Most of the time, our brains are very good at fusing input from all our senses into a seamless, unified conscious experience of ‘my body.’ When this process of integrating different sensory signals goes wrong, one theory goes, giving people inaccurate and distressing perceptions of their own bodies, a condition called ‘body image disorder.’
There are different types of body image disorder, including dissatisfaction with your body and body misperceptions. Although we don’t know how many people experience body misperceptions, we do know that body dissatisfaction is very common. A survey of more than 1,600 Australians aged 12-18 last year found that almost half were unhappy with the way they looked.
Body image disorders are closely related to eating disorders and body dysmorphic disorder (a perceived flaw in one’s appearance), and existing treatments for these disorders have high relapse rates.
In our latest paper, my colleagues and I reviewed evidence that a surprising approach may address the root causes of these disorders and ameliorate their symptoms: “embodiment illusion,” which uses virtual reality and other methods to trick the mind into thinking it is inhabiting a different body or body part.
Flexible body image
Perhaps the best-known embodiment illusion is the “rubber hand illusion.” When you show someone stroking a rubber hand while simultaneously stroking their own hand (which is invisible), the combination of vision and touch often makes the person feel like they “own” the rubber hand.
With virtual reality, this illusion can also be extended to other parts of the body, or even the entire body.
A systematic review of 32 previous studies found compelling evidence that individuals with higher levels of body image disturbance tend to be more susceptible to such somatization illusions than others.
High flexibility in remapping body image is consistent with theories suggesting that body image disorders involve impaired multisensory integration.
For example, relying more on vision than touch might lead you to value seeing your skinny self in the mirror more than touching your protruding ribs. This can occur in combination with prioritizing expectations (e.g., “my body should be skinnier”) over accurate sensory input.
Positive Effects
And most studies have shown that tricking the brain into experiencing these illusions actually has some positive effects: participants experienced reduced perceptual distortions about their body size and shape, as well as distressing thoughts and feelings.
The idea is to experience the artificial body as one’s own, and this can “update” rigid and distorted mental representations of an individual’s actual physical appearance, especially if that body appears to have a desired shape and size.
In one study, women with anorexia were given a virtual reality avatar of a healthy weight, and afterwards they were less likely to overestimate their (real-life) body size than they were before the experiment.
Another study found that healthy women reported feeling thinner and less dissatisfied with their bodies after identifying with a fictional thin body.
New treatments needed
Treating body image-related conditions, such as eating disorders and body dysmorphic disorder, is extremely difficult, and recovery can take a long time.
The first-line treatment for many of these disorders is cognitive behavioral therapy, which primarily targets negative thoughts, feelings, and behaviors related to the body, but relapse rates are high.
This is one of the reasons for the search for new complementary therapies that directly address our false perception of the body: Here, embodiment illusions, which can change distorted perceptions, may be useful.
Many questions remain
There’s still a lot we don’t know about how body illusions affect people with misidentified bodies, including how long potential treatments last and how long their effects last. We also need better ways to measure body image disturbances. Another limitation of existing studies is their bias towards participants from Western cultures.
Future research could also explore the “enfacement illusion,” which induces a sense of ownership over another face, which could help understand and improve face misidentification, especially in people with body dysmorphic disorder.
Disrupting people’s bodily self-awareness is inherently dangerous, and the potential negative effects of such illusions, such as increased misperception of body size and shape, require further research.
There are also ethical concerns: Even if anorexics are dangerously underweight, could experiencing a “healthy weight” body reduce their motivation to gain weight?
Despite these doubts, the use of immersive illusions to temporarily remap body image shows promise and may represent an innovative complementary approach to understanding and treating painful body image distortions alongside current therapies.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
