We feel as if a fake body is our own body by synchronicity between the fake body and the real body (illusory body ownership). The illusory body ownership can be induced to an invisible full body via the synchronous movement of only the hands and feet. We aimed to investigate whether the illusory ownership occurs to a virtual body with an elongated arm by changing position of the one of the hands, and it changes reaching behavior and/or postural stability. We found that the illusory body ownership was induced to the transformed body by synchronous movement of the hands and feet. Participants’ reaching behavior gradually changed to use the longer arm more than the normal arm during learning of the transformed body within 10 min. Postural stability did not change. These results suggest that we can have illusory ownership of the transformed body with the elongated arm, and our behavior adaptively changes to utilize the new body.
