Hemispheric differences in body image in anorexia nervosa.

OBJECTIVE: This study tested the hypothesis that women with anorexia nervosa (AN) have an inappropriately fatter body image in the left cerebral hemisphere (LH) than in the right cerebral hemisphere (RH).
METHOD: Women with AN symptomatology were compared with thin controls in a divided visual field experiment. Distorted and undistorted pictures of their own and someone else's body were flashed briefly in the left and right visual fields. Participants judged the pictures as thinner than, equal to, or fatter than the actual body size.
RESULTS: The AN participants judged a higher proportion of fatter distortions as equal to their own size. They responded faster when stimuli were presented initially to the LH than when they were presented initially to the RH. In contrast, fewer thinner distortions were judged as equal to their own body size, and were judged more slowly, on LH trials than on RH trials. Controls did not show hemispheric differences when judging their own body and AN participants did not show hemispheric differences when judging pictures of somebody else. Additional analyses revealed that these findings were carried entirely by a subgroup who had AN in the past, not by the subgroup who currently had AN. DISCUSSION: The brain lateralization paradigm may prove useful in understanding body image disturbance in AN patients. Copyright 2001 by John Wiley & Sons, Inc.