The Effect of Temporal Alignment on Audiovisual Integration in a Divided Attention Task

Human brains can integrate various kinds of information from different modalities to perceive the complex environment. When an event produces sound and light, we usually do not notice any temporal disparities between the two sensory inputs even though the sound arrives before or after the light. The aim of this study is to investigate the effect of asynchrony audiovisual stimuli on audiovisual integration. In present study, visual and auditory stimuli onset asynchrony (SOA = +/- 250 ms, +/- 200 ms, +/- 150 ms, +/- 100 ms, +/- 50 ms, 0 ms), both the auditory and visual stimuli were attended. From the results, reaction times to AV target stimuli (excepted -250ms condition) were significantly shorter than that to unimodal auditory condition; The Reaction times to SOA = -100ms, -50ms, 0, 50ms were significantly shorter than that to unimodal visual condition. The result of cumulative distribution functions (CDFs) shown that the significant audiovisual integration were found at SOA = -100ms, -50ms, 0, 50ms conditions. These results revealed the multimodal audiovisual stimuli enhanced the detection and the audiovisual integration was elicited by temporal approach of audiovisual stimuli.