Viewing One's Own Face Being Touched Modulates Tactile Perception: An fMRI Study

摘要

The perception of tactile stimuli on the face is modulated ifnsubjects concurrently observe a face being touched; this effect,ntermed visual remapping of touch (VRT), is maximum for observingnoneʼs own face. In the present fMRI study, we investigatednthe neural basis of the VRT effect. Participants in the scanner receivedntactile stimuli, near the perceptual threshold, on their right,nleft, or both cheeks. Concurrently, they watched movies depictingntheir own face, another personʼs face, or a ball that could bentouched or only approached by human fingers. Participants werenrequested to distinguish between unilateral and bilateral tactilenstimulation. Behaviorally, perception of tactile stimuli was modulatednby viewing a tactile stimulation, with a stronger effect whennviewing oneʼs own face being touched. In terms of brain activity,nviewing touch was related with an enhanced activity in the ventralnintraparietal area. The specific effect of viewing touch on oneselfnwas instead related with a reduced activity in both the ventralnpremotor cortex and the somatosensory cortex. The present findingsnsuggest that VRT is supported by a network of fronto-parietalnareas. The ventral intraparietal area might remap visual informationnabout touch onto tactile processing. Ventral premotor cortexnmight specifically modulate multisensory interaction when sensoryninformation is related to oneʼs own body. Then this activitynmight back project to the somatosensory cortices, thus affectingntactile perception. ■