Pain is an individual experience. Previous studies have highlighted changes in brain activation and morphology associated with within- and interindividual pain perception. In this study we sought to characterize brain mechanisms associated with between-individual differences in pain in a sample of healthy adolescent and adult participants (N = 101). Here we show that pain ratings varied widely across individuals and that individuals reported changes in pain evoked by small differences in stimulus intensity in a manner congruent with their pain sensitivity, further supporting the utility of subjective reporting as a measure of the true individual experience. Furthermore, brain activation related to interindividual differences in pain was not detected, despite clear sensitivity of the Blood Oxygenation Level-Dependent (BOLD) signal to small differences in noxious stimulus intensities within individuals. These findings suggest fMRI may not be a useful objective measure to infer reported pain intensity.

疼痛是一种个人体验。以前的研究强调了与个体内部和个体间疼痛感知相关的大脑激活和形态的变化。在这项研究中，我们试图在健康的青少年和成人参与者（N = 101）样本中描述与个体间疼痛差异相关的大脑机制。在这里，我们表明，个体之间的疼痛等级差异很大，并且个体报告的疼痛变化是由刺激强度的微小差异引起的，其方式与其疼痛敏感性一致，进一步支持了主观报告作为衡量真实个人体验的效用。此外，没有检测到与个体间疼痛差异相关的脑激活，尽管血氧水平依赖性（BOLD）信号对个体内有害刺激强度的微小差异具有明显的敏感性。这些发现表明 fMRI 可能不是推断报告的疼痛强度的有用的客观测量方法。