Abstract
Male and female show significant differences in important behavioral features such as shyness, yet the neural substrates of these differences remain poorly understood. Previous neuroimaging studies have demonstrated that both shyness and social anxiety in healthy subjects are associated with increased activation in the fronto-limbic and cognitive control areas. However, it remains unknown whether these brain abnormalities would be shared by different genders. Therefore, in the current study, we used resting-state fMRI (r-fMRI) to investigate sex differences in intrinsic cerebral activity that may contribute to shyness and social anxiety. Sixty subjects (28 males, 32 females) participated in r-fMRI scans, and the amplitude of low-frequency fluctuations (ALFF) and fractional ALFF (fALFF) were used to measure the spontaneous regional cerebral activity in all subjects. We first compared the differences between male and female both in the ALFF and fALFF and then we also examined the whole brain correlation between the ALFF/fALFF and the severity of shyness as well as social anxiety by genders. Referring to shyness measure, we found a significant positive correlation between shyness scores (CBSS) and ALFF/fALFF value in the frontoparietal control network and a negative correlation in the cingulo-insular network in female; while in male, there is no such correlation. For the social anxiety level, we found positive correlations between Leibowitz Social Anxiety Scale (LSAS) scores and spontaneous activity in the frontal-limbic network in male and negative correlation between the frontal-parietal network; however, such correlation was not prominent in female. This pattern suggests that shy female individuals engaged a proactive control process, driven by a positive association with activity in frontoparietal network and negative association in cingulo-insular network, whereas social anxiety males relied more on a reactive control process, driven by a positive correlation of frontal-limbic network and negative correlation of frontoparietal network. Our results reveal that shyness or social anxiety is associated with disrupted spontaneous brain activity patterns and that these patterns are influenced by sex.
Highlights
Shyness is a fundamental trait that has been conceptualized as anxious self-preoccupation and behavioral inhibition in social contexts that derives from the prospect of interpersonal evaluation (Amico et al, 2004)
We investigated the relationships between amplitude of low-frequency fluctuations (ALFF)/fractional ALFF (fALFF) and shyness using resting fMRI
There were no significant differences in age (p = 0.412) or shyness or social anxiety measurements between genders (p−correlation between shyness scores (CBSS) = 0.082, p−Leibowitz Social Anxiety Scale (LSAS) = 0.223)
Summary
Shyness is a fundamental trait that has been conceptualized as anxious self-preoccupation and behavioral inhibition in social contexts that derives from the prospect of interpersonal evaluation (Amico et al, 2004). Using seed-based functional connectivity analysis, we found that shyness is either positively or negatively associated with various brain functional connectivity differences that involve the superior temporal gyrus, parahippocampal gyrus, amygdala, and insula (Yang et al, 2013); these results suggest that these brain areas may constitute a network that is prominently linked to shyness. We used functional connectivity strength (FCS), an unbiased method to investigate brain-wide intrinsic connectivity patterns, and observed that the FCS of the insula positively correlated with shyness scores (Yang et al, 2015). This result could indicate impaired neural network communication between the insular hub and other brain regions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
