Impaired Reactive Control But Preserved Proactive Control in Hyperactive Children.

Objective: To examine the manifestation of cognitive control deficit of children with different levels of hyperactivity, an "at risk" dimension for ADHD. Method: A group of children with high hyperactivity (N = 40) and another group of children with low levels of hyperactivity (N = 38) performed a modified stop-signal anticipation task, a revised Go/NoGo task, and the AX-continuous performance test (AX-CPT). Results: Children with higher levels of hyperactivity displayed: (1) significantly prolonged stop signal reaction time (SSRT) in the modified stop-signal anticipation task; (2) no notable differences in commission errors in the revised Go/NoGo task; (3) increased reaction time (RT) in stop-signal task and Go/NoGo task with increased probabilities of stop or NoGo signal; and (4) positive proactive behavioral index scores in AX-CPT. Conclusion: The results suggested that children with heightened hyperactivity exhibited impaired reactive control, especially for responses already underway, but preserved proactive control. Further studies concerning these children are warranted. [ABSTRACT FROM AUTHOR]