科学美国人60秒:Anorexics Move as Though They Are Larger

People with anorexia see themselves as heavier than they actually are. But does this distorted self-image inform unconscious behavior? Scientists are opening doors to find out. Literally.

Body image and doorways are linked, because the ability to navigate your environment depends on a sense of how the body exists in space. For example, your unconscious perception of your body's width makes you automatically swivel your shoulders to squeeze through a narrow opening.

To test this kind of body perception in anorexic patients, researchers recruited 39 women, 19 with anorexia and 20 without the condition. All 39 women walked through portals of varying sizes while performing a distracting memorization task. The non-anorexics began turning their shoulders to edge through when openings got down to 25% wider than their bodies. But the anorexics, perceiving themselves as large, started turning when the openings were 40% wider than their bodies. The study is in the journal PLoS ONE. [Anouk Keizer et al., Too Fat to Fit through the Door: First Evidence for Disturbed Body-Scaled Action in Anorexia Nervosa During Locomotion]

The researchers say that body image distortion thus affects not just perception, but action—which could have implications for treatments.

—Sophie Bushwick