Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Neuroimage. 2019 Jan 1;184:954-963. doi: 10.1016/j.neuroimage.2018.10.020. Epub 2018 Oct 6.
Classical theories suggest placebo analgesia and nocebo hyperalgesia are based on expectation and conditioned experience. Whereas the neural mechanism of how expectation modulates placebo and nocebo effects during pain anticipation have been extensively studied, little is known about how experience may change brain networks to produce placebo and nocebo responses. We investigated the neural pathways of direct and observational conditioning for conscious and nonconscious conditioned placebo/nocebo effects using magnetoencephalography and a face visual cue conditioning model. We found that both direct and observational conditioning produced conscious conditioned placebo and nocebo effects and a nonconscious conditioned nocebo effect. Alpha band brain connectivity changes before and after conditioning could predict the magnitude of conditioned placebo and nocebo effects. Particularly, the connectivity between the rostral anterior cingulate cortex and middle temporal gyrus was an important indicator for the manipulation of placebo and nocebo effects. Our study suggests that conditioning can mediate our pain experience by encoding experience and modulating brain networks.
经典理论认为，安慰剂镇痛和反安慰剂痛觉过敏是基于期望和条件经验的。虽然已经广泛研究了期望如何在疼痛预期期间调节安慰剂和反安慰剂效应的神经机制，但对于经验如何改变大脑网络以产生安慰剂和反安慰剂反应知之甚少。我们使用脑磁图和面部视觉线索条件作用模型研究了直接和观察条件作用对于有意识和无意识条件作用的安慰剂/反安慰剂效应的神经途径。我们发现，直接和观察条件作用都产生了有意识的条件作用的安慰剂和反安慰剂效应，以及无意识的条件作用的反安慰剂效应。条件作用前后的 alpha 波段脑连接变化可以预测条件作用的安慰剂和反安慰剂效应的幅度。特别是，额前扣带皮质和中颞叶之间的连接是操纵安慰剂和反安慰剂效应的重要指标。我们的研究表明，通过编码经验和调节大脑网络，条件作用可以调节我们的疼痛体验。
