De Pascalis Vilfredo, Scacchia Paolo, Vecchio Arianna
La Sapienza University of Rome, Rome, Italy.
Am J Clin Hypn. 2021 Apr;63(4):302-328. doi: 10.1080/00029157.2020.1863182.
We tested the role of hypnotic suggestibility, involuntariness, pain expectation, and subjective hypnotic depth in the prediction of placebo analgesia (PA) responsiveness. We also tested the link of lower and upper alpha sub-band (i.e., 'alpha1' and 'alpha2') power changes with tonic PA responding during waking and hypnosis conditions. Following an initial PA manipulation condition, we recorded EEG activity during waking and hypnosis under two treatments: (1) painful stimulation (Pain); (2) painful stimulation after application of a PA cream. Alpha1 and alpha2 power were derived using the individual alpha frequency method. We found that (1) PA in both waking and hypnosis conditions significantly reduced relative pain perception; (2) during waking, all the above mentioned contextual measures were associated with pain reduction, while involuntariness alone was associated with pain reduction within hypnosis. Enhanced alpha2 power at the left-parietal lead was solely associated with pain reduction in waking, but not in hypnosis condition. Using multiple regression and mediation analyses we found that: (i) during waking, the enhancement of relative left-parietal alpha2 power, directly influenced the enhancement in pain reduction, and, indirectly, through the mediating positive effect of involuntariness; (j) during hypnosis, the enhancement of left-temporoparietal alpha2 power, through the mediation of involuntariness, influenced pain reduction. Current findings obtained during waking suggest that enhanced alpha2 power may serve as a direct-objective measure of the subjective reduction of tonic pain in response to PA treatment. Overall, our findings suggest that placebo analgesia during waking and hypnosis involves different processes of top-down regulation.
我们测试了催眠易感性、不由自主性、疼痛预期和主观催眠深度在预测安慰剂镇痛（PA）反应性中的作用。我们还测试了在清醒和催眠状态下，较低和较高的阿尔法子带（即“阿尔法1”和“阿尔法2”）功率变化与持续性PA反应之间的联系。在初始PA操作条件之后，我们在清醒和催眠状态下记录了两种治疗方式下的脑电图活动：（1）疼痛刺激（疼痛）；（2）涂抹PA乳膏后进行疼痛刺激。阿尔法1和阿尔法2功率采用个体阿尔法频率方法得出。我们发现：（1）清醒和催眠状态下的PA均显著降低了相对疼痛感知；（2）在清醒状态下，上述所有情境指标均与疼痛减轻相关，而在催眠状态下仅不由自主性与疼痛减轻相关。左顶叶导联处增强的阿尔法2功率仅与清醒状态下的疼痛减轻相关，而与催眠状态无关。通过多元回归和中介分析我们发现：（i）在清醒状态下，相对左顶叶阿尔法2功率的增强直接影响疼痛减轻的增强，并且通过不由自主性的中介积极作用间接影响；（j）在催眠状态下，左颞顶叶阿尔法2功率的增强通过不由自主性的中介作用影响疼痛减轻。在清醒状态下获得的当前研究结果表明，增强的阿尔法2功率可能作为对PA治疗反应中持续性疼痛主观减轻的直接客观指标。总体而言，我们的研究结果表明，清醒和催眠状态下的安慰剂镇痛涉及不同的自上而下调节过程。
