Kakumanu Ratna Jyothi, Nair Ajay Kumar, Sasidharan Arun, John John P, Mehrotra Seema, Panth Ravindra, Kutty Bindu M
Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru, India.
Department of Psychiatry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru, India.
Prog Brain Res. 2019;244:115-136. doi: 10.1016/bs.pbr.2018.10.027. Epub 2019 Jan 22.
Several studies have demonstrated that meditation naïve subjects can, in just a few weeks, become proficient enough in meditation to show cognitive improvements accompanied with functional and structural changes in the brain. Would long-term exposure to qualitatively different levels of meditative training bring about differences in cognitive processing? Would meditation prior to task performance help separate out these differences? Could the nature of the task influence the findings related to cognitive enhancements? To address these questions, we evaluated cognitive functions in three groups of experienced Vipassana practitioners (Novices: n=22, Mean±SD meditation experience=989±595h; Senior practitioners: 21, 10,510±5313; Teachers: 16, 14,648±9623) who differed in terms of duration and quality of meditative practice. Specifically, we employed "ANGEL" a gamified multilevel oddball paradigm, to assess P3 event-related potentials (ERPs) and associated EEG dynamics-power spectra, event related spectral perturbations (ERSP) and inter-trial coherence (ITC). In order to elicit the state-trait influences of meditation, the cognitive task was performed after the participants had undergone an hour long traditional meditation session. All participants could perform the task well and the gross ERP waveforms were similar for the three groups. As hypothesized, we found distinct state-trait influences of meditation leading to graded differences in P3 EEG dynamics. Specifically, we found reduced theta synchrony, enhanced alpha de-synchrony and lesser theta-alpha coherence in the more proficient meditators. Post hoc analyses revealed several differences between the novice and teacher groups but not as many between novice and seniors suggesting that the senior meditators formed an intermediate group. Our study demonstrates that both quantity and quality of meditation influence EEG dynamics during cognitive processing and that meditation prior to a task can provide additional state-trait effects involved in meeting the specific cognitive demands.
多项研究表明，从未接触过冥想的受试者在短短几周内就能熟练掌握冥想，从而表现出认知能力的提升，并伴有大脑功能和结构的变化。长期接触质量不同的冥想训练会导致认知加工出现差异吗？在任务执行前进行冥想有助于区分这些差异吗？任务的性质会影响与认知增强相关的研究结果吗？为了解决这些问题，我们评估了三组有经验的内观禅修者（新手：n = 22，平均±标准差冥想经验 = 989±595小时；高级修行者：21人，10510±5313小时；教师：16人，14648±9623小时）的认知功能，他们在冥想练习的时长和质量上存在差异。具体而言，我们采用了“ANGEL”，一种游戏化的多级异常球范式，来评估P3事件相关电位（ERP）以及相关的脑电图动态——功率谱、事件相关谱扰动（ERSP）和试次间相干性（ITC）。为了引出冥想的状态——特质影响，在参与者进行了一小时的传统冥想 session 后执行认知任务。所有参与者都能很好地完成任务，三组的总体ERP波形相似。正如所假设的，我们发现冥想有明显的状态——特质影响，导致P3脑电图动态出现分级差异。具体来说，我们发现熟练程度更高的冥想者中，theta同步性降低，alpha去同步化增强，theta-alpha相干性降低。事后分析揭示了新手组和教师组之间的一些差异，但新手组和高级修行者组之间的差异没有那么多，这表明高级冥想者形成了一个中间组。我们的研究表明，冥想的数量和质量都会影响认知加工过程中的脑电图动态，并且在任务前进行冥想可以提供额外的状态——特质效应，涉及满足特定的认知需求。
