The Study of Face Processing in Social Anxiety Disorder Based on Face-Specific N170 Component

Although previous studies showed that social anxiety disorder (SAD) exhibits the attentional bias for angry faces, few studies investigated effective face recognition combined with event-related potential (ERP) technique in SAD patients, especially the treatment effect. This study examines the differences in face processing in SAD patients before and after treatment and healthy control people (H-group). High-density EEG scans were registered in response to emotional schematic faces, particularly interested in the face processing N170 component. Analysis of N170 amplitude revealed a larger N170 for P-group-pre in response to inverted and upright stimuli than H-group in the right hemisphere. The result of the intragroup t-test showed that N170 was delayed for inverted relative to upright faces only in P-group-post and H-group but not in P-group-pre. Remarkably, the results of ANOVAs manifested that emotional expression cannot modulate N170 for SAD patients. Besides, the N170-based asymmetry index (AI) was introduced to analyze the left- and right-hemisphere dominance of N170 for three groups. It was found that, with the improvement of patients' treatment, the value of AI(N170−base d) presented a decreasing trend. These results together suggested that there was no inversion effect observed for patients with SAD. The change in the value of AI(N170−base d) can be used as potential electrophysiological markers for the diagnosis and treatment effects on patients with SAD.