Effects of clinical dosage levels of methylphenidate on two-flash thresholds and perceptual motor performance in hyperactive children.

Three groups (ns = 10) of children (normals, hyperactives, hyperactives on medication) were administered eight perceptual-motor tasks. The normal controls were significantly superior in performance in comparison with the hyperactives taken off methylphenidate on three tasks but only superior on one task (Digit Symbol) when compared to hyperactives on methylphenidate. The hyperactives on medication were also significantly superior to the hyperactives not on medication on the Digit Symbol task.