Reduced early visual processing of own body images in anorexia nervosa: An event-related potentials study

Introduction. Although body image distortion in anorexia nervosa (AN) has been extensively studied over the past decades, its underlying mechanisms are not yet fully understood. Neuro-imaging studies have identified functional and structural alterations in brain areas involved in visual body perception, but the time course of visual body processing in AN remains mostly unexplored. The current study used event-related brain potentials (ERPs) to investigate single processing steps along the time course, particularly the visual processing of physical body image characteristics (featural processing, P1) and the recognition of a body as such (configural processing, N1). Methods. Twenty in-patients with AN, and 20 healthy women viewed photographs of themselves, of another woman’s body and of their own and another woman’s standardized object (cup) with concurrent EEG recording. Results. Body images elicited an accentuation of the P1 component (105-160 ms), which was absent for the comparison between own-body and own-cup images in the AN group. Results regarding the N1 component suggest alterations in object processing in AN. Conclusions. Our results demonstrate that individuals with AN show reduced featural processing of their own body image, a process which, due to its position early in the visual processing stream, is unlikely to involve higher cognitive stimulus processing. This suggests a possible role of previously undetected pre-conscious mechanisms in body image disturbance