UCLA

Early life adversity (ELA) is a potent and common risk factor for a number of mental health challenges. ELA is thought to increase risk for psychopathology in part by sensitizing threat-responsive neural circuitry and heightening vigilance to potential threat. This hypervigilance is thought to result in a tendency to overestimate threat in the face of ambiguity or uncertainty, a core feature of several internalizing disorders. However, few studies have examined how ELA shapes neural or behavioral responses to ambiguous and uncertain stimuli. Across three studies, this dissertation integrates neuroimaging, behavioral, and self-report data to examine how ELA shapes responses to ambiguity and uncertainty. We examine these associations in children, adolescents, and emerging adults with varying histories of caregiving adversity. In Study 1 and Study 2, we use representational similarity analysis to evaluate whether similarity in neural representations of ambiguity and threat varies depending on adversity history. In Study 1, we find that emerging adults who experienced higher levels of abuse and neglect demonstrate greater representational similarity between ambiguous and threatening stimuli within threat-sensitive neurocircuitry. These results indicate that ELA may predispose an individual to represent ambiguity as threatening at the neural level. In Study 2, we sought to replicate these findings in a population of adopted youth who had experienced institutionalization in orphanage care, a rare and extreme form of caregiving adversity. However, we find that the degree of similarity in neural representations of ambiguity and threat does not significantly differ between previously institutionalized and control youth. In Study 3, we demonstrate that emerging adults who experienced higher levels of abuse and neglect exhibit less avoidance of uncertainty in an explore-exploit task. Together, these three studies provide novel insights into how ELA shapes neural and behavioral functioning in the face of the unknown and how these processes relate to wellbeing following caregiving adversity.