Anomalous lateral dominance patterns in women with eating disorders: clues to neurobiological bases.

OBJECTIVES We tested the hypothesis that there is differential hemispheric functioning in women with eating disorders as compared to controls. METHOD A divided visual field paradigm, with a language task [for which we assume left hemisphere (LH) specialization] and a spatial task [for which we assume right hemisphere (RH) specialization]. The participants were 20 healthy women, 17 women with anorexia nervosa (AN), and 18 women with bulimia nervosa (BN). RESULTS The groups did not differ in accuracy. The latency of responses revealed different asymmetry patterns among the groups. The AN group was indistinguishable from the control group in the spatial task, and showed no evidence of LH specialization for the language task. The BN group revealed evidence for LH specialization in the language task, but no specialization in the spatial task. DISCUSSION Our results converge with other reports of asymmetric functional deficits in AN and BN, and support the hypothesis that AN involves specific LH dysfunction and BN involves specific RH dysfunction.