Brain Activity Associated with Self-touch Rubber Hand Illusion

Abstract

[Purpose] The purpose of this study was to investigate the brain mechanisms of body ownership through self-touch using the rubber hand illusion method. [Subjects and Methods] Twenty healthy individuals participated in this study. Using functional near-infrared spectroscopy, brain activity was measured under four conditions: 1) self-touch, 2) self rubber hand illusion (illusion induced by touching self with a rubber hand), 3) other-touch (touched by others), and 4) other rubber hand illusion (illusion induced by being touched by a rubber hand held by an experimenter). [Results] The premotor cortex was bilaterally activated under all the conditions. The supplementary motor cortex was only activated in Condition 2. [Conclusion] The results reveal that increase of body ownership due to self-touch is related to the activity of the supplementary motor area.