A task-irrelevant sound modulates the effects of simultaneous visual cue on visual discrimination: An fMRI study

In present study, we used functional magnetic resonance imaging (fMRI) to explore the neural mechanism of how a task-irrelevant sound modulates the effects of simultaneous visual cue on visual discrimination. Behavioral results showed that response to bimodal audiovisual stimulus was significantly slower when an audiovisual stimulus was accompanied by a simultaneous visual cue than it was not accompanied. The fMRI results showed left premotor cortex was activated by unimodal visual stimulus accompanied with simultaneous visual cue. This result indicated a simultaneous visual cue provided reliable spatial information to visual stimulus, resulting in intramodal visual integration. Left inferior frontal gyrus, letft somatosensory association cortex and left supramarginal cortex were significantly activated by bimodal audiovisual stimulus accompanied with simultaneous visual cue. These activation regions indicated different roles were need for multisensory integration network. This study provides potential theory support for developing brain computer interface device or wearable intelligent device.