Association between uncontrolled eating and caudate responses to reward cues
Reward sensitivity has been hypothesized to play a significant role in a range of eating behaviors, including overeating. Previous functional magnetic resonance imaging (fMRI) findings in overweight individuals indicate heightened responses to food, but also to other reward types, suggesting generalized overactivity of the reward system. The current fMRI study investigated the relationship between general reward sensitivity and eating behavior in normal-weight individuals, while controlling for trait impulsivity. Participants were young adults, some demonstrating ADHD symptoms, allowing for a range of impulsivity profiles. A classical conditioning task was used to measure striatal responses to monetary reward stimuli. Uncontrolled eating scores from the Three Eating Factor Questionnaire were positively correlated with caudate responses to reward predicting cues. This association was not explained by self-reported impulsivity. The current findings provide support for heightened reward anticipation as a neural phenotype contributing to overeating.