Body-swapping experiment with an android robot: Investigation of the relationship between agency and a sense of ownership toward a different body

This study extends existing Rubber Hand Illusion (RHI) experiments to employ life-size full-body humanlike android robot to investigate body ownership illusion and the sense of agency. For this study, we designed a novel experimental setting. The android robot moved synchronously with a participant's head and arm motion. Furthermore, a stereoscopic camera was mounted on the android's head and the video stream from the camera was provided to a head mounted display (HMD) that the participant wore. Then, the participant and the robot were facing each other, so that the participant could see his/her own body in the HMD like a reflection in a mirror. During the experiment, the participant was asked to touch his/her own body by the hands of an android robot. The results of our study confirmed that the body ownership process worked with the full body android robot. The results also showed that our system enabled the participants to feel the sense of agency to some extent.