Most of the time, our brains are excellent at blending input from all our senses into a seamless, unified conscious experience of “my body.” When this process of integrating different sensory signals goes wrong, it can lead to an inaccurate and distressing sense of one’s body, known as “body image disturbance.”

The Need for New Treatments

Treating conditions related to body image, such as eating disorders and body dysmorphic disorder (BDD), is highly challenging, and recovery can take a long time. Cognitive behavioral therapy (CBT) is often the first line of treatment, focusing on negative thoughts, emotions, and behaviors related to the body. However, high relapse rates highlight the need for supplementary treatments that directly address body misperception. Embodiment illusions could be beneficial here.

Exploring Embodiment Illusions

In our latest paper, my colleagues and I reviewed evidence suggesting a novel approach might help address the root causes of these disorders: “embodiment illusions.” These illusions, using virtual reality (VR) or other methods, trick the mind into feeling it inhabits a different body or body part.

One of the best-known embodiment illusions is the “rubber hand illusion.” If you show a person a rubber hand being stroked while simultaneously stroking their hidden hand, the combined visual and tactile sensations usually make the person feel like the rubber hand is part of their body.

With VR, this illusion can be extended to other body parts or even an entire body. Our systematic review of 32 studies found compelling evidence that individuals with higher levels of body image disturbance are more susceptible to embodiment illusions.

Positive Outcomes

Most studies we reviewed showed that inducing these illusions had positive effects. Participants reported improvements in perceptual distortions and reduced distressing thoughts and emotions about body size and shape.

The goal is to experience an artificial body as one’s own, especially if that body has a desirable shape or size. This can help “update” an individual’s distorted mental representation of their actual physical appearance.

For instance, one study involved women with anorexia nervosa using a healthy-weight VR avatar. After the experiment, they overestimated the size of their real bodies less than before. Another study found that healthy women felt thinner and less dissatisfied with their bodies after identifying with a thin virtual body.

Understanding Body Image Disturbance

Body image disturbances can show up in various ways, like dissatisfaction with our bodies or inaccurate perceptions of them. While we don’t have comprehensive data on how many people experience body misperceptions, we know that body dissatisfaction is widespread. For example, a survey last year of more than 1,600 Australians aged 12–18 found that nearly half were unhappy with their appearance.

Body image disturbances are closely linked to eating disorders and BDD, where individuals perceive flaws in their appearance. Current treatments for these disorders often have high relapse rates, indicating the need for more effective solutions.

Unanswered Questions

There are still many unknowns about how embodiment illusions affect people with body misperceptions. For example, we need to understand how long potential treatments should last and how long their effects will persist. We also need better methods for measuring body image disturbances. Existing research shows a bias towards participants from Western cultures.

Future studies might explore “enfacement illusions,” which induce a sense of ownership over another face. This could help in understanding and improving facial misperception, particularly in individuals with BDD.

Altering a person’s perception of their physical self carries inherent risks. Research is needed to explore potential adverse effects of these illusions, such as increased misperception of body size or shape. Ethical concerns also arise; for instance, could experiencing a “healthy-weight” body reduce an anorexic person’s motivation to gain weight, even if they are dangerously underweight?

Expanding Research Horizons

To build on existing research, scientists should consider long-term studies to determine the enduring effects of embodiment illusions. Additionally, exploring diverse populations across different cultures can provide a more comprehensive understanding of these interventions globally.

By expanding research and addressing ethical and practical concerns, embodiment illusions could become a valuable tool for treating body image disturbances, offering hope to those struggling with these challenging conditions.

Despite these questions, the use of immersive illusions to temporarily remap body image shows promise. It may offer an innovative complementary approach for understanding and treating distressing body image distortions alongside current treatments.