Huskey Alisa, Taylor Daniel J, Friedman Bruce H
Department of Psychology, Virginia Tech, Blacksburg, Virginia, USA.
Department of Psychology, University of Arizona, Tucson, Arizona, USA.
Dev Psychobiol. 2022 May;64(4):e22242. doi: 10.1002/dev.22242.
The Generalized Unsafety Theory of Stress posits that low heart rate variability contributes to a perception of "generalized unsafety" (i.e., constantly perceiving oneself to be unsafe), independent of stressful events or stress-related symptomatology. We tested this claim by examining if resting heart rate variability, trait worry, posttraumatic stress symptoms, trauma history, and age of onset predicted fear inhibition, a measure of generalized unsafety. A Pavlovian discriminant conditioning paradigm was used to assess fear inhibition level by comparing eyeblink startle potentiation to a threat cue (presented with air blast) with startle potentiation to a safety signal (never presented with air blast). Survey and laboratory responses were collected from 42 adults who were 20 years old on average, 86% Women, and 76% White. Heart rate variability did not independently predict variation in fear inhibition, as hypothesized. Rather, higher levels of posttraumatic stress symptoms and greater cumulative interpersonal trauma predicted lower fear inhibition. Individuals reporting childhood trauma had higher trait worry, which predicted more severe posttraumatic stress symptoms. These findings highlight the role of attenuated inhibitory learning in stress-related symptomatology and developmentally disruptive trauma. Ability to distinguish threat from safety is a plausible biobehavioral mechanism by which adversity impacts development.
应激的广义不安全理论认为，低心率变异性会导致一种“广义不安全”的认知（即持续感觉自己不安全），这与应激事件或与应激相关的症状无关。我们通过检验静息心率变异性、特质担忧、创伤后应激症状、创伤史和发病年龄是否能预测恐惧抑制（一种广义不安全的指标）来验证这一说法。采用巴甫洛夫辨别性条件作用范式，通过比较对威胁线索（伴随气爆呈现）的眨眼惊跳增强与对安全信号（从未伴随气爆呈现）的惊跳增强来评估恐惧抑制水平。从42名平均年龄为20岁、86%为女性、76%为白人的成年人中收集了调查和实验室反应数据。与假设相反，心率变异性并不能独立预测恐惧抑制的变化。相反，创伤后应激症状水平较高和累积人际创伤较大预示着恐惧抑制较低。报告童年创伤的个体特质担忧较高，这预示着创伤后应激症状更严重。这些发现突出了减弱的抑制性学习在与应激相关的症状学和发育性破坏创伤中的作用。区分威胁与安全的能力是逆境影响发育的一种合理的生物行为机制。
