Hello Alice-vic! Thank you for responding. I posted several places but got the most response from the Buddhists, who informed me repeatedly that proper Buddhist meditation involves observing but not controlling the breath. The practice of breath control is more yogic. It is my experience that after a while I do not need to focus on the breath anymore, just as using a mantra grounds me and then I do not need it anymore. Both serve the same purpose: to anchor the mind on something so that it does not wander in thought.

I have learned more about the nerves and I will add to the original post with what I have learned about the breathing centers in the medulla and pons.

I will follow your name link and find out more about you if I can. Where do you live? What language(s) do you speak? Your English is good.