Hyperactivity and Delay Aversion—II. The Effect of Self versus Externally Imposed Stimulus Presentation Periods on Memory

The memory of hyperactive and non-hyperactive children for "attended" and "unattended" picture cards was compared under two conditions. Under Self Imposed Presentation (SI) conditions children set their own limits on presentation time while under Externally Imposed Presentation (EI) conditions children were encouraged to spend 30 seconds attending to the cards. Hyperactive children selected shorter presentation times than non-hyperactive children and recognized fewer "attended" cards under SI conditions, while the two groups performed equally well under EI conditions. These findings suggest that a major determinant of memory deficits in hyperactivity is a self imposed limitation on presentation time rather than more specific cognitive process limitations.