The role of the interaction between the inferior parietal lobule and superior temporal gyrus in the multisensory Go/No-go task.

Information from multiple sensory modalities interacts. Using functional magnetic resonance imaging (fMRI), we aimed to identify the neural structures correlated with how cooccurring sound modulates the visual motor response execution. The reaction time (RT) to audiovisual stimuli was significantly faster than the RT to visual stimuli. Signal detection analyses showed no significant difference in the perceptual sensitivity (d') between audiovisual and visual stimuli, while the response criteria (β or c) of the audiovisual stimuli was decreased compared to the visual stimuli. The functional connectivity between the left inferior parietal lobule (IPL) and bilateral superior temporal gyrus (STG) was enhanced in Go processing compared with No-go processing of audiovisual stimuli. Furthermore, the left precentral gyrus (PreCG) showed enhanced functional connectivity with the bilateral STG and other areas of the ventral stream in Go processing compared with No-go processing of audiovisual stimuli. These results revealed that the neuronal network correlated with modulations of the motor response execution after the presentation of both visual stimuli along with cooccurring sound in a multisensory Go/Nogo task, including the left IPL, left PreCG, bilateral STG and some areas of the ventral stream. The role of the interaction between the IPL and STG in transforming audiovisual information into motor behavior is discussed. The current study provides a new perspective for exploring potential brain mechanisms underlying how humans execute appropriate behaviors on the basis of multisensory information.