The effect of similarities in skin texture and hand shape on perceived ownership of a fake limb

Abstract

In the rubber-hand illusion (RHI), people attribute an artificial object to their own body. In the present study, we investigate the extent to which RHI is affected by visual discrepancies between the artificial object and a human hand. We tested Armel and Ramachandran's (2003) hypothesis that people will experience a stronger RHI when the artificial object is a skin-like textured sheet instead of a tabletop. We did not find support for their hypothesis, but the strength of the RHI diminished when the texture of a hand-shaped object did not resemble the human skin (manipulated by putting a white glove over the cosmetic prosthesis). We provide an alternative explanation for this finding, based on a skill-based sensorimotor account of perceived body ownership. Such an explanation supports Armel and Ramachandran's more general claim that discrepancies in the nature of expected and felt touch diminish the RHI.