Sleep Recordings from Wearable Devices in Meditators

Abstract

The dataset comes from a study assessing the impact of meditation on sleep quality and brain health.

DESIGN: A prospective single-site cohort study (conducted August 25th, 2021, through September 26th, 2021) of meditators attending a retreat at the Isha Institute of Inner Sciences, McMinnville, Tennessee.

PARTICIPANTS: Current U.S. adult residents attending Isha Institute’s “Samyama Sadhana” retreat (September 1st-5th, 2021) were contacted before the program. 34 of 35 enrolled participants in this volunteer sample are included in the analysis; one subject withdrew following the retreat. Two healthy comparison groups and four comparison groups with varying degrees of age-related brain pathology are included.

Background

Worldwide cases of dementia and age-related cognitive decline are escalating due to increased life expectancy, placing greater burden on healthcare systems. Meditation appears to improve brain health. Magnetic Resonance Imaging (MRI) studies claim beneficial effects of meditation on brain health, associated with structural changes in gray and white matter. Mindfulness meditation may increase neural synchrony and coherence. Some researchers hypothesize these effects are related to improved sleep quality and efficiency. A scholarly review of 3,303 records, with 18 trials and 1,654 participants, researchers found moderate support that mindfulness meditation improves sleep quality.

Brain age (BA) estimates the biological age of the brain, calculated by comparing measurements of brain structure or function with age norms and selecting the age that matches best. Brain age index (BAI) is the difference between BA and chronologic age (CA); that is, BAI = BA - CA. BAI has been calculated using structural measurements from MRI and functional measurements of overnight sleep electroencephalography (EEG). Increased sleep-EEG-based BAI is a predictor of increased mortality and is elevated in chronic diseases affecting brain health including hypertension and diabetes, HIV infection,  and neurodegenerative disease. In contrast, long-term meditation has been associated with reduced brain aging in MRI studies. In 2016, researchers estimated that at age 50, the MRI-based BAI of long-term meditators were 7.5 years younger than controls. EEG changes have been identified in advanced meditators, although sleep-EEG measures of BA have not been reported for this population.

Our research aimed to measure sleep BA in a cohort of advanced meditators compared to control populations. We hypothesized sleep BAI would be lower in the meditation group, which would correlate with higher scores on cognition tests.

Methods

Cohort:

This single-site prospective cohort study aimed to track sleep quality and brain health in a sample (n = 35) of advanced meditators within one week prior and three weeks following a silent meditation retreat. Participants scheduled to attend the “Samyama Sadhana” retreat from September 1st to 5th, 2021, at the Isha Institute of Inner Sciences, McMinnville, Tennessee, were contacted by researchers at Massachusetts General Hospital (MGH). Inclusion criteria were (1) 18 years or older; (2) current U.S. resident; (3) previous experience attending the 8-day “Samyama” retreat; and (4) attending the “Samyama Sadhana” retreat. Participants reported no existing insomnia and were not currently taking antidepressants, benzodiazepines, neuroleptics, or opiates. One participant self-reported mild sleep apnea without use of CPAP/BiPAP machines as treatment.

This study was approved by the Institutional Review Board (IRB) at MGH, including the participation of members at Beth Israel Deaconess Medical Center (BIDMC) for data analysis. The Mass General Brigham Human Research Committee approved the use of verbal consent due to minimal risk to participants.

Study Procedures:

Meditation: Samyama is an intensive 8-day residential program involving long hours of silent meditation. Samyama Sadhana is a shortened version of Samyama last 4 days for previous attendees of the Samyama program who want to refresh or boost their practice and experience.

Sleep-EEG recording: We measured the sleep-EEG of meditators using the Dreem headband, worn for up to four consecutive nights both before and after the retreat.  For pre-retreat sleep-EEG’s, two participants had four nights, fourteen had three nights, seven had two nights, eight had one night, and three had none. For post-retreat sleep-EEGs, five participants had four nights, fifteen had three nights, seven had two nights, three had one night, and four had none. Recordings shorter than three hours or longer than ten hours, containing more than 50% artifact, or at unusual sleep times (4am to 6pm) were excluded from analysis.

Data Description

Dataset is de-identified. The format is EDF format.

Usage Notes

See GitHub repo: https://github.com/bdsp-core/meditation-sleep-brain-age.

Ethics

 In this dataset, all data were anonymized with all identifiable patient information removed. The MGB IRB approval number is 2021P002264.

Acknowledgements

Dr. Westover's lab was supported by grants from the NIH (R01NS102190, R01NS102574, R01NS107291, RF1AG064312, RF1NS120947, R01AG073410, R01HL161253, R01NS126282, R01AG073598), and NSF (2014431). Dr. Subramaniam’s lab is funded by grants (AG065554; 3AG065554-EEG administrative supplement) and organizations (MASIMO, Inc; Merck, Inc; Wishing Wellness Foundation). We would like to thank the Dreem company and especially Alexandre Chouraki for providing deidentified results from one of their studies, which was used as the Dreem Healthy Control Cohort for this study.

Conflicts of Interest

Dr. Westover is a co-founder and holds equity in Beacon Biosignals and receives royalties for authoring Pocket Neurology from Wolters Kluwer and Atlas of Intensive Care Quantitative EEG by Demos Medical; these entities played no role in the present work. Dr. Pierrick Arnal was an employee of Dreem when the study was done. Sun reports no conflicts of interest to disclose. None of the other authors have any conflicts of interest to disclose.