Reliability and Replicability of Implicit and Explicit Reinforcement Learning Paradigms in People With Psychotic Disorders

Background: Motivational deficits in people with psychosis may be a result of impairments in reinforcement learning (RL). Therefore, behavioral paradigms that can accurately measure these impairments and their change over time are essential. Methods: We examined the reliability and replicability of 2 RL paradigms (1 implicit and 1 explicit, each with positive and negative reinforcement components) given at 2 time points to healthy controls (n=75), and people with bipolar disorder (n= 62), schizoaffective disorder (n = 60), and schizophrenia (n = 68). Results: Internal consistency was acceptable (mean a= 0.78 +/- 0.15), but test-retest reliability was fair to low (mean intraclass correlation = 0.33 +/- 0.25) for both implicit and explicit RL. There were no clear effects of practice for these tasks. Largely, performance on these tasks shows intact implicit and impaired explicit RL in psychosis. Symptom presentation did not relate to performance in any robust way. Conclusions: Our findings replicate previous literature showing spared implicit RL and impaired explicit reinforcement in psychosis. This suggests typical basal ganglia dopamine release, but atypical recruitment of the orbitofrontal and dorsolateral prefrontal cortices. However, we found that these tasks have only fair to low test-retest reliability and thus may not be useful for assessing change over time in clinical trials.

Automated summary

The study found that implicit reinforcement learning remains intact in individuals with psychosis, while explicit reinforcement learning is impaired. Symptom presentation did not show a robust relationship with task performance.