Abstract
Animals forage within their environment to extract valuable resources at lowest cost. Previous studies have suggested that animals simply maximize the current flow of reward without predicting the future outcomes of their actions and that this recent reward rate is represented in various brain areas. To test this, we devised a foraging task in which the relevant reward dynamics were hidden from the animal, and wirelessly record population activity in dorsolateral prefrontal cortex (dlPFC) while monkeys forage freely in their environment. We discover that their brains indeed contain predictions of future rewards and plans of their next actions. By decoding the dynamic reward probability and the memory of recent outcomes from the dlPFC population response, we show that monkeys create an internal representation of reward dynamics. The decoded variables predicted animal’s subsequent actions better than either the true experimental variables or the raw neural responses. Our results suggest that the relevant task variables and behavioral decisions are dynamically encoded in prefrontal cortex during the time course of foraging.