Caudate responses to reward anticipation associated with delay discounting behavior in healthy youth

BACKGROUND Choices requiring delay of gratification made during adolescence can have significant impact on life trajectory. Willingness to delay gratification can be measured using delay discounting tasks that require a choice between a smaller immediate reward and a larger delayed reward. Individual differences in the subjective value of delayed rewards are associated with risk for development of psychopathology including substance abuse. The neurobiological underpinnings related to these individual differences early in life are not fully understood. Using functional magnetic resonance imaging (fMRI), we tested the hypothesis that individual differences in delay discounting behavior in healthy youth are related to differences in responsiveness to potential reward. METHOD Nineteen 10-14 year-olds performed a monetary incentive delay task to assess neural sensitivity to potential reward and a questionnaire to measure discounting of future monetary rewards. RESULTS Left ventromedial caudate activation during anticipation of potential reward was negatively correlated with delay discounting behavior. There were no regions where brain responses during notification of reward outcome were associated with discounting behavior. CONCLUSIONS Brain activation during anticipation of potential reward may serve as a marker for individual differences in ability or willingness to delay gratification in healthy youth.