Effects of Interpupillary Distance and Visual Avatar’s Shape on the Perception of the Avatar’s Shape and the Sense of Ownership

Owing to the spread of virtual reality (VR) content, avatars that can be used have become more diverse. Several studies have been conducted on the effects of avatars on users. The investigation on the effects of avatar shape on the perception of object size and the sense of ownership of the avatar has been limited; however the effects on the perception of the avatar’s shape have not been investigated. Studies focusing on visual effects have reported that the interpupillary distance (IPD) influences object-size perception and distance perception. It has also been reported that lowering the height of the camera and shortening the IPD can make the surrounding space seem larger. This suggests that the IPD may affect the shape perception and the sense of ownership of avatars. In this study, we focused on changing both the shape of the avatar and the IPD. We prepared avatars with a shape similar to that of the participant's body and avatars with extremely long/short limbs. Then, we examined the changes in the shape perception and the sense of ownership of the avatar by manipulating the prepared avatar based on one of the three IPDs (short, normal, and long). The results confirmed that the length of arms and legs and IPD may affect the perception of length and thickness of arms and legs and the sense of ownership of avatars.