Preliminary Evidence for Sex-Specific Developmental Trajectories of Fear Learning in Trauma-Exposed Children

• In Event: 2-067 - Childhood Adversity and Fear Learning Mechanisms

Integrative Statement

INTRODUCTION: Fear conditioning paradigms can offer insight into the mechanisms underlying the neurobiological ontogeny of mental health problems, including anxiety and post-traumatic stress disorder. To date, however, there has been limited characterization of fear learning across development, particularly for children who experience high levels of childhood adversity. Thus, there remains a need to more fully characterize normative and pathological fear learning across development. To address this need, we tested for developmental change in fear learning during middle childhood and early adolescence in girls and boys who experience high levels of childhood adversity, including trauma exposure.

METHODS: Seventy-one 8- to 13-year-old children (37 girls) from a low-income, urban setting participated in an 18-month longitudinal study. Participants completed a developmentally appropriate fear-conditioning paradigm in which neutral geometric shapes are conditioned stimuli (CS) and an aversive airblast to the larynx is the unconditioned stimulus. Three separate visits were conducted at 9-month intervals. Acoustic startle response data from the orbicularis oculi muscle were collected via EMG to measure fear-potentiated startle (FPS) during each CS type, CS+ and CS-. We then examined participants’ discrimination between the CSs by calculating the difference between their CS+ and CS- FPS response (FPS CS+ - FPS CS-). We evaluated developmental change in discrimination across visits with latent growth curve models. We also collected multiple reports of participants’ mental health and exposure to trauma at each session.

HYPOTHESES: We hypothesized that: a) participants’ discrimination between CS+ and CS-, measured as FPS, would increase across sessions, reflecting the participants’ increasing age, and b) there could be sex differences in these developmental changes in discrimination ability.

RESULTS: Participants accurately discriminated between the CS+ and CS-, as indicated by positive FPS difference scores that were significantly greater than 0 (MVisit1 = 21.7, MVisit2 = 28.3, MVisit3 = 27.8, all ps < .01). Participants’ discrimination was statistically equivalent across visits (S = -0.15, p > .5), contrary to our first hypothesis. Results of a latent growth model with the covariate sex indicate that girls discriminated significantly more than boys initially, and that this sex difference increased across the visits (I = 58.15, p = .01; S = -1.33, p < .01).

DISCUSSION: These preliminary results suggest that, in general, children who experience considerable adversity effectively discriminate between threat (CS+) and safety (CS-) cues. We observed that this ability is generally consistent across 18 months, however, when sex was included as a covariate, we found that discrimination was improving across visits in girls, but not in boys. This preliminary evidence suggests that there may be sex differences in the developmental trajectory of fear learning. Forthcoming analyses will also examine the impact of anxiety and trauma exposure on participants’ FPS growth trajectories. We anticipate that incorporating these factors into the latent growth models could reveal a more complex developmental account of fear learning, in which sex- and age-related change is impacted by individual differences in adverse exposures. The results of these analyses will provide novel information about how childhood adversity impacts basic fear learning processes.

Authors

• Anais Stenson, Emory University
  Presenting Author

• Alisha B. Compton, Emory University
  Non-Presenting Author

• Sean T. Minton, Wayne State University School of Medicine
  Non-Presenting Author

• Nicole R. Nugent, Brown University School of Medicine
  Non-Presenting Author

• Tanja Jovanovic, Emory University School of Medicine, Wayne State University School of Medicine
  Non-Presenting Author