The role of perception in eating disorders

honors thesisCollege of Social & Behavioral SciencePsychologyJeanine StefanucciIndividuals with eating disorders often suffer from severe body dissatisfaction and distorted perceptions of the body (Bruch, 1969; Cash & Deagle, 1997; Farrell, Lee, & Shafran, 2005). Though populations with eating disorders may perceive their body sizes differently, most previous work has investigated body misperception using measures assessing memory for body shape and size rather than actual perception (see Smeets, 1997). This research examined whether distorted perceptions in individuals with eating disorders are truly perceptual, and whether these biases occur for all parts of one's body or only those areas often associated with the most body dissatisfaction (e.g., hips and stomach). Clinical (individuals with a history of anorexia nervosa, bulimia nervosa, and/or eating disorder not otherwise specified; (n=28)) and nonclinical samples (n=116) completed five perceptual measures of action capability that involved judging whether they could 1) walk straight through a doorway (passability), 2) walk sideways through a doorway (sidestepping), 3) pick up a box (grasping), 4) jump a distance (jumping), and 5) walk under a horizontal barrier (height). Eating disorder assessments were also employed, which included the Eating Attitudes Test (EAT) the Thought-Shape Fusion questionnaire (TSF), the Binge Eating Scale (BES) and the Intuitive Eating Scale (IES). Additionally, Body Mass Index (BMI) was calculated for each participant. The clinical sample significantly overestimated height and significantly underestimated hand size (measuring a neutral body part) while accurately perceiving passability (measuringbody width), sidestepping (measuring body depth) and jumping ability (measuring a weight/size-dependent task). The nonclinical sample significantly overestimated height and jumping ability, significantly underestimated hand size, and accurately perceived passability and sidestepping. In the clinical sample, perceptual judgments of passability significantly positively correlated with EAT (r=.350, p<.05) scores. Perceptual judgments of sidestepping significantly positively correlated with BMI (r=.345, p<.05). No significant correlations were found for perceptual measures and eating disorder assessments in the nonclinical sample. The results suggest that individuals with and without eating disorders differentially misperceive body parts. Additionally, for individuals with eating disorders, an eating disorder assessment score correlated with the perceptual measure (passability) referencing a specific dimension of the body (hips and stomach) for which clinical participants are sensitive. Participants may have used perceptions of body size to decide whether they can perform certain actions. These preliminary findings suggest that body misperception in individuals with eating disorders is at least partly influenced by true perception and that eating disorder screening tools should include perceptual measures, which could provide a method for earlier detection of such disorders