Event-related potential evidence for attentional inhibition of return in audition

Orienting attention to a spatial location facilitates responding to a subsequent target at that location, but inhibits the response if attention is oriented away from that location before the target appears there. This inhibitory effect of attention re-orienting, called inhibition of return (IOR), occurs in vision, hearing, touch, and cross-modally, and has been well studied behaviorally. However, little is known about its underlying neural mechanism(s). We report a study of the neural mechanism of auditory IOR using event-related potentials (ERPs). Auditory IOR was associated with elimination, but not reversal, of the Nd1 difference wave. Previous research indicates that the Nd1 represents an enhanced neural response to attended sounds. Also, auditory IOR was associated with a delay in the latency of the peak of the N1 component of the ERP at parietal sites. These effects are consistent with the accounts if inhibition of attention return that have been proposed for IOR, but are somewhat different from effects found in analogous ERP studies of visual IOR.