Examining social reinforcement learning in social anxiety

Abstract

Background and objectives: Reinforcement learning biases have been empirically linked to anhedonia in depression and theoretically linked to social anhedonia in social anxiety disorder, but little work has directly assessed how socially anxious individuals learn from social reward and punishment.

Methods: N = 157 individuals high and low in social anxiety symptoms completed a social probabilistic selection task that involved selecting between pairs of neutral faces with varying probabilities of changing to a happy or angry face. Computational modeling was performed to estimate learning rates. Accuracy in choosing the more rewarding face was also analyzed.

Results: No significant group differences were found for learning rates. Contrary to hypotheses, participants high in social anxiety showed impaired punishment learning accuracy; they were more accurate at choosing the most rewarding face than they were at avoiding the most punishing face, and their punishment learning accuracy was lower than that of participants low in social anxiety. Secondary analyses found that high (vs. low) social anxiety participants were less accurate at selecting the more rewarding face on more (vs. less) punishing face pairs.

Limitations: Stimuli were static, White, facial images, which lack important social cues (e.g., movement, sound) and diversity, and participants were largely non-Hispanic, White undergraduates, whose social reinforcement learning may differ from individuals at different developmental stages and those holding more marginalized identities.

Conclusions: Socially anxious individuals may be less accurate at learning to avoid social punishment, which may maintain negative beliefs through an interpersonal stress generation process.

Keywords: Avoidance; Probabilistic learning; Punishment; Reinforcement learning; Reward; Social anxiety.

Figure 1. Social Probabilistic Selection Task

Note. The Social Probabilistic Selection Task consisted of two phases: training and testing. In the training phase, neutral face stimuli were presented in pairs with varying probabilities of reward (becoming a happy face) or punishment (becoming an angry face) when chosen. In the example above, stimuli are referred to by their reward probabilities, and their punishment probabilities are 100-p(reward) (e.g., stimulus 80 would reward the participant 80% of the times chosen and punish the participant 20% of the times chosen). The instructions for the training phase explained, “Two faces will appear simultaneously on the computer screen. One person will become HAPPY when you choose them and the other will become ANGRY. At first you will not know which is which. You will learn through trial and error. Try to guess the HAPPY person as quickly and accurately as possible. In this task, no person is ALWAYS happy when you choose them, but some people have a higher chance of being happy than others. Try to pick the person you find to have the highest chance of becoming happy when you choose them.” During the testing phase, neutral faces were recombined into all the possible pairs, and participants were told to decide between them based on what they had learned in the training phase. No feedback was given during the testing phase. Instructions explained, “It is time to test what you have learned! During this set of trials you will NOT receive feedback (happy or angry) to your responses. If you see new combinations of faces in the test, please choose the person that seems more likely to become happy based on what you learned during the training sessions. If you are not sure which one to pick, just go with your gut instinct!” Although all possible face pairs were presented during the testing phase, only the pairs included in the calculation of reward and punishment learning accuracy are presented in this figure.

Figure 2. Reward and Punishment Learning Accuracy by Social Anxiety Group

Note: Avoid Most Punishing Face = rate of choosing the more rewarding face on pairs that included the most punishing face. Choose Most Rewarding Face = rate of choosing the more rewarding face on pairs that included the most rewarding face.

Figure 3. Accuracy as a Function of Difficulty by Social Anxiety Group

Note: Difficulty = difference between reward probabilities of faces in a pair, such that higher scores reflect easier pairs (note that this variable is centered). Accuracy = rate of choosing the more rewarding face.

Figure 4. Accuracy as a Function of Magnitude by Social Anxiety Group

Note: Magnitude = mean reward probability of faces in a pair, such that higher scores reflect more rewarding pairs (note that this variable is centered). Accuracy = rate of choosing the more rewarding face.