Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena I-41125, Italy.
Pain. 2013 Sep;154(9):1509-1518. doi: 10.1016/j.pain.2013.03.031. Epub 2013 Mar 28.
Identifying personality traits and neural signatures that predict placebo responsiveness is important, both on theoretical and practical grounds. In the present functional magnetic resonance imaging (fMRI) study, we performed multiple-regression interaction analysis to investigate whether hypnotic susceptibility (HS), a cognitive trait referring to the responsiveness to suggestions, explains interindividual differences in the neural mechanisms related to conditioned placebo analgesia in healthy volunteers. HS was not related to the overall strength of placebo analgesia. However, we found several HS-related differences in the patterns of fMRI activity and seed-based functional connectivity that accompanied placebo analgesia. Specifically, in subjects with higher HS, the placebo response was related to increased anticipatory activity in a right dorsolateral prefrontal cortex focus, and to reduced functional connectivity of that focus with brain regions related to emotional and evaluative pain processing (anterior mid-cingulate cortex/medial prefrontal cortex); an opposite pattern of fMRI activity and functional connectivity was found in subjects with lower HS. During pain perception, activity in the regions reflecting attention/arousal (bilateral anterior thalamus/left caudate) and self-related processing (left precuneus and bilateral posterior temporal foci) was negatively related to the strength of the analgesic placebo response in subjects with higher HS, but not in subjects with lower HS. These findings highlight HS influences on brain circuits related to the placebo analgesic effects. More generally, they demonstrate that different neural mechanisms can be involved in placebo responsiveness, depending on individual cognitive traits.
确定人格特质和神经特征，这些特质和特征可以预测安慰剂反应性，这在理论和实践方面都很重要。在本项功能磁共振成像（fMRI）研究中，我们进行了多元回归交互分析，以研究催眠易感性（HS）是否可以解释健康志愿者中与条件性安慰剂镇痛相关的神经机制的个体差异，HS 是指对暗示的反应性，这是一种认知特质。HS 与安慰剂镇痛的总体强度无关。然而，我们发现与安慰剂镇痛相关的 fMRI 活动和基于种子的功能连接模式中存在与 HS 相关的几个差异。具体而言，在 HS 较高的受试者中，安慰剂反应与右背外侧前额叶皮质焦点的预期活动增加有关，并且与该焦点与情绪和评估性疼痛处理相关的大脑区域的功能连接减少有关（前扣带回皮质/内侧前额叶皮质）；在 HS 较低的受试者中，发现了相反的 fMRI 活动和功能连接模式。在疼痛感知过程中，反映注意力/唤醒的区域（双侧前丘脑/左侧尾状核）和自我相关处理的区域（左侧楔前叶和双侧颞叶后焦点）的活动与 HS 较高的受试者中镇痛安慰剂反应的强度呈负相关，但在 HS 较低的受试者中则没有。这些发现强调了 HS 对与安慰剂镇痛效果相关的大脑回路的影响。更普遍地说，它们表明，取决于个体认知特质，不同的神经机制可能参与安慰剂反应性。
