When I meditate, I get this hard-to-describe feeling in the back of my head/neck/spine. It is the same feeling I get when I listen to some really good music, I see a really beautiful sight, or I read a heart-moving story. It is a physical sensation, and it feels like a slow-moving energetic presence rolling through my body. Typically, it starts at the back of my head and moves gradually down my neck/back. It reminds me of electricity (though I'm not exactly sure why), and it feels good. Sometimes when the feeling is strong I am moved to tears. As it travels through my head it is often accompanied by a rushing sensation in my ears. I am somewhat able to control the feeling in that I can summon it with certain breathing patterns and visualization exercises, but my control of it is inconsistent and oftentimes the energy comes through spontaneously.
What is this feeling? Is it Kundalini or Tummo or something like that? How can I improve my understanding of it, and my skill at manipulating it?
Many thanks to any responses.