Wagenaar-Tison Alice, Deldar Zoha, Bergeron Antoine, Provencher Benjamin, Northon Stéphane, Rustamov Nabi, Blanchette Isabelle, Sirois Sylvain, Piché Mathieu
Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada.
Department of Psychology, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada.
J Physiol Sci. 2025 May 16;75(2):100026. doi: 10.1016/j.jphyss.2025.100026.
The aim of the present study was to examine the contribution of spinal and supraspinal processes to pain modulation by attention. It is hypothesized that pain inhibition by distraction is accompanied by reduced pain-evoked pupil dilation and cerebral activity, but no inhibition of the nociceptive flexion reflex (NFR), while pain anticipation is expected to increase pain perception and pain-related responses. Twenty healthy volunteers received 90 painful stimuli in control, distraction (mental arithmetic), and anticipation (visual cue) conditions. Anticipation did not modulate pain (p = .7), while distraction decreased pain significantly (p < .001). Moreover, pupil diameter increased 500-1000 ms post-stimulus in the control condition (p < .05), but this response was abolished by distraction. Distraction also decreased pain-related brain activity (high-gamma oscillations) (p = .004), but not the NFR (p = .3). These results suggest that pain inhibition by distraction is produced, in part, by supraspinal inhibition of nociceptive processes.
本研究的目的是探讨脊髓和脊髓上的过程对注意力介导的疼痛调节的作用。研究假设，通过分散注意力抑制疼痛伴随着疼痛诱发的瞳孔扩张和大脑活动的减少，但对伤害性屈曲反射（NFR）没有抑制作用，而预期疼痛会增加疼痛感知和与疼痛相关的反应。20名健康志愿者在对照、分散注意力（心算）和预期（视觉提示）条件下接受了90次疼痛刺激。预期并未调节疼痛（p = 0.7），而分散注意力显著减轻了疼痛（p < 0.001）。此外，在对照条件下，刺激后500 - 1000毫秒瞳孔直径增加（p < 0.05），但这种反应被分散注意力消除。分散注意力还降低了与疼痛相关的大脑活动（高伽马振荡）（p = 0.004），但对NFR没有影响（p = 0.3）。这些结果表明，通过分散注意力抑制疼痛部分是由脊髓上对伤害性过程的抑制产生的。
