The effect of spatial information of auditory stimuli on audiovisual interaction: Evidence from event-related potentials

Converging evidence indicates that spatial information of stimuli plays an important role in multisensory interaction. The spatial characteristics of auditory stimuli tended to be biased toward the spatial characteristics of visual stimuli. However, when and where the multimodal audiovisual interaction is affected by the spatial characteristics of auditory stimuli remains unclear. This study used event-related potentials (ERPs) to demonstrate that the auditory stimuli come from 0°, 90°, 180° or 270° location affect the audiovisual interaction. The behavioral results showed that the responses to audiovisual target stimuli were faster than that to unimodal visual target stimuli. Moreover, the ERPs were recorded in response to unimodal auditory (A), unimodal visual (V) and bimodal (AV) stimuli. Cross-modal interactions were estimated using the additive [AV - A] model. At 0° location, four ERP components related to audiovisual interaction were observed: (1) Central and occipital effect was observed at around80 to 160ms; (2) over the central and occipital areas at around 160 to 200ms; (3) over the occipital areas at around 200 to 260ms. (4) Central and occipital areas after 350ms. These findings confirmed the main neural activity of audiovisual interaction. In addition, our study provided evidence that multimodal interaction can be generated even if the auditory stimuli come from different spatial locations.