Neural and physiological correlates of parent-child observational threat extinction.

The dyadic relationship between a parent and child is a critical facilitator of social learning, particularly in the management of fear. Vicarious extinction, the process of learning by observing a parent extinguish learned threat responses, holds critical translational potential in understanding adolescent psychopathology involving aberrant threat responses. However, biological profiles of vicarious extinction irrespective of psychopathology have yet to be uncovered. Here, a community-representative sample of 97 parent-child dyads, enriched for trauma-exposure, completed a validated vicarious extinction paradigm. Youth completed all phases during functional magnetic resonance imaging, while caregivers simultaneously completed the behavioral task. Linear models interrogating behavioral, physiological, and neural correlates of acquisition and direct and vicarious extinction, controlled for trauma and symptom severity. The degree of parent-child autonomic synchrony was used to predict the strength of extinction learning. Youth behavioral and skin conductance response markers suggest successful threat acquisition and direct and vicarious extinction. Autonomic arousal during active vicarious extinction learning processes was significantly associated with the strength of parent-child synchrony. Neural activation analyses reveal patterns of early encoding of threat and safety discrimination that were reactivated during later threat reinstatement. Finally, results corroborate and expand known models of direct and vicarious extinction, respectively involving the ventromedial and ventrolateral prefrontal cortex. Altogether, this data confirms that youth can directly and vicariously modify learned threat associations with distinct neurobiological profiles. This delineation of vicarious extinction neural circuitry within a representative population is pivotal for understanding how these processes may be altered by the environment and/or psychopathology during adolescence.