Neural evidence for persistent attentional bias to threats in patients with social anxiety disorder

Does the biased attention toward social threats dwells on or disappears in patients with social anxiety disorder (SAD)? We investigated the neural mechanism of attentional bias in terms of attentional capture and holding in SAD. A total of 31 SAD patients and 30 healthy controls performed a continuous performance task detecting the orientation of a red letter ‘T’ while angry or neutral face distractors appeared or disappeared at the center of the screen. Behaviorally, typical attentional capture effects were found in response to abruptly appearing distractors in both groups. The patient group showed significant attentional dwelling effects in response to the angry face distractor only. Patients showed increased neural activity in the amygdala, insula/inferior frontal gyrus (IFG) and temporo-parietal junction (TPJ) compared with those of controls for the abruptly appearing angry distractor. Patients also maintained increased activities in brain regions related to attentional reorienting to distractor, namely the TPJ and IFG in line with their behavioral results of attentional holding effects. Our results indicate that patients with SAD showed prolonged attentional bias to task-irrelevant social threats. The underlying mechanism of prolonged attentional bias in SAD was indicated with amygdala hyperactivity and continued activity of the bottom-up attention network including the TPJ and IFG.