Crossmodal links in spatial attention between vision, audition, and touch: evidence from event-related brain potentials

Results from event-related potential (ERP) studies are reviewed that investigated crossmodal links in spatial attention between vision, audition and touch to find out which stages in the processing of sensory stimuli are affected by such crossmodal links. ERPs were recorded in response to visual, auditory, and tactile stimuli under conditions where attention was directed to a specific location within one (primary) modality, while stimuli in another (secondary) modality were to be ignored regardless of their position. Systematic ERP effects of spatial attention were observed not only in the primary modality, but also for secondary modality stimuli, thus revealing crossmodal links in spatial attention. These links affected relatively early sensory-specific ERP components between 100 and 200 ms post-stimulus. Beyond 200 ms, ERPs to secondary modality stimuli were little affected by the current focus of attention within another modality. This pattern of results suggests that crossmodal links in spatial attention may affect sensory-perceptual processes within modality-specific cortical regions, but have little impact on later post-perceptual processing stages.