Pediatric Pain Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, University of Cincinnati School of Medicine, Cincinnati, Ohio; Laboratory of Pain Research, Institute of Physiotherapy and Health Sciences, The Jerzy Kukuczka Academy of Physical Education, Katowice, Poland.
Laboratory of Pain Research, Institute of Physiotherapy and Health Sciences, The Jerzy Kukuczka Academy of Physical Education, Katowice, Poland.
J Pain. 2023 Jun;24(6):1116-1125. doi: 10.1016/j.jpain.2023.03.005. Epub 2023 Mar 23.
When the source of nociception expands across a body area, the experience of pain increases due to the spatial integration of nociceptive information. This well-established effect is called spatial summation of pain (SSp) and has been the subject of multiple investigations. Here, we used cold-induced SSp to investigate the effect of attention on the spatial tuning of nociceptive processing. Forty pain-free volunteers (N = 40, 20 females) participated in this experiment. They took part in an SSp paradigm based on three hand immersions into cold water (5°C): Participants either immersed the radial segment ("a"), ulnar segment ("b") or both hand segments ("a+b") and provided overall pain ratings. In some trials based on "a+b" immersions, they were also asked to provide divided (ie, first pain in "a" then in "b"; or reversed) and directed attention ratings (ie, pain only in "a" or "b"). Results confirmed a clear SSp effect in which reported pain during immersions of "a" or "b" was less intense than pain during immersions of "a+b" (P < .001). Data also confirmed that spatial tuning was altered. SSp was abolished when participants provided two ratings in a divided fashion (P < .001). Furthermore, pain was significantly lower when attention was directed only to one segment ("a" OR "b") during "a+b" immersion (P < .001). We conclude that spatial tuning is dynamically driven by attention as reflected in abolished SSp. Directed attention was sufficient to focus spatial tuning and abolish SSp. Results support the role of cognitive processes such as attention in spatial tuning. PERSPECTIVE: This article presents experimental investigation of spatial tuning in pain and offers mechanistic insights of contiguous spatial summation of pain in healthy volunteers. Depending on how pain is evaluated in terms of attentional derivative (overall pain, directed, divided attention) the pain is reduced and spatial summation abolished.
当伤害感受的来源在身体区域内扩大时，由于伤害感受信息的空间整合，疼痛的体验会增加。这种已被充分证实的效应被称为疼痛的空间总和（SSp），并已成为多项研究的主题。在这里，我们使用冷诱导的 SSp 来研究注意力对伤害感受处理的空间调谐的影响。40 名无痛志愿者（N=40，20 名女性）参与了这项实验。他们参与了基于三种手部浸入冷水（5°C）的 SSp 范式：参与者要么浸入桡侧段（“a”）、尺侧段（“b”）或双手段（“a+b”），并提供整体疼痛评分。在基于“a+b”浸入的一些试验中，他们还被要求提供分开的（即先在“a”然后在“b”；或相反）和定向注意力评分（即仅在“a”或“b”处有疼痛）。结果证实了明显的 SSp 效应，即在“a”或“b”浸入时报告的疼痛强度小于在“a+b”浸入时的疼痛强度（P<0.001）。数据还证实空间调谐发生了变化。当参与者以分开的方式提供两个评分时，SSp 被消除（P<0.001）。此外，当注意力仅在“a+b”浸入期间指向一个节段（“a”或“b”）时，疼痛明显降低（P<0.001）。我们得出结论，空间调谐是由注意力动态驱动的，这反映在 SSp 的消除中。定向注意力足以集中空间调谐并消除 SSp。结果支持认知过程（如注意力）在空间调谐中的作用。观点：本文对疼痛的空间调谐进行了实验研究，并为健康志愿者中连续空间疼痛总和提供了机制见解。根据注意力衍生的疼痛评估方式（整体疼痛、定向注意力、分开注意力），疼痛减轻，空间总和消除。
