How exerting control over outcomes affects the neural coding of tasks and outcomes

Humans make choices every day, which are often intended to lead to desirable outcomes. While we often have some degree of control over the outcomes of our actions, in many cases this control remains limited. Here, we investigate the effect of control over outcomes on the neural correlates of outcome valuation and implementation of behavior, as desired outcomes can only be reached if choices are implemented as intended. In a value-based decision-making task, reward outcomes were either contingent on trial-by-trial choices between two different tasks, or were unrelated to these choices. Using fMRI, multivariate pattern analysis, and model-based neuroscience methods, we identified reward representations in a large network including the striatum, dorso-medial prefrontal cortex (dmPFC) and parietal cortex. These representations were amplified when rewards were contingent on subjects’ choices. We further assessed the implementation of chosen tasks by identifying brain regions encoding tasks during a preparation or maintenance phase, and found them to be encoded in the dmPFC and parietal cortex. Importantly, outcome contingency did not affect neural coding of chosen tasks. This suggests that controlling choice outcomes selectively affects the neural coding of these outcomes, but has no effect on the means to reach them. Overall, our findings highlight the role of the dmPFC and parietal cortex in processing of value-related and task-related information, linking motivational and control-related processes in the brain. These findings inform current debates on the neural basis of motivational and cognitive control, as well as their interaction