Effect of Shifting Own Hand Position in Virtual Space on Mental Body Model

People have knowledge and images of their bodies called the mental body model. Several studies have revealed that the mental body model is changed based on visuo-tactile information, which changes behavior. Virtual reality (VR) and Augmented Reality (AR) technologies have attracted significant attention in various fields. Here, one may identify with a virtual avatar that has a different structure than one's actual body, or one's own body may be displayed differently from the actual position. Such visual changes in a body may affect the mental body model. This paper investigates whether and what extent we could change it by manipulating the visual position of the body parts in virtual space. We answered the following two research questions by analyzing the behavioral changes of the participants. One was whether visual or proprioceptive information was more weighted to determine the movement of the body. Another was whether the participant's movement in the target action changed after they completed a task by observing their bodies at different positions than at the actual position. The results showed that people relied on visual information more than proprioceptive information for determining body movement, and larger visual image of position changes led to a larger change in latter behaviors. This study revealed the possibility that the mental body model can be changed by controlling a visual image of the body.