Deciding about courses of action involves an estimation of costs and benefits. Decision neuroscience studies have suggested a dissociation between the ventral and dorsal medial prefrontal cortex (vmPFC and dmPFC), which would process reward value and effort cost, respectively. However, several results appeared inconsistent with this general idea of opponent reward and effort systems. These contradictions might reflect the diversity of tasks used to investigate the trade-off between effort cost and reward value. They might also reflect the confusion with a meta-decision process about the amount of deliberation needed to reach a sufficient confidence in the reward/effort estimates. Here, we used fMRI to examine the neural correlates of reward and effort estimates across several preference tasks, from (dis-)likeability ratings to binary decisions involving attribute integration and option comparison. Results confirm the role of the vmPFC as a generic valuation system, across the different tasks (likeability rating or binary decision) and attributes (the activity increasing with reward value and decreasing with effort cost). However, meta-decision variables were represented in more dorsal regions, with confidence in the mPFC and deliberation time in the dmPFC. These findings suggest that assessing commonalities across preference tasks and distinguishing between decision and meta-decision variables might help reaching a unified view of how the brain chooses a course of action.
bioRxiv Subject Collection: Neuroscience