Rethinking pain threshold as a zone of uncertainty
Rethinking pain threshold as a zone of uncertainty
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重新思考疼痛阈值作为一个不确定区域
DOI：
10.1101/521302
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
G. Moseley
中科院分区：
文献类型：
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作者：
V. J. Madden;P. Kamerman;Mark J Catley;V. Bellan;L. Russek;Danny Camfferman;G. Moseley
背景痛阈值传统上被认为是位于痛苦和非痛苦事件之间的边界，这意味着刺激和反应之间存在着相当稳定的关系。在之前的两个实验中，参与者接受了不同强度的激光刺激，并在感觉和疼痛评级量表(SPAS)上对每个刺激进行了评级，该量表包括对疼痛和非疼痛事件进行评级的范围，并明确定义了它们之间的假定边界。在第二个实验中，参与者还提供了传统的0-100数字疼痛评级量表(NRS)和新的非疼痛事件评级量表。这些数据显示，这些大梁具有曲线刺激-反应关系，反映出在不同的试验中，几种不同的强度可能被评为疼痛和非疼痛。这表明，参与者对各种强度的痛苦都不确定，并对非痛苦事件和痛苦事件之间的界限提出了质疑。目前的研究旨在确定不同刺激强度的数量，通过这些刺激，每个参与者在不同的试验中提供“痛苦的”和“非痛苦的”报告。方法对上述两个实验(n=19，女性11例，年龄18~31岁；n=7，女性5例，年龄21~30岁)的数据进行新的探索性分析。我们使用二项检验来正式确定关于疼痛的这一“不确定区域”的宽度，使用SPAR和比较标尺上的评级，并使用数据可视化来评估刺激强度的逐个试验变化是否影响评级。结果我们发现，不确定区的宽度在不同个体之间存在显著差异，而且大多数被试的不确定区是不连续的。组级数据的曲线图掩盖了个体曲线图中明显的个体间差异，但仍然在SPAR和NRS上显示了较宽的不确定区域，但在非痛苦事件的规模上显示了较窄的区域。没有证据表明刺激强度的逐个试验的变化影响了评级。结论本研究揭示的可变性对于包括重复传递刺激的初始校准的实验具有重要的设计意义。这种可变性也会扩大实验的统计能力所需的样本大小，并为在疼痛研究中使用统计方法来解释个体可变性提供了理论基础。最后，高度的可变性意味着，如果要将实验刺激用于临床表型分析，可能需要进行多次试验才能获得代表单个患者实际反应情况的结果。
Background The pain threshold is traditionally conceptualised as a boundary that lies between painful and non-painful events, suggesting a reasonably stable relationship between stimulus and response. In two previous experiments, participants received laser stimuli of various intensities and rated each stimulus on the Sensation and Pain Rating Scale (SPARS), which includes ranges for rating painful and non-painful events and clearly defines the presumed boundary between them. In the second experiment, participants also provided ratings on the conventional 0-100 Numerical Rating Scale for pain (NRS) and a new rating scale for non-painful events. Those data showed the SPARS to have a curvilinear stimulus-response relationship, reflecting that several different intensities may be rated as painful and non-painful in different trials. This suggests that participants were uncertain about painfulness over a range of intensities and calls into question the idea of a boundary between non-painful and painful events. The current study aimed to determine the number of different stimulus intensities across which each participant provided ‘painful’ and ‘non-painful’ reports in different trials. Methods We undertook novel exploratory analyses on data from the aforementioned two experiments (n = 19, 11 female, 18-31 years old; n = 7, 5 female, 21-30 years old). We used the binomial test to formally determine the width of this ‘zone of uncertainty’ about painfulness, using ratings on the SPARS and the comparator scales, and data visualisation to assess whether trial-to-trial change in stimulus intensity influences ratings. Results We found that the width of the zone of uncertainty varied notably between individuals and that the zone was non-continuous for most participants. Plots of group-level data concealed the inter-individual variability apparent in the individual plots, but still showed a wide zone of uncertainty on both the SPARS and the NRS, but a narrow zone on the scale for non-painful events. There was no evidence that trial-to-trial change in stimulus intensity influenced ratings. Conclusions The variability revealed by this study has important design implications for experiments that include initial calibration of repeatedly delivered stimuli. The variability also stands to inflate the size of sample that is required for adequate statistical powering of experiments, and provides rationale for the use of statistical approaches that account for individual variability in studies of pain. Finally, the high variability implies that, if experimental stimuli are to be used in clinical phenotyping, many trials may be required to obtain results that represent a single patient’s actual response profile.
影响因子：
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作者：
Giesecke, T;Williams, DA;Clauw, DJ
通讯作者：
Clauw, DJ