The study investigates the neural substrates involved in the anticipation of increasing monetary rewards and punishments using event-related functional magnetic resonance imaging (FMRI). Eight healthy volunteers participated in the study, which involved a monetary incentive delay (MID) task. The MID task presented participants with cues indicating potential monetary gains or losses, followed by a variable anticipatory delay and a response period. The results showed that anticipation of increasing rewards led to both increased self-reported happiness and activation in the nucleus accumbens (NAcc), while anticipation of increasing punishments did not elicit such activation. However, 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 also highlights the role of the NAcc in the anticipation of rewards, providing insights into the neural mechanisms underlying reward anticipation and hedonic reactions.The study investigates the neural substrates involved in the anticipation of increasing monetary rewards and punishments using event-related functional magnetic resonance imaging (FMRI). Eight healthy volunteers participated in the study, which involved a monetary incentive delay (MID) task. The MID task presented participants with cues indicating potential monetary gains or losses, followed by a variable anticipatory delay and a response period. The results showed that anticipation of increasing rewards led to both increased self-reported happiness and activation in the nucleus accumbens (NAcc), while anticipation of increasing punishments did not elicit such activation. However, 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 also highlights the role of the NAcc in the anticipation of rewards, providing insights into the neural mechanisms underlying reward anticipation and hedonic reactions.