Abstract
The human brain develops a representation of one's own body by integrating visual, proprioceptive, and somatosensory information into a coherent whole. This representation can be altered or disrupted when the sensory input is altered. Notably, the Rubber Hand Illusion (RHI) can be used to induce ownership of a fake hand into a subject's self-representation. In one study with upper arm amputees, by stroking amputees' stumps while synchronously stroking a visible fake hand, the illusion caused the stroke to be felt in the location of the fake hand (Ehrsson et al. 2008). Although the RHI may be robustly induced by objects that only vaguely resemble a real hand (e.g., a rubber glove), it remains unknown whether the size representation of one's hand may be manipulated by changing the size of the inducer. In the current set of experiments, we tested whether induction of the Rubber Hand Illusion can consistently alter an observer's hand size representation toward the size of the fake hand. In a 2AFC task, observers were shown images of their own hand at various sizes and asked to respond as to whether the image was smaller or larger than their real hand, before and after induction of the Rubber Hand Illusion. After successful induction of the illusion, observers' responses did not show a change in perceived size of their own hand. This implies that while observers may experience ownership of the hand, they are not integrating all features of the hand (e.g., size) into their own body representations.
Meeting abstract presented at VSS 2018