The facilitating effects of exogenous spatial attention are often short lasting and replaced by inhibitory effects after attention has been withdrawn from a spatial location. In a new study, it was investigated whether this inhibitory after-effect (inhibition of return, IOR) could modulate multisensory integration. Visual exogenous spatial cues were presented before the onset of auditory, visual, or audiovisual targets to evoke IOR at the cued location. The participants were instructed to respond as fast as possible to the onset of auditory, visual, or audiovisual targets after the presentation of the cue. IOR only affected visual target processing as demonstrated by slower responses to cued relative to uncued visual targets. No IOR was observed for auditory and audiovisual targets. Importantly, decreases in multisensory response enhancement and race model inequality violation at cued relative to uncued locations indicate that IOR reduces multisensory integration. This modulation of multisensory integration by IOR is likely driven by an increase in the difference in unisensory signal strength at cued as compared to uncued locations. At previously attended locations visual information is inhibited due to IOR, but auditory information is not. This causes auditory information to be dominant and multisensory integration to be reduced at previously attended locations.
Van der Stoep, N., Van der Stigchel, S., Nijboer, T. C. W., & Spence, C. (in press). Visually-induced inhibition of return affects the integration of auditory and visual information. Perception.