In university students with no prior meditation experience, 21 days of bell meditation produced a large reduction in sympathetic arousal, as measured by galvanic skin response, while heartfulness meditation produced only modest autonomic changes and neither meditation style significantly altered resting brainwave patterns. The study compared nine students randomly assigned to heartfulness, bell, or a passive control group. Bell meditation reduced GSR by 3.90 microsiemens, compared to a 0.63 microsiemens reduction for heartfulness and 0.19 for controls. No adverse events occurred. The findings suggest distinct meditation techniques affect autonomic nervous system activity differently, with bell meditation showing a marked early calming effect.
A small pilot study compared heartfulness meditation, bell meditation, and a control condition in nine healthy male university students over 21 days. Heartfulness meditation was associated with observed increases in gamma and low-beta brain activity, while bell meditation showed a small increase in low-beta activity with minimal gamma change. Heart rate decreased across all groups. Heart-rate variability measures showed declines in low-frequency percentage for both meditation groups but an increase in the control group, and HRV amplitude decreased in all groups. These preliminary observations suggest potential trends toward neural-autonomic regulation, with heartfulness emphasizing attentional engagement and bell emphasizing relaxation, but the very small sample size and brief duration limit confidence.