Using a double-blind design, the authors investigated 1) caffeine's
effect in hyperkinetic children on a choice reaction time task, 2) whether
caffeine has different effects on simple reaction time and choice reaction
time, and 3) whether its effects in the hyperkinetic compared with the
normal group of children are best described by the law of initial values or
as a "paradoxical effect." The results indicate that caffeine produced an
increase in the accuracy of stimulus identification and processing and a
decrease in lapses of attention for the hyperkinetic group. The law of
initial values best represented the phenomena observed.Abstract Teaser