Scrambled Body: A Method to Compare Full Body Illusion and Illusory Body Ownership of Body Parts

Humans can feel as if a fake body is their own body in the illusory body ownership. The illusion can be induced to a full body by a visual-tactile synchronicity or visual-motor synchronicity. In our previous study, illusory full body ownership of invisible body was elicited by synchronous movements of virtual gloves and socks. In this study, we aimed to investigate whether the spatial relationship is necessary for the full body illusion using a stimulus of scrambled body. In the scrambled body, positions of gloves and socks were scrambled. The results suggest that spatial relationship of body parts is necessary for the full body illusion.