Lateral orbitofrontal cortex encodes presence of risk and subjective risk preference during decision-making.

Abstract

Adaptive decision-making requires consideration of risks and rewards associated with each option, as well as subjective preference for risky/safe alternatives. The lateral orbitofrontal cortex (lOFC) contributes to both reward and punishment processing as well as cost/benefit decision-making, but its role in punishment-driven risky decision-making remains unclear. To address this, we trained male rats in the Risky Decision-making Task, wherein subjects chose between a small, safe reward and a large reward with either 0% or 50% risk of foot shock punishment. We then recorded single unit activity in LOFC during task performance to determine how LOFC activity signals risky vs. safe options and choices. We observed that lOFC activity encodes risk in the environment prior to decision-making, then encodes reward magnitude independent of risk during action selection. Machine learning models revealed that lOFC activity accurately predicts risk but less effectively predicts impending choice, although integrating the outcome of the previous trial improved the accuracy of choice prediction. Finally, risk-preferring subjects demonstrated reduced encoding of risk and increased encoding of reward magnitude. This suggests that lOFC serves as a central hub wherein environmental information about risk and reward converges with internal, subjective information to guide risky decision-making.