جانبداری حافظه آشکار برای نشانه های والانس مثبت مرتبط با بدن در زنان مبتلا به اختلال پرخوری افراطی

Overweight women with and without binge eating disorder (BED) are characterized by a marked body dissatisfaction, which may in part be due to the negative comments about their weight. Weight-related teasing and discrimination is reported both by healthy overweight women and women with BED, whereas body dissatisfaction is markedly increased among women with BED. Therefore, a memory bias for negatively valenced body-related cues is suspected to occur as a mediating factor in women with BED. In an experimental study, 18 women with BED were compared to 18 overweight healthy female controls (HC) on a free recall task containing four word categories: positively valenced with and without body-related content and negatively valenced with and without body-related content. While both groups showed a bias towards negatively valenced shape-/weight-related words, women with BED retrieved positively valenced shape-/weight-related words significantly less often compared to overweight HC. Findings suggest that it may be the reduced ability to attend to positively valenced shape-/weight-related information, rather than the activation of negative body schemata that differentiates overweight women with BED from overweight women without BED. Results are discussed in the context of cognitive biases in the maintenance of body dissatisfaction.

The overevaluation of shape and weight and corresponding concerns are core features that characterize both overweight women (Cash, 1995, Eisenberg et al., 2003, Gleason et al., 2000 and Grilo et al., 1994) and women with binge eating disorder (BED; Eldredge and Agras, 1996, Hay and Fairburn, 1998, Hilbert and Tuschen-Caffier, 2005, Spitzer et al., 1993, Striegel-Moore et al., 1998, Telch and Stice, 1998, Wilfley et al., 2000 and Wilson et al., 1993), of whom mostly are overweight and obese (e.g., Cachelin et al., 1999 and Striegel-Moore and Franko, 2003). Given the evidence of a systematic discrimination including weight-related teasing of overweight and obese individuals with and without BED (Brownell et al., 2005, Crandall, 1995, Ding and Stillman, 2005, Fairburn et al., 1998, Falkner et al., 1999, Grilo and Masheb, 2001, Maranto and Stenoien, 2000, Neumark-Sztainer et al., 2002, Pingitore et al., 1994, Puhl and Brownell, 2001 and Strauss and Pollack, 2003), it is comprehensible that these women are marked considerably by shape and weight concerns compared to normal weight individuals. However, there is evidence that overweight women with BED are even more dissatisfied with their body than overweight women without BED. For example, a study conducted by Svaldi, Caffier, Blechert, and Tuschen-Caffier (2009) found women with BED to score almost twice as high on the body shape questionnaire (Cooper, Taylor, Cooper, & Fairburn, 1987) than a healthy overweight control group. Considering the comparable exposure to negative comments about shape and weight, it is still unclear why women with BED are so much more dissatisfied with their body than overweight women without eating disorders. Cognitive theories about the cause and maintenance of body dissatisfaction have focused on the relevance of cognitive biases. Vitousek and Hollon (1990) suggest that cognitive biases in eating disorders may arise from maladaptive schemata associated with food, shape, weight and self. In line with that, Williamson, Muller, Reas, and Thaw (1999) propose that such cognitive biases of attention, memory, judgment and body-image are responsible for the typical eating, shape and weight concerns eating-disordered patients usually express. Empirical evidence for a memory bias stems from a study conducted by Sebastian, Williamson, and Blouin (1996). The authors compared 30 eating-disordered subjects (AN, BN and eating disorders not otherwise specified [EDNOS]), 30 weight preoccupied controls and 30 healthy controls on a word recall memory task including fatness-related, nonfat and neutral words. Results indicate that eating-disordered subjects recalled significantly more fatness-related cues compared to the two control groups. Similarly, Hermans, Pieters, and Eelen (1998) used a recall test to compare patients with AN to healthy controls (HC) using four types of words: AN-related and three types of AN-unrelated words (positively, negatively valenced and neutral). Results revealed that patients with AN recalled significantly more AN-related words than words from the other categories, while there was no such difference in HC. The transfer of such a theory to BED has its limitations, however. First of all, studies testing memory bias in eating disorders have yielded contradictory results. For example, Hermans et al. (1998) did not find any difference between patients with AN and HC on a word completion task. Similarly, Sebastian et al. (1996) found subjects with various eating disorders to retrieve significantly more fatness-related words than control words, but the authors did not include positively valenced words and did not control for levels of depression. Hence, rather than being the result of an activation of negative self-schemata, the bias for fatness-related stimuli may have been a bias for negative words in general. Second, and more importantly, there is evidence of a bias towards negative body-related words in overweight individuals as well. For example King, Polivy, and Herman (1991) compared restrained and unrestrained eaters, patients with AN and obese women on the words they would retrieve from an essay. Included target words was weight-, food-, and appearance-related information. Results revealed that similar to patients with AN, obese women recalled significantly more weight- and food-related items than other items. Given the comparable experience of stigmatization reported by overweight women with and without BED, the bias towards negative body-related information may thus not be the differentiating factor between overweight women with and without BED. In a study conducted by Agliata, Tantleff-Dunn, and Renk (2007), girls with high body dissatisfaction recalled significantly fewer positively valenced body-related words compared to negatively valenced and neutral words. Hence, the capacity to focus on positive body-related information may be a protective factor against body dissatisfaction. We reasoned that such a skill may be even more important in the face of frequent weight teasing and discrimination. In light of the research just mentioned, the following hypotheses were stated. First, both women with BED and overweight women without BED are supposed to be characterized by a memory bias towards negatively valenced shape and weight-related cues. Second, compared to overweight women without BED, women with BED are supposed to have a reduced explicit memory recall for positively valenced shape and weight-related cues.