Neurophysiological and autonomic patterns associated with heartfulness and bell meditation: a three-arm exploratory...

Meditation facilitates brain-body integration by synchronizing neural oscillations with autonomic rhythms. Nonetheless, the effects of heartfulness (heart-centered) and bell (sound-based) meditation on electroencephalography (EEG) and autonomic markers remain insufficiently explored. In this randomized, exploratory pilot study, nine healthy male university students were allocated to the heartfulness meditation group (HMG; n = 3), bell meditation group (BMG; n = 3), or control group (CG; n = 3) for 21 days (30 min per session, 5 days per week). Resting EEG gamma and low-beta activity (12-15 Hz), blood volume pulse (BVP)-derived heart rate (HR), and heart-rate variability (HRV) indices, including low-frequency percentage (LF%) and HRV amplitude, were recorded both pre- and post-intervention. The analyses were descriptive and summarized using Hedges' g and 95% confidence intervals (CIs). The HMG exhibited exhibited observed increases in gamma and low-beta (g ≈ 1.0-2.3), the BMG demonstrated a very observed low-beta activity increase with a small gamma change, and the CG showed minimal change in both parameters. HR decreased across all groups, LF% declined in the HMG and BMG but increased in the CG, and HRV amplitude decreased in all groups. These preliminary observations indicate a potential trend toward neural-autonomic regulation, with heartfulness emphasizing attentional engagement and bell emphasizing relaxation. The limitations include the very small, male-only sample, brief duration, and reliance on BVP-derived HRV. Larger, adequately powered trials with more comprehensive EEG/HRV metrics and behavioral outcomes are required to confirm these findings.