Increased Gamma Brainwave Amplitude Compared to Control in Three Different Meditation Traditions

Intrinsic neural timescales exhibit different lengths in distinct meditation techniques

Meditation encompasses a range of practices employing diverse induction techniques, each characterized by a distinct attentional focus. In Mantra meditation, for instance, practitioners direct their attention narrowly to a given sentence that is recursively repeated, while other forms of meditation such as Shoonya meditation are induced by a wider attentional focus. Here we aimed to identify the neural underpinnings and correlates associated with this spectrum of distinct attentional foci. To accomplish this, we used EEG data to estimate the brain's intrinsic neural timescales (INTs), that is, its temporal windows of activity, by calculating the Autocorrelation Window (ACW) of the EEG signal. The autocorrelation function measures the similarity of a timeseries with a time-lagged version of itself by correlating the signal with itself on different time lags, consequently providing an estimation of INTs length. Therefore, through using the ACW metric, our objective was to explore whether there is a correspondence between the length of the brain's temporal windows of activity and the width of the attentional scope during various meditation techniques. This was performed on three groups of highly proficient practitioners belonging to different meditation traditions, as well as a meditation-naïve control group. Our results indicated that practices with a wider attentional focus, like Shoonya meditation, exhibit longer ACW durations compared to practices requiring a narrower attentional focus, such as Mantra meditation or body-scanning Vipassana meditation. Together, we demonstrated that distinct meditation techniques with varying widths of attentional foci exhibit unique durations in their brain's INTs. This may suggest that the width of the attentional scope during meditation relates and corresponds to the width of the brain's temporal windows in its neural activity. SIGNIFICANCE STATEMENT: Our research uncovered the neural mechanisms that underpin the attentional foci in various meditation techniques. We revealed that distinct meditation induction techniques, featured by their range of attentional widths, are characterized by varying lengths of intrinsic neural timescales (INTs) within the brain, as measured by the Autocorrelation Window function. This finding may bridge the gap between the width of attentional windows (subjective) and the width of the temporal windows in the brain's neural activity (objective) during different meditation techniques, offering a new understanding of how cognitive and neural processes are related to each other. This work holds significant implications, especially in the context of the increasing use of meditation in mental health and well-being interventions. By elucidating the distinct neural foundations of different meditation techniques, our research aims to pave the way for developing more tailored and effective meditation-based treatments.

Inducing a meditative state by artificial perturbations: A mechanistic understanding of brain dynamics underlying meditation

Contemplative neuroscience has increasingly explored meditation using neuroimaging. However, the brain mechanisms underlying meditation remain elusive. Here, we implemented a mechanistic framework to explore the spatiotemporal dynamics of expert meditators during meditation and rest, and controls during rest. We first applied a model-free approach by defining a probabilistic metastable substate (PMS) space for each condition, consisting of different probabilities of occurrence from a repertoire of dynamic patterns. Moreover, we implemented a model-based approach by adjusting the PMS of each condition to a whole-brain model, which enabled us to explore in silico perturbations to transition from resting-state to meditation and vice versa. Consequently, we assessed the sensitivity of different brain areas regarding their perturbability and their mechanistic local-global effects. Overall, our work reveals distinct whole-brain dynamics in meditation compared to rest, and how transitions can be induced with localized artificial perturbations. It motivates future work regarding meditation as a practice in health and as a potential therapy for brain disorders.

Meditation-type specific reduction in infra-slow activity of electroencephalogram

Purpose

Meditation is renowned for its positive effects on cognitive abilities and stress reduction. It has been reported that the amplitude of electroencephalographic (EEG) infra-slow activity (ISA, < 0.1 Hz) is reduced as the stress level decreases. Consequently, we aimed to determine if EEG ISA amplitude decreases as a result of meditation practice across various traditions.

Methods

To this end, we analyzed an open dataset comprising EEG data acquired during meditation sessions from experienced practitioners in the Vipassana tradition-which integrates elements of focused attention and open monitoring, akin to mindfulness meditation-and in the Himalayan Yoga and Isha Shoonya traditions, which emphasize focused attention and open monitoring, respectively.

Results

A general trend was observed where EEG ISA amplitude tended to decrease in experienced meditators from these traditions compared to novices, particularly significant in the 0.03-0.08 Hz band for Vipassana meditators. Therefore, our analysis focused on this ISA frequency band. Specifically, a notable decrease in EEG ISA amplitude was observed in Vipassana meditators, predominantly in the left-frontal region. This reduction in EEG ISA amplitude was also accompanied by a decrease in phase-amplitude coupling (PAC) between the ISA phase and alpha band (8-12 Hz) amplitude, which implied decreased neural excitability fluctuations.

Conclusion

Our findings suggest that not only does EEG ISA amplitude decrease in experienced meditators from traditions that incorporate both focused attention and open monitoring, but this decrease may also signify a diminished influence of neural excitability fluctuations attributed to ISA.

Augmenting complex and dynamic performance through mindfulness-based cognitive training: An evaluation of training adherence, trait mindfulness, personality and resting-state EEG

Human performance applications of mindfulness-based training have demonstrated its utility in enhancing cognitive functioning. Previous studies have illustrated how these interventions can improve performance on traditional cognitive tests, however, little investigation has explored the extent to which mindfulness-based training can optimise performance in more dynamic and complex contexts. Further, from a neuroscientific perspective, the underlying mechanisms responsible for performance enhancements remain largely undescribed. With this in mind, the following study aimed to investigate how a short-term mindfulness intervention (one week) augments performance on a dynamic and complex task (target motion analyst task; TMA) in young, healthy adults (n = 40, age range = 18-38). Linear mixed effect modelling revealed that increased adherence to the web-based mindfulness-based training regime (ranging from 0-21 sessions) was associated with improved performance in the second testing session of the TMA task, controlling for baseline performance. Analyses of resting-state electroencephalographic (EEG) metrics demonstrated no change across testing sessions. Investigations of additional individual factors demonstrated that enhancements associated with training adherence remained relatively consistent across varying levels of participants' resting-state EEG metrics, personality measures (i.e., trait mindfulness, neuroticism, conscientiousness), self-reported enjoyment and timing of intervention adherence. Our results thus indicate that mindfulness-based cognitive training leads to performance enhancements in distantly related tasks, irrespective of several individual differences. We also revealed nuances in the magnitude of cognitive enhancements contingent on the timing of adherence, regardless of total volume of training. Overall, our findings suggest that mindfulness-based training could be used in a myriad of settings to elicit transferable performance enhancements.

EEG changes induced by meditative practices: State and trait effects in healthy subjects and in patients with epilepsy

The effect of meditation on brain activity has been the topic of many studies in healthy subjects and in patients suffering from chronic diseases. These effects are either explored during meditation practice (state effects) or as a longer-term result of meditation training during the resting-state (trait). The topic of this article is to first review these findings by focusing on electroencephalography (EEG) changes in healthy subjects with or without experience in meditation. Modifications in EEG baseline rhythms, functional connectivity and advanced nonlinear parameters are discussed in regard to feasibility in clinical applications. Secondly, we provide a state-of-the-art of studies that proposed meditative practices as a complementary therapy in patients with epilepsy, in whom anxiety and depressive symptoms are prevalent. In these studies, the effects of standardized meditation programs including elements of traditional meditation practices such as mindfulness, loving-kindness and compassion are explored both at the level of psychological functioning and on the occurrence of seizures. Lastly, preliminary results are given regarding our ongoing study, the aim of which is to quantify the effects of a mindfulness self-compassion (MSC) practice on interictal and ictal epileptic activity. Feasibility, difficulties, and prospects of this study are discussed.

The potential of 5-methoxy-N,N-dimethyltryptamine in the treatment of alcohol use disorder: A first look at therapeutic mechanisms of action

Alcohol use disorder (AUD) remains one of the most prevalent psychiatric disorders worldwide with high economic costs. Current treatment options show modest efficacy and relapse rates are high. Furthermore, there are increases in the treatment gap and few new medications have been approved in the past 20 years. Recently, psychedelic-assisted therapy with psilocybin and lysergic acid diethylamide has garnered significant attention in the treatment of AUD. Yet, they require significant amounts of therapist input due to prolonged subjective effects (~4-12 h) leading to high costs and impeding implementation. Accordingly, there is an increasing interest in the rapid and short-acting psychedelic 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). This paper offers a first look at potential therapeutic mechanisms for AUD by reviewing the current literature on 5-MeO-DMT. Primarily, 5-MeO-DMT is able to induce mystical experiences and ego-dissolution together with increases in psychological flexibility and mindfulness. This could decrease AUD symptoms through the alleviation of psychiatric mood-related comorbidities consistent with the negative reinforcement and self-medication paradigms. In addition, preliminary evidence indicates that 5-MeO-DMT modulates neural oscillations that might subserve ego-dissolution (increases in gamma), psychological flexibility and mindfulness (increases in theta), and the reorganization of executive control networks (increases in coherence across frequencies) that could improve emotion regulation and inhibition. Finally, animal studies show that 5-MeO-DMT is characterized by neuroplasticity, anti-inflammation, 5-HT2A receptor agonism, and downregulation of metabotropic glutamate receptor 5 with clinical implications for AUD and psychiatric mood-related comorbidities. The paper concludes with several recommendations for future research to establish the purported therapeutic mechanisms of action.

Uncovering a stability signature of brain dynamics associated with meditation experience using massive time-series feature extraction

Previous research has examined resting electroencephalographic (EEG) data to explore brain activity related to meditation. However, previous research has mostly examined power in different frequency bands. The practical objective of this study was to comprehensively test whether other types of time-series analysis methods are better suited to characterize brain activity related to meditation. To achieve this, we compared >7000 time-series features of the EEG signal to comprehensively characterize brain activity differences in meditators, using many measures that are novel in meditation research. Eyes-closed resting-state EEG data from 49 meditators and 46 non-meditators was decomposed into the top eight principal components (PCs). We extracted 7381 time-series features from each PC and each participant and used them to train classification algorithms to identify meditators. Highly differentiating individual features from successful classifiers were analysed in detail. Only the third PC (which had a central-parietal maximum) showed above-chance classification accuracy (67 %, pFDR = 0.007), for which 405 features significantly distinguished meditators (all pFDR < 0.05). Top-performing features indicated that meditators exhibited more consistent statistical properties across shorter subsegments of their EEG time-series (higher stationarity) and displayed an altered distributional shape of values about the mean. By contrast, classifiers trained with traditional band-power measures did not distinguish the groups (pFDR > 0.05). Our novel analysis approach suggests the key signatures of meditators' brain activity are higher temporal stability and a distribution of time-series values suggestive of longer, larger, or more frequent non-outlying voltage deviations from the mean within the third PC of their EEG data. The higher temporal stability observed in this EEG component might underpin the higher attentional stability associated with meditation. The novel time-series properties identified here have considerable potential for future exploration in meditation research and the analysis of neural dynamics more broadly.

Brain waves spectral analysis of human responses to odorous and non-odorous substances: a preliminary study

OBJECTIVE

The aim of this study was to identify the potential electrophysiological biomarkers of human responses by comparing the electroencephalogram brain wave changes towards lavender versus normal saline in a healthy human population.

METHOD

This study included a total of 44 participants without subjective olfactory disturbances. Lavender and normal saline were used as the olfactory stimulant and control. Electroencephalogram was recorded and power spectra were analysed by the spectral analysis for each alpha, beta, delta, theta and gamma bandwidth frequency upon exposure to lavender and normal saline independently.

RESULTS

The oscillatory brain activities in response to the olfactory stimulant indicated that the lavender smell decreased the beta activity in the left frontal (F7 electrode) and central region (C3 electrode) with a reduction in the gamma activity in the right parietal region (P4 electrode) (p < 0.05).

CONCLUSION

Olfactory stimulants result in changes of electrical brain activities in different brain regions, as evidenced by the topographical brain map and spectra analysis of each brain wave.

Practice and proficiency of Isha Yoga for better mental health outcomes: insights from a COVID-19 survey

Introduction

The COVID-19 pandemic has brought about unparalleled suffering on a global scale, affecting both physical and mental well-being. In such challenging times, it becomes crucial to identify interventions that can alleviate negative mental health outcomes, such as stress, while promoting positive mental health outcomes, like well-being. We report the effectiveness of a mind-body practise, Isha Yoga, in promoting well-being.

Methods

We conducted an online survey, during the COVID-19 pandemic, with Yoga practitioners (n = 1,352) from the Isha Yoga tradition in Karnataka, India. We evaluated stress and well-being attributes using conventional psychometric questionnaires. Subsequently, we requested the Isha Yoga practitioners to share another survey with their friends and family members, assessing similar outcomes. From the respondents of this shared survey (n = 221), we identified individuals who currently did not engage in any form of Yoga or meditation, constituting the non-Yoga control group (n = 110). To enhance the reliability and validity of our study and minimize the limitations commonly associated with online surveys, we adhered to the CHERRIES guidelines for reporting survey studies.

Results

Isha Yoga practitioners had significantly lower levels of stress (p < 0.001, gHedges = 0.94) and mental distress (p < 0.001, gHedges = 0.75) while reporting significantly higher levels of well-being (p < 0.001, gHedges = 0.78) and affective balance (p < 0.001, gHedges = 0.80) compared to the control group. Furthermore, expertise-related improvements were observed in these outcomes, and a dose-response relationship was found between regularity of Isha Yoga practice and outcome changes. A minimum 3-4 days of weekly practice showed significant differences with the control group. In addition, we investigated the effect of Isha Yoga on stress and well-being among the healthcare workers (HCWs) in our sample and observed better mental health outcomes.

Discussion

These findings collectively underscore the benefits of Mind and Body practices like Isha Yoga on various aspects of mental health and well-being, emphasizing its potential as an effective and holistic approach for promoting a healthy lifestyle among diverse populations, including healthcare workers, even in difficult circumstances such as the COVID-19 pandemic.

Modulating Consciousness through Awareness Training Program and Its Impacts on Psychological Stress and Age-Related Gamma Waves

Aging often leads to awareness decline and psychological stress. Meditation, a method of modulating consciousness, may help individuals improve overall awareness and increase emotional resilience toward stress. This study explored the potential influence of the Awareness Training Program (ATP), a form of consciousness modulation, on age-related brain wave changes and psychological stress in middle-aged adults. Eighty-five participants with mild stress were recruited and randomly assigned to ATP (45.00 ± 8.00 yr) or control (46.67 ± 7.80 yr) groups, matched by age and gender. Ten-minute resting-state EEG data, obtained while the participants' eyes were closed, were collected using a 128-channel EEG system (EGI). A strong positive Pearson correlation was found between fast-wave (beta wave, 12-25 Hz; gamma wave, 25-40 Hz) EEG and age. However, after the 7-week ATP intervention, this correlation became insignificant in the ATP group. Furthermore, there was a significant reduction in stress levels, as measured by the Chinese version of the 10 item Perceived Stress Scale (PSS-10), in the ATP group. These results suggest that ATP may help modulate age-related effects on fast brain waves, as evidenced by the reduced correlation magnitude between age and gamma waves, and lower psychological stress. This suggests that ATP, as a form of consciousness modulation, may improve stress resilience and modulate age-related gamma wave changes.

L. M, Narawa Y, Srinath R, Kanitkar M. Improved sleep, cognitive processing and enhanced learning and memory task accuracy with Yoga nidra practice in novices

Complementary and Alternative medicine is known to have health benefits. Yoga nidra practice is an easy-to-do practice and has shown beneficial effects on stress reduction and is found to improve sleep in insomnia patients. Effect of yoga nidra practice on subjective sleep is known but its effect on sleep and cognition objectively is not documented. The aim of the study was to study the effect of yoga nidra practice on cognition and sleep using objective parameters. 41 participants were enrolled, and baseline sleep diary (SD) collected. Participants volunteered for overnight polysomnography (PSG) and cognition testing battery (CTB) comprising of Motor praxis test, emotion recognition task (ERT), digital symbol substitution task, visual object learning task (VOLT), abstract matching (AIM), line orientation task, matrix reasoning task, fractal-2-back test (NBACK), psychomotor vigilance task and balloon analog risk task. Baseline CTB and after one and two weeks of practice was compared. Power spectra density for EEG at central, frontal, and occipital locations during CTB was compared. Repeat SD and PSG after four weeks of practice were done. After yoga nidra practice, improved reaction times for all cognition tasks were seen. Post intervention compared to baseline (95%CI; p-value, effect size) showed a significant improvement in sleep efficiency of +3.62% (0.3, 5.15; p = 0.03, r = 0.42), -20min (-35.78, -5.02; p = 0.003, d = 0.84) for wake after sleep onset and +4.19 μV2 (0.5, 9.5; p = 0.04, r = 0.43) in delta during deep sleep. Accuracy increased in VOLT (95% CI: 0.08, 0.17; p = 0.002, d = 0.79), AIM (95% CI: 0.03, 0.12; p = 0.02, d = 0.61) and NBACK (95% CI: 0.02, 0.13; p = 0.04, d = 0.56); ERT accuracy increased for happy, fear and anger (95% CI: 0.07, 0.24; p = 0.004, d = 0.75) but reduced for neutral stimuli (95% CI: -0.31, -0.12; p = 0.04, r = 0.33) after yoga nidra practice. Yoga Nidra practice improved cognitive processing and night-time sleep.

Digitally Assisted Mindfulness in Training Self-Regulation Skills for Sustainable Mental Health: A Systematic Review

The onset of the COVID-19 pandemic has led to an increased demand for mental health interventions, with a special focus on digitally assisted ones. Self-regulation describes a set of meta-skills that enable one to take control over his/her mental health and it is recognized as a vital indicator of well-being. Mindfulness training is a promising training strategy for promoting self-regulation, behavioral change, and mental well-being. A growing body of research outlines that smart technologies are ready to revolutionize the way mental health training programs take place. Artificial intelligence (AI); extended reality (XR) including virtual reality (VR), augmented reality (AR), and mixed reality (MR); as well as the advancements in brain computer interfaces (BCIs) are ready to transform these mental health training programs. Mindfulness-based interventions assisted by smart technologies for mental, emotional, and behavioral regulation seem to be a crucial yet under-investigated issue. The current systematic review paper aims to explore whether and how smart technologies can assist mindfulness training for the development of self-regulation skills among people at risk of mental health issues as well as populations with various clinical characteristics. The PRISMA 2020 methodology was utilized to respond to the objectives and research questions using a total of sixty-six experimental studies that met the inclusion criteria. The results showed that digitally assisted mindfulness interventions supported by smart technologies, including AI-based applications, chatbots, virtual coaches, immersive technologies, and brain-sensing headbands, can effectively assist trainees in developing a wide range of cognitive, emotional, and behavioral self-regulation skills, leading to a greater satisfaction of their psychological needs, and thus mental wellness. These results may provide positive feedback for developing smarter and more inclusive training environments, with a special focus on people with special training needs or disabilities.

Changes in Stress Reduction Following a 28-Day Prostate Cancer Patient Empowerment Program (PC-PEP) among Prostate Cancer Survivors

Prostate cancer (PCa) survivors often experience post-treatment challenges that impact their well-being and mental health. The Prostate Cancer Patient Empowerment Program (PC-PEP) aims to address these issues through a comprehensive intervention, involving daily meditation/breathing exercises, physical activity, pelvic floor exercises, emotional connection strategies, and peer support. This study presents a secondary analysis of a Phase 2 feasibility study that evaluated the effects of a 28-day PC-PEP intervention on stress reduction. Thirty patients with PCa from the Maritimes, Canada, underwent pre- and post-intervention assessments to measure brainwave activity (delta, theta, alpha, beta, and gamma) using the Muse™ headband, and heart rate variability (HRV) using the HeartMath® Inner Balance™ as indicators of stress reduction. A statistically significant Time × Sensor Scalp Assessment Time interaction emerged for all brain waves. Amplitudes were generally higher during the first half of the meditation assessment time but became comparable afterward. A statistically significant Time × Sensor Scalp Location × Sensor Scalp Assessment Time interaction also emerged for alpha waves, indicating higher prefrontal lobe amplitudes than temporal lobe amplitudes from pre- to post-assessment. There were no statistically significant differences in HRV metrics from pre- to post-intervention, except for a marginally significant achievement score, indicating increased HRV coherence post-intervention. The findings suggest that the stress reduction component of PC-PEP successfully improved outcomes related to decreased stress. These results have implications for the development of future iterations of PC-PEP interventions, aiming to optimize participant benefits.

Evaluating brain spectral and connectivity differences between silent mind-wandering and trance states

Trance is an altered state of consciousness characterized by alterations in cognition. In general, trance states induce mental silence (i.e., cognitive thought reduction), and mental silence can induce trance states. Conversely, mind-wandering is the mind's propensity to stray its attention away from the task at hand and toward content irrelevant to the current moment, and its main component is inner speech. Building on the previous literature on mental silence and trance states and incorporating inverse source reconstruction advances, the study's objectives were to evaluate differences between trance and mind-wandering states using: (1) electroencephalography (EEG) power spectra at the electrode level, (2) power spectra at the area level (source reconstructed signal), and (3) EEG functional connectivity between these areas (i.e., how they interact). The relationship between subjective trance depths ratings and whole-brain connectivity during trance was also evaluated. Spectral analyses revealed increased delta and theta power in the frontal region and increased gamma in the centro-parietal region during mind-wandering, whereas trance showed increased beta and gamma power in the frontal region. Power spectra at the area level and pairwise comparisons of the connectivity between these areas demonstrated no significant difference between the two states. However, subjective trance depth ratings were inversely correlated with whole-brain connectivity in all frequency bands (i.e., deeper trance is associated with less large-scale connectivity). Trance allows one to enter mentally silent states and explore their neurophenomenological processes. Limitations and future directions are discussed.

Brain activity during meditation in first-time meditators

AIM OF THE STUDY

The electrophysiological correlates of meditation states in both short and long-term meditators have been increasingly documented; however, little is known about the brain activity associated with first-time meditation experiences. The goal of this study was to investigate the electrophysiological correlates of a single guided mindfulness meditation session in subjects with no previous meditation experience.

MATERIALS AND METHODS

We analyzed electroencephalogram (EEG) changes in signal power, hemispheric asymmetry, and information flow between EEG channels, in 16 healthy subjects who were new to meditation practice.

RESULTS

Our results show that information flow decreases in the theta (4-8 Hz) and alpha ranges (8-13 Hz) during mindfulness meditation exercise as compared to control: a passive listening condition. These changes are accompanied by a general trend in the decrease of alpha power over the whole scalp. One possible interpretation of these results is that there is an increased level of alertness/vigilance associated with the meditation task rather than reaching the target state.

CONCLUSIONS

Our study expands on the existing body of knowledge concerning neural oscillations during breathing meditation practice by showing that in participants with no previous meditation training, EEG correlates are different from the electrophysiological signatures of mindfulness meditation found in studies of more advanced practitioners.

Effectiveness of Anapana, Body scan and Metta meditation techniques on chronic neck and shoulder region pain and disability in adult patients in Sri Lanka: study protocol for a cluster clinic-level randomised controlled trial

BACKGROUND

Chronic neck and shoulder region pain affects many people around the world. This study aims to compare the effectiveness of three 8-week meditation training programmes (each using a different meditation technique: Anapana, Body scan or Metta) on pain and disability in a patient population affected with chronic neck and shoulder region pain, with a usual care control group and with each other.

METHODS

This four-arm parallel clinic-level randomised controlled trial will be conducted with male and female patients aged 18-65 years, who are affected with chronic neck and shoulder region pain, and who attend one of four clinics held on four different days of the week in a single medical centre in the Colombo North region, Sri Lanka. Clinics will be considered as clusters and randomly allocated to intervention and control arms. Data will be collected using validated questionnaires, clinical examinations and focus groups. To compare primary (differences in changes in pain (Numeric Pain Rating Scale) at 8 weeks) and secondary (differences in changes in pain, physical disability, range of movement and quality of life (SF-36) at 4 and 12 weeks) outcomes between groups, a two-way ANOVA will be used if data are normally distributed. If data are not normally distributed, a nonparametric equivalent (Kruskal-Wallis) will be used. Focus group transcriptions will be thematically analysed using the Richie and Spencer model of qualitative data analysis.

DISCUSSION

This is a four-arm trial which describes how three different 8-week meditation technique (Anapana, Body Scan, Metta) interventions will be implemented with adult patients affected with chronic neck and shoulder region pain. The effectiveness of each meditation intervention on the pain, physical and psychosocial disabilities of patients will be compared between groups and with a usual care control group. The results of this study will contribute to recommendations for future meditation interventions for chronic neck and shoulder pain.

TRIAL REGISTRATION

ISRCTN12146140 . Registered on 20 August 2021.

Modulation of Heart and Brain Function by Surah Al-Rehman Recitation Among Distressed Diabetic Patients in Pakistan

Distress causes psychophysiological alterations that affect autonomic function. The current study explores psychophysiological modulation in diabetic distress in response to Surah Al-Rehman recitation. A single-group experimental study with before and after intervention assessments was conducted during April 2018 to February 2019 in which participants (n = 10) listened to Surah Al-Rehman recitation. Blood pressure, blood glucose, cortisol, ECG and EEG were recorded before and after recitation. Significant reduction in systolic blood pressure, increase in low frequency and absolute alpha power at Fp2 were observed. Heartbeat evoked potentials (HEP) were also significantly modulated at Fp1, Fp2 and F4. These findings suggest that Surah Al-Rehman modulated baroreflex activity thereby reducing sympathetic activity and improved heart brain coherence as reflected by HEP.

Beyond mindfulness: Arousal-driven modulation of attentional control during arousal-based practices

Here we report meditative techniques, which modulate attentional control by arousal-driven influences and not by monitoring continuous thought processes as during mindfulness-related practices. We focus on Vajrayana (Tantric Buddhism) practices, during which a sequence of generation (self-visualization as a deity - Yidam) or completion with sign (inner heat -Tummo) stages necessarily precedes non-dual awareness (NDA) Tantric Mahamudra. We compared the electrocardiographic and electroencephalographic correlates of Mahamudra performed after rest (non-Tantric Mahamudra) with Mahamudra performed after Yidam (Tantric Mahamudra) in 16 highly experienced Vajrayana practitioners, 10 of whom also performed Tummo. Both Yidam and Tummo developed the state of PNS withdrawal (arousal) and phasic alertness, as reflected by HF HRV decreases and Alpha2 power increases, later neurophysiologically employed in Tantric Mahamudra. The latter led to the unique state of high cortical excitability, “non-selective” focused attention, and significantly reduced attentional control, quantified by power reductions in all frequency bands, except Theta. In contrast, similar to mindfulness-related practices, non-Tantric Mahamudra was performed in a state of PNS dominance (relaxation), tonic alertness, and active monitoring, as suggested by Alpha1 power increases and less pronounced decreases in other frequency bands. A neurobiological model of meditation is proposed, differentiating arousal-based and mindfulness-related practices.

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Arousal-based meditations involve the state of PNS withdrawal and phasic alertness.

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Top-down control during arousal-based practices is modulated by arousal.

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Mindfulness-based practices involve the state of PNS dominance and tonic alertness.

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Top-down control during mindfulness-based practices is regulated by monitoring.

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NDA practices aim at non-selectivity of attention and reduction of top-down control.

Psychoneuroimmunology of Meditation

Background:

Meditation is a conscious mental discipline, that has been implicated in the relaxation response. The mechanism behind such a relaxing effect is psychoneuroimmunology (PNI), based on the interaction between mind, physical health, and self-healing; that conceptualizes that stress and an individual’s emotional state led to predisposition to diseases. Research to date suggests that meditation may play an active role in remodeling the imbalance between mind and body by modulating the psychoneuroimmunological effects of stress. However, to date, the multi-dimensional psychoneuroimmune aspects of meditation together have not been completely explicated. An evidence-based mechanism has been framed for the first time in India to explain the psychoneuroimmunology of regular and long-term meditation practice.

Summary:

Present evidence-based mechanism confirms prefrontal cortex (PFC) acts as a ‘Functional Connectome’ where psycho-neuro-immune aspects of meditation function simultaneously to exert positive benefits in the regulation of cognitive and emotional behavior. Also, this mechanism will help us to understand how human augmentation with lifestyle modification fosters brain plasticity to overcome various neuropsychiatric illnesses.

Key Message:

Meditation is a scientific tool against neuro-psychiatric illnesses.

How to play under pressure: EEG monitoring of mental activation training in a professional tennis player

The aim of this study was to monitor the mental activation training during match pressure imageries using a protocol with (MT) and without mental training (wMT) performed in the office and on the tennis court based on the analysis of heart rate, brain waves and subjective ratings in a professional tennis player with high imagery experience. Results showed that both in the office (MTo/wMTo) and on the court (MTc/wMTc) the tennis player's heart rate increased in the match pressure imagery (I.3-8), being higher in the MTo. It decreased in the pressure imagery using mental tools (I.8-13) in the MT. In the case of brainwaves, beta and gamma waves increased in the match pressure imagery (I.3-8); while beta, gamma, delta and theta waves decreased in the pressure imagery using mental tools (I.8-13), being higher in the office. Entropy decreased in the match pressure imagery (I.3-8), being higher in the MTo. It increased in the pressure imagery using mental tools (I.8-13), being higher in the MTo. Regarding subjective ratings, the tennis player felt the pressure in the match pressure imagery, being higher in MT. In the pressure imagery using mental tools he regulated the activation to feel it at an optimal level (7). In the imagery reality, the olfactory and gustatory dimensions were the most difficult to feel in both imageries.

Tackling the Electro-Topography of the Selves Through the Sphere Model of Consciousness

In the current hypothesis paper, we propose a novel examination of consciousness and self-awareness through the neuro-phenomenological theoretical model known as the Sphere Model of Consciousness (SMC). Our aim is to create a practical instrument to address several methodological issues in consciousness research. We present a preliminary attempt to validate the SMC via a simplified electrophysiological topographic map of the Self. This map depicts the gradual shift from faster to slower frequency bands that appears to mirror the dynamic between the various SMC states of Self. In order to explore our hypothesis that the SMC's different states of Self correspond to specific frequency bands, we present a mini-review of studies examining the electrophysiological activity that occurs within the different states of Self and in the context of specific meditation types. The theoretical argument presented here is that the SMC's hierarchical organization of three states of the Self mirrors the hierarchical organization of Focused Attention, Open Monitoring, and Non-Dual meditation types. This is followed by testable predictions and potential applications of the SMC and the hypotheses derived from it. To our knowledge, this is the first integrated electrophysiological account that combines types of Self and meditation practices. We suggest this electro-topographic framework of the Selves enables easier, clearer conceptualization of the connections between meditation types as well as increased understanding of wakefulness states and altered states of consciousness.

Possible Role of Parvalbumin Interneurons in Meditation and Psychiatric Illness

Parvalbumin (PV) interneurons are present in multiple brain regions and produce complex influences on brain functioning. An increasing number of research findings indicate that the function of these interneurons is more complex than solely to inhibit pyramidal neurons in the cortex. They generate feedback and feedforward inhibition of cortical neurons, and they are critically involved in the generation of neuronal network oscillation. These oscillations, generated by various brain regions, are linked to perceptions, thought processes, and cognitive functions, all of which, in turn, influence human emotions and behavior. Both animal and human studies consistently have found that meditation practice results in enhancement in the effects of alpha-, theta-, and gamma-frequency oscillations, which may correspond to positive changes in cognition, emotion, conscious awareness, and, subsequently, behavior. Although the study of meditation has moved into mainstream neuroscience research, the link between PV interneurons and any role they might play in meditative states remains elusive. This article is focused primarily on gamma-frequency oscillation, which is generated by PV interneurons, to develop insight and perspective into the role of PV interneurons in meditation. This article also points to new and emerging directions that address whether this role of PV interneurons in meditation extends to a beneficial, and potentially therapeutic, role in the treatment of common psychiatric disorders, including schizophrenia.

Revisiting consciousness: Distinguishing between states of conscious focused attention and mind wandering with EEG

Fluctuating between external conscious processing and mind wandering is inherent to the human condition. Past research showed that in tasks requiring sustained attention, mind wandering episodes in which attention is directed internally constrain conscious processing of external stimuli. Conversely, conscious processing of internal stimuli is enhanced during mind wandering. To investigate this, we developed and administered a visuomotor tracking task in which participants were instructed to track the path of a stimulus on a screen with a mouse while responding to rare targets. Prior to reports of mind wandering we found the following: The P3 event-related potential component for targets, indicative of conscious stimulus processing, was attenuated at electrodes Cz and Pz. Moreover, alpha power, indicative of internal mental states, increased globally. Theta power increased along the centroparietal area, and beta decreased along right frontal and right centroparietal areas. Interestingly, trait mind wandering was positively correlated with delta power and gamma power, but negatively correlated with the theta-beta ratio. These results demonstrate that mind wandering is characterized by distinct neural signatures at both a state and trait level.

The Effect of Juingong Meditation on the Theta to Alpha Ratio in the Temporoparietal and Anterior Frontal EEG Recordings

(1) Background: The effect of Juingong meditation on brainwave patterns has not been explored yet. This study aimed to study the changes in brainwave patterns produced by Juingong meditation, through electroencephalography (EEG) measurements. (2) Methods: The study included 23 participants from the Hanmaum Seon Center in Korea. EEG measurements were performed using InteraXon’s four-channel EEG measurement equipment, Muse. It measures EEG patterns in the temporoparietal and anterior frontal lobes. Brainwaves were measured in two different states: when Juingong meditation was practiced and when instructed mind wandering (IMW) was practiced. The EEG recordings were analyzed using the theta/alpha index. (3) Results: In the Juingong meditation state, the power of alpha was relatively higher than that of theta and these results were valid in the temporal parietal lobe channel. This indicates that relatively more alpha waves were induced in the temporal parietal lobe when Juingong meditation was practiced. (4) Conclusions: When Juingong meditation is practiced, the theta/alpha ratio changes without delay, which means that the practical effect of Juingong meditation on brainwave patterns is immediately apparent.

Cortical correlation structure of aperiodic neuronal population activity

Electrophysiological population signals contain oscillatory and non-oscillatory aperiodic (1/frequency-like) components. So far research has largely focused on oscillatory activity, and only recently, interest in aperiodic population activity has gained momentum. Accordingly, while the cortical correlation structure of oscillatory population activity has been characterized, little is known about the correlation of aperiodic neuronal activity. To address this, we investigated aperiodic neuronal population activity in the human brain using resting-state magnetoencephalography (MEG). We combined source-analysis, signal orthogonalization and irregular-resampling auto-spectral analysis (IRASA) to systematically characterize the cortical distribution and correlation of aperiodic neuronal activity. We found that aperiodic population activity is robustly correlated across the cortex and that this correlation is spatially well structured. Furthermore, we found that the cortical correlation structure of aperiodic activity is similar but distinct from the correlation structure of oscillatory neuronal activity. Anterior cortical regions showed the strongest differences between oscillatory and aperiodic correlation patterns. Our results suggest that correlations of aperiodic population activity serve as robust markers of cortical network interactions. Furthermore, our results show that aperiodic and oscillatory signal components provide non-redundant information about large-scale neuronal correlations. This may reflect at least partly distinct neuronal mechanisms underlying and reflected by oscillatory and aperiodic neuronal population activity.

Advanced Meditation Alters Resting-State Brain Network Connectivity Correlating With Improved Mindfulness

Purpose: The purpose of this study was to investigate the effect of an intensive 8-day Samyama meditation program on the brain functional connectivity using resting-state functional MRI (rs-fMRI).

Methods: Thirteen Samyama program participants (meditators) and 4 controls underwent fMRI brain scans before and after the 8-day residential meditation program. Subjects underwent fMRI with a blood oxygen level dependent (BOLD) contrast at rest and during focused breathing. Changes in network connectivity before and after Samyama program were evaluated. In addition, validated psychological metrics were correlated with changes in functional connectivity.

Results: Meditators showed significantly increased network connectivity between the salience network (SN) and default mode network (DMN) after the Samyama program (p < 0.01). Increased connectivity within the SN correlated with an improvement in self-reported mindfulness scores (p < 0.01).

Conclusion: Samyama, an intensive silent meditation program, favorably increased the resting-state functional connectivity between the salience and default mode networks. During focused breath watching, meditators had lower intra-network connectivity in specific networks. Furthermore, increased intra-network connectivity correlated with improved self-reported mindfulness after Samyama.

Clinical Trials Registration: [https://clinicaltrials.gov], Identifier: [NCT04366544]. Registered on 4/17/2020.

Alpha and theta oscillations are inversely related to progressive levels of meditation depth

Meditation training is proposed to enhance mental well-being by modulating neural activity, particularly alpha and theta brain oscillations, and autonomic activity. Although such enhancement also depends on the quality of meditation, little is known about how these neural and physiological changes relate to meditation quality. One model characterizes meditation quality as five increasing levels of ‘depth’: hindrances, relaxation, concentration, transpersonal qualities and nonduality. We investigated the neural oscillatory (theta, alpha, beta and gamma) and physiological (respiration rate, heart rate and heart rate variability) correlates of the self-reported meditation depth in long-term meditators (LTMs) and meditation-naïve controls (CTLs). To determine the neural and physiological correlates of meditation depth, we modelled the change in the slope of the relationship between self-reported experiential degree at each of the five depth levels and the multiple neural and physiological measures. CTLs reported experiencing more ‘hindrances’ than LTMs, while LTMs reported more ‘transpersonal qualities’ and ‘nonduality’ compared to CTLs, confirming the experiential manipulation of meditation depth. We found that in both groups, theta (4–6 Hz) and alpha (7–13 Hz) oscillations were related to meditation depth in a precisely opposite manner. The theta amplitude positively correlated with ‘hindrances’ and increasingly negatively correlated with increasing meditation depth levels. Alpha amplitude negatively correlated with ‘hindrances’ and increasingly positively with increasing depth levels. The increase in the inverse association between theta and meditation depth occurred over different scalp locations in the two groups—frontal midline in LTMs and frontal lateral in CTLs—possibly reflecting the downregulation of two different aspects of executive processing—monitoring and attention regulation, respectively—during deep meditation. These results suggest a functional dissociation of the two classical neural signatures of meditation training, namely, alpha and theta oscillations. Moreover, while essential for overcoming ‘hindrances’, executive neural processing appears to be downregulated during deeper meditation experiences.

Increased Entropy of Gamma Oscillations in the Frontal Region during Meditation

Meditation practices are considered mental training and have increasingly received attention from the scientific community due to their potential psychological and physical health benefits. We compared the EEG data recorded from long-term rajayoga practitioners during different meditative and non-meditative periods. Minimum variance modified fuzzy entropy (MVMFE) is computed for each EEG band for all channels of a given lobe. The means across all the channel entropy values were obtained and compared during meditative and non-meditative states. Meditators showed higher frontal entropy in the lower gamma band (25-45Hz) during the meditative states. Independent component analysis was applied to ensure that muscle or eye artifacts did not contribute to the gamma activity. Our results extend previous findings on the changes in entropy observed in long-term meditators during rajayoga practice. Gamma band in EEG is implicated in cognitive processes requiring high-level processing such as attention, learning, memory control, and retrieval. Gamma activity is also suggested as a potential biomarker for therapeutic progress in patients with clinical depression. Based on our findings, there is an excellent possibility to utilize the practice of meditation as a training tool to strengthen the neural circuits, where age-related degeneration is making its pathological impact.

Mining the Mind: Linear Discriminant Analysis of MEG Source Reconstruction Time Series Supports Dynamic Changes in Deep Brain Regions During Meditation Sessions

Meditation practices have been claimed to have a positive effect on the regulation of mood and emotions for quite some time by practitioners, and in recent times there has been a sustained effort to provide a more precise description of the influence of meditation on the human brain. Longitudinal studies have reported morphological changes in cortical thickness and volume in selected brain regions due to meditation practice, which is interpreted as an evidence its effectiveness beyond the subjective self reporting. Using magnetoencephalography (MEG) or electroencephalography to quantify the changes in brain activity during meditation practice represents a challenge, as no clear hypothesis about the spatial or temporal pattern of such changes is available to date. In this article we consider MEG data collected during meditation sessions of experienced Buddhist monks practicing focused attention (Samatha) and open monitoring (Vipassana) meditation, contrasted by resting state with eyes closed. The MEG data are first mapped to time series of brain activity averaged over brain regions corresponding to a standard Destrieux brain atlas. Next, by bootstrapping and spectral analysis, the data are mapped to matrices representing random samples of power spectral densities in [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] frequency bands. We use linear discriminant analysis to demonstrate that the samples corresponding to different meditative or resting states contain enough fingerprints of the brain state to allow a separation between different states, and we identify the brain regions that appear to contribute to the separation. Our findings suggest that the cingulate cortex, insular cortex and some of the internal structures, most notably the accumbens, the caudate and the putamen nuclei, the thalamus and the amygdalae stand out as separating regions, which seems to correlate well with earlier findings based on longitudinal studies.

Inter-brain co-activations during mindfulness meditation. Implications for devotional and clinical settings

Mindfulness meditation usually takes place as personal, introspective activity. It is not known if this practice activates the brain differently when done alone or with someone else. Sixteen couples of expert meditators performed mindfulness-oriented meditation (MOM) and instructed mind-wandering (IMW) tasks in two conditions: once sitting in the same room (SR) and once in two different rooms (DR). Spontaneous electroencephalographic (EEG) data was collected during 7-minute recording sessions in the four experimental settings (MOM/SR, MOM/DR, IMW/SR, IMW/DR). Power in band was computed in separate clusters of independent components of the EEG signals. In addition to significant task effects, found in frontolimbic (MOM > IMW in gamma) and frontoparietal locations (MOM < IMW in theta), significant condition effects were found in frontal (SR > DR in delta) and in temporo-occipital regions (SR > DR in theta and alpha). Moreover, a significant interaction between task and condition revealed higher gamma activity in limbic areas during MOM/SR vs. MOM/DR settings. This effect was not attributable to gender, age nor the meditation expertise of participants. We thus show that the brains of two people work differently when they are doing something together or alone; some of these differences are specific to mindfulness meditation. Implications for devotional and clinical settings are discussed.

The Impact of Mindfulness Meditation on the Wandering Mind: a Systematic Review

Through the practice of Mindfulness Meditation (MM), meditators become familiar with the observation of ongoing spontaneous thoughts, while maintaining an attitude of openness and equanimity. The aim of this systematic review is to present a synthesis of available findings of the short and long-term effects of MM on mind wandering (MW). We included studies that considered both first-person and behavioral/physiological measures of MW. The search resulted in 2035 papers, 24 of which were eligible. Reviewed studies revealed a high heterogeneity in designs, outcome measures and interventions. Most of the pre-post intervention studies showed that a protracted practice of MM (at least 2 weeks) reduced MW, limiting its negative effects on different cognitive tasks. Cross-sectional studies highlighted differences between expert meditators and naïve individuals: meditators self-reported less MW and showed decreased Default Mode Network activity, during meditation and resting-state. Further studies are needed to replicate available findings and to more deeply explore how MW is influenced by meditation, also considering its qualitative characteristics that remain largely unexplored.

Virtual Reality-Guided Meditation for Chronic Pain in Patients With Cancer: Exploratory Analysis of Electroencephalograph Activity

BACKGROUND

Mindfulness-based stress reduction has demonstrated some efficacy for chronic pain management. More recently, virtual reality (VR)-guided meditation has been used to assist mindfulness-based stress reduction. Although studies have also found electroencephalograph (EEG) changes in the brain during mindfulness meditation practices, such changes have not been demonstrated during VR-guided meditation.

OBJECTIVE

This exploratory study is designed to explore the potential for recording and analyzing EEG during VR experiences in terms of the power of EEG waveforms, topographic mapping, and coherence. We examine how these measures changed during a VR-guided meditation experience in participants with cancer-related chronic pain.

METHODS

A total of 10 adult patients with chronic cancer pain underwent a VR-guided meditation experience while EEG signals were recorded during the session using a BioSemi ActiveTwo system (64 channels, standard 10-20 configuration). The EEG recording session consisted of an 8-minute resting condition (pre), a 30-minute sequence of 3 VR-guided meditation conditions (med), and a final rest condition (post). Power spectral density (PSD) was compared between each condition using a cluster-based permutation test and across conditions using multivariate analysis of variance. A topographic analysis, including coherence exploration, was performed. In addition, an exploratory repeated measures correlation was used to examine possible associations between pain scores and EEG signal power.

RESULTS

The predominant pattern was for increased β and γ bandwidth power in the meditation condition (P<.025), compared with both the baseline and postexperience conditions. Increased power in the δ bandwidth was evident, although not statistically significant. The pre versus post comparison also showed changes in the θ and α bands (P=.02) located around the frontal, central, and parietal cortices. Across conditions, multivariate analysis of variance tests identified 4 clusters with significant (P<.05) PSD differences in the δ, θ, β, and γ bands located around the frontal, central, and parietal cortices. Topographically, 5 peak channels were identified: AF7, FP2, FC1, CP5, and P5, and verified the changes in power in the different brain regions. Coherence changes were observed primarily between the frontal, parietal, and occipital regions in the θ, α, and γ bands (P<.0025). No significant associations were observed between pain scores and EEG PSD.

CONCLUSIONS

This study demonstrates the feasibility of EEG recording in exploring neurophysiological changes in brain activity during VR-guided meditation and its effect on pain reduction. These findings suggest that distinct altered neurophysiological brain signals are detectable during VR-guided meditation. However, these changes were not necessarily associated with pain. These exploratory findings may guide further studies to investigate the highlighted regions and EEG bands with respect to VR-guided meditation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00102401; http://clinicaltrials.gov/ct2/show/NCT00102401.

Isha Yoga Practices and Participation in Samyama Program are Associated with Reduced HbA1C and Systemic Inflammation, Improved Lipid Profile, and Short-Term and Sustained Improvement in Mental Health: A Prospective Observational Study of Meditators

Background: Meditation is gaining recognition as a tool to impact health and well-being. Samyama is an 8-day intensive residential meditation experience conducted by Isha Foundation requiring several months of extensive preparation and vegan diet. The health effects of Samyama have not been previously studied. The objective was to assess physical and emotional well-being before and after Samyama participation by evaluating psychological surveys and objective health biomarkers. Methods: This was an observational study of 632 adults before and after the Isha Samyama retreat. All participants were invited to complete surveys. Controls included household significant others. Surveys were completed at baseline (T1), just before Samyama (T2), immediately after Samyama (T3), and 3 months later (T4) to assess anxiety, depression, mindfulness, joy, vitality, and resilience through validated psychometric scales. Voluntary blood sampling for biomarker analysis was done to assess hemoglobin (Hb), HbA1c, lipid profile, and C-reactive protein (CRP). Primary outcomes were changes in psychometric scores, body weight, and blood biomarkers. Results: Depression and anxiety scores decreased from T1 to T3, with the effect most pronounced in participants with baseline depression or anxiety. Scores at T4 remained below baseline for those with pre-existing depression or anxiety. Vitality, resilience, joy, and mindfulness increased from T1 to T3 (sustained at T4). Body weight decreased by 3% from T1 to T3. Triglycerides (TG) were lower from T2 to T3. Participants had lower HbA1c and HDL at T2, and lower CRP at all timepoints compared with controls. Conclusions: Participation in the Isha Samyama program led to multiple benefits. The 2-month preparation reduced anxiety, and participants maintained lower anxiety levels at 3 months post-retreat. Physical health improved over the course of the program as evidenced by weight loss and improved HbA1C and lipid profile. Practices associated with the Samyama preparation phase and the retreat may serve as an effective way to improve physical and mental health. Future studies may examine their use as an alternative therapy in patients with depression and/or anxiety. Clinical Trial Registration: www.ClinicalTrials.gov, Identifier: 1801728792. Registered retrospectively on 4/17/2020.

The Function of Color and Structure Based on EEG Features in Landscape Recognition

Both color and structure make important contributions to human visual perception, as well as the evaluation of landscape quality and landscape aesthetics. The EEG equipment liveamp32 was used to record the EEG signals of humans when viewing landscape images, structure images with filtered color, and color images with a filtered structure. The results show that the SVM classifier was the most suitable classifier for landscape classification based on EEG features. The classification accuracy of the landscape picture recognition was up to 98.3% when using beta waves, while the accuracy of the color recognition was 97.5%, and that of the structure recognition was 93.9% when using gamma waves. Secondly, color and structure played a major role in determining the alpha and gamma wave responses, respectively, for all the landscape types, including forest, desert, and water. Furthermore, structure only played a decisive role in forest, while color played a major role in desert and water when using beta waves. Lastly, statistically significant differences between landscape groups and scenario groups with regard to alpha, beta, and gamma rhythms in brain waves were confirmed. The reasonable usage and layout of structure and color will have a very important guiding value for landscape aesthetics in future landscape design and landscape planning.

Contrasting Electroencephalography-Derived Entropy and Neural Oscillations With Highly Skilled Meditators

Meditation is an umbrella term for a number of mental training practices designed to improve the monitoring and regulation of attention and emotion. Some forms of meditation are now being used for clinical intervention. To accompany the increased clinical interest in meditation, research investigating the neural basis of these practices is needed. A central hypothesis of contemplative neuroscience is that meditative states, which are unique on a phenomenological level, differ on a neurophysiological level. To identify the electrophysiological correlates of meditation practice, the electrical brain activity of highly skilled meditators engaging in one of six meditation styles (shamatha, vipassana, zazen, dzogchen, tonglen, and visualization) was recorded. A mind-wandering task served as a control. Lempel-Ziv complexity showed differences in nonlinear brain dynamics (entropy) during meditation compared with mind wandering, suggesting that meditation, regardless of practice, affects neural complexity. In contrast, there were no differences in power spectra at six different frequency bands, likely due to the fact that participants engaged in different meditation practices. Finally, exploratory analyses suggest neurological differences among meditation practices. These findings highlight the importance of studying the electroencephalography (EEG) correlates of different meditative practices.

Neural and subjective effects of inhaled N,N-dimethyltryptamine in natural settings

BACKGROUND

N,N-dimethyltryptamine is a short-acting psychedelic tryptamine found naturally in many plants and animals. Few studies to date have addressed the neural and psychological effects of N,N-dimethyltryptamine alone, either administered intravenously or inhaled in freebase form, and none have been conducted in natural settings.

AIMS

Our primary aim was to study the acute effects of inhaled N,N-dimethyltryptamine in natural settings, focusing on questions tuned to the advantages of conducting field research, including the effects of contextual factors (i.e. "set" and "setting"), the possibility of studying a comparatively large number of subjects, and the relaxed mental state of participants consuming N,N-dimethyltryptamine in familiar and comfortable settings.

METHODS

We combined state-of-the-art wireless electroencephalography with psychometric questionnaires to study the neural and subjective effects of naturalistic N,N-dimethyltryptamine use in 35 healthy and experienced participants.

RESULTS

We observed that N,N-dimethyltryptamine significantly decreased the power of alpha (8-12 Hz) oscillations throughout all scalp locations, while simultaneously increasing power of delta (1-4 Hz) and gamma (30-40 Hz) oscillations. Gamma power increases correlated with subjective reports indicative of some features of mystical-type experiences. N,N-dimethyltryptamine also increased global synchrony and metastability in the gamma band while decreasing those measures in the alpha band.

CONCLUSIONS

Our results are consistent with previous studies of psychedelic action in the human brain, while at the same time the results suggest potential electroencephalography markers of mystical-type experiences in natural settings, thus highlighting the importance of investigating these compounds in the contexts where they are naturally consumed.

Neural Correlates of the Shamanic State of Consciousness

Psychedelics have been recognized as model interventions for studying altered states of consciousness. However, few empirical studies of the shamanic state of consciousness, which is anecdotally similar to the psychedelic state, exist. We investigated the neural correlates of shamanic trance using high-density electroencephalography (EEG) in 24 shamanic practitioners and 24 healthy controls during rest, shamanic drumming, and classical music listening, followed by an assessment of altered states of consciousness. EEG data were used to assess changes in absolute power, connectivity, signal diversity, and criticality, which were correlated with assessment measures. We also compared assessment scores to those of individuals in a previous study under the influence of psychedelics. Shamanic practitioners were significantly different from controls in several domains of altered states of consciousness, with scores comparable to or exceeding that of healthy volunteers under the influence of psychedelics. Practitioners also displayed increased gamma power during drumming that positively correlated with elementary visual alterations. Furthermore, shamanic practitioners had decreased low alpha and increased low beta connectivity during drumming and classical music and decreased neural signal diversity in the gamma band during drumming that inversely correlated with insightfulness. Finally, criticality in practitioners was increased during drumming in the low and high beta and gamma bands, with increases in the low beta band correlating with complex imagery and elementary visual alterations. These findings suggest that psychedelic drug-induced and non-pharmacologic alterations in consciousness have overlapping phenomenal traits but are distinct states of consciousness, as reflected by the unique brain-related changes during shamanic trance compared to previous literature investigating the psychedelic state.

Activation of the orbitofrontal cortex by both meditation and exercise: A near-infrared spectroscopy study

In some types of meditation, such as mindfulness and Zen, breathing is the focus of attention, whereas during an excessive, short-period of anaerobic exercise, the muscles become the focus of attention. Thus, during both efforts, one’s attention is focused on a certain feature of the body. Both meditation and exercise generally provide mental refreshment to humans. We hypothesized that the same brain regions are activated by both efforts in humans. To examine this hypothesis, we engaged participants in 3 tasks: meditation, exercise, and a control task. After each task, the participants underwent a 2-back test to concentrate their thoughts, while changes in their blood hemoglobin levels were simultaneously monitored using near-infrared spectroscopy (NIRS). Seventeen participants (20–24 years of age; 11 men, 6 women) were enrolled. We applied a fast-Fourier transform (FFT) analysis to the NIRS wave data and calculated the correlation coefficients of the FFT data between (1) meditation and control, (2) exercise and control, and (3) meditation and exercise, at the orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex (DLPFC), brain areas that are generally involved in mental refreshment. A significant difference in the correlation coefficients between the OFC and DLPFC was detected in the meditation and exercise analysis, and signal source analysis confirmed that the NIRS waves spread from the right and left OFC edges (i.e., right and left temples) toward the center. Our results suggest that both meditation and exercise activate the OFC, which is involved in emotional reactions and motivation behavior, resulting in mental refreshment.

Short-term meditation training influences brain energy metabolism: A pilot study on 31 P MR spectroscopy

BACKGROUND

Meditation is increasingly attracting interest among neuroimaging researchers for its relevance as a cognitive enhancement technique and several cross-sectional studies have indicated cerebral changes. This longitudinal study applied a distinct and standardized meditative technique with a group of volunteers in a short-term training program to analyze brain metabolic changes.

METHODS

The effect of 7 weeks of meditation exercises (focused attention meditation, FAM) was assessed on 27 healthy volunteers. Changes in cerebral energy metabolism were investigated using ³¹ P-MR spectroscopy. Metabolite ratios were compared before (T1) and after training (T2). Additional questionnaire assessments were included.

RESULTS

The participants performed FAM daily. Depression and anxiety scores revealed a lower level of state anxiety at T2 compared to T1. From T1 to T2, energy metabolism ratios showed the following differences: PCr/ATP increased right occipitally; Pi/ATP decreased bilaterally in the basal ganglia and temporal lobe on the right; PCr/Pi increased in occipital lobe bilaterally, in the basal ganglia and in the temporal lobe on the right side. The pH decreased temporal on the left side and frontal in the right side. The observed changes in the temporal areas and basal ganglia may be interpreted as a higher energetic state, whereas the frontal and occipital areas showed changes that may be related to a down-regulation in ATP turnover, energy state, and oxidative capacity.

CONCLUSIONS

The results of the current study indicate for the first time in a longitudinal study that even short-term training in FAM may have considerable effects on brain energy state with different local energy management in specific brain regions. Especially higher energetic state in basal ganglia may represent altered function in their central role in complex cerebral distributed networks including frontal and temporal areas. Further studies including different forms of relaxation techniques should be performed for more specific and reliable insights.

Changes in the Electrical Activity of the Brain in the Alpha and Theta Bands during Prayer and Meditation

Focused attention meditation (FAM) is a category of meditation based on an EEG pattern, which helps the wandering mind to focus on a particular object. It seems that prayer may, in certain respects, be similar to FAM. It is believed that emotional experience correlates mainly with theta, but also with selective alpha, with internalized attention correlating mainly with the synchronous activity of theta and alpha. The vast majority of studies indicate a possible impact of transcendence in meditation on the alpha wave in EEG. No such reports are available for prayer. Seventeen women and nineteen men aged 27–64 years with at least five years of intensive meditation/prayer experience were recruited to participate in the study. We identified the two largest groups which remained in the meditation trend originating from the Buddhist system (14 people) (Buddhist meditators) and in the Christian-based faith (15 people) (Christian meditators). EEG signal was recorded with open eyes, closed eyes, during meditation/prayer, and relaxation. After the EEG recording, an examination was conducted using the Scale of Spiritual Transcendence. Buddhist meditators exhibited a statistically significantly higher theta amplitude at Cz during meditation compared to relaxation. Meanwhile, spiritual openness favored a higher theta amplitude at Pz during relaxation. Our study did not reveal statistically significant differences in frontal areas with regard to alpha and theta, which was often indicated in previous studies. It seems necessary to analyze more closely the midline activity in terms of dispersed neural activity integration.

On the Neurobiology of Meditation: Comparison of Three Organizing Strategies to Investigate Brain Patterns during Meditation Practice

Three broad organizing strategies have been used to study meditation practices: (1) consider meditation practices as using similar processes and so combine neural images across a wide range of practices to identify the common underlying brain patterns of meditation practice, (2) consider meditation practices as unique and so investigate individual practices, or (3) consider meditation practices as fitting into larger categories and explore brain patterns within and between categories. The first organizing strategy combines meditation practices defined as deep concentration, attention to external and internal stimuli, and letting go of thoughts. Brain patterns of different procedures would all contribute to the final averages, which may not be representative of any practice. The second organizing strategy generates a multitude of brain patterns as each practice is studied individually. The rich detail of individual differences within each practice makes it difficult to identify reliable patterns between practices. The third organizing principle has been applied in three ways: (1) grouping meditations by their origin—Indian or Buddhist practices, (2) grouping meditations by the procedures of each practice, or (3) grouping meditations by brain wave frequencies reported during each practice. Grouping meditations by their origin mixes practices whose procedures include concentration, mindfulness, or effortless awareness, again resulting in a confounded pattern. Grouping meditations by their described procedures yields defining neural imaging patterns within each category, and clear differences between categories. Grouping meditations by the EEG frequencies associated with their procedures yields an objective system to group meditations and allows practices to “move” into different categories as subjects’ meditation experiences change over time, which would be associated with different brain patterns. Exploring meditations within theoretically meaningful categories appears to yield the most reliable picture of meditation practices.

Effect of meditation on intracerebral EEG in a patient with temporal lobe epilepsy: A case report

Meditation has been deemed a miracle cure for a wide range of neurological disorders. However, it is unclear whether meditation practice would be beneficial for patients suffering from epilepsy. Here we report on the comparison of the effects of focused-attention meditation and a control task on electroencephalographic (EEG) activity in a patient undergoing stereoencephalographic (SEEG) investigation for drug-resistant epilepsy. The patient routinely practiced focused-attention meditation and reported that she found it beneficial. During the SEEG investigation, intracerebral EEG data were recorded during meditation as well as during mind-wandering task. The EEG data were analyzed for type of electrical activity (labeled) by two expert epileptologists. We found that the proportion of EEG segments containing activity classified as interictal epileptiform discharges (IEDs; abnormal electrical activity that occurs between seizures) increased significantly during meditation practice. Although the finding was surprising, this increase in IEDs may not correlate with an increase in seizure frequency, and the patient might still benefit from practicing meditation. The finding does, however, warrant further studies on the influence of meditation on epileptic activity.

Age-related memory decline, dysfunction of the hippocampus and therapeutic opportunities

While the aging of the population is a sign of progress for societies, it also carries its load of negative aspects. Among them, cognitive decline and in particular memory loss is a common feature of non-pathological aging. Autobiographical memories, which rely on the hippocampus, are a primary target of age-related cognitive decline. Here, focusing on the neurobiological mechanisms of memory formation and storage, we describe how hippocampal functions are altered across time in non-pathological mammalian brains. Several hallmarks of aging have been well described over the last decades; among them, we consider altered synaptic communication and plasticity, reduction of adult neurogenesis and epigenetic alterations. Building on the neurobiological processes of cognitive aging that have been identified to date, we review some of the strategies based on lifestyle manupulation allowing to address age-related cognitive deficits.

Analogy between classical Yoga/Zen breathing and modern clinical respiratory therapy

Anesthesiologists and intensivists are modern-day professionals who provide appropriate respiratory care, vital for patient survival. Recently, anesthesiologists have increasingly focused their attention on the type of spontaneous breathing made by non-intubated patients with pulmonary disease cared for in an intensive care unit, and also patients with chronic pain receiving cognitive behavioral therapy. Prior to our modern understanding of respiratory physiology, Zen meditators recognized that breathing has a significant impact on a person’s mental state and general physical well-being. Examples of this knowledge regarding respiration include the beneficial effects of deep inhalation and slow exhalation on anxiety and general wellness. The classical literature has noted many suggestions for breathing and its psycho-physical effects. In the present review, we examine the effect of classical breathing methods and find an analogy between typical Yoga/Zen breathing and modern clinical respiratory therapy. Evidence is increasing about historical breathing and related meditation techniques that may be effective in modern clinical practice, especially in the field of anesthesiology, such as in improving respiratory function and reducing chronic pain. Clarification of the detailed mechanisms involved is anticipated.

A Critical Analysis on Characterizing the Meditation Experience Through the Electroencephalogram

Meditation practices, originated from ancient traditions, have increasingly received attention due to their potential benefits to mental and physical health. The scientific community invests efforts into scrutinizing and quantifying the effects of these practices, especially on the brain. There are methodological challenges in describing the neural correlates of the subjective experience of meditation. We noticed, however, that technical considerations on signal processing also don't follow standardized approaches, which may hinder generalizations. Therefore, in this article, we discuss the usage of the electroencephalogram (EEG) as a tool to study meditation experiences in healthy individuals. We describe the main EEG signal processing techniques and how they have been translated to the meditation field until April 2020. Moreover, we examine in detail the limitations/assumptions of these techniques and highlight some good practices, further discussing how technical specifications may impact the interpretation of the outcomes. By shedding light on technical features, this article contributes to more rigorous approaches to evaluate the construct of meditation.

Meditation and the Wandering Mind: A Theoretical Framework of Underlying Neurocognitive Mechanisms

During the practice of meditation, the tendency of the mind to wander away from the object of focus is ubiquitous. The occurrence of mind wandering in the context of meditation provides individuals a unique and intimate opportunity to closely examine the nature of the wandering mind by cultivating an awareness of ongoing thought patterns, while simultaneously aiming to cultivate equanimity (evenness of temper or disposition) and compassion toward the content of thoughts, interpretations, and bodily sensations. In this article we provide a theoretical framework that highlights the neurocognitive mechanisms by which contemplative practices influence the neural and phenomenological processes underlying spontaneous thought. Our theoretical model focuses on several converging mechanisms: the role of meta-awareness in facilitating an increased moment-to-moment awareness of spontaneous thought processes, the effects of meditation practice on key structures underlying both the top-down cognitive processes and bottom-up sensory processes implicated in attention and emotion regulation, and the influence of contemplative practice on the neural substrates underlying perception and perceptual decoupling.

Inner Engineering Practices and Advanced 4-day Isha Yoga Retreat Are Associated with Cannabimimetic Effects with Increased Endocannabinoids and Short-Term and Sustained Improvement in Mental Health: A Prospective Observational Study of Meditators

Background

Anxiety and depression are common in the modern world, and there is growing demand for alternative therapies such as meditation. Meditation can decrease perceived stress and increase general well-being, although the physiological mechanism is not well-characterized. Endocannabinoids (eCBs), lipid mediators associated with enhanced mood and reduced anxiety/depression, have not been previously studied as biomarkers of meditation effects. Our aim was to assess biomarkers (eCBs and brain-derived neurotrophic factor [BDNF]) and psychological parameters after a meditation retreat.

Methods

This was an observational pilot study of adults before and after the 4-day Isha Yoga Bhava Spandana Program retreat. Participants completed online surveys (before and after retreat, and 1 month later) to assess anxiety, depression, focus, well-being, and happiness through validated psychological scales. Voluntary blood sampling for biomarker studies was done before and within a day after the retreat. The biomarkers anandamide, 2-arachidonoylglycerol (2-AG), 1-arachidonoylglycerol (1-AG), docosatetraenoylethanolamide (DEA), oleoylethanolamide (OLA), and BDNF were evaluated. Primary outcomes were changes in psychological scales, as well as changes in eCBs and BDNF.

Results

Depression and anxiety scores decreased while focus, happiness, and positive well-being scores increased immediately after retreat from their baseline values (P < 0.001). All improvements were sustained 1 month after BSP. All major eCBs including anandamide, 2-AG, 1-AG, DEA, and BDNF increased after meditation by > 70% (P < 0.001). Increases of ≥20% in anandamide, 2-AG, 1-AG, and total AG levels after meditation from the baseline had weak correlations with changes in happiness and well-being.

Conclusions

A short meditation experience improved focus, happiness, and positive well-being and reduced depression and anxiety in participants for at least 1 month. Participants had increased blood eCBs and BDNF, suggesting a role for these biomarkers in the underlying mechanism of meditation. Meditation is a simple, organic, and effective way to improve well-being and reduce depression and anxiety.