The estimation of body mass index and physical attractiveness is dependent on the observer's own body mass index.

A disturbance in the evaluation of personal body mass and shape is a key feature of both anorexia and bulimia nervosa. However, it is uncertain whether overestimation is a causal factor in the development of these eating disorders or is merely a secondary effect of having a low body mass. Moreover, does this overestimation extend to the perception of other people's bodies? Since body mass is an important factor in the perception of physical attractiveness, we wanted to determine whether this putative overestimation of self body mass extended to include the perceived attractiveness of others. We asked 204 female observers (31 anorexic, 30 bulimic and 143 control) to estimate the body mass and rate the attractiveness of a set of 25 photographic images showing people of varying body mass index (BMI). BMI is a measure of weight scaled for height (kg m(- 2)). The observers also estimated their own BMI. Anorexic and bulimic observers systematically overestimated the body mass of both their own and other people's bodies, relative to controls, and they rated a significantly lower body mass to be optimally attractive. When the degree of overestimation is plotted against the BMI of the observer there is a strong correlation. Taken across all our observers, as the BMI of the observer declines, the overestimation of body mass increases. One possible explanation for this result is that the overestimation is a secondary effect caused by weight loss. Moreover, if the degree of body mass overestimation is taken into account, then there are no significant differences in the perceptions of attractiveness between anorexic and bulimic observers and control observers. Our results suggest a significant perceptual overestimation of BMI that is based on the observer's own BMI and not correlated with cognitive factors, and suggests that this overestimation in eating-disordered patients must be addressed directly in treatment regimes.

A computer-graphic technique for the study of body size perception and body types.

We present a novel approach for measuring body size estimation in normal and eating-disordered women and men. Clinical categories of body types were used as prototypes. By comparing the subjective appearance of a person's body with prototypes, we can understand how different attributes of his or her body shape contribute to perception of body size. After lifelike random distortions have been applied to parts of their body image, individuals adjust their body shapes until they converge on their perceived veridical appearance. Exaggeration and minimization of particular body areas measured with respect to their true shape and with different prototypes can be expressed as numerical deviations. In this way, perceived body size and body attractiveness can be appraised during the course of diagnosis and treatment of eating disorders.

Working memory: trouble in mind.

Visual working memory has been found to depend on interactions between the prefrontal cortex and visual association areas; the neurons involved can be modulated by dopamine. These new findings have relevance for the treatment of Parkinson's disease and schizophrenia.

Depressed mood and concern with weight and shape in normal young women.

The possible role of depression in accentuating the concerns with weight and shape found in some members of the normal female population was investigated using mood induction procedures. A depressed mood was induced in two groups of normal young women; a group placing a high personal value on shape or weight, and a group placing a low value on shape and weight. The concerns with shape were significantly elevated in the former group compared with the latter. This result is consistent with a mechanism for the development of a disturbance in body image proposed by Cooper and Taylor (British Journal of Psychiatry 153 [Suppl. 2] 20-22, 1988).