Kribakaran Sahana, Odriozola Paola, Cohodes Emily M, McCauley Sarah, Zacharek Sadie J, Hodges H R, Haberman Jason T, Pierre Jasmyne C, Gee Dylan G
Department of Psychology, Yale University, New Haven, CT, USA.
Yale School of Medicine, Yale University, New Haven, CT, USA.
Neurobiol Stress. 2022 Oct 17;21:100497. doi: 10.1016/j.ynstr.2022.100497. eCollection 2022 Nov.
Exposure to trauma throughout the lifespan is prevalent and increases the likelihood for the development of mental health conditions such as anxiety and post-traumatic stress disorder (PTSD). Safety signal learning (SSL)--a form of conditioned inhibition that involves reducing fear via conditioned safety--has been shown to effectively attenuate fear responses among individuals with trauma exposure, but the association between trauma exposure and the neural mechanisms of SSL remains unknown. Adults with varied prior exposure to trauma completed a conditioned inhibition task during functional MRI scanning and collection of skin conductance response (SCR). Conditioned safety signals reduced psychophysiological reactivity (i.e., SCR) in the overall sample. Although exposure to a higher number of traumatic events was associated with elevated SCR across all task conditions, SCR did not differ between threat in the presence of conditioned safety (i.e., SSL) relative to threat alone in a trauma-related manner. At the neural level, however, higher levels of trauma exposure were associated with lower hippocampal, amygdala, and dorsolateral prefrontal cortical activation during SSL. These findings suggest that while conditioned safety signals can reduce fear in the presence of threat even among individuals exposed to higher degrees of trauma, the neural circuitry involved in SSL is in fact sensitive to trauma exposure. Future research investigating neural processes during SSL among individuals with PTSD or anxiety can further elucidate the ways in which SSL and its neural correlates may reduce fear and link trauma exposure with later mental health conditions.
一生中遭受创伤的情况很普遍,这增加了出现焦虑和创伤后应激障碍(PTSD)等心理健康问题的可能性。安全信号学习(SSL)——一种条件性抑制形式,涉及通过条件性安全来减轻恐惧——已被证明能有效减轻遭受创伤个体的恐惧反应,但创伤暴露与SSL神经机制之间的关联仍不清楚。有不同创伤暴露史的成年人在功能磁共振成像扫描和皮肤电导反应(SCR)收集过程中完成了一项条件性抑制任务。条件性安全信号降低了总体样本中的心理生理反应性(即SCR)。尽管在所有任务条件下,遭受更多创伤事件与较高的SCR相关,但在有条件性安全(即SSL)存在时的威胁与单独威胁相比,SCR在创伤相关方面并无差异。然而,在神经层面,较高水平的创伤暴露与SSL期间海马体、杏仁核和背外侧前额叶皮质的较低激活有关。这些发现表明,虽然条件性安全信号即使在遭受更高程度创伤的个体中也能在威胁存在时减轻恐惧,但SSL所涉及的神经回路实际上对创伤暴露敏感。未来对PTSD或焦虑症患者在SSL期间神经过程的研究可以进一步阐明SSL及其神经关联可能减轻恐惧的方式,以及将创伤暴露与后期心理健康状况联系起来。