Early behavioural inhibition, a temperamental characteristic defined by fearful, overly-sensitive, avoidant, or withdrawn reactions to the unknown, is a predictor of later social anxiety. However,... Show moreEarly behavioural inhibition, a temperamental characteristic defined by fearful, overly-sensitive, avoidant, or withdrawn reactions to the unknown, is a predictor of later social anxiety. However, not all behaviourally inhibited children develop anxiety problems, and attentional bias to threat has been proposed to moderate the relation between behavioural inhibition and anxiety. The current study aimed to further specify the relation between early behavioural inhibition and later social anxiety by testing this potentially moderating role of childhood attentional bias to threat. Behavioural inhibition was assessed during toddlerhood (age 2.5 years) using laboratory observations of children's behaviours in response to unknown objects and situations. When children were 7.5 years old, attentional bias was measured in 86 children (46 girls) using both a visual probe task and a visual search task with angry and happy faces. Child social anxiety was measured using questionnaires completed by the child and both parents, and clinical interviews conducted with both parents. Our results showed that while early behavioural inhibition was related to later social anxiety, there was no evidence for a moderation of this relation by attentional bias, suggesting that the relation between early fearful temperament and later social anxiety holds across children, independent of their attentional biases. Show less
Previous research has found an association between a smaller cerebellar volume and higher levels of neuroticism. The steroid hormone testosterone reduces stress responses and the susceptibility to... Show morePrevious research has found an association between a smaller cerebellar volume and higher levels of neuroticism. The steroid hormone testosterone reduces stress responses and the susceptibility to negative mood. Together with in vitro studies showing a positive effect of testosterone on cerebellar gray matter volumes, we set out to explore the role of testosterone in the relation between cerebellar gray matter and neuroticism. Structural magnetic resonance imaging scans were acquired, and indices of neurotic personality traits were assessed by administering the depression and anxiety scale of the revised NEO personality inventory and Gray’s behavioural avoidance in one hundred and forty-nine healthy volunteers between 12 and 27 years of age. Results demonstrated an inverse relation between total brain corrected cerebellar volumes and neurotic personality traits in adolescents and young adults. In males, higher endogenous testosterone levels were associated with lower scores on neurotic personality traits and larger cerebellar gray matter volumes. No such relations were observed in the female participants. Analyses showed that testosterone significantly mediated the relation between male cerebellar gray matter and measures of neuroticism. Our findings on the interrelations between endogenous testosterone, neuroticism and cerebellar morphology provide a cerebellum-oriented framework for the susceptibility to experience negative emotions and mood in adolescence and early adulthood. Show less
