| Abstract: | This study investigates the effects of methylphenidate (Ritalin) on hyperactive children's performance on a paired-associate learning task under 3 presentation rates (4, 8, and 12 sec per item). The total-time hypothesis states that a fixed amount of time is necessary to learn a fixed amount of material, regardless of the number of trials into which that time is divided. In a double-blind crossover design, the total-time hypothesis was supported by performance in a drug state, but not by performance in a placebo state, where slower presentation rates were not utilized effectively. These results are discussed in terms of inattention in the placebo state and improved attention and use of learning time in the drug state. The methodology presented is suggested as a means of assessing attentional deficits as well as providing a diagnostic procedure for objectively evaluating the appropriateness of stimulant treatment for children referred for symptoms of hyperactivity. |
