The neural basis of regret and relief during a sequential risk-taking task.

Regret and relief are associated with counterfactual thinking and are sensitive to various social contexts. In the present fMRI study, we investigated the neural basis for regret and relief and how social context (following vs. not following advice) modulates them by employing a sequential risk-taking task. Participants were asked to open a series of boxes consecutively until they decided to stop. Each box contained a reward (gold), except for one that contained an adverse stimulus (devil), which caused the participant to lose all the gold collected in that trial. Before each trial, participants received advice about when to stop, which they then chose to follow or not. Behaviorally, subjective regret and relief were primarily dependent on the number of missed chances and the trade-off between obtained gains and missed chances, respectively. Participants felt less regret when they chose not to follow the advice than when they did. At the neural level, striatum, vmPFC/mOFC, and vACC activations were associated with greater relief. Meanwhile, dmPFC and left superior temporal gyrus were associated with greater regret. Additionally, dACC showed stronger activation in the Not-Follow context than the Follow context.