What is this sort of out of body feeling i get sometimes?

once in a blue moon i get this really wierd feeling. this time i was experimenting with the ganzfeld effect (if you dont know what that is, look it up) and it was like i was dreaming with my eyes open. and after i while i got this feeling that i have gotten a few times in my life, and its hard to describe, but it kind of feels like my body is shrinking into stick figure size, and like when i interlock my fingers my fingers feel really thin, and when i grasp something really thin between my fingers, such as headphone wire, it feels really thick. what is this? or at least what would you call this?