Relaxed Alertness in Novice and Advanced Meditators – A Neurophysiological and Psychological Study of Isha Yoga Practices

Mind-body practices, such as meditation, are increasingly recognized for their stress-reducing and well-being-enhancing effects. While research on meditation's impact on brain oscillations is extensive, studies on Yogic traditions like Isha Yoga are limited. This study addresses this gap by investigating the effects of Isha Yoga practices on brain oscillations and mental well-being. The study's importance lies in providing neuroscientific insights into the efficacy of Isha Yoga, a comprehensive system of yoga practices that encompasses various techniques like pranayama (breathwork), breath-watching meditation, and shoonya meditation (a non-dual awareness practice). The growing global interest in mindfulness and mind-body practices highlights the need to understand their neurophysiological mechanisms to provide evidence-based support for their use in improving mental health. The study aims to clarify how different levels of expertise (novice vs. advanced meditators) within the Isha Yoga tradition influence brain activity and psychological well-being during specific practices. This understanding will contribute to a broader scientific framework for understanding the science of meditation and inform interventions for improving mental health outcomes.

Existing literature extensively documents the benefits of meditation on attention, emotion regulation, and overall well-being. Electroencephalography (EEG) studies consistently reveal increased alpha, theta, and gamma power in meditators, suggesting a state of relaxed alertness. Low-frequency oscillations (delta, theta, alpha) are associated with relaxation, while high-frequency oscillations (beta, gamma) are linked to alertness and perceptual clarity. However, most research focuses on attentional meditation, with fewer studies examining deconstructive practices like non-dual meditation. Pranayama, a preparatory step for meditation in Yogic traditions, shows promise in stress reduction and improving mental clarity, supported by a growing body of evidence. Limited EEG research on pranayama and deconstructive practices emphasizes the need for more detailed neurophysiological studies. Psychometric assessments consistently demonstrate positive impacts of mind-body practices on stress, mental distress, well-being, and mental health. Previous studies on Isha Yoga practices report positive cardiovascular, neurophysiological, immune system-related, neurological, and mental health benefits, highlighting the need to investigate their neurophysiological mechanisms in detail. The Isha Yoga system incorporates various practices including pranayama (sukha kriya), breath-watching, and shoonya meditation (non-dual awareness practice). The present study addresses this knowledge gap by focusing on these three practices within the Isha Yoga system.

This cross-sectional study included 103 healthy adults categorized into three groups: advanced meditators (n=42), novice meditators (n=33), and meditation-naïve controls (n=28). Advanced meditators had completed at least one Samyama retreat, while novice meditators had not. Controls had no prior yoga or meditation experience. Participants were recruited through the Isha Foundation and social media. High-density (128-channel) EEG recordings were collected during four sessions: rest (eyes-closed and eyes-open), sukha kriya pranayama (alternate nostril breathing), breath-watching, a cognitive task (visual oddball paradigm), and shoonya meditation. A washout period with a meditation depth questionnaire was included after rest and breath-watching sessions. Standard questionnaires assessed perceived stress (PSS), anxiety and depression (PHQ-4), well-being (WHO-WBI), non-attachment (NAS-7), and meditation depth (MEDEQ). The Stanford Sleepiness Scale (SSS) measured alertness before and after breath-watching and shoonya meditation. EEG data were pre-processed using EEGLAB, removing artifacts and applying filtering techniques. Power spectral analysis extracted power values for delta, theta, alpha, beta, and gamma frequency bands. Statistical analyses included LIMO toolbox for EEG data, and R packages for psychometric data. Robust t-statistics with 2000 permutations and multiple comparisons were performed for EEG data, corrected using threshold-free cluster enhancement (TFCE). For psychometric data, Kruskal-Wallis tests, Dunn tests, Welch's one-way ANOVA, Games-Howell tests, and Pearson correlations were employed, with Holm's method for multiple comparisons.

Resting-state EEG revealed significant group differences. Advanced meditators showed heightened frontal midline theta, alpha, and beta power compared to controls and novices. During pranayama, both novice and advanced meditators showed increased power across all frequency bands compared to rest, reflecting relaxed alertness. Controls exhibited increases only in low-frequency bands. Breath-watching meditation also induced increased power in low and high-frequency bands in meditators but not in controls. Shoonya meditation resulted in reduced power in all frequency bands for novices and controls, whereas advanced meditators maintained power across all bands. Psychometric assessments showed significant differences between groups in perceived stress, well-being, non-attachment, and mental distress, with advanced meditators reporting lower stress and distress and higher well-being and non-attachment. Strong negative correlations were observed between lifetime hours of practice and perceived stress/mental distress. Positive correlations existed between practice hours and well-being/non-attachment. The meditation depth questionnaire revealed significant differences in meditation depth during breath-watching and shoonya, with advanced meditators exhibiting greater depth in both, reflected by scores on hindrances, relaxation, concentration, essential qualities, and non-duality. The Stanford Sleepiness Scale indicated fewer instances of drowsiness among meditators compared to controls during breath-watching and shoonya meditation.

The findings demonstrate that Isha Yoga practices elicit distinct state and trait changes at neural and psychological levels. The heightened frontal midline theta, alpha, and beta power in advanced meditators during rest suggests a trait effect of relaxed alertness achieved through extensive practice. The increased power across frequency bands during pranayama and breath-watching in meditators supports the state of relaxed alertness. The sustained power during shoonya in advanced meditators aligns with their reported experiences of non-duality. The study's correlation between practice hours and better mental health outcomes underscores the significant impact of Isha Yoga on well-being. The integration of EEG and psychometric findings into the phenomenological matrix model provides a comprehensive understanding of how Isha Yoga practices impact various aspects of consciousness, such as meta-awareness, dereification, clarity, stability, and effort. The findings suggest that the state of relaxed alertness achieved through Isha Yoga might be crucial in improving mental health outcomes.

This study provides valuable insights into the neurophysiological and psychological effects of Isha Yoga practices. Advanced meditators displayed trait-like EEG patterns indicative of relaxed alertness, while novice meditators and controls exhibited state-related changes during practice. The findings highlight the positive impact of Isha Yoga on mental well-being and support the development of mind-body interventions. Future research should adopt a longitudinal design to investigate causal relationships and explore additional factors influencing outcomes. Neurophenomenological studies could provide a richer understanding of subjective experiences associated with different meditative states.

The cross-sectional design prevents causal inferences. The inability to control session order might influence results, and the session lengths may have induced fatigue. The study did not consider individual personality traits or motivation levels, and lacked neurophenomenological investigation. Future research should address these limitations using longitudinal studies and more detailed subjective experience assessments.