The Impact of Missing Fingers in Virtual Reality

Avatars in virtual reality (VR) can have body structures that differ from the physical self. Game designers, for example, often stylize virtual characters by reducing the number of fingers. Previous work found that the sensation of presence in VR depends on avatar realism and the number of limbs. However, it is currently unknown how the removal of individual fingers affects the VR experience, body perception, and how fingers are used instead. In a study with 24 participants, we investigate the effects of missing fingers and avatar realism on presence, phantom pain perception, and finger usage. Our results show that particularly missing index fingers decrease presence, show the highest phantom pain ratings, and significantly change hand interaction behavior. We found that relative usage of thumb and index fingers in contrast to middle, ring, and little finger usage was higher with abstract hands than with realistic ones - even when the fingers were missing. We assume that dominant fingers are firstly integrated into the own body schema when an avatar does not resemble one's own appearance. We discuss cognitive mechanisms in experiencing virtual limb loss.