Probabilistic Learning by Positive and Negative Reinforcement in Generalized Anxiety Disorder

This experiment examined learning tendencies in generalized anxiety disorder (GAD) using reinforcement feedback for probabilistic outcomes. One hundred sixty-six GAD and 105 non-GAD participants were randomized to a computerized probabilistic learning task that used either negative or positive reinforcement. Participants chose between stimuli with specific probabilities of reinforcement to learn which of each pair had the highest probability. Reinforced choices either removed an angry face (negative reinforcement) or made a happy face appear (positive reinforcement). Results showed that those with GAD learned the correct probabilistic choices at a slower rate over time and to a lesser degree than control participants regardless of reinforcement type. Estimations of the likelihood of receiving a good outcome posttask were also more inaccurate for those with GAD, especially when true likelihoods were high. Furthermore, compared with control participants, those with GAD reported lower perceived reinforcement sensitivity, higher behavioral inhibition sensitivity, and higher undesirable feelings toward probabilistic learning.