Biology subjects

Kutty, B. M.

Publications and source records attributed to Kutty, B. M..

8 recordsLinked to original sources

bioRxiv2026

The Neurodynamic Core of Meditation: Dissociating Meditation from Rest and Task in a Reliability-based EEG study

BackgroundElectroencephalographic (EEG) studies attempting to characterise the neural signature of meditation typically rely on contrasts with passive rest or comparisons among practitioners based on experience. However, these approaches rarely include active control states and seldom establish the reliability and robustness of identified quantitative EEG features. Consequently, the validity of proposed neurophysiological markers of meditative state remains uncertain. The present study addressed these limitations by using a reliability-informed, multi-session within-subject design to characterise distinct state-dependent EEG dynamics in experienced meditators from the Brahmakumaris Rajayoga tradition. MethodsThirty long-term meditators underwent repeated EEG recordings over two days, comprising two meditation sessions per day. Each meditation block was flanked by rest periods, with a cognitive task between sessions to reduce carryover effects. We quantified broadband spectral power, aperiodic slope and intercept, and nonlinear dynamical measures, including detrended fluctuation analysis (DFA), Higuchi fractal dimension, and permutation entropy (PE), across meditation, rest, and task conditions. ResultsCompared with both rest and task states, meditation was associated with increased theta-alpha power, an elevated aperiodic intercept, and systematic modulation of nonlinear indices (DFA, Higuchi, PE). Further meditative core features demonstrated high inter-session test-retest reliability, strong inter-individual consistency, stability across guided and silent meditation states, and were not moderated by years of meditative experience. ConclusionThe present framework identifies a reproducible neurodynamic core of meditation, distinct from passive and active control states, spanning spectral, aperiodic, and nonlinear EEG domains in long-term meditators. These findings enhance the construct validity and measurement reliability of meditation-specific neural markers.

neuroscience↗

bioRxiv2025

Similar States, Different Paths: Neurodynamics of diverse meditation techniques

Meditation encompasses diverse practices that train attention inward, in contrast to externally oriented task states. However, the neurodynamic features distinguishing meditative states from non-meditative states across traditions remain unclear. We analyzed high-density EEG data (N=170; 121 advanced meditators, 49 controls) across four traditions: Vipassana, Brahma Kumaris Raja Yoga, Heartfulness, and Isha Yoga. EEG features spanned oscillatory, aperiodic, nonlinear, and timescale components. Using random forest classifiers, we distinguished meditative from non-meditative states with robust classification performance (91%). Nonlinear features contributed the most, suggesting a core neurodynamic profile. Classification performance was higher in advanced meditators (92%) than in controls (85%), with distinct feature importance: nonlinear and aperiodic features dominated in meditators, and oscillatory and timescale features in controls. Each tradition showed distinct neurodynamic profiles, indicating technique-specific constellations. Our findings revealed shared yet distinct neurodynamic signatures across meditation techniques, suggesting that multiple neurodynamic pathways lead to meditative states.

neuroscience↗

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

The Balanced Mind and its Intrinsic Neural Timescales in Advanced Meditators

A balanced mind, or equanimity, cultivated through meditation and other spiritual practices, is considered one of the highest mental states. Its core features include deidentification and non-duality. Despite its significance, its neural correlates remain unknown. To address this, we acquired 128-channel EEG data (n = 103) from advanced and novice meditators (from the Isha Yoga tradition) and controls during an internal attention (breath-watching) and an external attention task (visual-oddball paradigm). We calculated the auto-correlation window (ACW), a measure of brains intrinsic neural timescales (INTs) and assessed equanimity through self-report questionnaires. Advanced meditators showed higher levels of equanimity and shorter duration of INTs (shorter ACW) during breath-watching, indicating deidentification with mental contents. Furthermore, they demonstrated no significant differences in INTs between tasks, indicating non-dual awareness. Finally, shorter duration of INTs correlated with the participants subjective perceptions of equanimity. In conclusion, we show that the shorter duration of brains INT may serve as a neural marker of equanimity.

neuroscience↗

bioRxiv2020

Ageing and MPTP- sensitivity depend on molecular and ultrastructural signatures of astroglia and microglia in mice nigra

Both astroglia and microglia show region-specific distribution in CNS and often maladapt to age-associated alterations within their niche. Studies on autopsied substantia nigra (SN) of Parkinsons disease (PD) patients and experimental models propose gliosis as a trigger for neuronal loss. Epidemiological studies propose an ethnic bias in PD prevalence, since Caucasians are more susceptible than non-whites. Similarly, different mice strains are variably sensitive to MPTP. We had earlier likened divergent MPTP-sensitivity of C57BL/6J and CD-1 mice with differential susceptibility to PD, based on the numbers of SN neurons. Here, we examined whether the variability was incumbent to inter-strain differences in glial features of male C57BL/6J and CD-1 mice. Stereological counts showed relatively more microglia and fewer astrocytes in the SN of normal C57BL/6J mice, suggesting persistence of an immune-vigilant state. MPTP-induced microgliosis and astrogliosis in both strains, suggests their involvement in pathogenesis. ELISA of pro-inflammatory cytokines in the ventral-midbrain revealed augmentation of TNF- and IL-6 at middle-age in both strains that reduced at old-age, suggesting middle-age as a critical, inflamm-aging associated time-point. TNF- levels were high in C57BL/6J, through aging and post-MPTP; while IL-6 and IL-1{beta} were upregulated at old-age. CD-1 had higher levels of anti-inflammatory cytokine TGF-{beta}. MPTP-challenge caused upregulation of enzymes MAO-A, MAO-B and iNOS in both strains. Post-MPTP enhancement in fractalkine and hemeoxygenase-1; may be neuron-associated compensatory signals. Ultrastructural observations of elongated astroglial/microglial mitochondria vis-a-vis the shrunken ones in neurons, suggest a scale-up of their functions with neurotoxic consequences. Thus, astroglia and microglia modulate aging and PD-susceptibility. HighlightsO_LISubstantia nigra of C57BL/6J and CD-1 show no baseline differences in glial numbers C_LIO_LIBoth mice show age and MPTP-induced gliosis in the substantia nigra pars compacta C_LIO_LICD-1 nigra has lower levels of pro- and higher levels of anti-inflammatory cytokines C_LIO_LITilt of balance between pro- and anti-inflammatory cytokines begins at middle age C_LIO_LIAstrocytes and microglia show elongated mitochondria and intact ER upon MPTP-injection C_LI

neuroscience↗

bioRxiv2019

Simultaneous assessment of P50, MMN, ERN and P300 event-related potentials among patients with Schizophrenia - an exploratory study

PurposeP50 suppression (sensory gating or inhibition), MMN (mismatch negativity; bottom-up detection of change), ERN (error related negativity; conflict monitoring) and P300 (attention allocation and memory updating for salient events) are event related potentials (ERPs) widely reported to show abnormal cognitive functioning among patients with schizophrenia. In real-life scenarios the brain processing underlying these ERPs occur simultaneously, and yet prior ERP studies have evaluated them in isolation. The current study uses a novel paradigm that can examine these multiple ERPs simultaneously, and explore if the reported ERP deficits would hold true during a more realistic setting.\n\nMethodData from 21 patients with schizophrenia and 25 age- and gender-matched healthy controls were used, who underwent ERP recordings during the Assessing Neurocognition via Gamified Experimental Logic (ANGEL) paradigm. This is a gamified visual odd-ball paradigm that generates P300, the error responses generate ERN, and paired-tone audio distractors generate P50 and MMN. Peak-peak amplitude, mean amplitude and area-under-curve measures of ERP were measured at electrodes reflecting best morphology.\n\nResultsThough patients showed apparent ERP morphology differences relative to the controls, the standard ERP measures were comparable between groups, except for reduced ERN among patients. Interestingly, significant group differences were seen in N1-P2 complex suppression, despite comparable P50 suppression.\n\nContribution of the researchThe current study is the first to report multiple ERP component measures simultaneously evoked among patients with schizophrenia, and shows greater signs for impaired prediction mechanism. The findings of the study would provide a more ecologically valid evaluation of ERP-based cognitive functioning, and need to be replicated in a larger sample as well as other mental disorders.

neuroscience↗

bioRxiv2019

Schizophrenia patients show aberrant brain dynamics associated with gestalt-perception and corollary discharge: Reflections from ERP and fMRI findings

BackgroundSchizophrenia is a disorder of higher mental attributes, and is characterized by psychotic symptoms that are believed to involve a basic inability to make valid predictions about expected sensations and experiences. These have been reported separately while monitoring either externally generated environmental patterns (e.g. gestalt-perception) or self-generated sensory experiences (e.g. corollary-discharge). As the pathophysiology behind predictive dysfunction is better viewed as an aberration in brains functional synchrony, a whole brain assessment using electroencephalographic (EEG) event related potential (ERP) and functional magnetic resonance imaging (fMRI) techniques, would offer a wider perspective to brain network abnormalities in schizophrenia.\n\nMethodWe used our lab-developed game-based task which presents degraded two-tone images to assess gestalt-perception, and simultaneously alters the congruency between participants button-press response and its auditory feedback to assess corollary-discharge. In both patients with schizophrenia and age-matched healthy controls, we explored event-related changes in an EEG-ERP study (n=21 each) and whole brain functional connectivity changes in a fMRI study (patients,n=12; controls,n=16), using the same task.\n\nResultsPatients showed reduced event-related EEG dynamics during both the error-prediction conditions (gestalt-perception and corollary-discharge), which include reduction in average waveforms (around N170 and N1-P2 complex, respectively) and altered theta dynamics (power and phase). Source-level EEG measures were clustered around the cingulo-insular network. fMRI functional connectivity analysis also found the abnormality in these brain regions, forming significantly weak connections with right insular/opercular cortex.\n\nConclusionsThis is the first study to explore thalamo-cortical dysfunction hypothesis in schizophrenia by integrating prediction-error-coding during perception ( gestalt-perception) and action ( corollary-discharge) using two neuroimaging modalities (EEG-ERP and fMRI). Besides adding to the knowledgebase of schizophrenia research, our novel task design and findings on theta-oscillation could benefit in the development of effective neuromodulatory therapeutic tools for patients with schizophrenia such as neurofeedback and transcranial brain stimulation.

neuroscience↗