Departments of Neurobiology and Anatomy and Biomedical Engineering, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, and Psychology Department, Marquette University, Milwaukee, Wisconsin 53233, USA.
J Neurosci. 2011 Apr 6;31(14):5540-8. doi: 10.1523/JNEUROSCI.5791-10.2011.
The subjective experience of one's environment is constructed by interactions among sensory, cognitive, and affective processes. For centuries, meditation has been thought to influence such processes by enabling a nonevaluative representation of sensory events. To better understand how meditation influences the sensory experience, we used arterial spin labeling functional magnetic resonance imaging to assess the neural mechanisms by which mindfulness meditation influences pain in healthy human participants. After 4 d of mindfulness meditation training, meditating in the presence of noxious stimulation significantly reduced pain unpleasantness by 57% and pain intensity ratings by 40% when compared to rest. A two-factor repeated-measures ANOVA was used to identify interactions between meditation and pain-related brain activation. Meditation reduced pain-related activation of the contralateral primary somatosensory cortex. Multiple regression analysis was used to identify brain regions associated with individual differences in the magnitude of meditation-related pain reductions. Meditation-induced reductions in pain intensity ratings were associated with increased activity in the anterior cingulate cortex and anterior insula, areas involved in the cognitive regulation of nociceptive processing. Reductions in pain unpleasantness ratings were associated with orbitofrontal cortex activation, an area implicated in reframing the contextual evaluation of sensory events. Moreover, reductions in pain unpleasantness also were associated with thalamic deactivation, which may reflect a limbic gating mechanism involved in modifying interactions between afferent input and executive-order brain areas. Together, these data indicate that meditation engages multiple brain mechanisms that alter the construction of the subjectively available pain experience from afferent information.
人的环境主观体验是由感觉、认知和情感过程的相互作用构建的。几个世纪以来，人们一直认为冥想通过对感觉事件进行非评价性的表达来影响这些过程。为了更好地理解冥想如何影响感觉体验，我们使用动脉自旋标记功能磁共振成像来评估正念冥想如何影响健康人类参与者的疼痛的神经机制。在 4 天的正念冥想训练后，与休息相比，在进行疼痛刺激时进行冥想会使疼痛的不愉快感降低 57%，疼痛强度评分降低 40%。采用双因素重复测量方差分析来识别冥想与与疼痛相关的大脑激活之间的相互作用。冥想减少了对侧初级体感皮层与疼痛相关的激活。采用多元回归分析来识别与冥想相关的疼痛减轻程度的个体差异相关的脑区。冥想引起的疼痛强度评分降低与前扣带皮层和前岛叶的活动增加有关，这些区域参与对伤害性加工的认知调节。疼痛不愉快感评分的降低与眶额皮层的激活有关，眶额皮层是重新构建感觉事件的上下文评估的一个区域。此外，疼痛不愉快感的降低还与丘脑去激活有关，这可能反映了参与改变传入信息与执行命令大脑区域之间相互作用的边缘门控机制。总之，这些数据表明冥想涉及多个改变主观可获得的疼痛体验的大脑机制，这些机制来自于传入信息。
