The Bodily Illusion in Adverse Conditions: Virtual Arm Ownership During Visuomotor Mismatch.

Classically, body ownership illusions are triggered by cross-modal synchronous stimulations, and hampered by multisensory inconsistencies. Nonetheless, the boundaries of such illusions have been proven to be highly plastic. In this immersive virtual reality study, we explored whether it is possible to induce a sense of body ownership over a virtual body part during visuomotor inconsistencies, with or without the aid of concomitant visuo-tactile stimulations. From a first-person perspective, participants watched a virtual tube moving or an avatar's arm moving, with or without concomitant synchronous visuo-tactile stimulations on their hand. Three different virtual arm/tube speeds were also investigated, while all participants kept their real arms still. The subjective reports show that synchronous visuo-tactile stimulations effectively counteract the effect of visuomotor inconsistencies, but at slow arm movements, a feeling of body ownership might be successfully induced even without concomitant multisensory correspondences. Possible therapeutical implications of these findings are discussed.