CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, 100101, China.
Department of Psychology, University of Chinese Academy of Sciences, Beijing, 100101, China.
Sci Rep. 2021 Jan 14;11(1):1322. doi: 10.1038/s41598-020-79196-z.
Pain perception is a subjective experience and highly variable across time. Brain responses evoked by nociceptive stimuli are highly associated with pain perception and also showed considerable variability. To date, the test-retest reliability of laser-evoked pain perception and its associated brain responses across sessions remain unclear. Here, an experiment with a within-subject repeated-measures design was performed in 22 healthy volunteers. Radiant-heat laser stimuli were delivered on subjects' left-hand dorsum in two sessions separated by 1-5 days. We observed that laser-evoked pain perception was significantly declined across sessions, coupled with decreased brain responses in the bilateral primary somatosensory cortex (S1), right primary motor cortex, supplementary motor area, and middle cingulate cortex. Intraclass correlation coefficients between the two sessions showed "fair" to "moderate" test-retest reliability for pain perception and brain responses. Additionally, we observed lower resting-state brain activity in the right S1 and lower resting-state functional connectivity between right S1 and dorsolateral prefrontal cortex in the second session than the first session. Altogether, being possibly influenced by changes of baseline mental state, laser-evoked pain perception and brain responses showed considerable across-session variability. This phenomenon should be considered when designing experiments for laboratory studies and evaluating pain abnormalities in clinical practice.
疼痛感知是一种主观体验，在时间上变化很大。伤害性刺激引起的大脑反应与疼痛感知高度相关，也表现出相当大的可变性。迄今为止，激光诱发的疼痛感知及其相关大脑反应在不同时间点的测试-重测信度仍然不清楚。在这里，在 22 名健康志愿者中进行了一项具有个体内重复测量设计的实验。在两次相隔 1-5 天的会议中，在受试者的左手背部上发送辐射热激光刺激。我们观察到，随着双侧初级体感皮层（S1）、右侧初级运动皮层、辅助运动区和中扣带皮层的大脑反应减少，激光诱发的疼痛感知在不同会议中显著下降。两次会议之间的组内相关系数显示，疼痛感知和大脑反应的测试-重测信度为“一般”到“中等”。此外，我们观察到在第二次会议中，右侧 S1 的静息态大脑活动较低，右侧 S1 和背外侧前额叶皮层之间的静息态功能连接较低。总的来说，激光诱发的疼痛感知和大脑反应可能受到基线心理状态变化的影响，表现出相当大的跨会议可变性。在设计实验室研究实验和评估临床实践中的疼痛异常时，应该考虑到这种现象。
