Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Winston-Salem, North Carolina.
Department of Psychology, Wake Forest University, Winston-Salem, North Carolina.
J Pain. 2020 Mar-Apr;21(3-4):306-323. doi: 10.1016/j.jpain.2019.07.003. Epub 2019 Aug 1.
Mindfulness meditation is a self-regulatory practice premised on sustaining nonreactive awareness of arising sensory events that reliably reduces pain. Yet, the specific analgesic mechanisms supporting mindfulness have not been comprehensively disentangled from the potential nonspecific factors supporting this technique. Increased parasympathetic nervous system (PNS) activity is associated with pain relief corresponding to a number of cognitive manipulations. However, the relationship between the PNS and mindfulness-based pain attenuation remains unknown. The primary objective of the present study was to determine the role of high-frequency heart rate variability (HF HRV), a marker of PNS activity, during mindfulness-based pain relief as compared to a validated, sham-mindfulness meditation technique that served as a breathing-based control. Sixty-two healthy volunteers (31 females; 31 males) were randomized to a 4-session (25 min/session) mindfulness or sham-mindfulness training regimen. Before and after each group's respective training, participants were administered noxious (49°C) and innocuous (35°C) heat to the right calf. HF HRV and respiration rate were recorded during thermal stimulation and pain intensity and unpleasantness ratings were collected after each stimulation series. The primary analysis revealed that during mindfulness meditation, higher HF HRV was more strongly associated with lower pain unpleasantness ratings when compared to sham-mindfulness meditation (B = -.82, P = .04). This finding is in line with the prediction that mindfulness-based meditation engages distinct mechanisms from sham-mindfulness meditation to reduce pain. However, the same prediction was not confirmed for pain intensity ratings (B = -.41). Secondary analyses determined that mindfulness and sham-mindfulness meditation similarly reduced pain ratings, decreased respiration rate, and increased HF HRV (between group ps < .05). More mechanistic work is needed to reliably determine the role of parasympathetic activation in mindfulness-based pain relief as compared to other meditative techniques. Perspective: Mindfulness has been shown to engage multiple mechanisms to reduce pain. The present study extends on this work to show that higher HRV is associated with mindfulness-induced reductions in pain unpleasantness, but not pain intensity ratings, when compared to sham-mindfulness meditation. These findings warrant further investigation into the mechanisms engaged by mindfulness as compared to placebo.
正念冥想是一种自我调节的实践，其前提是持续地对出现的感官事件保持无反应的意识，这种意识可以可靠地减轻疼痛。然而，支持正念的具体镇痛机制尚未从支持该技术的潜在非特异性因素中全面分离出来。增加副交感神经系统（PNS）活动与许多认知操作的止痛作用有关。然而，PNS 与基于正念的疼痛缓解之间的关系尚不清楚。本研究的主要目的是确定高频心率变异性（HF HRV）在基于正念的疼痛缓解中的作用，HF HRV 是 PNS 活动的标志物，与经过验证的假正念冥想技术（作为呼吸控制）进行比较。62 名健康志愿者（31 名女性；31 名男性）被随机分为 4 组（每组 25 分钟）进行正念或假正念训练。在每组各自的训练前后，向右侧小腿施加有害（49°C）和无害（35°C）的热刺激。在热刺激过程中记录 HF HRV 和呼吸频率，并在每次刺激系列后收集疼痛强度和不愉快程度的评分。主要分析表明，与假正念冥想相比，在正念冥想期间，HF HRV 较高与较低的疼痛不愉快程度评分更密切相关（B = -.82，P =.04）。这一发现与基于正念的冥想通过与假正念冥想不同的机制来减轻疼痛的预测一致。然而，对于疼痛强度评分，同样的预测并没有得到证实（B = -.41）。二次分析确定，正念和假正念冥想同样降低了疼痛评分，降低了呼吸率，增加了 HF HRV（组间 p <.05）。需要更多的机制研究来可靠地确定与其他冥想技术相比，副交感神经激活在基于正念的疼痛缓解中的作用。观点：正念已被证明可以通过多种机制来减轻疼痛。本研究扩展了这一工作，表明与假正念冥想相比，当正念冥想时，较高的 HRV 与正念引起的疼痛不愉快感降低相关，而与疼痛强度评分无关。这些发现值得进一步研究正念与安慰剂相比所涉及的机制。
