Experienced Meditators Show Enhanced Interaction between Brain and Heart Functioning

Abstract

Objectives Regulation of the heart by the brain is a vital function of the autonomic nervous system (ANS), and healthy ANS function has been linked to a wide range of well-being measures. Although there is evidence of mindfulness-meditation related changes to brain functioning and heart functioning independently, few studies have examined the interaction between the brain and heart in experienced meditators. Methods This study compared measures of the brain-heart relationship between 37 experienced meditators and 35 non-meditators (healthy controls) using three different analysis methods: 1) the heartbeat evoked potential (HEP; thought to reflect neural sensitivity to interoceptive feedback); 2) the relationship between fronto-midline theta neural oscillations (fm-theta) and the root mean square of successive differences (RMSSD) in electrocardiogram activity (an estimate of vagally-mediated heart rate variability); and 3) the correlation between heart rate wavelet entropy and electroencephalographic wavelet entropy – a measure of signal complexity. Results The HEP analysis indicated that meditators showed a more central-posterior distribution of neural activity time-locked to the heartbeat (p < .001, partial η² = .06) than controls. A significant positive relationship was also found between fm-theta and RMSSD in meditators (F(2,34) = 4.18, p = .02, R2 = .2) but not controls. No significant relationship was found between EEG entropy and ECG entropy in either group. Conclusions The altered distribution of evoked neural activity, and the correlation between brain and heart biomarkers of vagal activity suggests greater neural regulation and perhaps greater sensitivity to interoceptive signals in experienced meditators.