Crossmodal congruency effects based on stimulus identity.

We investigated whether the crossmodal congruency effect, normally observed in spatial compatibility tasks, would also affect performance on a task based on discriminating stimulus identity (i.e., a non-spatial dimension). Two rhythms were presented to participants' eyes, ears, and/or hands in a 4-alternative rhythm discrimination task. Stimulus identity and stimulus modality were varied orthogonally. When the target and distractor rhythms were presented in different sensory modalities, significant crossmodal congruency effects were observed in all conditions (i.e., performance on the incongruent distractor trials was significantly more error-prone than on the congruent distractor trials). In contrast to the results of previous studies, these crossmodal distractor effects were neither based on the spatial compatibility of the stimuli nor on an abstract semantic matching of stimulus identity, but instead on the identity of the target rhythm. Intriguingly, the magnitude of the crossmodal congruency effects differed as a function of the target modality, but were unaffected by the modality of the distractor.