Interactions Among Amygdala Volume, Cortical Thickness, and Structural Connectivity in Youth: Relationship to Emotion Regulation
Doctor of Philosophy (PhD)
Emotion regulation includes adaptive (e.g., reappraisal) and non-adaptive behaviors (e.g., avoidance) designed to alter ones’ affective responses. The central hypothesis is that emotional consciousness – being self-aware that you are currently in a particular emotional state – and emotion regulation share the same underlying brain mechanisms/networks. In addition, it is argued that the more appropriate dichotomy, in regard to non-adaptive and adaptive emotion regulation strategies, is dependent on whether they are unconscious or conscious (respectively), positing a two-system framework of emotion regulation. Evidence for the proposed framework draws and builds off of recent theories of higher-order emotional consciousness (LeDoux & Brown, 2017) and supported frameworks of fear/anxiety (LeDoux & Pine, 2016). The literature reviewed suggests that the difference between emotional consciousness and emotion regulation lies in the variations in recruitment of lower-order, subcortical networks and the higher-order interpretation by the same overarching general network of cognition. In the second section, an empirical examination of this theory was conducted using neuroimaging and self-reported anxiety in a sample of youth. I provide evidence for my first hypothesis by identifying significant clusters of grey-matter thickness in the general linear analyses that qualitatively overlap with the general network of cognition proposed to underlie emotional consciousness. Our second hypothesis was partially supported as grey-matter thickness of these regions of the PFC, but not amygdala volume, significantly related to self-reported anxiety. Next, it is demonstrated that this relationship was significantly moderated by youths’ structural connectivity. Post-hoc analyses indicated that prefrontal grey-matter cortical thickness had a significant indirect effect on the relationship between amygdala volume and youth’s self-reported anxiety. The current results provide support for the central hypothesis that emotional consciousness and emotion regulation share many of the same underlying brain networks and mechanisms.
Castagna, Peter James, "Interactions Among Amygdala Volume, Cortical Thickness, and Structural Connectivity in Youth: Relationship to Emotion Regulation" (2020). LSU Doctoral Dissertations. 5145.