Computational Dysfunctions in Anxiety: Failure to Differentiate Signal From Noise

• Published in: Biological psychiatry (1969) Vol. 82; no. 6; pp. 440 - 446
• Main Authors: Huang, He, Thompson, Wesley, Paulus, Martin P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-09-2017
• Subjects: Adult; Anxiety; Anxiety Disorders - drug therapy; Anxiety Disorders - psychology; Bayesian models; Change point detection; Computational psychiatry; Computer Simulation; Decision Making; Discrimination (Psychology); Female; Humans; Male; Models, Psychological; Neuropsychological Tests; Psychiatric Status Rating Scales; Psychotropic Drugs - therapeutic use; Reinforcement (Psychology); Reinforcement learning; Uncertainty; Bayesian models; Anxiety; Computational psychiatry; Change point detection; Decision making; Reinforcement learning
• ISSN: 0006-3223; 1873-2402
• DOI: 10.1016/j.biopsych.2017.07.007

Differentiating whether an action leads to an outcome by chance or by an underlying statistical regularity that signals environmental change profoundly affects adaptive behavior. Previous studies have shown that anxious individuals may not appropriately differentiate between these situations. This investigation aims to precisely quantify the process deficit in anxious individuals and determine the degree to which these process dysfunctions are specific to anxiety.
One hundred twenty-two subjects recruited as part of an ongoing large clinical population study completed a change point detection task. Reinforcement learning models were used to explicate observed behavioral differences in low anxiety (Overall Anxiety Severity and Impairment Scale score ≤ 8) and high anxiety (Overall Anxiety Severity and Impairment Scale score ≥ 9) groups.
High anxiety individuals used a suboptimal decision strategy characterized by a higher lose-shift rate. Computational models and simulations revealed that this difference was related to a higher base learning rate. These findings are better explained in a context-dependent reinforcement learning model.
Anxious subjects’ exaggerated response to uncertainty leads to a suboptimal decision strategy that makes it difficult for these individuals to determine whether an action is associated with an outcome by chance or by some statistical regularity. These findings have important implications for developing new behavioral intervention strategies using learning models.