Mindfulness meditation acutely increases frontal theta brain activity during practice, but long-term practitioners show lower trait frontal theta activity compared to short-term practitioners. This lower baseline activity may reflect expert meditators' ability to limit unnecessary information processing and enhance awareness of present experience. The acute theta increases during meditation appear related to concentration rather than mindfulness specifically. Twenty participants were studied, including ten experienced Buddhist meditators.
Heart rate variability (HRV) differs among practitioners of Zen meditation (Zazen) depending on their level of experience. Nineteen subjects with varying experience participated; in four cases both HRV and respiration were recorded. Analysis using frequency-domain methods and continuous wavelet transform showed that shifts in respiratory sinus arrhythmia (RSA) reflect differing levels of practice. The modulation of RSA may indicate changes in breathing patterns and parasympathetic outflow related to attention quality and focus in each stage of meditation.