title: Tactile mental body parts representation in obesity.
abstract: Obese people׳s distortions in visually-based mental body-parts representations have been reported in previous studies, but other sensory modalities have largely been neglected. In the present study, we investigated possible differences in tactilely-based body-parts representation between an obese and a healthy-weight group; additionally we explore the possible relationship between the tactile- and the visually-based body representation. Participants were asked to estimate the distance between two tactile stimuli that were simultaneously administered on the arm or on the abdomen, in the absence of visual input. The visually-based body-parts representation was investigated by a visual imagery method in which subjects were instructed to compare the horizontal extension of body part pairs. According to the results, the obese participants overestimated the size of the tactilely-perceived distances more than the healthy-weight group when the arm, and not the abdomen, was stimulated. Moreover, they reported a lower level of accuracy than did the healthy-weight group when estimating horizontal distances relative to their bodies, confirming an inappropriate visually-based mental body representation. Our results imply that body representation disturbance in obese people is not limited to the visual mental domain, but it spreads to the tactilely perceived distances. The inaccuracy was not a generalized tendency but was body-part related.
authors.affiliation: Psychology Research Laboratory, IRCCS Istituto Auxologico Italiano, Ospedale San Giuseppe, Piancavallo (VCO), Italy. Electronic address: f.scarpina@auxologico.it.
authors.forename: Federica
authors.initials: F
authors.lastname: Scarpina
authors.affiliation: Psychology Research Laboratory, IRCCS Istituto Auxologico Italiano, Ospedale San Giuseppe, Piancavallo (VCO), Italy; Department of Psychology, Università Cattolica del Sacro Cuore, Milan, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Castelnuovo
authors.affiliation: Psychology Research Laboratory, IRCCS Istituto Auxologico Italiano, Ospedale San Giuseppe, Piancavallo (VCO), Italy; Department of Psychology, Università Cattolica del Sacro Cuore, Milan, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Molinari
mesh_terms: D000328:Adult; D001828:Body Image / Q000523:psychology*; D001835:Body Weight / Q000502:physiology; D005260:Female; D018594:Human Body; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis* / Q000523:psychology*; D010812:Physical Stimulation / Q000379:methods; D014110:Touch / Q000502:physiology; D055698:Touch Perception / Q000502:physiology*
keywords: Body representation; Mental imagery; Obesity; Size perception; Somatosensory input