A Causal Role of the Right Dorsolateral Prefrontal Cortex in Random Exploration

Abstract

Our brain faces the dilemma of exploiting familiar options to gain immediate rewards or exploring new options to increase probable future rewards, in many real-life decisions, and solves it by direct and random exploration. Previous studies show that these two explorative strategies have dissociable neural correlates in the brain. Using the continuous theta burst stimulation (cTBS) and horizon task, we investigate the causal role of the right dorsolateral prefrontal cortex (rDLPFC) in direct and random exploration. Twenty-five healthy right handed adult participants underwent cTBS, and vertex stimulation sessions, and then completed the horizon tasks. Both model-free and model-based analysis showed that cTBS over rDLPFC selectively reduced random exploration, but not direct exploration. This suggests a causal role for rDLPFC especially in random exploration, and further supports dissociable neural implementations for direct and random exploration.