EEG evidence for reproducible neural states during Buddhist Highest Yoga Tantra meditation

Scientific Reports. 2026. Vol. 16. Article 23560.

Mikhaylets E. V., Razorenova A. М., Chernyshev V. L., Norbu N., Sangpo L., Zhironkina Y. S., Kaplan A. Y.

Meditation offers a naturalistic paradigm for studying introspection, yet the neural dynamics of advanced tantric practices remain largely unexplored. Buddhist Highest Yoga Tantra (BHYT) comprises a sequence of eight dissolution stages culminating in the “clear light” state. We recorded EEG during eyes-closed BHYT meditation performed in monasteries and hermitages (51 sessions from 36 male practitioners; age 31–69 years); analyses compared sessions within this single cohort, and some participants contributed multiple sessions. Using a state-detecting algorithm that combines EEG power spectrum and EEG synchronization features, we segmented each session into discrete EEG-defined states and clustered them. Six reproducible state types emerged, forming three symmetric pairs dominated by delta, alpha/theta, and beta/gamma activity, along with two background-like states. Representing each meditation as a 8-symbolic alphabet sequence enabled quantitative comparison across sessions and practitioners. Although all followed the same canonical BHYT protocol, sequences differed systematically and formed six meditation clusters. Greater expertise was associated with longer and more diverse states within a meditation, with increased presence of oscillatory alpha/theta and beta/gamma states, whereas lower-experience sessions were represented by shorter sequences dominated by background or delta activity. These findings suggest BHYT practice unfolds as structured neural state sequences and provide a quantitative bridge between canonical contemplative descriptions and measurable EEG dynamics.

Keywords: кластеризация временных рядов, time-series clustering, EEG, ЭЭГ, meditation, медитация