Background

Deficits in safety signal learning are well-established in fear-related disorders (e.g., PTSD, phobias). The current study used a fear conditioning paradigm to test associations among eye blink startle and event-related brain potential (ERP) latency measures of safety signal learning, as well as the role of cardiac vagal control (a measure of top-down inhibition necessary for safety learning).

Methods

Participants were 49 trauma-exposed women ages 17 to 28 years. Eyeblink startle response and ERP amplitudes/latencies were derived for conditioned stimuli associated (CS+) and not associated (CS-) with an aversive unconditioned stimulus. ERPs included the P100 and late positive potential (LPP), which index early visual processing and sustained emotional encoding, respectively. Cardiac vagal control was assessed with resting heart rate variability (HRV).

Results

P100 and LPP latencies for the CS- (safety signal stimulus) were significantly negatively associated with startle to the CS-, but not the CS + . LPP CS- latencies were significantly negatively associated with PTSD Intrusion scores, and this relationship was moderated by vagal control, such that the effect was only present among those with low HRV.

Conclusions

ERP-based markers of safety signal learning were associated with startle response to the CS- (but not CS+) and PTSD symptoms, indicating that these markers may have relevance for fear-related disorders. Cardiac vagal control indexed by HRV is a moderating factor in these associations and may be relevant to safety signal learning.

中文翻译：

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对安全信号的神经生理反应和心脏迷走神经控制的作用

背景

安全信号学习的缺陷在与恐惧相关的疾病（例如，创伤后应激障碍、恐惧症）中很明显。目前的研究使用恐惧条件反射范式来测试眨眼惊吓和事件相关脑电位 (ERP) 安全信号学习延迟测量之间的关联，以及心脏迷走神经控制的作用（一种自上而下的抑制措施）安全学习）。

方法

参与者是 49 名年龄在 17 至 28 岁之间的创伤暴露女性。眨眼惊跳反应和 ERP 振幅/延迟是由条件刺激相关 (CS+) 和不相关 (CS-) 与厌恶的无条件刺激得出的。ERP 包括 P100 和晚期正电位 (LPP)，它们分别指示早期视觉处理和持续情绪编码。用静息心率变异性 (HRV) 评估心脏迷走神经控制。

结果

CS-（安全信号刺激）的 P100 和 LPP 延迟与对 CS- 的惊吓显着负相关，但与 CS + 无关。LPP CS- 潜伏期与 PTSD 侵入评分显着负相关，这种关系通过迷走神经控制得到缓和，因此这种影响仅存在于低 HRV 的人群中。

结论

基于 ERP 的安全信号学习标记与对 CS-（但不是 CS+）和 PTSD 症状的惊吓反应相关，表明这些标记可能与恐惧相关疾病有关。HRV 指示的心脏迷走神经控制是这些关联中的调节因素，可能与安全信号学习有关。