Electroencephalographic dynamics of rhythmic breath-based meditation

Abstract

Meditation has been practised for millennia but the neuroscientific understanding of the dynamics is still lacking. Sudarshan Kriya Yoga (SKY) is an evidence based breathing based meditation technique that utilizes rhythmic breathing to induce a deep state of relaxation and calm. Multiple studies have found benefits of the SKY technique from genetic, physiological, psychological to behaviour levels. We collected Electroencephalographic (EEG) data in 43 subjects who underwent the SKY technique and analysed the brain rhythms at different stages of the technique namely preparatory breathing (Pranayama), rhythmic breathing (Kriya) and meditation (Yoga Nidra) using newly developed methods to analyse periodic and aperiodic components. Alpha waves amplitude in the parieto-occipital region decreased as the rhythmic breathing progressed and dropped sharply during the meditation period. Theta amplitudes and peak frequency increased in the centro-frontal region during the rhythmic breathing period but were marked by sustained low theta waves during the meditation period. The delta wave amplitude was not affected by breathing but both delta band power and peak frequency increased during the meditation period in the centro-frontal region. We also saw a decrease in the 1/f aperiodic signal across the brain during the meditation period suggesting a modification of excitation-inhibition balance. We see an overall slowing down of brain oscillations from alpha to theta to delta as the meditation progressed. The paper studies in depth the transitional dynamics of the SKY technique analysing the alpha, theta, delta waves and aperiodic signals and demonstrates that each phase in a breathing based meditation has a unique electrophysiological signature.

EEG brain oscillations are modulated by interoception in response to a synchronized motor vs. cognitive task

“…The manifestation of frontal midline theta rhythm was correlated before with mental concentration, taskdependent attention, and a focused meditative state (Kubota et al, 2001). In the study of Tripathi et al (2022), theta amplitudes and peak frequency increased in the centro-frontal region during the rhythmic breathing period but were marked by sustained low theta waves during the meditation period.…”

“…Indeed, cortical oscillations provide useful information to monitor the process beyond localization that could be not linked to the specific processes. Future research in this field would benefit from some methodological improvements, such as (i) the integration of a fNIRS-EEG co-registration over multiple cortical sites; (ii) the implementation of an EEG hyperscanning paradigm, collecting the information of the other partner's brain; and (iii) the integration of more extensive EEG biosignal analysis to parameterize neural power, for instance, the analysis of the oscillatory portion of the spectrum of specific frequency bands (as previously operated by Tripathi et al, 2022).…”

Hemodynamic and Electrophysiological Biomarkers of Interpersonal Tuning during Interoceptive Synchronization

“…Specifically, during the focus on the breath condition, we hypothesized to detect an EEG inter-brain coherence effect for specific frequency bands, namely low frequency bands, such as delta, theta, and alpha, given their twofold role in sustained attention and focus on the meditative state [12,36,37], and controlled motor synchronization [38].…”