2018 年 10 巻 1 号 p. 29-44
Background: Patients with social anxiety disorder (SAD) have heightened self-reflection. In the self-focused cognition, they ruminate negative self-image or evaluation both by themselves and others. It leads to self-conscious emotions, such as embarrassment. Previous functional magnetic resonance imaging (fMRI) studies with healthy subjects revealed that anterior rostral medial prefrontal cortex (arMPFC) plays a key role in self-reflection. However, neural basis of self-reflection in patients with SAD has not been studied in detail. This study aimed to investigate the neural basis of self-reflection in patients with SAD using self-face images. We hypothesized that patients with SAD would show excessive embarrassment and it would cause aberrant neural hyperactivity in arMPFC as compared to controls (CTL).
Methods: Thirteen outpatients with SAD and 17 CTLs enrolled in this study. fMRI was acquired while participants reported the degree of their embarrassment by the visually presented their self-face image and images of others' with and without an observer.
Results: The SAD group reported significantly greater embarrassment for self-face images than the CTL regardless of observation. The SAD group showed enhanced self-related activation in the left arMPFC as compared with the CTL. Furthermore, positive correlation between the self-related activity and Liebowitz Social Anxiety Scale was observed only in the arMPFC.
Conclusion: We suggest that the arMPFC takes charge of their elevated-level of self-reflection in patients with SAD, and the level of the neural activity was correlated to the severity of the symptom.