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Body transfer illusion is the illusion of owning either a part of a body or an entire body other than one's own, thus it is sometimes referred to as "body ownership" in the research literature. It can be induced experimentally by manipulating the visual perspective of the subject and also supplying visual and sensory signals which correlate to the subject's body.〔Petkova VI, Ehrsson HH, 2008 (If I Were You: Perceptual Illusion of Body Swapping ). PLoS ONE 3(12): e3832. 〕〔M. P.M. Kammers, I.J.M. van der Ham, H.C. Dijkerman, (Dissociating body representations in healthy individuals: Differential effects of a kinaesthetic illusion on perception and action ), Neuropsychologia, Volume 44, Issue 12, 2006, Pages 2430–2436, ISSN 0028-3932, .〕 For it to occur, bottom-up perceptual mechanisms, such as the input of visual information, must override top-down knowledge that the certain body (or part) does not belong. This is what results in an illusion of transfer of body ownership.〔Slater M, Spanlang B, Sanchez-Vives MV, Blanke O, 2010 (First Person Experience of Body Transfer in Virtual Reality ). PLoS ONE 5(5): e10564. 〕 It is typically induced using virtual reality.〔 ==Rubber hand illusion== Ehrsson, Spence, and Passingham (2004) did studies on the "rubber hand illusion." Subjects with normal brain function were positioned with their left hand hidden out of sight. They saw a lifelike rubber left hand in front of them. The experimenters stroked both the subjects hidden left hand and the visible rubber and with a paintbrush. The experiment showed that if the two hands were stroked synchronously and in the same direction, the subjects began to experience the rubber hand as their own. Even more surprising is that, when asked to use their right hand to point to their left hand, most of the time they pointed toward the rubber hand. If the real and rubber hands were stroked in different directions or at different times, the subjects did not experience the rubber hand as their own. While the experiment was going on the experimenters also recorded the activity of their brains with a functional MRI scanner. The scans showed increased activity in the parietal lobe and then, right after, as the subjects began to experience the rubber hand as their own, in the premotor cortex, the region of the brain involved in planning movements. On the other hand, when the stroking of the real and rubber hands was uncoordinated and the subjects did not experience the rubber hand as their own, the premotor cortex did not become activated. From this the experimenters concluded that the parietal cortex was involved with visual and touch processing. The premotor cortex, getting transmitted information from the parietal cortex, was involved with the feeling of ownership of the rubber hand. Another study from the same laboratory provided further evidence of this ownership of the rubber hand (Ehrsson et al., 2007; Slater et al., 2009). The experimenters used the same procedure as the previous experiment to establish that feeling of ownership involved with the stimulation of the premotor cortex. Then, threatened the rubber hand by making a stabbing movement toward it with a needle (not actually making contact with the rubber hand). MRI scans showed increase activity in a region of the brain called the anterior cingulate cortex that is normally activated when a person anticipates pain, along with the supplementary motor area, that is normally activated when a person feels the urge to move his or her arm (Fried et al., 1991; Peyron, Laurent, and Garcia-Larrea, 2000). The anticipation of the needle made the subjects react as if the rubber hand was their own, moving their real hand to avoid the needle even though it was never actually in danger. 〔Carlson, N. R. (2010). Physiology of behavior, 11th Edition. New York: Allyn & Bacon. A LA CARTE version MyPsychLab w/e-Text.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Body transfer illusion」の詳細全文を読む スポンサード リンク
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