Body image-a person’s sense of his or her own body-is highly malleable. For example, people with anorexia nervosa may begin perceiving themselves as fat even when they are thin, and people who have a unilateral amputation can reduce phantom limb pain by viewing their intact limb in a mirror while imagining it is their missing limb. Now, European researchers speculate that the malleability of body image may lead to novel treatments for certain movement problems.
G. Lorimer Mosely, PhD, of the University of Oxford, England, and P. Brugger, PhD, of University Hospital Zurich, Switzerland, conducted a study reported in the Proceedings of the National Academy of Sciences online version for November 3. The study was meant to determine whether body image can be altered by imagination alone, and whether body image necessarily conforms to the natural physics of the human body. In the study, seven transradial amputee participants with vivid phantom-limb sensations imagined spinning their missing hand 360 degrees, as if the missing wrist joint was a pivot. Four participants reported succeeding said that they now experienced a greater sense of control over the wrist. Two of the ones who succeeded said that they now found it more difficult to move the phantom hand from side to side because of the arm’s new shape.
As part of the study, Mosely and Brugger also used a test of reaction time that required the participants to determine whether an image was of a left or a right hand. Previous research has shown that response time in this test corresponds to how long it would take the test taker to rotate his or her own arm to match the position of the image. Before working to master the spinning-wrist exercise, all participants responded fastest if the image was positioned similarly to their intact hand. After the imagination training, the four participants who succeeded responded even more quickly to images that matched the missing hand, meaning that they could mentally “spin” the hand on its new joint.
According to the researchers, these findings a “speculative, but not outrageous” possibility that persons with mobility problems due to a variety of conditions, including stroke and back pain, could achieve some relief by changing their body image of the effected body part or parts.
