Inhibition of return in children with attention deficit hyperactivity disorder.

Earlier studies have suggested an impairment in the attention and eye movement control of children with ADHD. An important phenomenon in the control of attentional shifts and eye movements is the inhibition of return (IOR), which states that our brain works in a way that prevents our attention from returning to a spatial location that has been attended to, either overtly or covertly. This current study addresses whether the IOR in oculomotor planning is compromised in children with ADHD. Eleven ADHD and 12 age- and gender-matched control subjects participated in a behavioral task, in which they made saccades to a peripheral target after a valid, invalid or neutral cue. The latency difference between cued and uncued saccades over a range of cue-target onset asynchrony as well as the positive component of this latency profile (i.e., IOR) was compared between groups. The results show that ADHD children demonstrate a biphasic latency profile that is grossly similar to that observed in control subjects, although the magnitude of IOR appears to be slightly smaller in ADHD subjects. These preliminary results suggest that the inhibitory attention mechanism subserving IOR is at least not fully compromised in ADHD children.