Vandael Kristof, Meulders Michel, Vanden Boer Celine, Meulders Ann
Experimental Health Psychology, Maastricht University, Maastricht, The Netherlands.
Center for Information Management, Modeling and Simulation, KU Leuven, Brussels, Belgium.
Scand J Pain. 2019 Dec 18;20(1):151-165. doi: 10.1515/sjpain-2019-0065.
Background and aims Pain-related fear and its subsequent generalization is key to the development and maintenance of chronic pain disability. Research has shown that pain-related fear acquired through classical conditioning generalizes following a gradient, that is, novel movements that are proprioceptively similar to the original pain-associated movement elicit more fear. Studies suggest that classical conditioning can also modulate pain and conditioned fear seems to mediate this effect. However, it remains uninvestigated whether this is also the case for generalized fear. Methods In a voluntary joystick movement paradigm, one movement (conditioned stimulus; CS+) was followed by pain (pain-US), and another was not (CS-). Generalization to five novel movements (generalization stimuli; GSs) with varying levels of similarity to the CSs was tested when paired with an at-pain-threshold intensity stimulus (threshold-USs). We collected self-reported fear and pain, as well as eyeblink startle responses as an additional index of conditioned fear. Results Results showed a fear generalization gradient in the ratings, but not in the startle measures. The data did not support the idea that fear generalization mediates spreading of pain. Conclusions Despite the lack of effects in the current study, this is a promising novel approach to investigate pain modulation in the context of chronic pain. Implications This study replicates the finding that pain-related fear spreads selectively towards movements that are proprioceptively more similar to the original pain-eliciting movement. Although results did not support the idea that such generalized fear mediates spreading of pain, the study provides a promising approach to investigate pain modulation by pain-associated movements.
背景与目的 与疼痛相关的恐惧及其随后的泛化是慢性疼痛残疾发展和维持的关键。研究表明，通过经典条件作用获得的与疼痛相关的恐惧会呈梯度泛化，也就是说，在本体感觉上与原始疼痛相关运动相似的新运动会引发更多恐惧。研究表明，经典条件作用也可以调节疼痛，条件性恐惧似乎介导了这种效应。然而，对于泛化恐惧是否也是如此仍未得到研究。方法 在一个自愿的操纵杆运动范式中，一种运动（条件刺激；CS+）之后会出现疼痛（疼痛性非条件刺激），而另一种运动则不会（CS-）。当与疼痛阈值强度刺激（阈值非条件刺激）配对时，测试对与CS有不同相似程度的五种新运动（泛化刺激；GSs）的泛化情况。我们收集了自我报告的恐惧和疼痛，以及眨眼惊吓反应作为条件性恐惧的另一个指标。结果 结果在评分中显示出恐惧泛化梯度，但在惊吓测量中未显示。数据不支持恐惧泛化介导疼痛扩散的观点。结论 尽管本研究未发现相关效应，但这是一种在慢性疼痛背景下研究疼痛调节的有前景的新方法。意义 本研究重复了这一发现，即与疼痛相关的恐惧会选择性地扩散到在本体感觉上与原始引发疼痛的运动更相似的运动上。尽管结果不支持这种泛化恐惧介导疼痛扩散的观点，但该研究为研究与疼痛相关的运动对疼痛调节提供了一种有前景的方法。
