yes it all stems from heartrate. monks use this in meditation, also why meditation is so effective. another unknown, well more known now is gut biome also, regarding meditation, pray is a form of meditation. just a quick link to show im not full of poo... https://www.stressresilientmind.co.uk/articles/heart-rate-coherence-during-meditation#:~:text=Not%20all%20monks%20showed%20the,some%20faster%20but%20still%20regularly. >The monks in the study showed this coherence effect, which is seen as a clear peak in the spectral analysis graph of the heart rate data. Not all monks showed the peak at around 6 bpm, though most of them did. My interpretation of this is there is a synchronisation between the breath and the "heart wave", but there is variability in the actual breathing rate - most breathing slowly and regularly at around 6 bpm, and some faster but still regularly.