CHOOSE-OCD

BACKGROUND

Patients with obsessive-compulsive disorder (OCD) experience intrusive thoughts (obsessions) and repetitive behaviors (compulsions) that provide temporary relief but lead to significant negative long-term consequences. These patients have difficulty making decisions, including marked indecisiveness and excessive caution, even when advantageous choices are obvious. Reinforcement learning (RL), a relevant theoretical framework for modeling decision-making, suggests that OCD may result from an altered learning policy, leading to an overestimation of positive reinforcement or an underestimation of negative reinforcement. Dysfunctions in the lateral orbitofrontal cortex, which is involved in attributing credit to actions, confirm impairments in learning action-outcome contingencies. Furthermore, OCD is increasingly viewed as a disorder of doubt and uncertainty, characterized by difficulties in updating the values of actions in volatile environments. This project aims to investigate whether OCD patients have difficulty adapting their choices in contexts where action-outcome relationships change.

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GOING THE EXTRA MILE WITH THE SUPPORT OF LABEX CerCoG

To this end, 25 patients with OCD and 25 healthy controls, matched for age, gender, and education level, will participate in a reinforcement learning task with reversal. This task requires participants to learn and review action-outcome associations in the presence of reversals, and their choices will be analyzed using reinforcement learning (RL) and counterfactual learning (CL) models. Concurrently, pupil dilation will be measured to study arousal associated with exploratory versus exploitative choice strategies. The protocol, which has already received ethical approval, is in the pilot phase, with recruitment scheduled to begin in September 2025. The project is coordinated by GIN (Grenoble) in collaboration with LJK for modeling and the Paris Institute of Neuromodulation for patient access.