Objective: Capability for suicide, which refers to an individual's ability to enact potentially lethal harm to oneself and overcome the fear of dying, is an empirically supported component of the Interpersonal-Psychological Theory of Suicide. Although an abundance of research has examined capability for suicide through the use of self-report data, little research has assessed specific psychophysiological mechanisms that may contribute to capability for suicide. We assessed relationships between capability for suicide (fearlessness about death and pain tolerance), high frequency heart rate variability (HF HRV), and subjectively reported fear during a death related event. Given that greater HRV is associated with calmness and lack of distress, we predicted that HRV during a fearful event would be positively associated with the capability for suicide. Method: Data were collected from 101 undergraduates. Participants self-reported fearlessness about death and had their pain tolerance assessed with an algometer. HF HRV was assessed prior to, during, and following a film-viewing task designed to elicit fear of death. Results: Correlations revealed that fearlessness about death was negatively associated with self-reported fear during the film viewing and positively associated with self-reported and objective pain tolerance. Linear regressions found that fearlessness about death, but not self-reported or objective pain tolerance, was positively associated with HF HRV during the film-viewing and recovery. Discussion: During a fearful, death related event, greater HF HRV was associated with greater fearlessness about death, suggesting that HF HRV may represent one possible mechanism through which fearlessness about death is maintained.

中文翻译：

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适应恐惧：对死亡的恐惧与心率变异性有关

目标：自杀能力是指个人对自己造成潜在致命伤害并克服对死亡的恐惧的能力，是人际-心理自杀理论的经验支持的组成部分。尽管大量研究通过使用自我报告数据检查了自杀能力，但很少有研究评估可能有助于自杀能力的特定心理生理机制。我们评估了自杀能力（对死亡的无畏和疼痛耐受性）、高频心率变异性（HF HRV）和在死亡相关事件中主观报告的恐惧之间的关系。鉴于更大的 HRV 与平静和没有痛苦有关，我们预测，可怕事件中的 HRV 与自杀能力呈正相关。方法：数据来自101名本科生。参与者自我报告了对死亡的无畏精神，并用海量计评估了他们的疼痛耐受性。在旨在引发对死亡的恐惧的电影观看任务之前、期间和之后评估 HF HRV。结果：相关性显示，对死亡的无畏与观影期间自我报告的恐惧呈负相关，与自我报告的客观疼痛耐受性呈正相关。线性回归发现，在电影观看和康复期间，对死亡的无畏，但不是自我报告或客观的疼痛耐受性，与 HF HRV 呈正相关。讨论：在一个可怕的、与死亡有关的事件中，