In the Visual Enhancement of Touch (VET), simply viewing one’s hand improves tactile spatial perception, even though vision is non-informative. While previous studies had suggested that looking at another person’s hand could also enhance tactile perception, no previous study had systematically investigated the differences between viewing one’s body and someone else’s. The aim of this study was to shed light on the relation between visuo-tactile interactions and the self-other distinction. In Experiment 1 we manipulated the spatial location where a hand was seen. Viewing one’s hand enhanced tactile acuity relative to viewing a neutral object, but only when the image of the hand was spatially aligned with the actual location of the participant’s unseen hand. The VET effect did not occur when one’s hand was viewed at a location other than that experienced proprioceptively. In contrast, viewing another’s hand produced enhanced tactile perception irrespective of spatial location.
In Experiment 2, we used a multisensory stimulation technique, known as Visual Remapping of Touch, to reduce perceived spatial misalignment of vision and touch. When participants saw an image of their own hand being touched at the same time as the tactile stimulation, the reduction in perceived misalignment caused VET effect to return, even though the spatial location of the images was not consistent with the actual body posture. Our results suggest that multisensory modulation of touch depends on a representation of one’s body that is fundamentally spatial in nature. In contrast, representation of others is free from this spatial constraint.