Gaze-centered gating and reactivation 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 looked at the offers in sequence, as expected. Surprisingly, during the delay epochs, we found that subjects still tend to look at empty locations where the visual offers were formerly presented; and, moreover, longer fixation to given empty location increases the probability of choosing the associated offer, even after controlling for the offer values. We show that activity in orbitofrontal cortex (OFC) reflects the value of the gazed offer, but also the value of the offer associated to the gazed spatial location, even if it is not the most recently viewed. This reactivation reflects a reevaluation process, as fluctuations in neural spiking during offer stimuli presentation and delays correlate with upcoming 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.