Research on Updating of Body Schema Using AR Limb and Measurement of the Updated Value

The body schema, an internal model in the brain used to recall the body position, is known to be updated by adapting to the changes in the body figure due to the body growth. Furthermore, the recent research has reported the active updating of the body schema by misunderstanding one's body position using the illusion phenomenon. However, the current method of actively updating the body schema has limited effects and does not handle selective updating of each body part. Therefore, in this paper, a new method using an augmented reality (AR) limb is proposed for the selective updating of unitary parts of the body image in a short period of time. The AR limb is the virtual limb composed by actively extendable and retractable parts, projected by head-mounted display. The basic concept is that the body schema is updated to match the extended and retracted part of the AR limb based on the body schema learning mechanism in the sensory integration of visual and somatic information. The potential effectiveness of the method was verified by actual experiment applying the body schema update to the right forearm.