Conference on Cognitive Computational Neuroscience

In value-based decision-making tasks, we tend to perform overt visual search for visually displayed reward offers during the sampling of options, followed by alternation between them, until a choice is committed. For this kind of tasks, neurons in orbitofrontal cortex (OFC) have been reported to encode offer value, bringing up questions about the dynamics of value-based computation. However, the neural basis of how gaze aids at value-based decisions is unknown. We recorded simultaneous gaze and OFC activity of two macaque monkeys performing a two-alternative reward gambling task. The offers were sequentially presented at opposite sides of the screen, each followed by a blank screen delay time. Interestingly, we found that the looking time of either offer was predictive of the final choice during the whole task time, including delay times. We found that cells encode expected value (EV) of the offers, predominantly during their respective presentation and at subsequent delay time. We found that fixation gates the encoding of ipsilateral EV, even when the offer is not visible. In addition, looking back to the first offer side during second delay re-activated the encoding of first offer EV, even if the subjects looked to opposite side during second offer presentation.