The Effects of Indirect Real Body Cues of Irrelevant Parts on Virtual Body Ownership and Presence

Abstract

The employment of visual, auditory and tactile senses directly related to specific body limbs associated with task performance has been shown to give a person a perception of body ownership. However, there is much less evidence of the influence on body ownership of sensory data associated with parts of the user’s body that are not directly associated with the task being performed. For example, if arms and hands are the functional parts in a first person perspective game, do other body parts such as the torso or legs affect the person’s sense of illusion in ways that can increase or decrease the sense of body ownership? To show the effectiveness of appropriate indirect cues to an irrelevant body part, we conducted a virtual mirror based experiment. Specifically, we created a virtual reality system that has four mirror-reflected body conditions in which a participant can see his or her real lower body, a human avatar’s lower body, a generic avatar’s lower body or no lower body in the virtual mirror. With this system, we observed the effects of each condition on the user’s sense of body ownership and presence, even when the lower body parts played no role in the participant’s activities. The results represent a tendency that an indirect real body cue associated with one’s legs can arouse a higher sense of body ownership and unexpected result for presence during the performance of a task involving only virtual hands.