‘Inhibition of return’ without visual input

Inhibition of return (IOR) is the name that is associated with a response time (RT) delay to a visual stimulus presented at a recently cued spatial location. Two experiments with 26 undergraduates used an auditory analog to the visual IOR paradigm to examine whether manual RT inhibition would occur in the absence of visual input. In Experiment 1, subjects were instructed to prepare saccades, with their eyes closed, to the location of an auditory cue, and an RT delay to targets presented at the cued location was observed throughout the 1400 msec timecourse. Experiment 2 was used to examine the role of spatial distance between the auditory cue and the target, and found that as in the visual domain, there is a decrease in the magnitude of RT inhibition with increasing distance. Additionally, as in vision, support was found for the inhibition of targets presented in the same hemispace as the cue, whereas targets presented contralaterally were generally found to be facilitated. It was concluded that IOR is capable of acting in the auditory domain, and the possible neural origins of this effect are discussed. The result that IOR can occur even in the absence of visual input supports recent findings that perceptual representations of visual input are not the source of inhibition in this paradigm.