Incentivized random exploration associated with dorsal-ventral reinforcement learning circuit connectivity

Poster Session D - Monday, April 15, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Ethan Campbell¹ (ecampbell@unm.edu), Wanting Zhong², Teagan Mullins¹, Jeremy Hogeveen¹, Jordan Grafman³; ¹University of New Mexico, ²Shirley Ryan AbilityLab, ³Northwestern University

When exploring different alternatives, humans and other animals randomize choice as a function of increased noise in the state space. This type of ‘random exploration’ is typically studied using probabilistic reinforcement learning (RL) tasks. It's assumed there is an association between ‘external’ and ‘internal’ drivers of decision noise on such tasks i.e., greater uncertainty about outcomes is thought to lead to increased ‘neural variability’ in decision-making circuits, driving stochastic choice. Meanwhile, the neural bases of RL are thought to involve a balance between a ventral circuit that computes the value of prospective goals, and a dorsal circuit that computes the value of relevant goal-directed actions. We determined whether resting-state functional connectivity (rsFC) in ventral and/or dorsal RL circuits predicts the degree of random exploration in a well-validated two-stage decision-making task. We were interested in whether low versus high incentives modulated random exploration at each choice stage, and whether this was predicted by individual differences in goal value computations (ventral rsFC) and/or goal-directed action valuation (dorsal rsFC). We found an increased weighting of model-based relative to model-free control under high vs. low incentives, and rsFC of ventral and dorsal RL circuits modestly predicted this change in decision-making strategies. Random exploration also decreased under high vs. low incentives, and the magnitude of this decrease was predicted by increased connectivity between dorsal and ventral circuits. These data suggest that incentivized random exploration is associated with individual differences in ventral-dorsal RL circuit connectivity.

Topic Area: THINKING: Decision making