Virtual food for real thought: how to improve extinction learning in anorexia nervosa

People with anorexia nervosa experience intense anxiety at mealtimes.

The anxiety is often related to the prospect of eating and to the consequences of eating, such as weight gain, unmanageable distress, and loss of control over food.

Current psychological treatments of anorexia nervosa encourage patients to develop a more positive relationship with food, but rarely demonstrate the use of practical strategies to cope with food-related anxiety.

This project will use exposure to virtual foods to establish which mechanisms underline successful reduction of food-related anxiety in anorexia nervosa.

Exposure therapy consists of gradual exposure to a feared stimulus and is the most effective treatment of anxiety disorders.

In anorexia nervosa, food exposure has been used with some degree of success to improve eating behaviour and favour weight gain.

However, the mechanisms of food exposure remain largely untested with the result that there is limited understanding of the strategies that can maximise its efficacy. This study will use the novel technology of virtual reality to test the mechanisms of food exposure.

Virtual reality enables researchers to create environments that resemble those experienced in real life, while ensuring high levels of control over the variables which are measured.

Participants with anorexia nervosa will be exposed to a virtual kitchen and asked to explore as many virtual food items as possible.

Their anxiety and behaviours in response to the virtual foods will be recorded (e.g. looking at, approaching, grabbing, holding virtual foods).

Each participant will be assigned by chance to one of three conditions: exposure to virtual foods (1), exposure to virtual foods while interacting with a virtual pet showing affection (2) and exposure to virtual foods while interacting with a talking human-like character (AVATAR) that encourages to challenge the eating disorder voice (3).

Following exposure to the virtual kitchen, participants will be invited to take part in a taste-test, during which anxiety and behaviours in response to a range of real foods will be measured.

The hypothesis is that participants exposed to the virtual foods while also receiving positive mood induction or recovery-focused social support will experience a greater reduction in food-related anxiety and will approach food more, both in the virtual environment and during the taste-test, compared to participants who only receive exposure to virtual foods.

This study will prove the efficacy of food exposure, positive mood induction and recovery-oriented social support to help people with anorexia nervosa to cope with eating-related anxiety.

The clinical potential of this project is to develop a novel intervention that helps people creating a positive relationship with food.

The use of virtual reality ensures that the intervention can be easily disseminated to, and used by, patients over time and in their own environments.