Effects of amphetamine on vigilance performance in normal and hyperactive children
Deficient sustained attention is a symptom of hyperactivity that can be improved by stimulant medication. Recently, amphetamine has been shown to increase detections during a vigilance task in both normal and hyperactive boys. The present study applied signal detection analysis to the vigilance performance of 15 hyperactive and 14 normal boys divided into two age groups (6–9 and 10–12). A computerized continuous performance test was administered under amphetamine and placebo. Overall group comparisons indicated that perceptual sensitivity or d′ was higher for the normal boys and the older groups, and analysis of drug treatments showed that amphetamine significantly increased d′. Interactions between drugs and age groups demonstrated that amphetamine affected the younger boys to a significantly greater degree than the older children for both d′ and response bias or β. It is notable that the results were essentially parallel for both normal and hyperactive children.