Though think about this, as your thalamus filtering mechanism is "switched off", and as serotonin temporarily looses its rather repressive control over the conscious state, you would technically be far more receptive to novel information from the outside...like I said, you are bombarded with billions of signals, billions of kinds of them as well, every second, now all of these, except for smell, enter your brain through the thalamus, which filters them before they are sent to the cortex regions, on psychedelics the thalamus eases up on its filtering, so I suppose you are getting information from the outside that you would not otherwise.
I also feel that in accordance with The many-worlds interpretation of quantum mechanics that there could be infinite alternate "lines"...
The quantum-mechanical "Schrödinger's cat" theorem according to the many-worlds interpretation. In this interpretation, every event is a branch point; the cat is both alive and dead, even before the box is opened, but the "alive" and "dead" cats are in different branches of the universe, both of which are equally real, but which do not interact with each other. -Wikipedia
Multiverse theory also makes some interesting claims...
Perhaps we do encounter entities from these other dimensions, perhaps when the conscious-being leaves it's physical body it's migrates into one of these other dimentions... it appears that physical objects can not cross the barrier, but consciousness and information can, and all consciousness traversing these dimensions are apparently using the same "highways" so extra-terrestrials, dead people, Gods and deities, and conscious-beings from other dimensional plains may all collide in these spaces...
-eg