Electrocortical Processing of Food and Emotional Pictures in Anorexia

Objective: To compare the electrocortical processing of food pictures in participants with anorexia nervosa (n = 21), bulimia nervosa (n = 22), and healthy controls (HCs) (n = 32) by measuring the early posterior negativity, an event-related potential that reflects stimulus salience and selective attention. Methods: We exposed these three groups to a rapid stream of high- and low-calorie food pictures, as well as standard emotional and neutral pictures. Results: Event-related potentials in the time range of 220 milliseconds to 310 milliseconds on posterior electrodes differed between groups: patients with eating disorders showed facilitated processing of both high- and low-calorie food pictures relative to neutral pictures, whereas HC participants did so only for the high-calorie pictures. Subjective palatability of the pictures was rated highest by patients with anorexia nervosa, followed by the HC and bulimia nervosa groups. Conclusions: Patients with eating disorders show a generalized attentional bias for food images, regardless of caloric value. This might explain the persistent preoccupation with food in these individuals. Key words: anorexia nervosa, bulimia nervosa, early posterior negativity, event-related potentials, food pictures, attentional bias. ANOVA = analysis of variance; AN = anorexia nervosa; BN = bulimia nervosa; EDs = eating disorders; DSM-IV = Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; EPN = early posterio