Interactions between multisensory inputs with voluntary spatial attention: an fMRI study.

Cross-modal attention and multisensory integration are very essential for us to perceive the world. The most intuitive feelings about the environment around us are based on what we see and what we hear. Therefore, it is important to understand the interactions between visual inputs and auditory inputs. Previous studies have shown that multisensory integration can be modulated by attention. However, how top-down attention is controlled or allocated across the sensory modalities remains unclear. In this study, we measured the cortical areas activated by the cue-target spatial attention paradigm in both visual and auditory fields using functional MRI. The reaction times of the behavioral results indicated that interactions between the two types of stimuli exist. The imaging results indicated that interactions between multisensory inputs can lead to enhancement or depression of the cortical response with top-down spatial attention. Moreover, the activation of the middle temporal gyrus and insula in tasks with irrelevant stimuli appears to indicate that multisensory integration proceeds automatically.