UC Berkeley

The orbitofrontal cortex (OFC) is a region critical to value-based decision making. Previous work from our lab showed that the neural population in OFC flip-flops between representing the available options while animals are deliberating between them. While these value dynamics were predictive of subjects' choices, they did not build toward the chosen option preceding the choice. We hypothesised that a downstream region with connections to both OFC and motor regions, for example the anterior cingulate cortex (ACC) or head of the caudate nucleus (CdN), may be integrating over these OFC value dynamics, leading to the choice. We recorded large neural populations simultaneously from OFC and each of these regions while two monkeys used a bidrectional lever to select between pairs of pictures, each associated with a unique probabilistic reward. In the ACC, we indeed observed a motor preparation signal that was influenced by OFC value dynamics on individual trials. However, in the CdN we observed a rapid choice direction signal, locked to the start of the trial instead of the motor response, that was independent of OFC value dynamics. Overall, our results are consistent with parallel, rather than serial, processing underlying value-based decision making.