Summary
Social Decision-making is driven by normative influence (leading to public compliance) and informational influence (overwriting private beliefs), but how the brain encodes these modulating forces in probabilistic environments remains unanswered. Using a novel goal-directed learning paradigm in 185 participants, we observed opposite effects of group consensus on choice and confidence: people succumbed to the group when confronted with dissenting information, but increased their confidence when observing confirming information. Leveraging computational modeling and functional neuroimaging we captured the nuanced distinction between normative and informational influence, and identified their unique but interacting neural representations in the right temporoparietal junction (processing social information) and in prefrontal cortices (representing value computations), whose functional coupling instantiates a reward prediction error and a novel social prediction error that modulate behavioral adjustment. These results suggest that a closed-loop network between the brain’s reward hub and social hub supports social influence in human decision-making.
Footnotes
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