Neural responses to intention and benefit appraisal are critical in distinguishing gratitude and joy.

Gratitude and joy are critical for promoting well-being. However, the differences between the two emotions and corresponding neural correlates are not understood. Here we addressed these issues by eliciting the two emotions using the same stimuli in an fMRI task. In this help reception task, participants imagined them in a situation where they need financial aid. Critically, we manipulated the benefactor's intention to provide help and the value of the benefit. Behaviorally, gratitude was stronger than joy when the benefactor-intention was strong and the benefit-value was low compared to other conditions. In parallel, gratitude activated mentalizing-related (e.g. precuneus) and reward-related regions (e.g. putamen) more strongly than joy in corresponding conditions compared to others. Moreover, gratitude was more negatively (or less positively) encoded in the region associated with mentalizing (i.e. the left superior temporal gyrus) than joy. Multivariate pattern analysis further demonstrated that the modulation patterns of benefactor-intention and benefit-value in mentalizing-related (e.g. precuneus, temporo-parietal junction) and reward-related regions (e.g. putamen, perigenual anterior cingulate/ventromedial prefrontal cortex) could distinguish the two emotions. The findings suggest that benefactor-intention and benefit-value appraisal and their neural correlates are critical in distinguishing gratitude and joy. Direct implications for gratitude interventions were discussed.