Feedback processing is enhanced following exploration in continuous environments

Decision-making is typically studied by presenting participants with a small set of options. However, real-world behaviour, like foraging, often occurs in continuous environments. The degree to which human decision-making in discrete tasks generalizes to continuous tasks is questionable. For example, successful foraging comprises both exploration (learning about the environment) and exploitation (taking advantage of what is known). Although progress has been made in understanding the neural processes related to this trade-off in discrete tasks, it is currently unclear how, or whether, the same processes are involved in continuous tasks. To address this, we recorded electroencephalographic data while participants "dug for gold" by selecting locations on a map. Participants were cued beforehand that the map contained either a single patch of gold, or many patches of gold. We then used a computational model to classify participant responses as either exploitations, which were driven by previous reward locations and amounts, or explorations. Our participants were able to adjust their strategy based on reward distribution, exploring more in multi-patch environments and less in single-patch environments. We observed an enhancement of the feedback-locked P300, a neural signal previously linked to exploration in discrete tasks, which suggests the presence of a general neural system for managing the explore-exploit trade-off. Furthermore, the P300 was accompanied by an exploration-related enhancement of the late positive potential that was greatest in the multi-patch environment, suggesting a role for motivational processes during exploration.