McGovern Institute for Brain Research, MIT, Cambridge 02139, MA
Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO 76230, México.
eNeuro. 2019 Dec 4;6(6). doi: 10.1523/ENEURO.0335-18.2019. Print 2019 Nov/Dec.
While brain default mode network (DMN) activation in human subjects has been associated with mind wandering, meditation practice has been found to suppress it and to increase psychological well-being. In addition to DMN activity reduction, experienced meditators (EMs) during meditation practice show an increased connectivity between the DMN and the central executive network (CEN). However, the gradual change between DMN and CEN configuration from pre-meditation, during meditation, and post-meditation is unknown. Here, we investigated the change in DMN and CEN configuration by means of brain activity and functional connectivity (FC) analyses in EMs across three back-to-back functional magnetic resonance imaging (fMRI) scans: pre-meditation baseline (trait), meditation (state), and post-meditation (state-to-trait). Pre-meditation baseline group comparison was also performed between EMs and healthy controls (HCs). Meditation trait was characterized by a significant reduction in activity and FC within DMN and increased anticorrelations between DMN and CEN. Conversely, meditation state and meditation state-to-trait periods showed increased activity and FC within the DMN and between DMN and CEN. However, the latter anticorrelations were only present in EMs with limited practice. The interactions between networks during these states by means of positive diametric activity (PDA) of the fractional amplitude of low-frequency fluctuations (fALFFs) defined as [Formula: see text] revealed no trait differences but significant increases during meditation state that persisted in meditation state-to-trait. The gradual reconfiguration in DMN and CEN suggest a neural mechanism by which the CEN negatively regulates the DMN and is probably responsible for the long-term trait changes seen in meditators and reported psychological well-being.
当人类受试者的大脑默认模式网络 (DMN) 激活与心流相关时,冥想练习已被发现可抑制它并提高心理健康。除了 DMN 活动减少外,经验丰富的冥想者 (EM) 在冥想过程中显示 DMN 和中央执行网络 (CEN) 之间的连接增加。然而,从冥想前、冥想中和冥想后 DMN 和 CEN 配置之间的逐渐变化尚不清楚。在这里,我们通过 EM 在三个连续的功能磁共振成像 (fMRI) 扫描中的大脑活动和功能连接 (FC) 分析来研究 DMN 和 CEN 配置的变化:冥想前基线 (特质)、冥想 (状态) 和冥想后 (状态到特质)。还在 EM 和健康对照组 (HC) 之间进行了冥想前基线组比较。冥想特质的特点是 DMN 内的活动和 FC 显著减少,DMN 和 CEN 之间的反相关增加。相反,冥想状态和冥想状态到特质期间,DMN 内和 DMN 和 CEN 之间的活动和 FC 增加。然而,只有在练习有限的 EM 中才存在后反相关。通过正直径活动 (PDA) 定义的网络之间的相互作用[公式:见文本]没有显示出特质差异,但在冥想状态下显着增加,并且在冥想状态到特质中持续存在。DMN 和 CEN 的逐渐重新配置表明了一种神经机制,其中 CEN 负调节 DMN,并且可能负责在冥想者中观察到的长期特质变化和报告的心理健康。