Garrison Kathleen A, Zeffiro Thomas A, Scheinost Dustin, Constable R Todd, Brewer Judson A
Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA.
Cogn Affect Behav Neurosci. 2015 Sep;15(3):712-20. doi: 10.3758/s13415-015-0358-3.
Meditation has been associated with relatively reduced activity in the default mode network, a brain network implicated in self-related thinking and mind wandering. However, previous imaging studies have typically compared meditation to rest, despite other studies having reported differences in brain activation patterns between meditators and controls at rest. Moreover, rest is associated with a range of brain activation patterns across individuals that has only recently begun to be better characterized. Therefore, in this study we compared meditation to another active cognitive task, both to replicate the findings that meditation is associated with relatively reduced default mode network activity and to extend these findings by testing whether default mode activity was reduced during meditation, beyond the typical reductions observed during effortful tasks. In addition, prior studies had used small groups, whereas in the present study we tested these hypotheses in a larger group. The results indicated that meditation is associated with reduced activations in the default mode network, relative to an active task, for meditators as compared to controls. Regions of the default mode network showing a Group × Task interaction included the posterior cingulate/precuneus and anterior cingulate cortex. These findings replicate and extend prior work indicating that the suppression of default mode processing may represent a central neural process in long-term meditation, and they suggest that meditation leads to relatively reduced default mode processing beyond that observed during another active cognitive task.
冥想与默认模式网络活动相对减少有关，默认模式网络是一个涉及自我相关思维和走神的脑网络。然而，以往的影像学研究通常将冥想与休息进行比较，尽管其他研究报告了冥想者与静息状态下的对照组在大脑激活模式上存在差异。此外，休息与个体间一系列大脑激活模式相关，而这一点直到最近才开始得到更好的描述。因此，在本研究中，我们将冥想与另一项主动认知任务进行比较，一方面是为了重复冥想与默认模式网络活动相对减少有关的研究结果，另一方面是通过测试在冥想过程中默认模式活动是否减少（超出在费力任务中观察到的典型减少）来扩展这些结果。此外，以往研究使用的样本量较小，而在本研究中，我们在更大的样本中检验了这些假设。结果表明，与主动任务相比，冥想者的默认模式网络激活相对于对照组有所减少。显示出组×任务交互作用的默认模式网络区域包括后扣带回/楔前叶和前扣带回皮质。这些发现重复并扩展了先前的研究工作，表明抑制默认模式处理可能是长期冥想的核心神经过程，并且它们表明冥想导致默认模式处理相对于另一项主动认知任务中观察到的情况有相对减少。
