Increased plasticity of the bodily self in eating disorders

The rubber hand illusion (RHI) has been widely used to investigate the bodily self in healthy individuals. The aim of the present study was to extend the use of the RHI to examine the bodily self in eating disorders (EDs).

The RHI and self-report measures of ED psychopathology [the Eating Disorder Inventory - 3 (EDI-3) subscales of Drive for Thinness, Bulimia, Body Dissatisfaction, Interoceptive Deficits, and Emotional Dysregulation; the 21-item Depression, Anxiety and Stress Scale (DASS-21); and the Self-Objectification Questionnaire (SOQ)] were administered to 78 individuals with an ED and 61 healthy controls.

Individuals with an ED experienced the RHI significantly more strongly than healthy controls on both perceptual (i.e. proprioceptive drift) and subjective (i.e. self-report questionnaire) measures. Furthermore, both the subjective experience of the RHI and associated proprioceptive biases were correlated with ED psychopathology. Approximately 23% of the variance for embodiment of the fake hand was accounted for by ED psychopathology, with interoceptive deficits and self-objectification significant predictors of embodiment.

These results indicate that the bodily self is more plastic in people with an ED. These findings may shed light on both aetiological and maintenance factors involved in EDs, particularly visual processing of the body, interoceptive deficits, and self-objectification.