Alterations in neural processing of emotional faces in adolescent anorexia nervosa patients – an event-related potential study

• Neurophysiological correlates of face processing in anorexia nervosa patients.
• Adolescent anorexia nervosa patients were compared to healthy controls.
• Patients exhibited a less pronounced EPN in response to all facial expressions.
• No group differences in earlier (P100, N170) and later (LPP) processing stages.
• No behavioural group differences.

The present study explored the neurophysiological correlates of perception and recognition of emotional facial expressions in adolescent anorexia nervosa (AN) patients using event-related potentials (ERPs). We included 20 adolescent girls with AN and 24 healthy girls and recorded ERPs during a passive viewing task and three active tasks requiring processing of emotional faces in varying processing depths; one of the tasks also assessed emotion recognition abilities behaviourally. Despite the absence of behavioural differences, we found that across all tasks AN patients exhibited a less pronounced early posterior negativity (EPN) in response to all facial expressions compared to controls. The EPN is an ERP component reflecting an automatic, perceptual processing stage which is modulated by the intrinsic salience of a stimulus. Hence, the less pronounced EPN in anorexic girls suggests that they might perceive other people’s faces as less intrinsically relevant, i.e. as less “important” than do healthy girls.