Changes in auditory selective attention and event-related potentials following oral administration of D-amphetamine in humans

The effect of d-amphetamine on selective attention in humans was investigat ed by measuring event-related potentials (ERPs) during a complex auditory s elective attention task (CSAT). The CSAT required subjects to make a button press response to infrequent target tones presented amongst tones that var ied in pitch (high vs, low), location (left vs. right ear) and duration (51 ms vs. 102 ms). Healthy subjects completed the CSAT under three conditions : placebo, 10 mg and 20 mg d-amphetamine, at least one week apart. D-amphet amine produced a significant dose response increase in hit-rate and decreas e in reaction time without changing false alarm rate. D-amphetamine reduced late PN to location irrelevant stimuli and pitch irrelevant stimuli in bot h the attended ann unattended location. The effect of d-amphetamine was int erpreted as a decrease in the maintenance of tie attentional trace to irrel evant stimuli. However, these changes were accompanied by some evidence of processing of stimulus features in the unattended location. These results s uggest that d-amphetamine improves selective attention, and decreases the m aintenance of attention to irrelevant stimuli. (C) 1999 American College of Neuropsychopharmacology. Published by Elsevier Science Inc.