[jheriko]

i think there are studies on the much broader range of phenomena associated with meditation in general. its hard to find good examples of such things quickly with google though because there are a large number of poor quality studies too...

i don't think its particularly crazy to suggest that people practising mental discipline can alter their minds or perceptions.

its very easy to convince oneself that the left arm is paralysed for instance... or to hallucinate by fixating on an object or point in space.

also, its very well evidenced that psychology has an effect on health...

on the other hand there is no evidence of, nor any need for explanations involving, "mystical energies" of any kind, as far as i can see.