Attention rivalry under irrelevant audiovisual stimulation.

Audiovisual integration has been known to enhance perception; nevertheless, another fundamental audiovisual interaction, i.e. attention rivalry, has not been well investigated. This paper studied the attention rivalry under irrelevant audiovisual stimulation using event-related potential (ERP) and behavioral analysis, and tested the existence of a vision dominated rivalry model. Participants need respond to the target in a bi- or unimodal audiovisual stimulation paradigm. The enhanced amplitude of central P300 under visual target bimodal stimulus indicated that vision demanded more cognitive resources, and the significant amplitude of frontal P200 under bimodal stimulus with non-target auditory stimulus implied that the brain mostly restrained the process of the non-target auditory information. ERP results, together with the analysis of the behavioral data and the subtraction waves, indicated a vision dominated attention rivalry model involved in audiovisual interaction. Furthermore, the latencies of P200 and P300 components implied that audiovisual attention rivalry occurred within the first 300ms after stimulus onset, i.e. significant differences were found in P200 latencies among three target bimodal stimuli, while no difference existed in P300 latencies. Attention shifting and re-directing might be the cause of such early audiovisual rivalry.