Temporal judgments, hemispheric equivalence, and interhemispheric transfer in adolescents with attention deficit hyperactivity disorder.

Abstract

This study investigated temporal processing abilities, hemispheric asymmetry, interhemispheric transfer, and stimulant medication effects in adolescents with attention deficit hyperactivity disorder (ADHD). Pairs of light emitting diodes in a visual half-field display (i.e., bilateral and unilateral presentations) were presented to examine medication effects, temporal judgments, hemispheric asymmetry, and interhemispheric transfer in male adolescents with ADHD and matched controls on age and gender. Participants responded (YES/NO) whether pairs of spatially separated diodes were illuminated simultaneously. Stimulant medication did not have an affect on temporal judgments, hemispheric equivalence, or interhemispheric transfer. No group differences in temporal judgments in any of the paired conditions were revealed. Both the ADHD and control groups demonstrated hemispheric equivalence for temporal judgments. Unexpectedly, the ADHD group demonstrated significantly faster interhemispheric transfer times when compared to the control group. The overall findings indicate that the reported deficit in time perception among individuals with ADHD may be restricted to tasks that involve response inhibition, reaction time, and/or motor movements (e.g., replicate durations of stimuli by pressing a lever).