Our previous study demonstrated that incongruent audiovisual change could result in the illusory perception of the change in sound intensity. In this study, we investigated the causal cortical networksfor audiovisual interactions during this visual-affected auditory discrimination using partial directed coherence. In the early stage (49-198 ms), the audiovisual trials activated more left-to-right connections than unimodal ones, especially those inter-hemispheric frontal-to-occipital and left-centroparietal-to-right-occipital connections.
In the middle-late stage (271-420 ms), the audiovisual network presented a right hemispheric dominance, involving more connections to right frontal and occipital areas. More inter-hemispheric connections, including bilateral connections from parietal to frontal cortex, were activated for audiovisual mismatched information processing and decision making.