Effects of a stimulant drug on extraversion level in hyperactive children.

7 hyperactive children in a pilot study, and 15 hyperactive and 15 non-hyperactive control children in a later study, were assessed for salivation to lemon juice stimulation, reactive inhibition on an audio-vigilance task, and visual-motor maze errors. Hyperactive children were tested under stimulant drug and nondrug conditions and nonhyperactive children twice under nondrug conditions. Pilot study hyperactive children displayed significantly fewer maze errors and somewhat greater salivation and lesser reactive inhibition levels under the drug than the nondrug conditions. Follow-up study control children did not differ significantly between test occasions on any measure, while the hyperactive children displayed significantly fewer maze errors, more salivation, and less reactive inhibition under the stimulant drug, indicating significant decreases in extraversion after the stimulant drug.