Many researchers have demonstrated the change of body representation, including the rubber hand illusion and pinocchio illusion. However, they focused on the change of a single body part. The human body has a symmetric structure; therefore, the modification of body representation can be facilitated by the corresponding movement of symmetric parts. In our four experiments, participants moved their hands in different manners with distorted vision and were measured whether their behavior changed throughout the task. The four tasks differed in whether participant's hands were moving simultaneously or separately and whether they moved their hands to the same point or a different point. A behavioral change occurred in all experiments. When the participants moved their hands to the same point simultaneously the greatest behavioral change was facilitated. Neither moving both hands simultaneously or moving to the same position facilitated the change.

The mental model of one’s body plays an important role in de-termining subsequent actions. We changed the mental modelusing visual information and observed the effects of suchchange on pain perception. These effects were compared tothe effects of changes in the sense of body ownership, which isthe sensation that something is a part of one’s own body. Someresearchers have shown that the sense of ownership is a factormodulating pain perception. In our experiments, we manipu-lated the visibility of participants’ limbs using Mixed Reality(MR) techniques and measured their perceived pain and feel-ings while observing their limbs. Results showed the sensationthat nothing can touch one’s limbs decreased the strength ofperceived pain.

Through training using distorted vision, the perception of the trained limb position is shifted based on visual information. We investigated whether and how such proprioceptive recalibration transfers to untrained limbs. The results of experiments using human-like virtual limbs confirmed that transfer to some limbs occurred. The manner in which the transfer occurred varied according to the participants' body posture and the type of trained limb. When the participants sat, the recalibration transferred from one arm to another arm symmetrically around the body midline. Conversely, in the case of a sitting leg and standing arm, it was directly copied to another leg or arm.