Biology subjects

Subramaniam, B.

Publications and source records attributed to Subramaniam, B..

4 recordsLinked to original sources

bioRxiv2025

Non-duality in brain and experience of advanced meditators - Key role for Intrinsic Neural Timescales

Distinguishing between self (internal) and environment (external) is fundamental to human experience, with ordinary waking consciousness structured around this duality. However, contemplative traditions describe non-dual states where this distinction dissolves. Despite its significance, the neural basis of non-duality remains underexplored. Using psychological questionnaires for non-duality experience and EEG-based intrinsic neural timescales as measured by the autocorrelation window (ACW), we studied non-duality in advanced meditators, novice meditators, and controls. All subjects underwent breath-watching meditation (internal attention) and a visual oddball cognitive task (external attention); this allowed us to conceptualize non-duality as a lack of distinction between internal and external attention. Our key findings include: (a) advanced meditators report greater experience of non-duality during breath-watching (psychological scales), (b) EEG-based ACW is longer during internal attention (breath watch) than external attention (oddball task) in all subjects taken together, (c) advanced meditators show no such distinction with equal duration of their ACW during both internal and external attention (we replicated this finding in another dataset of expert meditators); (d) the advanced meditators internal-external ACW difference correlated with their experience of the degree of non-duality (psychological scales) during internal attention. Together, these findings suggest that the brains intrinsic neural timescales during internal and external attention play a key role in mediating the experience of non-duality in advanced meditators.

neuroscience↗

bioRxiv2025

Time-to-onset and temporal dynamics of EEG during breath-watching meditation

IntroductionMind-body practices, such as meditation, enhance mental well-being. Research studies consistently demonstrate improved brain function and psychological well-being in meditation practitioners. A substantial body of neuroscientific evidence highlights changes in alpha and theta frequency bands during meditation among practitioners. Neurophysiological effects of meditation are reported as average power changes from resting to meditative states. However, there is a notable gap in research concerning the time-to-onset and temporal dynamics of these changes during meditation. MethodOur study addresses this gap by recording high-density 128-channel EEG data during breath- watching meditation in three groups: meditation-naive controls (n = 28), novice meditators (n = 33), and advanced meditators (n = 42). Meditators were trained in the Isha Yoga tradition. Real-time changes in brain power across different frequency bands were analyzed by segmenting the EEG data into 1-minute intervals. Using the first 30 seconds of breath- watching as the baseline, we calculated within-group power differences between this baseline and successive 1-minute segments (non-overlapping, non-sliding windows). For between- group comparisons, we assessed power differences among the three groups at 0.5, 3, 6, and 9 minutes. ResultsOur results indicate that time-to-onset of statistically significant increases in alpha, theta, and beta1 power, as well as decreases in delta and gamma1 power, occur around the 2-3 minute mark, with effects starting to peak between 7- and 10-minutes duration across all three groups. Statistically significant differences were observed between groups in the magnitude of these changes: advanced practitioners exhibited higher theta and theta-alpha power at all time points compared to the other groups. ConclusionOur findings suggest that neurophysiological changes begin around 2-3 minutes after starting meditation and peak around 7-10 minutes across all three groups. However, the magnitude of these effects is greater in the advanced meditator group. As long as meditation retreats are not possible for many individuals, brief meditation practices of 7 minutes or more, delivered through digital platforms, could offer accessible, effective, and scalable solutions to improve mental well-being. This suggests a broader application of meditation practices in daily life, encouraging even those with tight schedules to incorporate such beneficial practices.

neuroscience↗

bioRxiv2024

Cortical Changes Associated with Isha Kriya Meditation Revealed by Encephalography in Novice and Experienced Meditators - a Longitudinal Pilot Study

AO_SCPLOWBSTRACTC_SCPLOWO_ST_ABSBackgroundC_ST_ABSIsha Kriya (IK) is a widely available meditation practice that incorporates breathing regulation that has shown to improve self-reported symptoms of stress, anxiety, and depression. An increasing amount of research has been published on the effects of various meditative practices on scalp electroencephalography (EEG). However, the effects of IK on cortical activity have not been reported previously. MethodsHealthy volunteers aged 18 years or older were invited to participate. Participants were categorized as novice or experienced in meditation. EEG spectral features, computed during the eyes-closed condition before and soon after each IK meditation practice, were evaluated both at the start and after 6 weeks of IK meditation training. ResultsThis longitudinal study examined the effects of IK meditation on cortical state and trait patterns in a cohort of eight participants who practiced IK meditation over a period of 6 weeks. Across the two sessions, a simultaneous increase in global periodic alpha power was observed in multiple subjects (N=6) but this was not observed in all subjects/sessions. We observed an increase in periodic theta band power, particularly in the frontal regions, which emerged as a common state effect in all participants. Longitudinally, we observed an increased periodic gamma power in the resting state EEG in all the experienced meditators in the parietal occipital region. The changes in novices on the other hand was in the alpha and beta bands. ConclusionOverall, in this pilot study, we report the changes in the quantitative EEG of the practitioners of Isha Kriya meditation over a 6-week cycle and investigated the difference between the start and end of that period at an individual level. We recommend future studies with a larger sample size and over a longer duration. Trial registrationThis trial is registered with the US National Institutes of Health on ClinicalTrials.gov with the trial identification number NCT03459690 on February 14, 2018.

neuroscience↗

bioRxiv2021

Large-scale genomic study reveals robust activation of the immune system following advanced Inner Engineering meditation retreat.

The positive impact of meditation on human wellbeing is well documented, yet its molecular mechanisms are incompletely understood. We applied a comprehensive systems biology approach starting with whole blood gene expression profiling combined with multi-level bioinformatic analyses to characterize the co-expression, transcriptional, and protein-protein interaction networks to identify meditation-specific core network after an advanced 8-day Inner Engineering retreat program. We found the response to oxidative stress, detoxification, and cell cycle regulation pathways were downregulated after meditation. Strikingly, 220 genes directly associated with immune response, including 68 genes related to interferon (IFN) signaling were upregulated, with no significant expression changes in the inflammatory genes. This robust meditation-specific immune response network is significantly dysregulated in multiple sclerosis and severe COVID-19 patients. The work provides a foundation for understanding the effect of meditation and potential implications to voluntarily and non-pharmacologically improve the immune response before immunotherapy for many conditions, including multiple sclerosis and COVID-19 vaccination.

genomics↗