The study investigates the role of dopamine-dependent prediction errors in reward-seeking behavior in humans. Using a combination of behavioral, pharmacological, computational, and functional magnetic resonance imaging techniques, the researchers found that the magnitude of reward prediction errors in the striatum is modulated by the administration of drugs enhancing (l-DOPA) or reducing (haloperidol) dopaminergic function. Subjects treated with l-DOPA showed a greater propensity to choose the most rewarding action compared to those treated with haloperidol. The study also demonstrated that incorporating the magnitude of prediction errors into a standard action-value learning algorithm accurately reproduced subjects' behavioral choices under different drug conditions. These findings suggest that dopamine-dependent modulation of striatal activity is crucial for how the human brain uses reward prediction errors to improve future decisions. The results provide new insights into the functional link between dopamine, striatal activity, and reward-seeking behavior, and may have implications for understanding clinical disorders such as Parkinson's disease and schizophrenia.The study investigates the role of dopamine-dependent prediction errors in reward-seeking behavior in humans. Using a combination of behavioral, pharmacological, computational, and functional magnetic resonance imaging techniques, the researchers found that the magnitude of reward prediction errors in the striatum is modulated by the administration of drugs enhancing (l-DOPA) or reducing (haloperidol) dopaminergic function. Subjects treated with l-DOPA showed a greater propensity to choose the most rewarding action compared to those treated with haloperidol. The study also demonstrated that incorporating the magnitude of prediction errors into a standard action-value learning algorithm accurately reproduced subjects' behavioral choices under different drug conditions. These findings suggest that dopamine-dependent modulation of striatal activity is crucial for how the human brain uses reward prediction errors to improve future decisions. The results provide new insights into the functional link between dopamine, striatal activity, and reward-seeking behavior, and may have implications for understanding clinical disorders such as Parkinson's disease and schizophrenia.