Madden Victoria J, Bellan Valeria, Russek Leslie N, Camfferman Danny, Vlaeyen Johan W S, Moseley G Lorimer
Sansom Institute for Health Research, University of South Australia, Adelaide, Australia.
Body in Mind Research Group, University of South Australia, Adelaide, Australia; Department of Physical Therapy, Clarkson University, Potsdam, New York.
J Pain. 2016 Oct;17(10):1105-1115. doi: 10.1016/j.jpain.2016.06.012. Epub 2016 Jul 22.
A classical conditioning framework is often used for clinical reasoning about pain that persists after tissue healing. However, experimental studies demonstrating classically conditioned pain in humans are lacking. The current study tested whether non-nociceptive somatosensory stimuli can come to modulate pain thresholds after being paired with painful nociceptive stimuli in healthy humans. We used a differential simultaneous conditioning paradigm in which one nonpainful vibrotactile conditioned stimulus (CS(+)) was simultaneously paired with an unconditioned painful laser stimulus, and another vibrotactile stimulus (CS(-)) was paired with a nonpainful laser stimulus. After acquisition, at-pain-threshold laser stimuli were delivered simultaneously with a CS(+) or CS(-) vibrotactile stimulus. The primary outcome was the percentage of at-threshold laser stimuli that were reported as painful. The results were as expected: after conditioning, at-threshold laser trials paired with the CS(+) were reported as painful more often, as more intense, and as more unpleasant than those paired with the CS(-). This study provides new evidence that pain thresholds can be modulated via classical conditioning, even when the stimulus used to test the threshold cannot be anticipated. As such, it lays a critical foundation for further investigations of classical conditioning as a possible driver of persistent pain.
This study provides new evidence that human pain thresholds can be influenced by non-nociceptive somatosensory stimuli, via a classical conditioning effect. As such, it lays a critical foundation for further investigations of classical conditioning as a possible driver of persistent pain.
经典条件作用框架常用于对组织愈合后仍持续存在的疼痛进行临床推理。然而，缺乏在人类中证明经典条件作用性疼痛的实验研究。当前研究测试了在健康人类中，非伤害性体感刺激在与疼痛性伤害性刺激配对后是否会调节疼痛阈值。我们使用了一种差异同时条件作用范式，其中一个非疼痛性振动触觉条件刺激（CS(+)）与一个无条件疼痛性激光刺激同时配对，另一个振动触觉刺激（CS(-)）与一个非疼痛性激光刺激配对。在习得之后，在疼痛阈值的激光刺激与CS(+)或CS(-)振动触觉刺激同时呈现。主要结果是报告为疼痛阈值的激光刺激的百分比。结果正如预期：在条件作用后，与CS(+)配对的阈值激光试验比与CS(-)配对的试验更常被报告为疼痛、更强烈且更不愉快。这项研究提供了新的证据，即即使测试阈值的刺激无法被预期，疼痛阈值也可以通过经典条件作用来调节。因此，它为进一步研究经典条件作用作为持续性疼痛的可能驱动因素奠定了关键基础。
这项研究提供了新的证据，即人类疼痛阈值可通过经典条件作用效应受到非伤害性体感刺激的影响。因此，它为进一步研究经典条件作用作为持续性疼痛的可能驱动因素奠定了关键基础。
