Memory trace imbalance in reinforcement and punishment systems can reinforce implicit choices leading to obsessive-compulsive behavior

We may view most of our daily activities as rational action selections; however, we sometimes reinforce mal-adaptive behaviors despite having explicit environmental knowledge. In this study, we model obsessive -compulsive disorder (OCD) symptoms as implicitly learned maladaptive behaviors. Simulations in the rein-forcement learning framework show that agents implicitly learn to respond to intrusive thoughts when the memory trace signal for past actions decays differently for positive and negative prediction errors. Moreover, this model extends our understanding of therapeutic effects of behavioral therapy in OCD. Using empirical data, we confirm that patients with OCD show extremely imbalanced traces, which are normalized by sero-tonin enhancers. We find that healthy participants also vary in their obsessive-compulsive tendencies, consistent with the degree of imbalanced traces. These behavioral characteristics can be generalized to var-iations in the healthy population beyond the spectrum of clinical phenotypes.

Automated summary

This study models obsessive-compulsive disorder (OCD) symptoms as implicitly learned maladaptive behaviors using reinforcement learning framework, extends understanding of therapeutic effects of behavioral therapy in OCD, and discovers imbalanced traces in OCD patients and healthy participants.