Modulation of feedback processing by social context in social anxiety disorder (SAD)-an event-related potentials (ERPs) study.

The ability to learn from feedback, especially under social scrutiny, is an essential prerequisite for successful interaction with the environment. Patients suffering from social anxiety disorder (SAD) have been proposed to show altered processing of and learning from feedback, especially depending on social context. However, the neural basis and behavioral consequences of altered reinforcement learning in SAD are not clear yet. In the present event-related potentials (ERPs) study, 34 SAD patients and 30 healthy control subjects (HC) performed an adapted version of a probabilistic feedback learning task in two distinct social conditions. In the observation condition, participants were observed by a confederate; in the control condition, they performed the task without being observed. Patients as compared to healthy controls experienced more subjective discomfort under social observation. Moreover, they showed better learning from negative feedback in the control condition, but reduced learning from negative feedback in the observation condition. This effect correlated with reduced differentiation of positive and negative feedback in the time range of the feedback-related negativity (FRN) under high action-feedback contingency. In addition, SAD patients demonstrated increased FRN amplitudes in the first half of the observation condition, in particular to positive feedback. The present results demonstrate that processing of and learning from feedback are altered in SAD, especially under social scrutiny. In particular, it appears that SAD patients do not process positive information adequately on the neural level, which may impair their ability to differentiate between negative and positive outcomes.