Reshaping restriction: virtual embodiment modulates eating biases in anorexia nervosa

Area of Science:

• Neuroscience
• Psychology
• Virtual Reality

Background:

• Anorexia nervosa (AN) is characterized by food restriction and body image issues.
• Altered responses to food cues, including avoidance, contribute to AN.
• Implicit and behavioral biases toward high-calorie foods are prominent in AN.

Purpose of the Study:

• To investigate if virtual reality (VR) full-body illusions (FBIs) can modulate implicit food-related biases in anorexia nervosa.
• To examine the effects of embodying different body sizes in VR on food approach-avoidance behaviors.

Main Methods:

• Participants: 29 female restricting-subtype AN (AN-R) and 31 healthy controls (HC).
• VR intervention: Participants embodied avatars of slimmer or larger body sizes than their own during FBIs.
• Tasks: Binocular rivalry, food-specific approach-avoidance, body-size estimation, and symptom measures were administered across baseline and FBI sessions.

Main Results:

• At baseline, AN-R participants exhibited heightened perceptual salience and avoidance of high-calorie foods compared to HC.
• Embodying a larger avatar in VR significantly attenuated food avoidance in AN-R participants.
• Healthy controls showed an opposite pattern, with increased avoidance when embodying a larger avatar.

Conclusions:

• Virtual reality-induced body ownership illusions can transiently modify implicit food-related avoidance behaviors in anorexia nervosa.
• The findings suggest a potential therapeutic avenue for AN by manipulating body representation in VR.
• Body ownership and size perception in VR offer a novel approach to understanding and potentially treating eating disorder-related biases.