Gaze-centered gating and re-activation of value encoding in orbitofrontal cortex

During economic choice, we often consider options in alternation, until we commit to one. Nonetheless, neuroeconomics typically ignores the dynamic aspects of deliberation. We trained macaques to perform a value-based decision-making task where two risky offers were presented in sequence at different locations of the visual field, each followed by a delay epoch where offers were invisible. Subjects look at the offers in sequence, as expected. Surprisingly, during the delay epochs, the empty locations where the visual offers were formerly presented are looked at; and longer fixation to an empty location increases the probability of choosing the associated offer, even after controlling for the offer values. We show that activity in orbitofrontal (OFC) cortex reflects the value of the offer that is gazed, but also when its empty location is gazed. In particular, the value of the first offer is reactivated when animals gaze to its empty location in the last delay epoch. This reactivation reflects reevaluation, as activity fluctuations correlate with choice. Our results suggest that look-at-nothing gazing triggers the reactivation of a previously seen offer for further reevaluation, revealing novel aspects of deliberation.