Structural and functional connectivity changes in the brain associated with shyness but not with social anxiety.

Xun Yang,Xiaoqi Huang,Sunima Lama,Qiyong Gong,Keith Maurice Kendrick,Qizhu Wu,Bochao Cheng,Taolin Chen,Shiguang Li

doi:10.1371/journal.pone.0063151

Abstract

Shyness and social anxiety are correlated to some extent and both are associated with hyper-responsivity to social stimuli in the frontal cortex and limbic system. However to date no studies have investigated whether common structural and functional connectivity differences in the brain may contribute to these traits. We addressed this issue in a cohort of 61 healthy adult subjects. Subjects were first assessed for their levels of shyness (Cheek and Buss Shyness scale) and social anxiety (Liebowitz Social Anxiety scale) and trait anxiety. They were then given MRI scans and voxel-based morphometry and seed-based, resting-state functional connectivity analysis investigated correlations with shyness and anxiety scores. Shyness scores were positively correlated with gray matter density in the cerebellum, bilateral superior temporal gyri and parahippocampal gyri and right insula. Functional connectivity correlations with shyness were found between the superior temporal gyrus, parahippocampal gyrus and the frontal gyri, between the insula and precentral gyrus and inferior parietal lobule, and between the cerebellum and precuneus. Additional correlations were found for amygdala connectivity with the medial frontal gyrus, superior frontal gyrus and inferior parietal lobule, despite the absence of any structural correlation. By contrast no structural or functional connectivity measures correlated with social or trait anxiety. Our findings show that shyness is specifically associated with structural and functional connectivity changes in cortical and limbic regions involved with processing social stimuli. These associations are not found with social or trait anxiety in healthy subjects despite some behavioral correlations with shyness.

Highlights

Shyness is a core dimension of temperament or personality trait that describes hesitation or discomfort in response to social situations, novel ones [1]
There is still debate as to whether shyness as a personality trait is distinct from social anxiety which, while present in healthy populations can become a clinical disorder under DSM-IV criteria
Shyness scores from the CBSS were significantly correlated with social anxiety ones from the LSAS (r = 0.376, p = 0.003) and with trait anxiety ones from the Gender (M/F) Age (m 6 sd) CBSS LSAS Total Fear Total Avoidance CSTAI-T

Summary

Introduction

Shyness is a core dimension of temperament or personality trait that describes hesitation or discomfort in response to social situations, novel ones [1]. For many individuals shyness occurs only during childhood, 10–25% of the population have an enduring shyness temperament [3,4]. There is still debate as to whether shyness as a personality trait is distinct from social anxiety which, while present in healthy populations can become a clinical disorder under DSM-IV criteria. A number of studies have reported significant correlations between shyness and social anxiety scores in healthy subjects [6], only around 40% of subjects with the highest shyness levels have social anxiety disorder [7]

Methods

Results

Conclusion