In recent years, research has been conducted on attaching a robot arm or finger-shaped machine to one's body and moving it with the movement of other body parts (for example, legs), but these are the functions and movements of existing body parts. Is merely replaced with that of an artificial body.The research group examined the possibility of a new artificial body that can be controlled independently of the functions and movements of the body that it has innately.

　In the research, we first developed an artificial finger system that can be controlled independently of the functions and movements of other body parts and can be easily attached to the palm of the hand.When attached to the little finger side of the palm, it looks like six fingers, so it was named "sixth finger".

　Next, with 18 adult subjects wearing the sixth finger, a proficiency task of bending and stretching the fingers and key tapping using both their own fingers and the sixth finger was performed for about an hour on average.Before and after this task, subjects were given tasks (subjective evaluation task and behavioral experiment task).As a result of verifying the effect of body formation, it became clear that an artificial body part that can be controlled independently of other body parts can be bodyized as a part of itself and can be moved freely.

　From this achievement, by engineering application, many possibilities such as playing the piano and guitar with six fingers, realizing the third arm and four legs, and embodying the tail and wings, etc. are realized. Can be expected.In the future, from a basic point of view, it will be important to examine changes in the brain due to the embodying of new body parts.

Paper information:[Scientific Reports] Body ownership of an independent supernumerary limb: an exploratory study