Perception it is: Processing level in multisensory selection

When repeatedly exposed to simultaneously presented stimuli, associations between these stimuli are nearly always established, both within as well as between sensory modalities. Such associations guide our subsequent actions and may also play a role in multisensory selection. Thus, crossmodal associations (i.e., associations between stimuli from different modalities) learned in a multisensory interference task might affect subsequent information processing. The aim of this study was to investigate the processing level of multisensory stimuli in multisensory selection by means of crossmodal aftereffects. Either feature or response associations were induced in a multisensory flanker task while the amount of interference in a subsequent crossmodal flanker task was measured. The results of Experiment 1 revealed the existence of crossmodal interference after multisensory selection. Experiments 2 and 3 then went on to demonstrate the dependence of this effect on the perceptual associations between features themselves, rather than on the associations between feature and response. Establishing response associations did not lead to a subsequent crossmodal interference effect (Experiment 2), while stimulus feature associations without response associations (obtained by changing the response effectors) did (Experiment 3). Taken together, this pattern of results suggests that associations in multisensory selection, and the interference of (crossmodal) distractors, predominantly work at the perceptual, rather than at the response, level