Abstract
Background/Objectives: Individuals with eating disorders (EDs) experience stronger body illusions than control participants, suggesting that abnormalities in multisensory integration may underlie distorted body perception in these conditions. These illusions can also temporarily reduce body image disturbance. Given the centrality of the face to identity and social functioning-and emerging evidence of face image disturbance in EDs-this study examined, for the first time, whether individuals with EDs exhibit heightened susceptibility to a facial illusion (the enfacement illusion) and whether experiencing this illusion improves face and/or body image. Methods: White Australian female participants (19 with an ED and 24 controls) completed synchronous and asynchronous facial mimicry tasks to induce the enfacement illusion. Susceptibility was assessed via self-report and an objective self-face recognition task, alongside pre- and post-task measures of perceived facial attractiveness, facial adiposity estimation, and head/body dissatisfaction. Results: The illusion was successfully induced across both groups. Contrary to predictions, ED and control participants demonstrated comparable susceptibility, and neither group experienced improvements in face or body image. Notably, participants with EDs experienced increased head dissatisfaction following the illusion. Conclusions: These findings indicate that the multisensory integration processes underlying self-face perception, unlike those underlying body perception, may remain intact in EDs. Participant reflections suggested that the limited therapeutic benefit of the enfacement illusion for EDs may reflect the influence of maladaptive social-evaluative processing biases inadvertently triggered during the illusion. A novel dual-process model is proposed in which distorted self-face perception in EDs may arise from biased social-cognitive processing rather than sensory dysfunction alone.