Being right, but losing money: the role of striatum in joint decision making

Joint decision-making entails that you sometimes have to go along with the other's choice even though you disagree. In this situation, a resulting negative outcome may, however, elicit a feeling of satisfaction and an impulse to say "I told you so". Using fMRI, we investigated the neural correlates of this complex process comprised of both positive and negative outcomes. During a social visual search task, 19 participants gave their advice to a co-actor who then made the decision resulting in a mutual loss or gain. This design allowed direct comparisons of situations that resulted in the same monetary outcome but that differed with respect to the correctness of the initial advice of the participant. Increased striatal activations were found for gains compared to losses and for correct compared to incorrect advice. Importantly, ROI analyses also showed enhanced striatum activation for monetary losses that were preceded by correct compared to incorrect advices. The current study therefore suggests that reward-related neural mechanisms may be involved when being right even in situations that end in monetary losses.