Dimensions of Early Adversity as Distinct Predictors of Adolescent Brain Development

Understanding the development of neural circuitry underlying socioemotional function, as well as how this development may be altered by early adversity, is essential for informing prevention and intervention approaches that can be used to improve outcomes for children and families. The aim of this dissertation is to explore the relations between brain structure and function across levels of socioemotional function, as well as the distinct effects of childhood violence exposure and social deprivation on adolescent brain function and internalizing psychopathology. The first chapter reviews what is currently known about the development of neural circuitry underlying socioemotional function in adolescence, as well potential neural mechanisms linking early adversity to later mental health and the contributions of this work to policy and practice. The following two chapters provide original research examining how brain structure and function are related and how this brain function is impacted by qualitatively different early adverse experiences. The second chapter characterizes how structural connectivity of the uncinate fasciculus is related to amygdala habituation. The third chapter explores the unique effects of childhood violence exposure and victimization on adolescent threat-related brain function and childhood social deprivation on adolescent reward-related brain function. Importantly, both studies use data from a large, socioeconomically diverse sample of youth. In the fourth chapter, I discuss how this original research informs our understanding of the impacts of early adversity on socioemotional and neural development in adolescence and what this suggests for policy and practice.PHDPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/149945/1/heint_1.pd

Contextual Influences on Youth Socioemotional and Corticolimbic Development

The formation of adaptive socioemotional skills is a key developmental competency in childhood and such behaviors are supported, in part, by neural function within the corticolimbic system. Multiple features of the social context (e.g., harsh parenting) and individual-level markers of maturation (e.g., pubertal development) are robust predictors of youth socioemotional outcomes, but several gaps in the literature remain. However, more research is needed to investigate the timing and specificity of contextual and maturation effects on youth socioemotional and corticolimbic development, using population-based studies that allow for generalization of the results to a broader population. This three study dissertation integrates research on socioeconomic disadvantage, neural correlates of emotion processing, and internalizing and externalizing behaviors in childhood in service of these goals. Study 1 tests a longitudinal Family Stress Model using prospectively-collected data from a population-based nationwide study of children followed from birth through age 9, with an oversample of disadvantaged families. Study 2 builds on the results of Study 1 by examining the influence of initial levels and changes in harsh parenting across childhood on corticolimbic function during adolescence. Finally, Study 3 evaluates the effects of age and puberty on amygdala-prefrontal connectivity during face processing, using a large cross-sectional population-based sample of twins from Southeast Michigan. The general discussion chapter of this dissertation highlights theoretical and empirical considerations for this research, as well as outlines several future directions.PHDPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/153437/1/arigard_1.pd

Violence Exposure and Social Deprivation: Neural Connectivity Correlates and Protective Factors

Dimensions of early adversity, such as violence exposure and social deprivation, may have different effects associated with socioemotional functioning in the developing brain and different factors may be protective. This dissertation examined the downstream effects of childhood violence exposure and social deprivation in data from the Fragile Families and Child Wellbeing Study at birth, and ages 1, 3, 5, 9, and 15 years. Study one examined the association between violence exposure, social deprivation, and amygdala-prefrontal cortex white matter connectivity, a crucial circuit for emotion regulation. High violence exposure coupled with high social deprivation related to less amygdala–OFC white matter connectivity. Violence exposure was not associated with white matter connectivity when social deprivation was at mean or low levels (i.e., relatively socially supportive contexts). Therefore, social deprivation may exacerbate the effects of childhood violence exposure on the development of white matter connections involved in emotion processing and regulation. Conversely, social support may buffer against them. Study two investigated the association between violence exposure, social deprivation, and adolescent resting-state functional connectivity in two resting-state networks involved in socioemotional functioning (salience network, default mode network) using a person-specific modeling approach. Childhood violence exposure, but not social deprivation, was associated with reduced adolescent resting-state density of the salience and default mode networks. A data-driven algorithm, blinded to childhood adversity, identified youth with heightened violence exposure based on resting-state connectivity patterns. Childhood violence exposure was associated with adolescent functional connectivity heterogeneity, which may reflect person-specific neural plasticity and should be considered when attempting to understand the impacts of early adversity on the brain. Study three examined whether school connectedness was protective against violence exposure and social deprivation when predicting symptoms of internalizing and externalizing psychopathology and positive function and if school connectedness was uniformly protective against both dimensions of adversity. Results suggest that school connectedness is broadly related to better outcomes and may confer additional protection against social deprivation. These findings highlight the important role that the school environment can play for youth who have been exposed to adversity in other areas of their lives. Additionally, the interactive effect of school connectedness with social deprivation, but not violence exposure, supports modeling risk and resilience processes using dimensional frameworks to better identify specific groups of youth that may benefit from interventions that boost social connectedness at school in future research. Overall, this dissertation provides evidence for the complex and person-specific ways through which risk and resilience relate to development and points to considerations for future research. This research has implications for understanding how dimensions of adversity affect the brain and behavior during development and what factors can be protective, which can inform future neuroscience-informed policy interventions.PHDPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/167957/1/lcgayle_1.pd