Prolonged P300 latency in eating disorders

This study investigated event-related potential (ERP) indices of information-processing in eating disorders. ERPs during an auditory two-tone discrimination task were recorded at midline at 3 sites in 28 anorexic patients, 12 low-weight bulimic patients (body mass index (BMI) under 17.5), 12 normal-weight bulimic patients (BMI over 17.5), and 40 control subjects. The P300 latency was significantly prolonged at all sites in both bulimic groups compared with that in controls, and at frontal and central electrode sites in anorexics. In contrast, the P300 amplitude did not differ between these groups at any site. The prolonged P300 latency in eating disorders suggests a task-related slowing of perceptual decisions that reflects their cognitive impairment.