A common perceptual inference for cross-modally induced illusions of body schema

Abstract

Body-schema, or the multimodal representation of ones own body attributes, has been demonstrated previously to be malleable. In the rubber-hand illusion (Botvinick & Cohen, 1998), synchronous visual and tactile stimulation cause a fake hand to be perceived as ones own. Similarly, if a strangers voice is heard synchronously with ones own vocal production, that voice comes to be attributed to oneself (Zheng et al., 2011). Multimodal illusions like these involve distorting body schema based on correlated input, yet the degree to which different instances of distortion are perceived within the same individuals has never been examined. Here we show that participants embraced the ownership of a fake hand and a strangers voice to a similar degree, controlling both for individual suggestibility and for general susceptibility to illusion of body schema. Our findings suggest that the perceptual inference that leads to the distortion of body schema is a stable trait.