Neurobiological Signatures of Dyadic Transmission of Fear Extinction in Adolescent Trauma Exposure and Posttraumatic...

The use of social cues to attenuate prior learned fear associations is a critical skill for normative development. Impairments in extinction learning underlie emerging models of posttraumatic stress disorder (PTSD) in adults. However, few have investigated how trauma and/or related psychopathology may impact the unique neural and physiological processes of observed-parent vicarious safety learning during adolescence.

This study enrolled typically developing (TD) (n = 42) and trauma-exposed (TE) (n = 45) parent-child dyads, where youths were classified as having low (TE+low) or high (TE+high) posttraumatic stress symptoms (PTSSs). Dyads completed acquisition (day 1), direct and vicarious extinction by watching a video of parent direct (day 2), and extinction recall (day 3). Youths completed all phases during functional magnetic resonance imaging. Analysis of behavioral outcomes, parent-child autonomic synchrony, and whole-brain voxelwise activation were used to characterize trauma- and PTSS-related correlates of vicarious extinction.

Autonomic synchrony analyses suggest that TE youths did not exhibit normative vicarious extinction transmission, where stronger autonomic synchrony with their parent did not result in lower arousal. Next, TE+high youths uniquely exhibited less successful behavioral learning and atypically high arousal in response to safety cues during vicarious extinction as compared with TE+low and TD youths. Brain activation analyses revealed that patterns of ventral and dorsolateral prefrontal cortex (PFC) recruitment differentiated PTSS load during vicarious extinction.

This study identifies novel behavioral and neurobiological profiles of trauma and PTSD. Distinct behavioral impairments in vicarious learning may be related to disruptions in parent-child synchrony or altered recruitment of the lateral PFC during vicarious learning encoding.