Psychology

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    Understanding the Relevance of Extended Amygdala Reactivity to Dispositional Negativity
    (2021) Grogans, Shannon Elizabeth; Shackman, Alexander J; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Elevated dispositional negativity (DN; i.e., neuroticism/negative emotionality) is associated with a range of deleterious outcomes, including mental illness. Yet, DN’s neurobiology remains incompletely understood. Prior work suggests that DN reflects heightened threat-elicited reactivity in the extended amygdala (EAc), a circuit encompassing the central nucleus (Ce) and the bed nucleus of the stria terminalis (BST), and that this association may be intensified for uncertain threat. We utilized a multi-trait, multi-occasion DN composite and neuroimaging assays of threat anticipation and perception to demonstrate that individuals with elevated DN show heightened BST activation during threat anticipation. Analyses revealed that DN is uniquely predicted by BST reactivity to uncertain threat. DN was unrelated to Ce activation during threat anticipation or EAc activation during ‘threatening’-face presentation. Follow-up analyses revealed that the threat paradigms are not interchangeable probes of EAc function. These observations lay the foundation for future studies necessary to determine causation and improve interventions.
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    Exploring neural correlates of depression in childhood: The relation between amygdala:hippocampus ratios and CDI depression scores in 4-8 year olds
    (2021-05-11) Coley, Katherine; Riggins, Tracy
    Nationally representative studies have shown that mood disorders such as depression and anxiety are widely prevalent in children, with depression acting as one of the leading causes of disability in the United States (Ghandour et al., 2018; Schmaal et al., 2016). Research on adults suggests that depression and mood regulation can be linked to brain structure and function, specifically abnormalities with the amygdala and hippocampus (Yavas et al., 2019; Gerritsen et al., 2012). Interestingly, these brain regions have been shown to undergo structural and functional changes in early childhood that correspond with critical developmental changes in behavior (e.g., Riggins et al., 2018; Stern et al., 2019). Despite these changes, there is very little research investigating the relation between the brain and depressive symptoms in children, particularly during early childhood. Furthering the understanding of the relation between structural changes in brain and depressive symptoms is critically important not only for addressing high rates of childhood depression, but also for understanding the etiology and course of depression from early childhood into adulthood. This information could inform future intervention strategies and improve our understanding of normative and non-normative development in early childhood. This study aims to fill this gap by assessing the association between amygdala and hippocampus volumes and depressive symptoms cross sectionally and longitudinally in children ages 4-8 years.
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    Understanding the anxiolytic effects of alcohol on the central extended amygdala in humans
    (2017) Kaplan, Claire Marjorie; Shackman, Alexander J; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The anxiety-reducing properties of alcohol are thought to contribute to development of alcohol dependence, particularly among individuals with anxiety disorders. Remarkably little is known, however, about the neural circuitry underlying anxiolytic effects of alcohol in humans. In a sample of 72 healthy adults, we employed the novel MultiThreat Countdown (MTC) task to investigate the dose-dependent consequences of acute alcohol intoxication (BAL range: 0.061 - 0.145%) during anticipation of certain or uncertain threat, compared to placebo. Focal analyses of the central extended amygdala revealed significant activation during threat in the right, but not left, hemisphere for both the central nucleus [Ce] and bed nucleus of the stria terminalis [BST]. Increasing BALs were associated with decreasing activation in right BST and self-reported fear/anxiety levels during threat. This effect did not differ between certain and uncertain threat. These results build upon converging lines of evidence and suggest involvement of BST in alcohol-induced anxiolysis.