Signals related to decision-making and uncertainty in the primate prefrontal cortex

In this thesis, I describe results from three different experiments that together provide insight into how different cortical regions encode information related to decision making and uncertainty. In the first experiment, I investigate the role of cortical signals in a set of tasks designed to study the exploration/exploitation dilemma, a classic problem that animals face when making decisions under uncertainty. I analyzed single-cell data from awake, behaving monkeys in four different cortical regions: the supplementary eye field (SEF), the dorsolateral prefrontal cortex (DLPFC), the lateral intraparietal area (LIP), and the anterior cingulate cortex (ACC). I find evidence that only the SEF plays a unique role in exploration. In the second set of experiments, I turned my focus to how signals for decision-making are integrated in the DLPFC through the use of a novel probabilistic reversal task. In this task, animals had to track reward probabilities in a task-relevant color dimension while ignoring events related to a task-irrelevant spatial dimension. I describe properties in single neurons that are related to how the DLPFC selects relevant information while filtering out irrelevant information. In the final set of experiments, I used a modified version of the reversal task and studied how neurons in DLPFC, ACC, and orbitofrontal cortex (OFC) integrate information when environmental uncertainty is systematically manipulated. Consistent with theoretical predictions, I find that the animals integrate information from their prior experience to a greater degree when uncertainty is high. Together, these three experiments shed light on how single neurons in cortex may process information about uncertainty to ultimately help animals make decisions that maximize reward.