title: Neural substrate of body size: illusory feeling of shrinking of the waist.
abstract: The perception of the size and shape of one's body (body image) is a fundamental aspect of how we experience ourselves. We studied the neural correlates underlying perceived changes in the relative size of body parts by using a perceptual illusion in which participants felt that their waist was shrinking. We scanned the brains of the participants using functional magnetic resonance imaging. We found that activity in the cortices lining the left postcentral sulcus and the anterior part of the intraparietal sulcus reflected the illusion of waist shrinking, and that this activity was correlated with the reported degree of shrinking. These results suggest that the perceived changes in the size and shape of body parts are mediated by hierarchically higher-order somatosensory areas in the parietal cortex. Based on this finding we suggest that relative size of body parts is computed by the integration of more elementary somatic signals from different body segments.
authors.affiliation: Wellcome Department of Imaging Neuroscience, Institute of Neurology, London, United Kingdom. h.ehrsson@fil.ion.ucl.ac.uk
authors.forename: H Henrik
authors.initials: HH
authors.lastname: Ehrsson
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kito
authors.forename: Norihiro
authors.initials: N
authors.lastname: Sadato
authors.forename: Richard E
authors.initials: RE
authors.lastname: Passingham
authors.forename: Eiichi
authors.initials: E
authors.lastname: Naito
mesh_terms: D001828:Body Image; D049628:Body Size; D001921:Brain / Q000502:physiology*; D004644:Emotions; D006225:Hand; D006801:Humans; D007088:Illusions / Q000523:psychology*; D010465:Perception / Q000502:physiology*; D011601:Psychophysics; D015898:Tomography Scanners, X-Ray Computed