Affective judgement of social touch on a hand associated with hand embodiment.

Social touch constitutes a critical component of human interactions. A gentle tap on the hand, for instance, can sometimes create emotional bonding and reduce interpersonal distance in social interactions. Evidence of tactile empathy suggests that touch can be experienced through both physical sensation and observation, yet vicarious perception of observed touch on an object as a function of the object's conceptual representation (e.g., Is this object identified as mine? Does this object feel like part of me?) remains less explored. Here we examined the affective judgement of social touch when the illusory sense of ownership over a dummy hand was manipulated through the rubber-hand illusion. When the same social touch was performed on either the real or the dummy hand, we found a similar sense of perceived pleasantness between the felt and observed touch, but only when the dummy hand was embodied; when it was not, the perceived pleasantness of the observed touch was lesser (an "embodiment effect"; Experiment 1). In addition, we found that the embodiment effect associated with the observed touch was insensitive to the way in which embodiment was manipulated (Experiment 2), and that this effect was specific to social but not neutral touch (Experiment 3). Taken together, our findings suggest a role of embodiment in the affective component of observed social touch and contribute to our understanding of tactile empathy for objects.