Neural correlates of the subjective experience of free-will during value-based risky decisions: a pilot study

ABSTRACT Underlying the first-person notion of choice is the fundamental idea of ‘free-will’, which is challenged by decision-neuroscience aiming to explain and predict choices as outcomes of neural processes embedded within an ongoing chain of physical causes. The question of whether any choice is truly a free-choice and born out of free-will has long been a subject of philosophical debate. In this work, we do not take a position on this debate; rather we investigate the subjective experience of free-will, whose existence is more universally accepted. We had healthy participants report the level of their experienced free-will while performing a value-based risky decision-making task during an fMRI session to find the neural and behavioral correlates of this experience. We identified regions in mid-cingulum and middle frontal gyrus showing positive association with self-reported free-will as well as a region in hippocampus and parahippocampal gyrus showing a negative association. The requirement to report the experience of free-will was associated at a trend-level with a higher BOLD signal in striatum during decision-making. Behaviorally, we found a positive trend between RT and free-will. While our sample size is small, these results help form hypotheses for further studies with larger cohorts and provide a proof-of-concept for the investigations of neural and behavioral mechanisms of the subjective experience of free-will in decision research.