title: Imagining one's own and someone else's body actions: dissociation in anorexia nervosa.
abstract: BACKGROUND
  Patients with anorexia nervosa (AN) usually report feeling larger than they really are. This body overestimation appears to be related not only to the patient's body image but also to an abnormal representation of the body in action. In previous work on a body-scaled anticipation task, anorexic patients judged that they could not pass through a door-like aperture even when it was easily wide enough--suggesting the involvement of the body schema. In the present study, we sought to establish whether this erroneous judgment about action is specifically observed when it concerns one's own body or whether it is symptomatic of a general impairment in perceptual discrimination.
  
  
  METHODS
  Twenty-five anorexic participants and 25 control participants were presented with a door-like aperture. They had to judge whether or not the aperture was wide enough for them to pass through (i.e. first-person perspective, 1PP) and for another person present in the testing room to pass through (i.e. third-person perspective, 3PP).
  
  
  RESULTS
  We observed a higher passability ratio (i.e. the critical aperture size to shoulder width ratio) in AN patients for 1PP but not for 3PP. Moreover, the magnitude of the passability ratio was positively correlated not only with the extent of the patient's body and eating concerns but also with the body weight prior to disease onset. Our results suggest that body overestimation can affect judgments about the capacity for action but only when they concern the patient's own body. This could be related to impairments of the overall network involved in the emergence of the body schema and in one's own perspective judgments.
  
  
  CONCLUSIONS
  Overestimation of the body schema might occur because the central nervous system has not updated the new, emaciated body, with maintenance of an incorrect representation based on the patient's pre-AN body dimensions.
authors.affiliation: Laboratoire de Neurosciences Fonctionnelles et Pathologies, EA-4559, Université Lille Nord de France, Lille, France. dewi.guardia@chru-lille.fr
authors.forename: Dewi
authors.initials: D
authors.lastname: Guardia
authors.forename: Léa
authors.initials: L
authors.lastname: Conversy
authors.forename: Renaud
authors.initials: R
authors.lastname: Jardri
authors.forename: Gilles
authors.initials: G
authors.lastname: Lafargue
authors.forename: Pierre
authors.initials: P
authors.lastname: Thomas
authors.forename: Vincent
authors.initials: V
authors.lastname: Dodin
authors.forename: Olivier
authors.initials: O
authors.lastname: Cottencin
authors.forename: Marion
authors.initials: M
authors.lastname: Luyat
mesh_terms: D000293:Adolescent; D000328:Adult; D000856:Anorexia Nervosa / Q000473:pathology / Q000503:physiopathology*; D001828:Body Image; D005260:Female; D006801:Humans; D007092:Imagination; D012649:Self Concept; D055815:Young Adult