Applicability of the stop-signal task for preschoolers with ADHD

Inhibitory deficits of children with attention deficit/hyperactivity disorder (ADHD) are well documented. However, the specific inhibition ability (stopping an ongoing response) of preschoolers with ADHD is little reported. This study adopted the tracking stop-signal task to examine preschoolers with ADHD. Twenty-eight children with ADHD (M=6.1 year, SD=0.6) were compared to 31 comparison children (M=6.0 year, SD=0.6) on a measure of inhibitory control. The results showed that preschool children with ADHD performed worse than their control groups on the stop-signal task, using the omission error index, implying an attention deficit. However, preschool children with ADHD did not exhibit significantly slower stopsignal reaction times relative to the control group. The ability of controlled response inhibition of preschool children may not be mature.