# Rethinking the bodily self: evidence from the enfacement illusion in women at risk for eating disorders

## TL;DR

The study explores how a face-based illusion affects body image in women at risk for eating disorders, finding that while the illusion is experienced similarly, emotional responses differ significantly between high and low risk groups.

## Contribution

The study introduces new insights into how body image disturbances in eating disorders may stem from higher-order cognitive processes rather than sensory integration deficits.

## Key findings

- High and low ED-risk participants experienced the enfacement illusion similarly, indicating no disruption in multisensory integration.
- Low ED-risk participants reported reduced body dissatisfaction after the illusion, while high ED-risk participants felt more dissatisfied.
- Body image disturbances in EDs may arise from altered evaluative or affective processing rather than sensory integration issues.

## Abstract

Bodily illusion research has demonstrated that altered bodily-self-perception in eating disorders (EDs) may be linked to abnormalities in the integration of sensory bodily signals. Experiencing bodily illusions can also temporarily reduce body image disturbance. Whether similar alterations in multisensory integration processes extend to self-face representation and whether face-based multisensory illusions can reduce face or body image disturbance remains unclear. This study investigated whether susceptibility to the enfacement illusion differs based on ED risk status and whether experiencing the illusion reduces face and body image disturbance.

The sample included 226 women classified as high (n = 102) or low (n = 124) ED risk, who underwent an enfacement illusion induction procedure involving synchronous (ilillusion-inducing) versus asynchronous (control) visuo-motor stimulation (via facial mimicry) between their own face and an unfamiliar person’s face. Illusion strength was assessed subjectively (via self-report) and objectively (via a self-face recognition task), alongside pre- and post-illusion face and body image outcomes.

Synchronous interpersonal visuo-motor stimulation led to modest changes in self-face recognition (i.e., the other person's face came to be perceived as more similar to one's own); however, these changes were not modulated by ED risk status (high versus low). Cognitive-affective responses to the illusion diverged in unexpected ways. Low ED-risk participants reported reduced body dissatisfaction and dysmorphic concern following synchronous interpersonal visuo-motor stimulation, whilst high ED-risk participants reported increased head and body dissatisfaction following both synchronous and asynchronous stimulation.

These findings suggest that the multisensory processes underlying self-face representation, and ultimately supporting self-recognition and the integrity of self-other boundaries, may not be disrupted in individuals with elevated ED symptomatology. This observation may challenge the notion of a globally disrupted sense of bodily self in EDs, at least with respect to self-face processing. Instead, current results suggest that ED-related body image disturbance may reflect altered higher-order evaluative or affective processing of self-related social information rather than a fundamental deficit in multisensory integration.

The online version contains supplementary material available at 10.1186/s40337-025-01461-1.

People with eating disorders (EDs) often experience a distorted sense of their own body. Researchers have used body illusions—like the "rubber hand illusion", where participants can experience a fake hand as their own—to explore how the brain combines sensory information to create a sense of "this is my body". Some of these illusions can even temporarily improve body image. The current study investigated how a face-based illusion—the “enfacement illusion,” which induces the feeling that another person’s facial features are blended with one’s own—affects how people at high versus low risk for EDs perceive themselves. Both groups experienced the illusion to a similar degree, suggesting that people at higher risk for EDs may not have deficits in basic brain processes that combine sensory signals to recognise their own face. However, cognitive and emotional responses to the illusion differed. After the illusion, low-ED-risk participants felt more satisfied with their physical appearance, whereas high-ED-risk participants felt more dissatisfied. These findings suggest that for people vulnerable to EDs, body image disturbances may not stem from the way that the brain perceives or integrates body-related sensory information. Instead, disturbances may arise from how these individuals interpret and evaluate such information, especially during social interactions involving another person.

The online version contains supplementary material available at 10.1186/s40337-025-01461-1.