring processes associated with the subjective/emotional, conscious evaluation of the error.