Increased plasticity of the bodily self in eating disorders

TLDR

The rubber hand illusion has been widely used to study the bodily self in healthy individuals. This study aimed to extend the RHI to investigate bodily self‑representation in people with eating disorders. Researchers administered the RHI alongside self‑report measures of eating‑disorder psychopathology (EDI‑3 subscales, DASS‑21, SOQ) to 78 ED patients and 61 healthy controls. ED participants exhibited stronger RHI effects on perceptual and subjective measures, with embodiment strongly linked to interoceptive deficits and self‑objectification, indicating greater bodily‑self plasticity in eating disorders.

Abstract

Background 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). Method 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. Results Individuals with an ED experienced the RHI significantly more strongly than healthy controls on both perceptual (i.e. propioceptive 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. Conclusions 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.