It's called sleep paralysis. It happens when your consciousness is awake and your body is asleep, not just deeply relaxed, but totally asleep. I think the vibrations would best described as energy.
Do you realize that were only a few steps away to have an OBE (Out of Body Experience), also called Astral Projection?
If you don't know what the heck I'm talking about and would like to know more, let me know!
