Assinatura eletrofisiológica das cessações

Assinatura eletrofisiológica das cessações

O artigo Investigation of advanced mindfulness meditation “cessation” experiences using EEG spectral analysis in an intensively sampled case study publicado na revista científica Neuropsychologia examina a assinatura neural das “cessações” (ausência momentânea de consciência) durante a meditação mindfulness. O estudo, liderado por Matthew Sacchet e desenvolvido no âmbito do projeto de investigação 99/20 - Beyond "mindfulness" and toward a modern science of meditative mastery and spiritual transformation, apoiado pela Fundação BIAL, demonstrou que a diminuição da magnitude da potência na banda alfa do EEG iniciou-se 40 segundos antes das cessações e foram das mais baixas imediatamente após as cessações. A análise deste resultado à luz da região de interesse (ROI) revelou que a diminuição na banda alfa foi mais pronunciada nas regiões occipital e parietal do cérebro e que foi diminuindo linearmente durante toda a duração da pré-cessação.

 

ABSTRACT

Mindfulness meditation is a contemplative practice informed by Buddhism that targets the development of present-focused awareness and non-judgment of experience. Interest in mindfulness is burgeoning, and it has been shown to be effective in improving mental and physical health in clinical and non-clinical contexts. In this report, for the first time, we used electroencephalography (EEG) combined with a neurophenomenological approach to examine the neural signature of “cessation” events, which are dramatic experiences of complete discontinuation in awareness similar to the loss of consciousness, which are reported to be experienced by very experienced meditators, and are proposed to be evidence of mastery of mindfulness meditation. We intensively sampled these cessations as experienced by a single advanced meditator (with over 23,000 h of meditation training) and analyzed 37 cessation events collected in 29 EEG sessions between November 12, 2019, and March 11, 2020. Spectral analyses of the EEG data surrounding cessations showed that these events were marked by a large-scale alpha-power decrease starting around 40 s before their onset, and that this alpha-power was lowest immediately following a cessation. Region-of-interest (ROI) based examination of this finding revealed that this alpha-suppression showed a linear decrease in the occipital and parietal regions of the brain during the pre-cessation time period. Additionally, there were modest increases in theta power for the central, parietal, and right temporal ROIs during the pre-cessation timeframe, whereas power in the Delta and Beta frequency bands were not significantly different surrounding cessations. By relating cessations to objective and intrinsic measures of brain activity (i.e., EEG power) that are related to consciousness and high-level psychological functioning, these results provide evidence for the ability of experienced meditators to voluntarily modulate their state of consciousness and lay the foundation for studying these unique states using a neuroscientific approach.