Relating proprioceptive embodiment to body dissatisfaction in anorexia and bulimia patients: effect of visual body images.

Eating disorders (ED) are associated with a maladaptive body schema and several cognitive biases. This pilot study aimed to investigate the effect of visual stimulation by body images on maladaptive body schema and body dissatisfaction in patients with ED. The rubber hand illusion (RHI) was applied to a sample of 33 women with anorexia or bulimia nervosa and 27 control subjects. The RHI was administered in a novel way using a standard-sized hand that had been distorted in appearance (perceived as unsatisfactory), and it was used before and after an ad hoc priming effect (exposure to thin-body media images). In accordance with the maladaptive body schema, ED patients exhibited higher scores on the Body Shape and Body Perception Questionnaires (with a positive correlation between the scores) and there was a significant increase in scores for all items in the location-proprioception and agency domains. However, before the priming effect, the ED sample showed significantly lower scores on all proprioceptive drift items during the distorted RHI condition and the regression analysis demonstrated a significant association between reduced proprioceptive drift (recording a similar embodiment index to healthy subjects) and improved body dissatisfaction. Following the priming effect, the proprioceptive drift embodiment index increased, and no ANOVA interaction was recorded. The maladaptive body schema in patients with bulimia or anorexia nervosa is characterised by both distorted proprioception and high interoceptive awareness. The visual body images that are perceived as unsatisfactory play a role in preserving proprioception and consequently in reducing body dissatisfaction. Conversely, the exposure effect of thin-body ideal images is involved in the maladaptive body schema.