Increased neurocardiological interplay after mindfulness meditation: a brain oscillation-based approach

Author: Junling Gao1, Rui Sun2, Hang Kin Leung1, Adam Roberts3, Bonnie Wai Yan Wu1, Eric W Tsang2, Andrew C W Tang4, Hin Hung Sik1
Affiliation: <sup>1</sup> Buddhist Practices and Counselling Science Lab, Centre of Buddhist Studies, The University of Hong Kong, Hong Kong, Hong Kong SAR, China. <sup>2</sup> Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China. <sup>3</sup> Singapore-ETH Centre, Future Resilient Systems Programme, Singapore, Singapore. <sup>4</sup> Department of Psychology, HKU School of Professional and Continuing Education, Hong Kong, Hong Kong SAR, China.
Conference/Journal: Front Hum Neurosci
Date published: 2023 Jun 19
Other: Volume ID: 17 , Pages: 1008490 , Special Notes: doi: 10.3389/fnhum.2023.1008490. , Word Count: 273

Brain oscillations facilitate interaction within the brain network and between the brain and heart activities, and the alpha wave, as a prominent brain oscillation, plays a major role in these coherent activities. We hypothesize that mindfully breathing can make the brain and heart activities more coherent in terms of increased connectivity between the electroencephalogram (EEG) and electrocardiogram (ECG) signals.

Eleven participants (28-52 years) attended 8 weeks of Mindfulness Based Stress Reduction (MBSR) training. EEG and ECG data of two states of mindful breathing and rest, both eye-closed, were recorded before and after the training. EEGLAB was used to analyze the alpha band (8-12 Hz) power, alpha peak frequency (APF), peak power and coherence. FMRIB toolbox was used to extract the ECG data. Heart coherence (HC) and heartbeat evoked potential (HEP) were calculated for further correlation analysis.

After 8 weeks of MBSR training, the correlation between APF and HC increased significantly in the middle frontal region and bilateral temporal regions. The correlation between alpha coherence and heart coherence had similar changes, while alpha peak power did not reflect such changes. In contrast, spectrum analysis alone did not show difference before and after MBSR training.

The brain works in rhythmic oscillation, and this rhythmic connection becomes more coherent with cardiac activity after 8 weeks of MBSR training. Individual APF is relatively stable and its interplay with cardiac activity may be a more sensitive index than power spectrum by monitoring the brain-heart connection. This preliminary study has important implications for the neuroscientific measurement of meditative practice.

Keywords: alpha peak frequency; brain-heart connection; effective connectivity; heart coherence; mindfulness meditation; resting-state EEG.

PMID: 37405324 PMCID: PMC10315629 DOI: 10.3389/fnhum.2023.1008490