Reward-Based Spatial Learning in Teens With Bulimia Nervosa

Abstract

Objective To assess the functioning of mesolimbic and fronto-striatal areas involved in reward-based spatial learning in teenaged girls with bulimia nervosa (BN) that might be involved in the development and maintenance of maladaptive behaviors characteristic of the disorder. Method We compared functional magnetic resonance imaging blood oxygen level dependent response in 27 adolescent girls with BN to that of 27 healthy, age-matched control participants during a reward-based learning task that required learning to use extra-maze cues to navigate a virtual 8-arm radial maze to find hidden rewards. We compared groups in their patterns of brain activation associated with reward-based spatial learning versus a control condition in which rewards were unexpected because they were allotted pseudo-randomly to experimentally prevent learning. Results Both groups learned to navigate the maze to find hidden rewards, but group differences in brain activity associated with maze navigation and reward processing were detected in fronto-striatal regions and right anterior hippocampus. Unlike healthy adolescents, those with BN did not engage right inferior frontal gyrus during maze navigation, activated right anterior hippocampus during the receipt of unexpected rewards (control condition), and deactivated left superior frontal gyrus and right anterior hippocampus during expected reward receipt (learning condition). These patterns of hippocampal activation in the control condition were significantly associated with the frequency of binge-eating episodes. Conclusion Adolescents with BN displayed abnormal functioning of anterior hippocampus and fronto-striatal regions during reward-based spatial learning. These findings suggest that an imbalance in control and reward circuits may arise early in the course of BN. Clinical trial registration information An fMRI Study of Self-regulation in Adolescents With Bulimia Nervosa; https://clinicaltrials.gov/ct2/show/NCT00345943; NCT00345943.

Altered regional gray matter volume in Chinese female patients with bulimia nervosa

“…The structural and functional abnormalities in the SFG in patients with BN or other eating disorders have been associated with deficits in self-regulation and reward processing [23]. Functional MRI studies have shown the SFG to be deactivated in BN in the presence of the expected reward during a reward-based learning task [24], during a Simon spatial incompatibility task [23]. The prefontal cortex is an important part of the fronto-striatal circuits, which is involved in selfregulatory control.…”

The Neurobiology of Eating Disorders

“…Other studies showed less frontal cortical, ventral striatal, and hippocampus activation in BN, which correlated with binge or purge frequency in a task that provided monetary reward when navigating through a maze. 78,79 Therefore, altered learning, executive control, and reward brain response could be effects of both abnormal brain development and BN illness behavior.…”

Reduced Inferior and Orbital Frontal Thickness in Adolescent Bulimia Nervosa Persists Over Two-Year Follow-Up

“…Previous cross-sectional findings from adolescents and adults with BN suggest that disturbances in control, reward, and learning processes underlie these symptoms due, in part, to functional 1–4 and anatomical 5, 6 alterations in fronto-striatal circuits, particularly inferior and orbital frontal regions. Previous cross-sectional findings suggested reduced cortical thickness (CT) and smaller local volumes on the surface of lateral frontal gyri in adolescents and adults with BN relative to their healthy counterparts.…”