Do movements contribute to sense of body ownership? Rubber hand illusion in expert pianists.

Currently, it is still debated whether, how and to what extent movements contribute to the sense of body ownership (i.e., the feeling that one's body belongs to oneself). To answer this question, here we examined if a prolonged increase of the amount of movements affects body ownership. Specifically, we administered the rubber hand illusion paradigm within a natural condition of long-term motor practice, namely in expert pianists. We compared the illusory effects of both static (visuotactile stimulation) and dynamic (active/passive movements) versions of that paradigm in a group of expert pianists and a group of non-musicians. The illusion was measured behaviorally (proprioceptive drift) and subjectively (questionnaire). Our results showed that pianists were significantly less susceptible to any type of the illusion, compared to the non-musicians. Moreover, they did not experience the illusion in general (presenting neither the proprioceptive drift, nor the subjective feeling of ownership). These findings suggest that the increased amount of motor-related afferent and efferent signals does affect the construction and the coherence of body ownership, thus showing the role of movements in this process.