It feels like it’s me: Interpersonal multisensory stimulation enhances visual remapping of touch from other to self

Abstract

We constantly feel, see and move our body, and have no doubt that it is our own, distinct from the body of other people. At the same time, understanding other people’s feelings in social interactions depends on the ability to map onto one’s own body the observed experiences on the bodies of others. It has been shown that the more similar others are perceived to be to our self, the stronger this mapping is. While previous studies have focused on existing similarities or differences between self and other, we ask whether the experimental change of the self-other boundaries can lead to changes in somatosensory processing. It has been shown that the perception of tactile stimuli on the face is enhanced if participants concurrently observe a face being touched. This Visual Remapping of Touch (VRT; Ladavas and Serino, 2010) is enhanced the more similar others are perceived to be to the self, and is strongest when viewing one’s face (Serino et al., 2008, 2009). We used the enfacement illusion that relies on synchronous interpersonal multisensory stimulation (IMS; Sforza et al., 2010; Tsakiris, 2008) to manipulate self-other boundaries. Following synchronous, but not asynchronous IMS, the self-related enhancement of the VRT effect was extended to the other individual. These findings suggest that shared multi-sensory experiences represent one key way in which the boundaries and perceived similarity between self and others can be overcome, as evidenced by changes in somatosensory processing of shared tactile stimuli.