Threatening a rubber hand that you feel is yours elicits a cortical anxiety response

doi:10.1073/pnas.0610011104

Threatening a rubber hand that you feel is yours elicits a cortical anxiety response

^†Wellcome Department of Imaging Neuroscience, Institute of Neurology, 12 Queen Square, London WC1N 3BG, United Kingdom;
^§Department of Human Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, United Kingdom; and
^¶Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, United Kingdom

Edited by Marcus E. Raichle, Washington University School of Medicine, St. Louis, MO, and approved April 16, 2007 (received for review November 15, 2006)

Abstract

The feeling of body ownership is a fundamental aspect of self-consciousness. The underlying neural mechanisms can be studied by using the illusion where a person is made to feel that a rubber hand is his or her own hand by brushing the person's hidden real hand and synchronously brushing the artificial hand that is in full view. Here we show that threat to the rubber hand can induce a similar level of activity in the brain areas associated with anxiety and interoceptive awareness (insula and anterior cingulate cortex) as when the person's real hand is threatened. We further show that the stronger the feeling of ownership of the artificial hand, the stronger the threat-evoked neuronal responses in the areas reflecting anxiety. Furthermore, across subjects, activity in multisensory areas reflecting ownership predicted the activity in the interoceptive system when the hand was under threat. Finally, we show that there is activity in medial wall motor areas, reflecting an urge to withdraw the artificial hand when it is under threat. These findings suggest that artificial limbs can evoke the same feelings as real limbs and provide objective neurophysiological evidence that the rubber hand is fully incorporated into the body. These findings are of fundamental importance because they suggest that the feeling of body ownership is associated with changes in the interoceptive systems.

Footnotes

^‡To whom correspondence should be addressed. E-mail: h.ehrsson{at}fil.ion.ucl.ac.uk
Author contributions: H.H.E. and K.W. designed research; H.H.E. and K.W. performed research; N.W. contributed new reagents/analytic tools; H.H.E. analyzed data; and H.H.E., R.J.D., and R.E.P. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/cgi/content/full/0610011104/DC1.
Abbreviations:

ACC,

anterior cingulate cortex;

BOLD,

blood-oxygenation-level-dependent;

fMRI,

functional MRI;

SMA,

supplementary motor area;

pre-SMA,

presupplementary motor area.