Department of Neurology, TUM-Neuroimaging Center, Technische Universität München, Munich, Germany.
Pain. 2017 Nov;158(11):2129-2136. doi: 10.1097/j.pain.0000000000001010.
Pain serves the protection of the body by translating noxious stimulus information into a subjective percept and protective responses. Such protective responses rely on autonomic responses that allocate energy resources to protective functions. However, the precise relationship between objective stimulus intensity, subjective pain intensity, autonomic responses, and brain activity is not fully clear yet. Here, we addressed this question by continuously recording pain ratings, skin conductance, heart rate, and electroencephalography during tonic noxious heat stimulation of the hand in 39 healthy human subjects. The results confirmed that pain intensity dissociates from stimulus intensity during 10 minutes of noxious stimulation. Furthermore, skin conductance measures were significantly related to stimulus intensity but not to pain intensity. Correspondingly, skin conductance measures were significantly related to alpha and beta oscillations in contralateral sensorimotor cortex, which have been shown to encode stimulus intensity rather than pain intensity. No significant relationships were found between heart rate and stimulus intensity or pain intensity. The findings were consistent for stimulation of the left and the right hands. These results suggest that sympathetic autonomic responses to noxious stimuli in part directly result from nociceptive rather than from perceptual processes. Beyond, these observations support concepts of pain and emotions in which sensory, motor, and autonomic components are partially independent processes that together shape emotional and painful experiences.
疼痛通过将有害刺激信息转化为主观感知和保护反应来保护身体。这种保护反应依赖于自主反应，自主反应将能量资源分配到保护功能上。然而，客观刺激强度、主观疼痛强度、自主反应和大脑活动之间的确切关系尚不完全清楚。在这里，我们通过在 39 名健康受试者的手部持续记录痛觉评分、皮肤电导、心率和脑电图，在手部持续进行 10 分钟的有害热刺激，来解决这个问题。结果证实，在 10 分钟的有害刺激期间，疼痛强度与刺激强度分离。此外，皮肤电导测量值与刺激强度显著相关，但与疼痛强度无关。相应地，皮肤电导测量值与对侧感觉运动皮层中的α和β振荡显著相关，α和β振荡已被证明编码刺激强度而不是疼痛强度。心率与刺激强度或疼痛强度之间没有显著关系。对左手和右手的刺激均得到了一致的结果。这些结果表明，有害刺激引起的交感自主反应部分直接来自伤害性感觉，而不是来自知觉过程。此外，这些观察结果支持疼痛和情绪的概念，即感觉、运动和自主成分是部分独立的过程，共同塑造了情绪和疼痛体验。
