Positive mood enhances reward-related neural activity

Abstract

Although behavioral research has shown that positive mood leads to desired outcomes in nearly every major life domain, no studies have directly examined the effects of positive mood on the neural processes underlying reward-related affect and goal-directed behavior. To address this gap, participants in the present fMRI study experienced either a positive (n = 20) or neutral (n = 20) mood induction and subsequently completed a monetary incentive delay task that assessed reward and loss processing. Consistent with prediction, positive mood elevated activity specifically during reward anticipation in corticostriatal neural regions that have been implicated in reward processing and goal-directed behavior, including the nucleus accumbens, caudate, lateral orbitofrontal cortex and putamen, as well as related paralimbic regions, including the anterior insula and ventromedial prefrontal cortex. These effects were not observed during reward outcome, loss anticipation or loss outcome. Critically, this is the first study to report that positive mood enhances reward-related neural activity. Our findings have implications for uncovering the neural mechanisms by which positive mood enhances goal-directed behavior, understanding the malleability of reward-related neural activity, and developing targeted treatments for psychiatric disorders characterized by deficits in reward processing.

Keywords: corticostriatal circuit; mood induction; nucleus accumbens; positive mood; reward.

Fig. 1.

The (A) trial structure and (B) possible reward and loss cues of the monetary incentive delay (MID) task used to examine reward and loss anticipation and outcome.

Fig. 2.

Happy, excited, sad, and tense ratings pre- and post- mood induction for positive and neutral mood induction groups. The efficacy of the positive mood induction is demonstrated by increased happy and excited ratings after induction in the positive mood induction group, and unchanged ratings in the neutral mood induction group. Note: error bars represent standard error of the mean (SEM).

Fig. 3.

Brain regions that showed a significant Group (positive mood induction vs neutral mood induction) × Value (reward vs loss) interaction during the anticipation period. The positive mood induction group showed greater activity than the neutral mood induction group during reward anticipation in the left ventromedial prefrontal cortex (VMPFC), left nucleus accumbens (NAc), right caudate, left putamen, left lateral orbitofrontal cortex (OFC), and left anterior insula. The positive mood induction group, in contrast, showed reduced or equivalent activity than the neutral mood induction group during loss anticipation. Note: error bars represent standard error of the mean (SEM).