d-Amphetamine-induced enhancement of inhibitory mechanisms involved in visual search.

The authors examined the effects of d-amphetamine on the ability to perform a cued target-detection task that measured inhibition of return (IOR). IOR is a reflexive inhibitory mechanism that delays attention from returning to a previously attended location and has been shown to increase the efficiency of a visual search. Adults (N=14) with a history of cocaine use performed the task under 4 doses of d-amphetamine (0, 10, 20, and 30 mg). The results showed active d-amphetamine doses increased the duration of IOR. By increasing the delay in returning attention to a previously attended location, d-amphetamine might reduce time spent searching previously attended locations, increasing the efficiency of visual searches.