National Institute of Mental Health and Neurosciences, Bangalore, India.
AU MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA; Department of Psychology, Auburn University, Auburn, AL, USA; Alabama Advanced Imaging Consortium, Auburn University and University of Alabama Birmingham, AL, USA.
Asian J Psychiatr. 2018 Oct;37:20-25. doi: 10.1016/j.ajp.2018.08.001. Epub 2018 Aug 3.
OM chanting is an ancient technique of Indian meditation. OM chanting is associated with an experience of relaxation, changes in autonomic balance and deactivation of limbic brain regions. While functional localization is important, how brain regions interact with each other has been shown to underlie various brain functions. Therefore, in this study, we tested the hypothesis that there is reduced communication between deactivated regions during OM chanting. In order to do so, we employed multivariate autoregressive model (MVAR) based Granger causality to obtain directional connectivity between deactivated regions. fMRI scans of 12 right handed healthy volunteers (9 Men) from a previously published study was used in which participants performed OM chanting and a control condition in a block design. We found that outputs from insula, anterior cingulate and orbitofrontal cortices were significantly reduced in OM condition. Of interest is the reduction of outputs from these regions to limbic area amygdala. Modulation of brain regions involved in emotion processing and implicated in major depressive disorder (MDD) raises a potential possibility of OM chanting in the treatment of MDD.
OM 唱诵是一种古老的印度冥想技巧。OM 唱诵与放松的体验、自主平衡的变化和边缘脑区域的失活有关。虽然功能定位很重要，但大脑区域之间的相互作用如何，已被证明是各种大脑功能的基础。因此，在这项研究中，我们假设在 OM 唱诵期间，失活区域之间的交流减少。为了做到这一点，我们采用了基于多变量自回归模型（MVAR）的 Granger 因果关系来获得失活区域之间的方向连通性。使用了先前发表的研究中 12 名右利手健康志愿者（9 名男性）的 fMRI 扫描，参与者在块设计中进行 OM 唱诵和对照条件。我们发现，在 OM 条件下，脑岛、前扣带皮层和眶额皮层的输出显著降低。有趣的是，这些区域到边缘区杏仁核的输出减少。涉及情绪处理并与重度抑郁症（MDD）有关的大脑区域的调节提出了 OM 唱诵在治疗 MDD 中的潜在可能性。
