Li Xueshan, Liu Min, Liu Bo, Yue Heng, Cheng Xiangjuan, Bao Hugejiletu
School of Psychology, Inner Mongolia Normal University, Hohhot, China.
School of Journalism and Communication, Xiamen University, Xiamen, China.
Front Psychol. 2025 Mar 17;16:1525216. doi: 10.3389/fpsyg.2025.1525216. eCollection 2025.
The psychological mechanisms that make Conditioned Pain Modulation (CPM) an effective non-pharmacological intervention are still not fully understood. Expectancy is believed to be a critical psychological factor affecting CPM effects, but its specific role has yet to be fully clarified. This study aims to explore the relationship between expectancy and CPM while providing physiological evidence using functional near-infrared spectroscopy (fNIRS).
A standardized CPM induction paradigm was implemented, with verbal guidance used to induce expectancy. The Numeric Rating Scale (NRS) assessed the intensity of the test stimulus (TS), while an 11-point scale evaluated participants' attentional focus on the TS and the effect of expectancy. fNIRS was employed to monitor changes in prefrontal cortex (PFC) activity.
Expectancy significantly amplified the CPM effect ( = 0.036) while markedly reducing attention to the experimental stimulus ( = 0.004). fNIRS findings indicated significant reductions in activity within the left frontal eye field, left dorsolateral prefrontal cortex, and left frontal pole regions. In the post-test, the control group demonstrated significantly higher cortical activity in the right frontal pole region compared to the expectancy group ( < 0.05). Within the expectancy group, bilateral frontal pole cortical activity was significantly lower in the post-test compared to the pre-test ( < 0.05).
Expectancy represents a key psychological mechanism underlying the CPM effect, potentially modulating its magnitude through attention regulation and accompanied by a reduction in oxygenated hemoglobin activity in the frontal pole region and introduced the Expectancy-Attention-CPM Modulation Model (ECAM).
使条件性疼痛调制（CPM）成为一种有效非药物干预措施的心理机制仍未完全明确。预期被认为是影响CPM效果的关键心理因素，但其具体作用尚未完全阐明。本研究旨在探讨预期与CPM之间的关系，并使用功能近红外光谱（fNIRS）提供生理证据。
实施标准化的CPM诱导范式，采用言语指导诱导预期。数字评分量表（NRS）评估测试刺激（TS）的强度，同时用11点量表评估参与者对TS的注意力集中程度以及预期的效果。采用fNIRS监测前额叶皮层（PFC）活动的变化。
预期显著增强了CPM效果（=0.036），同时显著降低了对实验刺激的注意力（=0.004）。fNIRS结果表明，左额叶眼区、左背外侧前额叶皮层和左额极区域的活动显著降低。在测试后，与预期组相比，对照组在右额极区域表现出显著更高的皮层活动（<0.05）。在预期组中，测试后双侧额极皮层活动与测试前相比显著降低（<0.05）。
预期是CPM效果背后的关键心理机制，可能通过注意力调节来调节其程度，并伴随着额极区域氧合血红蛋白活性的降低，进而提出了预期-注意力-CPM调节模型（ECAM）。
