Shifting the peripersonal space with the Rubber Hand Illusion
Summary
The rubber hand illusion (RHI) is a way to manipulate the sense of body ownership. It is induced by placing a fake rubber hand next to one’s own hidden hand and stroking them in synchrony. In this research it is hypothesized that the peripersonal space shifts from the real hand to the fake hand with the RHI. The peripersonal space (PPS) is the region surrounding the body, functional for body protection or goal directed action. Participants were confronted with a random set of landmarks and they had to determine whether a landmark was to the left or right from the middle, before and after they experienced the RHI. After the illusion, they determined the landmark significantly more as left. This research suggests that a shift in body ownership causes a shift in peripersonal space. Since the PPS is anchored to the body, and the RHI caused the rubber hand to be experienced as one’s real hand, the rubber hand becomes the new relevant action space. It is hypothesized that the shift in PPS causes the landmark to appear within the PPS of the left hand, where objects are more strongly represented in the brain, causing the landmark to seem left.