Avoidance-driven Decision Making and Learning in Anorexia Nervosa and Bulimia Nervosa

Inclusion Criteria: Eating Disorder Group: * Between the ages of 18 and 39 years old * Meet DSM-V criteria for anorexia nervosa or bulimia nervosa Healthy Controls: * Between the ages of 18 and 39 years old * Have maintained 85% to 120% ideal body weight since menarche Exclusion Criteria: * Psychotic illness/other mental illness requiring hospitalization * Current dependence on drugs or alcohol defined by DSM IV criteria. Additionally, positive test results for drug use on the day of the scan, apart of marijuana, will result in cancelling or rescheduling the scan because acute use will impact MRI measures. * Physical conditions (e.g. diabetes mellitus, pregnancy) known to influence eating or weight * Neurological disorder, neurodevelopmental disorder, or history of head injury with \>30 min loss of consciousness * Any contraindication to undergoing an MRI * Primary obsessive compulsive disorder or primary major depressive disorder Additional Exclusion Criteria for ED Group: * If taking other psychotropic medication, any change in dosage in the 2 weeks before scanning Additional Exclusion Criteria for Healthy Control Group: * Meet criteria for the diagnosis of any psychiatric disorder currently * Any history of binge eating or purging behaviors, including self-induced vomiting, laxative or diuretic misuse * Use of any psychoactive or other medication known to affect mood or concentration in the last 3 months