This study investigates the neural mechanisms underlying the anticipation of monetary rewards and punishments using event-related functional magnetic resonance imaging (fMRI). The nucleus accumbens (NAcc) is a key brain region involved in reward anticipation, but its response to rewards versus punishments remains unclear. The study involved eight healthy volunteers who participated in a monetary incentive delay (MID) task, where they anticipated potential monetary rewards or punishments. The results showed that anticipation of increasing rewards elicited both increased self-reported happiness and NAcc activation, while anticipation of punishments did not. However, anticipation of both rewards and punishments activated a different striatal region, the medial caudate. At the highest reward level ($5.00), NAcc activation was correlated with individual differences in self-reported happiness elicited by the reward cues. These findings suggest that while other striatal areas may code for expected incentive magnitude, the NAcc codes for expected positive incentive value. The study highlights the selective recruitment of the NAcc during reward anticipation and provides evidence for its role in processing positive incentive value. The results also indicate that the medial caudate may code for expected incentive magnitude. The study used a parametric version of the MID task to examine the graded response of the NAcc to varying amounts of potential reward versus punishment and its relationship to cue-elicited emotional responses. The findings contribute to the understanding of the neural basis of reward anticipation and its emotional correlates.This study investigates the neural mechanisms underlying the anticipation of monetary rewards and punishments using event-related functional magnetic resonance imaging (fMRI). The nucleus accumbens (NAcc) is a key brain region involved in reward anticipation, but its response to rewards versus punishments remains unclear. The study involved eight healthy volunteers who participated in a monetary incentive delay (MID) task, where they anticipated potential monetary rewards or punishments. The results showed that anticipation of increasing rewards elicited both increased self-reported happiness and NAcc activation, while anticipation of punishments did not. However, anticipation of both rewards and punishments activated a different striatal region, the medial caudate. At the highest reward level ($5.00), NAcc activation was correlated with individual differences in self-reported happiness elicited by the reward cues. These findings suggest that while other striatal areas may code for expected incentive magnitude, the NAcc codes for expected positive incentive value. The study highlights the selective recruitment of the NAcc during reward anticipation and provides evidence for its role in processing positive incentive value. The results also indicate that the medial caudate may code for expected incentive magnitude. The study used a parametric version of the MID task to examine the graded response of the NAcc to varying amounts of potential reward versus punishment and its relationship to cue-elicited emotional responses. The findings contribute to the understanding of the neural basis of reward anticipation and its emotional correlates.