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Music Therapy has been found to decrease pain, anxiety, psychological stress, tension, inflammation,  heart rate, blood pressure, respiratory rate, neurotransmitter imbalance, improve sleep and prevent or decrease delirium. 

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BREATH THERAPY - Improve your health with breath

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Kirtan Kriya is a simple meditation technique practiced as part of Kundalini yoga which is thought to have many health benefits, including improving memory, focus, and cognition as well as reducing the effects of stress and anxiety.

Kundalini yoga is a form of yoga that involves chanting, singing, breathing exercises, and repetitive poses which activate a spiritual energy located at the base of your spine. It is sometimes referred to as 'yoga of awareness' as it helps enhance your awareness and move past your ego. With regular practice, Kundalini yoga is believed to lead to spiritual enlightenment.

Kirtan Kriya meditation helps to stimulate the senses and activate parts of the brain. The practice combines chanting and finger movements. Kirtan Kriya meditation focuses on making four primal sounds: Saa Taa Naa Maa, which translates as Saa - Beginning, infinity; Taa - Life; Naa - Death; and Maa - Rebirth (the circle of life) (Kumari and Karunaratne, 2021). The placement of the tongue in the mouth when making these sounds stimulates 84 acupuncture meridian points on the palate which stimulates the hypothalamus, pituitary gland, and other areas in the brain.

While chanting the sounds of the mantra Saa Taa Naa Maa, the thumb moves along the tips of the fingers with a firm but gentle pressure starting first with the index finger for Saa, then the middle finger for Taa, the ring finger for Naa, and the pinky finger for Maa.

The combined finger pressure and mantra chanting enhance blood flow to the brain. It is believed to improve cognition, focus, and memory.

Traditional Kirtan Kriya practice dictates the mantra and accompanying hand movements be repeated first in a normal voice for two minutes, then a whisper for two minutes, then silently chanted in your mind for four minutes, then again whispered for two minutes, and chanted loudly for the final two minutes. After the 12-minute meditation, stretch arms up while inhaling deeply, then exhale and relax the arms (see the detailed instructions below). The eyes should be closed, spine straight, and arms relaxed with the hands placed on the thighs or knees throughout the meditation.

The science

Kundalini yoga was first mentioned in sacred texts dating back to 1000BC, but what does modern science say about its benefits? Research on meditation is still in its infancy but studies on meditation and benefits to cognition are promising.

A study published in 2021 in International Journal of Health Sciences and Research found that Kirtan Kriya can help to improve cognition, memory, and psychological well-being. It also proved beneficial in treating patients with stress and anxiety. (Kumari and Karunaratne, 2021)

A study on the effects of kundalini yoga on participants with memory problems concluded that "significant increases were found in the cerebral blood flow ratios in the prefrontal, superior frontal, and superior parietal cortices ( P < 0.05)" (Khalsa, 2015). Participants completing the study reported increased memory function. (Khalsa, 2015)

A study on dementia caregivers randomized to receive either Kirtan Kriya meditation or relaxing music for 12 minutes daily for 8 weeks showed improved markers of stress and inflammation in the meditation group. Those receiving Kirtan Kriya displayed changes in gene expression including up-regulated immunoglobulin-related transcripts and down-regulated pro-inflammatory cytokines. Researchers concluded that brief daily Kirtan Kriya may reverse increased pro-inflammatory cytokine activity in individuals with significant life stressors. (Black et al., 2013)

Kirtan Kriya technique

With your eyes closed, repeat the Saa Taa Naa Maa mantra while sitting with your spine straight.

If possible, with each syllable, your focus of concentration is imagining the sound and energy flowing in through the top of your head and out the middle of your forehead.

Chant Saa, Taa, Naa, Maa out loud for two minutes.

On Saa, touch the index fingers of each hand to your thumbs.

On Taa, touch your middle fingers to your thumbs.

On Naa, touch your ring fingers to your thumbs.

On Maa, touch your little fingers to your thumbs.

Chant this as a whisper for two minutes.

For four minutes, say the chant silently to yourself.

Chant in a whisper for two minutes.

Chant out loud for two minutes.

To end the exercise, inhale very deeply, stretch your hands above your head, and bring them down slowly in a sweeping motion as you exhale. The exercise should take 12 minutes.

(Albert, 2018)
To learn more about Kirtan Kriya, or to be taken through a guided meditation,
or watch the video below:

References:

Albert, A. (2018). "Meditation: The effects of Kirtan Kriya are instant - all care homes should do it". Online: https://tinyurl.com/537rts8v

Black, D.S. Cole, S.W. Irwin, M.R. et. al. (2013). "Yogic meditation reverses NF-κB and IRF-related transcriptome dynamics in leukocytes of family dementia caregivers in a randomized controlled trial", Psychoneuroendocrinology, 38(3), pp. 348-355).

Khalsa D. (2015). "Stress, meditation and Alzheimer's disease prevention: Where the evidence stands", J Alzheimers Dis., 48, pp. 1-12.

Kumari, M.G.W.R. and Karunaratne, H.K.B.M.S. (2021). "A review on therapeutic effect of kirtan kriya yoga", Int J Health Sci Res., 11(1), pp. 240-247.

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Kirtan Kriya Meditation - Saa Taa Naa Maa - BREATH THERAPY

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ditation technique practiced as part of Kundalini yoga which is thought to have many health benefits, including improving memory, focus, and cognition as well as reducing the effects of stress and anxiety.

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Devotional yogic chanting with a Western influence. CDs and cassettes for sale, artist background, schedule of live appearances.

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HEALING FREQUENCIES OF TIBETAN SINGING BOWLS

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HEALING FREQUENCIES OF TIBETAN SINGING BOWLS

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OM Chanting @417 Hz | Removes All Negative Blocks

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432Hz - 3 Hour Crystal Singing Bowl Healing Sound Bath (4K, No Talking) - Singing Bowls - Sound Bath

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Nature Sounds of a Forest River for Relaxing-Natural meditation music of a Waterfall & Bird Sounds

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Ragani: Heart of Kirtan - Explorations in Sound & Vibration

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10 Magnificent Gregorian Chants by Benedictine Nuns

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Listening to music at 432 Hz can reduce stress and anxiety.

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Randomized Controlled Trial

. 2022 May 12;93(S2):e2022149.

doi: 10.23750/abm.v93iS2.12915.

Affiliations

¹ University and Continuing Education Center, AUSL Toscana Centro - Empoli - Florence (Italy).. diletta.calamassi@gmail.com.

² Department of Neuroanesthesia and Intensive Care Medicine, Careggi University Hospital, Florence . myriam.livigni26@gmail.com.

³ Department of Experimental and clinical medicine, University of Florence. carlo.fumagalli@unifi.it.

⁴ Territorial Emergency 118 Florence-Prato, AUSL Toscana Centro . gheri.flavio@gmail.com.

⁵ Independent film score composer and sound engineer. gp.pomponi@gp432.com.

⁶ Health Sciences Department University of Florence, Florence. stefano.bambi@unifi.it.

Randomized Controlled Trial

Diletta Calamassi et al. Acta Biomed.

. 2022 May 12;93(S2):e2022149.

doi: 10.23750/abm.v93iS2.12915.

Affiliations

¹ University and Continuing Education Center, AUSL Toscana Centro - Empoli - Florence (Italy).. diletta.calamassi@gmail.com.

² Department of Neuroanesthesia and Intensive Care Medicine, Careggi University Hospital, Florence . myriam.livigni26@gmail.com.

³ Department of Experimental and clinical medicine, University of Florence. carlo.fumagalli@unifi.it.

⁴ Territorial Emergency 118 Florence-Prato, AUSL Toscana Centro . gheri.flavio@gmail.com.

⁵ Independent film score composer and sound engineer. gp.pomponi@gp432.com.

⁶ Health Sciences Department University of Florence, Florence. stefano.bambi@unifi.it.

Abstract

Background and aim: Healthcare providers in the emergency first response units have been exposed to a considerable stress during the SARS-CoV-2 pandemic. This study was designed to identify the effects of listening to music during the work break compared to the routine break (in the absence of listening to music) on the level of state anxiety and on the vital parameters of the nurses on duty at the operations center.

Methods: Randomized, controlled, three-arm, double-blind, single-center clinical study. Healthcare providers were divided into three groups according to study intervention (Group 1: listening to 440Hz music; Group 2: listening to 432Hz music; Group 3: liberal activity). The study was conducted during the working hours of dayshifts in an emergency first response unit station located in Tuscany, Italy. Outcomes were measured against measures of stress (State-Trait Anxiety Inventory - STAIX1), heart rate (HR), respiratory rate (RR), systolic/diastolic blood pressure (SBP/DBP), pain and productivity (Likert Scale) measured at baseline (T0) and at the end of exposure (T1).

Results: Overall, 54 healthcare providers were enrolled; 32 females (59.3%); mean age of 39.64 years (SD±9.94); the total measurements performed were 83. The median values of STAI X1 decreased in all the 3 groups from T0 to T1 (Group 1: 34.5 vs. 32, p=0.0001; Group 2: 34 vs. 29, p=0.001; Group 3: 33 vs. 31, p=0.028). In Group 2 a reduction of mean values of respiratory rate and systolic blood pressure was recorded at T1 (-2.714 b/min, p=0.000 and -3.821 mmHg, p=0.031, respectively).

Conclusions: Listening to music at 432 Hz is a low cost and short intervention that can be a useful resource to manage anxiety and stress. Further studies are needed to assess medium and long-term effects of listening to music.

PubMed Disclaimer

Conflict of interest statement

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Figures

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Calamassi D, Pomponi GP. Calamassi D, et al. Explore (NY). 2019 Jul-Aug;15(4):283-290. doi: 10.1016/j.explore.2019.04.001. Epub 2019 Apr 6. Explore (NY). 2019. PMID: 31031095 Review.

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Belland L, Rivera-Reyes L, Hwang U. Belland L, et al. J Integr Med. 2017 Nov;15(6):450-455. doi: 10.1016/S2095-4964(17)60341-8. J Integr Med. 2017. PMID: 29103414 Clinical Trial.

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Jun J, Tucker S, Melnyk BM. Clinician Mental Health and Well-Being During Global Healthcare Crises: Evidence Learned From Prior Epidemics for COVID-19 Pandemic. Worldviews Evidence-Based Nurs. 2020;17(3):182-184. - PubMed

Bambi S, Iozzo P, Rasero L, Lucchini A. Covid-19 in critical care units: Rethinking the humanization of nursing care. Dimens Crit Care Nurs. 2020;39(5):239-241. - PubMed

Hu D, Kong Y, Li W, et al. Frontline nurses' burnout, anxiety, depression, and fear statuses and their associated factors during the COVID-19 outbreak in Wuhan, China: A large-scale cross-sectional study. EClinicalMedicine. 2020:24. - PMC - PubMed

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national center for biotechnology information

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The Listening to music tuned to 440 Hz versus 432 Hz to reduce anxiety and stress in emergency nurses during the COVID-19 pandemic: a double-blind, randomized controlled pilot study - PubMed

# data[].attributes.attachment_link.description
Listening to music at 432 Hz is a low cost and short intervention that can be a useful resource to manage anxiety and stress. Further studies are needed to assess medium and long-term effects of listening to music.

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Abstract

Poor mood and elevated anxiety are linked to increased incidence of disease. This study examined the effects of sound meditation, specifically Tibetan singing bowl meditation, on mood, anxiety, pain, and spiritual well-being. Sixty-two women and men (mean age 49.7 years) participated. As compared with pre-meditation, following the sound meditation participants reported significantly less tension, anger, fatigue, and depressed mood (all Ps <.001). Additionally, participants who were previously naïve to this type of meditation experienced a significantly greater reduction in tension compared with participants experienced in this meditation ( P < .001). Feeling of spiritual well-being significantly increased across all participants ( P < .001). Tibetan singing bowl meditation may be a feasible low-cost low technology intervention for reducing feelings of tension, anxiety, and depression, and increasing spiritual well-being. This meditation type may be especially useful in decreasing tension in individuals who have not previously practiced this form of meditation.

Keywords: Tibetan bowls, anxiety, depression, spiritual well-being

Heart disease, diabetes, addiction, and mental health issues have all been linked to stress and tension. Meditation, including systems such as mindfulness-based meditations, has shown promise in inducing the relaxation response and helping alleviate anxiety and improve well-being. The relaxation response is the body's physiological response in relaxation, including lowered blood pressure to counter the fight-or-flight response and activation of the parasympathetic nervous system. As promising as mindfulness and other meditation systems may be, a common complaint is the time, patience, and discipline required to learn meditation. Thus, a form of relaxation and stress relief that does not require a steep learning curve or a great deal of discipline to utilize could potentially be a huge benefit to human wellness and health.

The authors set out to examine the possibility that merely lying down and listening to the high-intensity, low-frequency combination of singing bowls, gongs, and bells in a sound meditation could induce a deep relaxation response and positively affect mood and sense of well-being. Sound healing has been used for centuries and been utilized in various forms by cultures the world over, including native peoples. Australian aboriginal tribes have used the didgeridoo as a sound healing instrument for over 40 000 years. Ancient instruments have also been used for religious and spiritual ceremonies such as Tibetan (also called "Himalayan") singing bowls. Tibetan singing bowls are metal bowls usually consisting of a combination of metal alloys and originally used by Tibetan monks for spiritual ceremonies.

While sound healing is not a new concept, there is a paucity of research in areas such as Tibetan or quartz crystal singing bowls. The majority of singing bowl studies relate to the physics of these musical instruments, including the sonic and wave properties, as well as attempting to model the singing bowl's acoustic characteristics. In one study, singing bowls were used for emotional healing with high-risk youth as part of what was termed the best self-visualization method. The bowls were used in a psychotherapy model in combination with deep breathing, visualization, and a loving kindness meditation. The authors reported that this combination of healing methods may be a catalyst for emotional and psychological healing in counseling sessions.

The purpose of the present study was to further advance research in this area by examining the possible effects of singing bowls and sound healing on mood, anxiety, physical pain, and spiritual well-being, and to lay the foundation for a future more formal randomized control trial.

Methods

Participants

A convenience sample of 62 individuals participated (age range, 21-77 years; mean age = 49.7 years, SD = 13.0; 9 males and 53 females). The study was conducted at 3 locations: the Seaside Center for Spiritual Living in Encinitas, California (17 participants), the Chopra Center for Wellbeing in Carlsbad, California (39 participants), and the California Institute for Human Science (CIHS) in Encinitas, California (6 subjects). All participants provided written informed consent. The study was approved by the University of California, San Diego Institutional Review Board (#160174). Demographic information is presented in .

Design

Participants completed standardized questionnaires prior to and following the meditation, including the short from of the Profile of Mood States (POMS-SF) to assess tension, anger and confusion, the Hospital Anxiety and Depression Scale (HADS) to assess depressed mood and anxiety, and the 10-item Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale (FACIT-SP) to assess spiritual well-being.

Additionally, prior to the meditation, participants completed a demographic questionnaire which included questions regarding any prior experience with meditation or singing bowls, substance use, medications, and over-the-counter or herbal supplements. Additionally, the form asked if they were currently experiencing any physical pain or discomfort. If they were experiencing physical pain, they were asked the type of pain, and to rate the pain on a scale of 1 to 5.

Following the meditation, participants completed a 2-item questionnaire that asked if they had fallen asleep and if they were currently experiencing any physical pain. If they were experiencing pain at that point, they were again asked to rate the pain level on a scale of 1 to 5.

Sound Meditation Protocol

Participants were instructed to bring yoga mats on which to lie down and if desired, a pillow and/or blanket for the sound meditation. Participants were asked to lie down in a half-circle or an oblong-shaped configuration (depending on the size of the room and number of participants) around the room with their heads pointed toward the musical instruments, which were placed on the floor near their heads.

The musical instruments consisted of Tibetan singing bowls, crystal singing bowls, gongs, Ting-shas (tiny cymbals), dorges (bells), didgeridoos, and other small bells. The majority of the Tibetan singing bowls (approximately 90%) consisted of large-sized Jambati bowls (bells), which ranged in size from 9 to 12 inches and ranged in weight from 3 to 5 lbs. Approximately 5% of singing bowls were very small Thadobati bowls, approximately 4.5 inches in size and weighing 0.5 lbs. The remaining 5% of singing bowls were very large Jambati bowls, ranging from 12 to 14 inches in size and weighing 6 to 8 lbs.

The singing bowls (bells) were the primary instrument played during the meditations, played for approximately 95% of the time, while the additional instruments were played for approximately 5% of the meditation session. The major method of creating sound and vibration from the singing bowls was by tapping or striking the bowls with a mallet, which was utilized approximately 95% of the time.

Between 30 and 80 Tibetan bowls, 2 and 3 crystal bowls, and 2 and 6 gongs were used depending on the number of participants. Thus, participants at CIHS and the Chopra Center listened to approximately 25 Tibetan bowls, 2 crystal bowls, and 2 gongs while participants at the Seaside Center listened to approximately 80 Tibetan bowls, 6 crystal bowls, and 6 gongs. Each participant had at least 2 Tibetan bowls near his or her head. The bowls were struck with a cloth-covered wooden mallet called a puja stick. The instruments were all played in a regular sequence: tingshas, Tibetan bowls, bells, crystal bowls, gongs, and more Tibetan bowls, then the sequence was repeated. The duration of the sound meditation was approximately 60 minutes.

Additionally, Tibetan (metal) bowls were placed in the center (or near-center) of the room and the bowls were in turn struck by the mallet or rubbed along the rim of the bowls, creating a distinctive sound, which was allowed to trail off. Additionally, several quartz crystal bowls were placed near the center of the room and were played by rubbing the rim with a felt cloth-covered mallet and the sound trailed off after playing the bowl.

At the beginning of the sound healing meditation, the lead musician spoke to participants in a soothing tone. He instructed participants to lie down and if they wished to fall asleep, they were allowed to do so. He then told them to merely observe any sensations they felt in the body during the meditation without judging them and to simply relax and enjoy the meditation. Then the sound meditation began.

At the conclusion of the meditation, the lead musician instructed participants to gently become aware of their surroundings. Participants were also instructed to take their time in readjusting to a state of awareness.

Data Analysis

Analyses included 2-way (group by time) repeated-measures analysis of variance [(Statistical Program for the Social Sciences (SPSS Version 22)]. Data were normally distributed.

Results

There were significant differences between pre- and posttreatment for all subscale variables on the POMS, HADS, and FACIT measures (). Eta-squared revealed a large effect size for all subscale variables, except the FACIT Faith subscale, which demonstrated a moderate to large effect size. An effect for these variables was also observed by age (see ). Individuals in the age group 20 to 39 years displayed the largest change in tension, with a mean score of 1.6 at baseline and a mean of 0.2 posttreatment, followed by those in the age group 40 to 59 years who had a tension mean of 1.3 at baseline and 0.2 posttreatment ( P < .05).

Table 2.

Table 3.

Additionally, effects for participants who had prior experience with singing bowl meditations (termed "Bowl Experienced") versus those who had never experienced this type of meditation previously (termed "Bowl Naïve") were examined (). Significant effects were observed for tension, anxiety, and depressed mood (all P s <.01).

Table 4.

In order to assess any potential effects of the sound meditations on participants' levels of physical pain, participants were asked if they were experiencing pain prior to and following the meditation. Twenty-nine participants reported experiencing physical pain pre-meditation. If experiencing pain, they were asked to rate their pain on a scale of 1 to 5 (1 representing "very slight discomfort" and 5 representing "extremely painful") and describe the pain and location on the body. displays the mean pain rating of participants (by age group) who reported pain at pre-meditation and their mean pain rating post-meditation. Participants aged 40 to 59 years showed the most significant effects from the meditation, with a reduction (or elimination) of feelings of physical pain post-meditation, with a baseline mean pain rating of 2.00 and a posttreatment mean pain rating of 0.79.

Table 5.

Additionally, physical pain pre- and posttreatment was examined for Bowl Experienced and Bowl Naïve participants (see ). Change (decrease) in reported pain was most significant for participants who were previously naïve to singing bowl meditations, with a mean score of 1.88 at baseline and 0.69 posttreatment.

Table 6.

Discussion

This was an observational study designed to examine the potential effects of a singing bowl meditation on mood, tension, anxiety, physical pain, and spiritual well-being. A significant difference was found in all endpoints examined in response to the meditation.

The tension subscale in particular displayed highly significant effects for participants post-meditation, thus providing support to the hypothesis that a sound meditation would increase feelings of relaxation and decrease feelings of stress. Additionally, depressed mood and anxiety scores on the HADS were significantly reduced post-meditation compared with pre-meditation. Moreover, scores on the FACIT revealed increased feelings of spiritual well-being, as well as faith, immediately following the sound meditation. Thus, while less desirable mood states such as tension, anger, and depression decreased following the meditation, potentially desirable variables such as a sense of spiritual well-being increased.

Interestingly, previous experience with singing bowl meditations (or lack thereof) also appeared to be a factor in the effects of the meditations. Participants who were previously naïve to this meditation demonstrated larger effects than those who were experienced in these meditations. An unexpected effect was discovered in the significant mean change in the tension subscale from baseline to posttreatment for participants in the age group 40 to 59 years. Those participants in this age group who were previously naïve to singing bowl meditations ("Bowl Naïve") had a significant reduction in mean tension from baseline to posttreatment, indicating a dramatic effect of the meditation. On the other hand, Bowl Experienced participants in the age group 20 to 39 years reported a significant reduction in the tension subscale posttreatment.

Participants aged 40 to 59 years appeared to especially benefit from the sound meditation. This age group demonstrated the largest reduction in physical pain and a strong reduction in tension, especially for those who were previously naïve to this type of meditation. Thus, a follow-up sound meditation study might examine this age group in more depth.

The reason(s) for the beneficial effects of singing bowls is unclear; however, various theories have been proposed. One theory includes the potential effects of binaural beats in which the brain entrains to the hertz difference between tones played in each ear, propelling the brain into brainwave states of deep relaxation, such as beta waves or even meditative or trance-like brainwave states in theta waves. In addition, potentially the action of sound waves on the purported biofield or energy field of the body could be a factor. Such theories may begin to characterize the potential effects on mood as well as physiological changes associated with singing bowls. Physical healing was the goal of a study that utilized blood pressure data in relation to a singing bowl. This study attempted to quantify the sonification of blood pressure through 3-dimensional imprinting, designing, and fabricating of a singing bowl using blood pressure data. Allen and Shealy examined the use of a single quartz crystal singing bowl on participants' electrodermal responses (the body's electric responses) to toning and playing the crystal bowl. The authors recorded electrodermal responses of forty acupuncture meridian points on participants' left hands and right feet, which demonstrated increases and decreases, respectively, in electrical responses to playing the crystal bowl. Another study examined the potential effects of quartz crystal bowl playing on perception of pain and revealed mixed results. In a recent randomized crossover study, playing a single Tibetan (or Himalayan) singing bowl was found to decrease blood pressure and heart rate more than silence alone when conducted immediately prior to a guided visualization. Participants who listened to the singing bowl also had lowered scores on the Positive and Negative Affect Schedule (PANAS), a measure of affect and mood than meditation alone but had comparable PANAS scores to the silence-only group.

There were limitations with the present study. The most notable limitation was that this was a nonrandomized observational study without a control group. The study does, however, provide the groundwork for future research regarding the effects of singing bowl meditations on assessments of stress and well-being. As discovered by Landry, this low-tech form of meditation may have the capacity to lower blood pressure and heart rate, thus there are potential benefits to cardiovascular health yet to be further explored. The results provide promise for a form of stress reduction that does not require the individual to learn a disciplined form of meditation. In fact, the participant may even fall asleep if desired. At the very least, participants generally express feelings of deep relaxation and inner peace following the sound meditation.

Moreover, those in health professions such as nurses and counselors could easily provide these meditations to patients. While it may require a very minimal amount of practice, extensive training is not necessary to learn to play the singing bowls and other instruments; one merely taps or rubs the bowls gently with a mallet. Thus, this type of meditation could be taught to health and counseling professionals and provided in an almost unlimited number of settings to induce the relaxation response, reduce stress, and potentially stress-related disease in the body.

In summary, this observational study found significant beneficial effects of Tibetan singing bowl meditations on a number of markers related to well-being. Future randomized control trials are warranted to further examine the effects of these meditations on mood, well-being, and physical pain. In addition, future research could explore the meditation's effects on various age groups in more depth.

Acknowledgments

The authors are grateful to Deep Deoja, the Nepalese musician who conducted the Singing Bowl Sound Meditations.

Footnotes

Author Contributions: TLG conceived of and designed the study and MEG provided ideas on initial design. PJM provided design help and selection of assessment tools. TLG and MMcW conducted the bulk of the study, with assistance from MEG. TLG and MEG conducted the majority of the data analyses with guidance from PJM. TLG and MEG provided the initial draft of the manuscript, of which PJM provided further writing and editing.

Declaration of Conflicting Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding: The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The work was supported by the University of California, San Diego Center of Excellence for Research and Training in Integrative Health.

Ethical Approval: The study was approved by the University of California, San Diego Institutional Review Board. All participants provided written informed consent.

References

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Effects of Singing Bowl Sound Meditation on Mood, Tension, and Well-being: An Observational Study

# data[].attributes.attachment_link.description
Poor mood and elevated anxiety are linked to increased incidence of disease. This study examined the effects of sound meditation, specifically Tibetan singing bowl meditation, on mood, anxiety, pain, and spiritual well-being. Sixty-two women and men (mean age 49.7 years) participated.

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Practice the 12-Minute Yoga Meditation Exercise - Alzheimer's Research & Prevention Foundation

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Kirtan Kriya (which is pronounced KEER-tun KREE-a) is a type of meditation from the Kundalini yoga tradition, which has been practiced for thousands of years. This meditation is sometimes called a singing exercise, as it involves singing the sounds, Saa Taa Naa Maa along with repetitive finger movements, or mudras.

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Abstract

Despite extensive research on various types of meditation, research on the neural correlates of religious chanting is in a nascent stage. Using multi-modal electrophysiological and neuroimaging methods, we illustrate that during religious chanting, the posterior cingulate cortex shows the largest decrease in eigenvector centrality, potentially due to regional endogenous generation of delta oscillations. Our data show that these functional effects are not due to peripheral cardiac or respiratory activity, nor due to implicit language processing. Finally, we suggest that the neurophysiological correlates of religious chanting are likely different from those of meditation and prayer, and would possibly induce distinctive psychotherapeutic effects.

Introduction

Religious chanting is as common in Eastern cultures as praying is in Western. It is generally presumed that religious chanting can quieten fears and transcend the mind, thereby helping individuals to cope with hardship. Nonetheless, the scientific studies on religious chanting are surprisingly scarce. The neurophysiological mechanisms underpinning the positive effect that religious chanting has been claimed to exert have not been illustrated by any decisive evidence. To fill this research gap, the present study combined advanced multi-modal electrophysiological and neuroimaging methods to investigate the neural correlates of chanting Amitābha Buddha2.

Chanting in faith of the Buddha Amitābha is the most widespread form of religious chanting and one of the oldest documented religious practices that are actively preserved to date. It can be performed in a number of languages, including the ancient Indic Prakrit and Sanskrit, as well as Chinese and Japanese5. Based on the Mahayana Buddhist belief of the Western Paradise, monks and laity from different Mahayana schools traditionally chant the name of Amitābha Buddha as a daily ritual in order to be reborn in the Western Paradise, also referred to as the Pure Land. The chanting consists of repetitively reciting the few syllables comprising the name of Buddha Amitābha, either silently or aloud, as often as possible (typically at least for a few minutes per day) for arbitrary durations6. Performing the ritual in a quiet or isolated space is not mandatory and believers may even chant internally in public or while in transit, as long as the chanting is performed with sincere faith and focus. In essence, the philosophy of the Buddha Amitābha is easy and welcoming with a promise that all those who sincerely call upon this name will be reborn in his Pure Land, a philosophy that is reflected in the simplicity and accessibility of its main practice7. In Buddhist scripture, Buddha Amitābha is a fantastic figure associated with infinite light and infinite life5, as well as the creator of a world of equality and compassion, the Pure land, where all his believers and sentient beings can be reborn and saved in fair conditions that favor attaining enlightenment. Although chanting regularly suffices for being considered a religious believer, according to prominent Buddhist thinkers, the longer and more intensely a believer engages in chanting Amitābha Buddha, the more probable it becomes to remain in sympathetic resonance with the Buddha's pure mind and to be reborn in the Pure Land8. Chanting Amitābha Buddha faithfully on a long-term basis has been reported to be an effective meditational technique that can elicit blissful sensations and transcendental experiences9.

Being a religious meditative practice, religious chanting can be regarded as both meditation and prayer. The majority of relevant neurophysiological studies have focused on mindfulness meditation and have mainly demonstrated increased alpha and theta waves1. Very slow delta waves have been observed in a few EEG studies on mindfulness meditation without consistent findings10. A previous study on mindfulness meditation has shown that mindful breathing can induce coordination between the brain and heart activity11. The cardiac rhythm can be modulated by several factors including the sinus node activity, respiratory rate, and more importantly, the autonomic nervous system. Mindfulness training has been shown to improve cardiac sympatho-vagal balance12.

Up to date, very few EEG studies have been performed on the equally relevant practice of religious praying. For example, Doufesh and colleagues conducted a series of EEG studies on Muslim prayer, revealing increased alpha waves in occipital and posterior brain regions, as well as increases in high frequency (HF) of heart rate variability (HRV)13. However, the experimental paradigm employed featured resting state instead of a sham-prayer control condition, making it difficult to rule out potential confounding effects due to implicit language processing during prayer. More importantly, the EEG analyses employed did not feature source localization and thereby did not shed any light on specific brain regions involved in the neural processes under investigation.

With relatively recent advances in source localization, high-density EEG combines high temporal resolution with improved spatial resolution14. The traditional approach of comparing EEG results averaged across participants for each electrode channel poses potential problems in measuring signals from mixed sources or even different sources, across participants, due to variability in brain anatomy and electrode positioning. The alternative method of computing group statistics based on clusters of independent components of brain activity overcomes such limitations. Through independent component analysis (ICA) the independent components (ICs; sometimes referred to as factors, latent variables or sources) are identified by minimising the mutual information of signal sources. These components can then be grouped across participants via independent component clustering and statistical tests can compare the power of different frequency bands across conditions. Frequency bands in signal sources reflect rhythmic brain activity and can be informative of different states of neuronal activity or denote transitions between different mental states17. The present study aimed to adopt this methodology to illustrate the neural correlates of religious chanting.

We hypothesized that, similarly to meditation, repetitive religious chanting would lead to significant changes in brain activity and that such changes could be detected in sources of interest using high-density EEG and spectral analysis. Moreover, due to the positive emotions ascribed to Amitābha Buddha we expected affective changes to occur during religious chanting, accompanied by changes in peripheral physiological measurements, including the multi-band HRV indices and respiration rate.

Results

The fMRI analysis suggested that the maximal difference in eigenvector centrality, during religious chanting compared to non-religious chanting, was in an approximately spherical cluster located in the posterior cingulate cortex (PCC) [volume = 81 mm ³; radius ~3 mm; mean = −0.86; SD = 0.01; max = −0.87; peak MNI coordinates = "0 -51 19"; Fig. 1a ]. This result was used to assess and confirm the soundness of the EEG independent component clustering, the results of which also featured a cluster in the PCC. Moreover, because the fMRI finding suggested that the PCC is the area decreasing most in centrality during religious chanting (in a highly trained meditator), the EEG IC cluster in the PCC was the cluster selected for more in-depth investigation.

The EEG independent component clustering analysis generated 7 IC clusters corresponding to sources of EEG activity (Fig. S1). One of these seven clusters was located in the PCC, similarly to the fMRI results. This cluster was chosen for further analysis. A one-way ANOVA revealed a significant main effect of chanting on the power of the delta-band (1-4 Hz) [F (2,93) = 3.25, p = 0.043] (Fig. 1c ). Further post hoc analysis showed significantly higher power (p = 0.011) during religious chanting (mean = 37.30; SD = 5.23) compared to non-religious chanting (mean = 33.45; SD = 7.85). The delta power of the no chanting resting state condition (mean = 35.74; SD = 4.70) did not differ from those of the two chanting conditions. The differences in power were not significant (p > 0.05) for the theta-band (4-8 Hz), alpha-band (8-12 Hz), beta-band (12-30 Hz), and gamma-band (30-45 Hz). The traditional electrode-based spectrum analysis that was computed for comparative purposes did not show any significant differences in EEG power during religious chanting, apart from a marginal trend in the vicinity of the PCC, and sporadically, in some frontal electrodes (Fig. S2).

One-way repeated measures ANOVA revealed no significant difference in mean inter-beat interval across the three conditions [F(2, 42) = 0.026; p = 0.975] (religious chanting: mean = 862.9, SD = 115.1; no chanting: mean = 862.8, SD = 108.4; non-religious chanting: mean = 860.9, SD = 111.1). ANOVA revealed significant main effects in HRV total power [TP, F(2,42) = 5.92; p = 0.005], absolute high-frequency power [HF, F(2,42) = 5.90; p = 0.006] and absolute very-low-frequency power [VLF, F(2,42) = 4.16; p = 0.019]. Post hoc testing with Bonferroni correction revealed that compared to no chanting, religious chanting induced lower total power (p = 0.009), lower absolute high-frequency power (p = 0.014) and lower absolute very-low-frequency power (p = 0.037). Interestingly, non-religious chanting showed no significant HRV difference with the other two conditions, thereby ruling out the possibility that the EEG delta-band difference observed was due to cardiac confounds. HRV findings are summarized in Fig. 1d , and descriptive statistics are detailed in Tables 1 - 3 . ANOVA revealed no significant difference in thoracic respiration [F(2,42) = 1.752; p = 0.186], nor in abdominal respiration [F(2,42) = 3.118; p = 0.055]. Descriptive statistics are detailed in Tables 4 - 5 .

Discussion

Combining multi-modal data, the present study illustrates neural and physiological mechanisms related to religious chanting. Religious chanting appears to increase endogenous neural oscillations in the low frequency delta-band, especially in the posterior cingulate cortex (PCC). This brain region shows the largest decrease in centrality during religious chanting in a highly-trained meditator. Such changes are not due to implicit language processes and are not attributable to differences in cardiac activity between religious and non-religious chanting. Nonetheless, religious chanting does influence cardiac activity significantly, compared to resting state.

Strong delta waves have been localized in several brain regions, including the posterior cingulate cortex, during slow-wave sleep18. Less strong delta oscillations are present during the awake state and have been suggested to modulate behavioral performance and memory processes19. Several EEG studies have found increased delta-band power due to meditation practices such as transcendental meditation1 and Qigong20. Increased delta activity in the medial prefrontal cortex was also found during Zen meditation and this may facilitate detaching from attending to one's immediate surroundings21. Delta waves have also been proposed to act as inhibitory brain oscillations that prevent sources of distraction from interfering with internally focused concentration22.

Accumulating evidence suggest that the increased delta wave in posterior regions, especially the PCC, is related to the reduction of self-oriented thoughts23 and the suspension of sensory monitoring24. Because during Amitābha Buddha chanting individuals focus on chanting the Buddha's name repeatedly, they experience fewer random thoughts and less mind-wandering. The increase of delta-band power in the PCC during religious chanting is a finding with important implications, especially in relation to current research efforts on meditation assisted by real-time neurofeedback25 and on controlling addiction craving24. It is worth noting that, ceteris paribus, endogenous generation of delta waves in the PCC during wakefulness would naturally lead to a de-synchronization of the PCC in relation to the rest of the brain, thereby explaining the decrease in centrality that was observed in the fMRI data. The increased delta-band power observed in the vicinity of the PCC cannot be attributed to peripheral physiological changes, as there was no difference in HRV and respiration between the religious chanting and non-religious chanting. To our knowledge, this is the first study of religious chanting or prayer that has used an active control condition (non-religious chanting), providing stricter control over confounding effects due to implicit language processing.

Religious chanting, as an active faith-based practice, overlaps with both meditation and prayer. Nevertheless, it comprises a unique, special case. Practitioners of religious chanting are encouraged to chant the name of the Buddha Amitābha as an object of meditation, while practicing the development of two equally important mental processes: samatha which corresponds to concentration and vipassana which corresponds to mindful observation2. During the chanting of Amitābha Buddha, the practitioner contemplates on the vow and compassion of the Buddha as a practice of vipassana. Such contemplation is meant to induce affective priming that helps the practitioner remain concentrated on the meditation object (the practice of samatha). By frequently practicing samatha and vipassana during religious chanting, advanced practitioners become able to combine these two aspects of the practice and reach a state called samadhi, during which both mental processes run in parallel. The present study corroborates evidence suggesting that the neurophysiological correlates of religious chanting are distinct from correlates of the extensively researched mindfulness meditation.

Mindfulness enhances alpha and theta power and in our previous EEG study on mindfulness-based stress reduction (MBSR), the alpha-band power increased while the delta-band power decreased during MBSR meditation, compared to the resting state11. Therefore, it appears that despite certain overlaps between mindfulness and spiritual prayer28, different forms of meditative practices are associated with different patterns of brain activity29. This implies that different religious or meditative practices may be more effective for the alleviation of specific neuropsychiatric symptoms; e.g. chanting Amitābha Buddha and relevant practices that increase delta-band power are likely to be beneficial to a wide range of patients suffering from sleep disorders. We suggest this to be the case because, apart from being the dominant frequency band during sleep30, delta-band power reflects the physiological tendency for sleep, by increasing due to sleep deprivation31 and decreasing following extended sleep32.

Similarly to sleep, delta-band activity has been suggested to comprise a universal response to injury or pathology33, due to its role for neural plasticity as well as for the integration of cerebral activity and homeostatic processes33. That is, mental states dominated by delta-band activity are considered as evolutionarily ancient states, in which compensatory and restorative mechanisms replenish biological resources in the brain and peripheral organs, resulting in beneficial effects encompassing biological and cognitive domains33. Variations in delta activity originate in the reticular formation35, which receives afferent inputs from all sensory systems and can reach the PCC through ascending, efferent connectivity, via the thalamus36. The loci of the PCC findings are close to the center of mass of the posterior default mode network (DMN)37. Although the fMRI finding is specific to the PCC, it suggests that at least part of the DMN is affected by religious chanting. Previous studies have independently shown that 53% of DMN functional connectivity variance is explained by delta-band power38 and that DMN activity is related to self-monitoring functions39. In this context, through the described mechanisms involving the suspension of modal brain activity, religious chanting appears to provide a streamlined procedure for the modulation of biological processes.

While our study on religious chanting found increased delta-band power during practice, one previous EEG study compared the Buddhist loving-kindness meditation (LKM) with Christian religious prayer and found that LKM practice was associated with increased delta, alpha and beta waves, whereas the practice of religious prayer was associated with increased alpha and gamma waves40. Thereby, it seems that the neurophysiological correlates of religious chanting may be different from those of meditation and religious praying. Future studies should address to what extent increased delta-band power in the PCC is common to all religious chanting (e.g. Byzantine chanting) or specific to love-kindness oriented Buddhist mantras. Moreover, it is important to investigate the extent to which specific practices (e.g. chanting, praying, meditating) can transcend cultural differences associated with specific religions.

Practitioners of Buddhist religious chanting concede that chanting Amitābha Buddha is usually accompanied by spiritual feelings of bliss and calmness, as well as visualizations of the 'splendid Pure Land' or 'Land of Bliss' referenced in the Buddhist scriptures2. Positive feelings and calmness nurture relaxation. This is in line with previous studies showing that prayer facilitates relaxation, which is accompanied by lower metabolism, lower breath rate and distinctive slow brain waves41. The emerging perspective suggests that praying may indeed counteract the physiological and psychological effects of stress and pain42.

In addition to the difference in brain activity, our results also showed that religious chanting can increase the stability of cardiac function, compared to the resting state. The HRV analysis is sensitive to changes in autonomic nervous system activity43. The reactivity of the autonomic nervous system, approximated through HRV changes, has been linked to positive and negative moods44. The observed decrease in HRV during religious chanting is a very plausible finding in the context of the accompanying feelings of spiritual bliss and emotional tranquility. Indeed, our previous study showed that mindfulness meditation can also induce similar cardiac effects26. According to the polyvagal theory, HRV indicates the modulation of cardiac activity by the autonomic nervous system and can reflect affective states, including increased stress45.

The different components of the HRV have been proposed to reflect modulatory effects from different sources. The VLF component and TP of the HRV were significantly lower during religious chanting, and more than half of the TP is accounted by the VLF component. The VLF component may partly reflect a fluctuation in activity of the renin-angiotensin system, which regulates the cardiovascular tone. The VLF component also reflects the peripheral chemoreceptors and the thermoregulatory mechanism46. The decreased VLF power during religious chanting may indicate a reduction of the cardiac defensive response and general systemic stress level. It is worth noting that the relation of HRV to cardiac vagal effects is not linear. Respiratory activity can also influence the VLF component of HRV, especially in patients with chronic heart failure47. However, in the present study we did not find that religious chanting had any effect on respiration.

The power of the HF component of HRV decreased during religious chanting compared to the resting state, while the HF power during non-religious chanting showed a similar trend but did not differ significantly from the HF power of the resting state. HF power is associated with respiratory sinus arrhythmia which is mainly modulated by the nucleus ambiguus activity. In fact, the HF component of the HRV reflects the magnitude of fluctuation in the modulation of cardiac activity by the parasympathetic nervous system48. May and colleagues have shown that a mindfulness meditation intervention can also positively modulate cardiovascular function by decreasing cardiac sympathovagal tone, ventricular workload and vascular resistance49.

Due to the monotonous repetition of the brief chant and the ability of experienced meditators to effectively enter the meditational mental state at will, the associated brain activation is assumed to be relatively homogeneous across a meditative session, especially when lasting only a few minutes. Therefore, the EEG and fMRI versions of the paradigm can be considered equivalent, despite minor differences in the length of experimental trials between the fMRI conditions and between the two neuroimaging modalities. A possible limitation of the present study is that the fMRI and EEG data were acquired from different subjects, with considerable differences in religious chanting experience. For future research, we hypothesize that replicating the present study with a sample comprised of Buddhist monastics would yield similar results with stronger effect sizes, whereas replicating the present study with a sample comprised of non-believers would result in no significant difference between chanting conditions.

The lack of cognitive and affective ratings, with regards to either the effect of each experimental condition or the overall psychometric evaluation of each participant, is another potential shortcoming of the present study. Future studies should include the acquisition of such data, with regards to which we hypothesize that the effects reported herein would correlate positively with positive affect and negatively with the level of self-referential cognition. Further, we recommend that future studies acquire EEG data in an electromagnetically shielded EEG cabin, with a high sampling rate (e.g. 5000 Hz), to enable analysis of high gamma band activity as well.

In conclusion, compared to non-religious chanting, the PCC decreases in centrality due to a regional increase in endogenous generation of delta oscillations. These functional effects are not due to peripheral cardiac or respiratory activity, nor due to implicit language processing, and are associated to feelings of transcendental bliss and decreased self-oriented cognition. Compared to the resting state, religious chanting increases the stability of cardiac activity, reflecting enhanced stability in the regulation of cardiovascular tone and the parasympathetic modulation of cardiac function. Such physiological changes illustrate the mechanisms through which relaxing meditative practices exert positive stress-reducing effects. The neurophysiological correlates of religious chanting are somewhat different from those of mindfulness meditation and those of other types of religious prayer and future research should address the replicability and specificity of the neurophysiological effects of different religious and meditative practices, as well as their differential suitability as psychological interventions. Research in this field is still in a nascent stage and the tentative interpretations offered here can serve to provide several hypotheses for future research.

Materials and Methods

Participants

Twenty-two participants with at least one year of meditative experience in religiously chanting Amitābha Buddha, for at least 15 minutes per day, participated in the EEG/ECG study. The age range was 40 to 52 years old (mean = 46.5; SD = 2.6; 12 females). One participant's ECG data were usable but his EEG data were dropped due to operational error. One additional 43-year old female participant, who was a highly trained meditator by virtue of being a Bhikṣuṇī Buddhist monastic, participated in an fMRI case study measurement using the same paradigm. All participants were free from any neurological, psychiatric or other mental disorder. Ethical approval was granted by the Human Research Ethics Committee of the University of Hong Kong, and this research was performed in accordance with relevant guidelines/regulations. All participants signed an informed consent form prior to participation in the experiment.

Procedure

The experimental paradigm consisted of two parts. The first part featured a perceptual task that was published elsewhere26, and only the second part is described herein. All participants underwent three conditions in random order. The experimental condition consisted of mentally chanting Amitābha Buddha (religious chanting condition); that is participants chanted internally, silently and without any movement of the lips. It is worth noting that this type of internal, silent chanting is also a relatively common Buddhist practice, particularly when meditative moments are sought while being in public places (e.g. while waiting at an airport or train station). Resting state without chanting was used as a control condition (no chanting condition), similarly to a previous study13. During resting state, subjects maintained their eyes closed, similarly as during chanting. Additionally, to control for the potential effect of implicit language processes, a second control condition was employed, featuring mental chanting of the Santa Claus (non-religious chanting condition). Both chants comprised of four Chinese characters (阿彌陀佛 and 聖誕老人) and were comparable in terms of linguistic complexity. Approximate phonological representations of the two chants were [æ mʃ tæ fæ], corresponding to "Amitābha (Buddha)" and [ɪɛn dæn laʊ rɛn] corresponding to "Santa Claus old man". Both figures referred to in the chants are generally considered as supernatural and carry solely positive connotations, even for atheists, in popular culture, thereby controlling the objective affective content across the two conditions. EEG data analysis featured standard preprocessing, independent component analysis, and independent component clustering. FMRI data were used for eigenvector centrality mapping50. ECG and respiratory data were subjected to heart rate variability analysis.

EEG data

EEG data were acquired during all conditions in a quiet EEG laboratory room, in the presence of one researcher, using a 128-channel EGI TM system (Electrical Geodesics, Inc. USA). The impedances of all electrodes remained below 30 KΩ, in accordance with the requirements of the EGI system. The sampling rate of the EEG data was 1000 Hz. Each EEG condition, including the resting-state lasted 10 minutes. EEG data were processed and analyzed using the EEGLAB toolbox51 ( https://sccn.ucsd.edu/eeglab/) and Matlab 11.0 (MathWorks Inc. USA). In the preprocessing stage, the EEG data were resampled to 250 Hz and band-pass filtered by a finite impulse response filter between 0.1-100 Hz. To reduce artifacts caused by alternating current, data were additionally notch filtered by a short nonlinear infinite impulse response filter with a band-stop range between 47-53 Hz. Following visual inspection, segments of low data quality due to artifacts were deleted, while bad channels were reconstructed using spherical interpolation of the signals. Independent Component Analysis (ICA) was used to remove components due to eye movement, blinking, and other artifacts. Data were reconstructed from the retained components.

Using EEGLAB, the similarity of independent components (ICs) was estimated and similar components were grouped together into functionally equivalent clusters. Comparisons between conditions were based on major clusters rather than single channels. First, for each subject, ICA was performed on the data from each condition to generate ICs. Then, the dipole locations of each IC were generated using the DIPFIT2 (EEGLAB plug-in) function. IC clusters were generated by k-means clustering based on similar dipole location (weight: 2/3) and power spectrum (weight: 1/3). The weight distribution was chosen based on the assumption that functionally similar components should have similar spatial location and power activity. The outlier threshold was set at 2.5 standard deviations (SD). The clustering procedure was repeated more than 10 times, each time with a different k parameter setting. Six to twenty clusters were generated and the k parameter setting that generated the most distinctive clusters was identified, ensuring that the clusters were consistently generated under different k parameter settings. This procedure finally resulted in seven IC clusters. Spectrum analysis and a one-way ANOVA were performed on all major frequency bands, using the ICs from a specific cluster of interest (as well as using the traditional electrode channel approach, for comparative purposes).

MRI data

To identify ICs that are most influential, the same paradigm was used to acquire fMRI data from an additional participant with long-term experience of religious chanting by virtue of being an experienced Buddhist monastic. Scanning was performed with a 3.0 T Philips MRI scanner. First, a T1-weighted scanning sequence was acquired, featuring the following parameters: FoV = 256 × 150 × 240 mm, acquisition matrix = 256 × 256, TR = 15 ms, TE = 3.26 ms, flip angle = 25°, slice thickness = 1.5 mm, number of slices = 100, voxel resolution (x,y,z,) = 0.94 × 1 × 1.5 mm. FMRI images were obtained with gradient echo-planar imaging (EPI), with an 8-channel SENSE head coil, featuring FoV = 230 × 140 × 230 mm, acquisition matrix = 64 × 64, TR = 2000 ms, TE = 30 ms, flip angle = 90°, number of slices = 32, slice thickness = 3 mm, and slice gap = 1.5 mm. In total, 688 dynamic volumes were acquired, comprising the 3 conditions: religious chanting (243 dynamic volumes; duration 8.1 minutes), non-religious chanting (243 dynamic volumes; duration of 8.1 minutes) and resting state (202 dynamic volumes; duration 6.7 minutes). The resting-state acquisition was shorter due to scanning time constraints and because the resting-state condition was only meant to be used as a neutral baseline, to establish the directionality of any potentially ambiguous findings.

FMRI data were processed using the Leipzig Image Processing and Statistical Inference Algorithms52 (LIPSIA; version 2.2.7 - released in May 2011). Pre-processing consisted of slice time correction, movement correction, spatial smoothing with FWHM = 6 mm, affine non-linear normalization to MNI space, and regression of covariates of no interest (global mean and movement parameters). Eigenvector centrality mapping (ECM) was used to investigate whole-brain functional connectomics. ECM is a graph theory method, which can identify the most influential nodes of a network50. The long and continuous conditions of the paradigm were particularly suited for ECM, which was applied similarly to a previous study on the neural correlates of emotion elicited through continuous musical stimulation53. One ECM map was computed for each of the two chanting conditions (i.e. religious chanting and non-religious chanting) and the two conditions were compared via a 1 st-level contrast. The resulting ECM difference map was incrementally thresholded until only the region with the greatest difference in ECM between the two conditions remained (|z| > 0.85). The explorative results of the fMRI analysis were used to confirm the validity of the Independent Component Clustering results, as well as to guide the selection of a specific IC cluster for more detailed investigation.

ECG and respiratory data

Physiological data of cardiac and respiratory activity were collected using the ADInstrument's PowerLab system ( www.adinstruments.com/products/powerlab). Breath intervals, representing thoracic and abdominal respiratory activity, were computed for each participant and each condition, using Matlab. Raw ECG data were cleaned via a Butterworth band pass filter and the inter-beat-interval (IBI) was extracted following the replacement of outliers (3 standard deviation away from the mean) via spline interpolation. Using the HRVAS toolbox ( https://sourceforge.net/projects/hrvas), the IBI data were detrended and the time/frequency domain features of the HRV were computed. Frequency ranges for the VLF, LF, and HF bands were set to 0-0.04 Hz, 0.04-0.15 Hz, and 0.15-0.4 Hz respectively. The power of these frequency bands was estimated using the Lomb-Scargle periodogram. Derived HRV metrics were subjected to statistical testing using SPSS 24.0. One-way repeated measures ANOVA and post hoc tests (where applicable) were used to assess differences between conditions. The alpha level of significance was set at 0.05.

Supplementary information

Acknowledgements

We want to thank the participants and the funder. The research is supported by the Small Project Funding in the University of Hong Kong. The award number is SPF201209176152.

Author Contributions

J.G. designed and executed the study, analyzed and interpreted the data, collaborated in manuscript writing. H.K.L. analyzed and interpreted the E.E.G. and H.R.V. data, collaborated in manuscript writing. B.W.Y.W. assisted design and manuscript writing. S.S. analyzed and interpreted the fMRI data, collaborated in manuscript writing. H.H.S. collaborated on design and direction of the study.

Data Availability

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

Notes

Competing Interests

The authors declare no competing interests.

Footnotes

Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary information accompanies this paper at 10.1038/s41598-019-40200-w.

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The neurophysiological correlates of religious chanting

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Despite extensive research on various types of meditation, research on the neural correlates of religious chanting is in a nascent stage. Using multi-modal electrophysiological and neuroimaging methods, we illustrate that during religious chanting, the ...

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Kirtan: The Easy Meditation That Can Improve Your Brain

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New research shows that sleep, cognitive performance, and mood are significantly improved with a simple type of meditation you've probably never heard of.

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IMPROVE MOOD, BRAIN HEALTH,SLEEP AND QUALITY OF LIFE

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IMPROVE MOOD, BRAIN HEALTH,SLEEP AND QUALITY OF LIFE

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IMPROVE MOOD, BRAIN HEALTH, SLEEP AND QUALITY OF LIFE

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IMPROVE MOOD, BRAIN HEALTH, SLEEP AND QUALITY OF LIFE

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IMPROVE MOOD, BRAIN HEALTH, SLEEP AND QUALITY OF LIFE

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IMPROVE MOOD, BRAIN HEALTH, SLEEP AND QUALITY OF LIFE

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Barbara Koltuska-Haskin, Ph.D., is a neuropsychologist in Albuquerque, New Mexico and the author of How My Brain Works.

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Can the Sounds of Nature Help Heal Our Body and Brain?

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Listening to the sounds of nature may facilitate physical and mental healing.