The extension of the physical sensation by inducing rubber hand illusion.

Abstract

The rubber hand illusion (RHI) is well-known phenomenon, that the sense of ownership is extended over to the external objects in external area, is one of useful experimental models to understand the characteristic of somatosensory ownership. In this study, we made a real extended rubber hand with variable length of arm, and performed RHI by synchronous visual and tactile stimulation. The intensity of RHI was objectively evaluated by the questionnaire report, by the correlation of the electroencephalogram (EEG) activity between the electrodes labeled as C 3 -C 4 in international 10-20 system, and by electromyography accompanied with hand movement. As a result, the correlation of the EEG of C3 and C4, and the score of the questionnaire report increased during repetitive induction of RHI, suggesting that the effects of RHI-induction accumulated. In addition, even without subjective RHI, tension of muscle and c3-c4 correlation of EEG signal increased in some experimental participants, suggesting that RHI is often performed without awareness.