Department of Psychology, Research Group on Health Psychology, University of Leuven, Tiensestraat 102, Box 3726, 3000 Leuven, Belgium Department of Psychology, Centre for the Psychology of Learning and Experimental Psychopathology, University of Leuven, Tiensestraat 102, Box 3712, 3000 Leuven, Belgium Faculty of Psychology, Department of Clinical Psychological Science, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
Pain. 2011 Nov;152(11):2460-2469. doi: 10.1016/j.pain.2011.05.015. Epub 2011 Jul 1.
Current fear-avoidance models consider fear of pain as a key factor in the development of chronic musculoskeletal pain. Generally, the idea is that by virtue of the formation of associations or acquired propositional knowledge about the relation between neutral movements and pain, these movements may signal pain, and hence start to elicit defensive fear responses (eg, avoidance behavior). This assumption has never been investigated experimentally. Therefore, we developed a pain-relevant fear conditioning paradigm using a movement as a conditioned stimulus (CS) and a painful electrocutaneous stimulus as an unconditioned stimulus (US) to examine the acquisition of fear of movement-related pain in healthy subjects. In a within-subjects design, participants manipulated a joystick to the left/right in the experimental (predictable) condition, and upward/downward in the control (unpredictable) condition or vice versa. In the predictable condition, one movement direction (CS+), and not the other (CS-), was followed by painful stimuli. In the unpredictable condition, painful stimuli were always delivered during the intertrial interval. Both fear of movement-related pain ratings and eyeblink startle measures were more elevated in response to the CS+ than to the CS-, whereas no differences occurred between both unreinforced CSs in the control condition. Participants were slower initiating a CS+ movement than a CS- movement, while response latencies to CSs in the control condition did not differ. These data support the acquisition of fear of movement-related pain by associative learning. Results are discussed in the broader context of the acquisition of pain-related fear in patients with musculoskeletal pain.
目前的恐惧回避模型认为，对疼痛的恐惧是慢性肌肉骨骼疼痛发展的一个关键因素。一般来说，这种观点认为，由于形成了关于中性运动与疼痛之间关系的联想或习得的命题性知识，这些运动可能会发出疼痛信号，从而开始引发防御性恐惧反应（例如，回避行为）。这一假设从未在实验中得到过验证。因此，我们开发了一种与疼痛相关的恐惧条件反射范式，使用运动作为条件刺激（CS），电皮肤痛刺激作为非条件刺激（US），以检查健康受试者对运动相关疼痛的恐惧的获得。在一个被试内设计中，参与者在实验（可预测）条件下向左/向右操纵操纵杆，在控制（不可预测）条件下向上/向下操纵，或者反之亦然。在可预测的条件下，一个运动方向（CS+），而不是另一个（CS-），伴随着疼痛刺激。在不可预测的条件下，疼痛刺激总是在试验间间隔期间出现。与 CS-相比，CS+引起的运动相关疼痛恐惧评分和眨眼惊跳测量值更高，而在控制条件下，两个未强化的 CS 之间没有差异。与 CS-运动相比，参与者启动 CS+运动的速度较慢，而在控制条件下，对 CS 的反应时没有差异。这些数据支持通过联想学习获得运动相关疼痛的恐惧。结果在肌肉骨骼疼痛患者中获得与疼痛相关的恐惧的更广泛背景下进行了讨论。
