Dextroamphetamine and placebo practice effects on selective attention in hyperactive children

Three groups of three boys referred to a hospital study unit for evaluation of hyperactive behavior were tested on a classification task involving selective attention while on either dextroamphetamine (D) or placebo (P). In two sessions, groups had D first, P second (DP), or PD, or PP. Amphetamine reduces response times in general and reduces interference due to orthogonally varying irrelevant information. Practice while on placebo improves performance in a subsequent placebo session. Practice while on amphetamine does not, however, improve performance in the subsequent session on placebo. Assessment of the extent of the drug-state-related practice effect is necessary for evaluation of long-term benefits of dextroamphetamine therapy in these children.Thanks go to Ramona Roberts for assistance in running subjects. The University of Maryland Computer Science Center provided the computer facilities for data analysis.