
I think that might happen because you're disconnected from your body.
That's an experience I've only been able to trigger recently while stretching in the mornings.
When it happens, I blank out and remember nothing but pure thoughts for who knows how long, probably only a few seconds though, then I reconnect with my senses first and can notice that I'm lying on the floor twitching and unable to really control my body at all. Until I fully reconnect and can control my body again.
I've been doing some experimenting on it and now usually manage to lie down on the floor before I disconnect. Still haven't gotten the hang on recalling much though. But I guess it's the closest thing to having a trip I'll ever feel.

Let's see, my sense of time is still distorted during the reconnection, but I fingure it must be a minute or so during which I'm already connected to my senses, but not the rest of my body, though I can accelerate the speed of reconnection now by sort of seizing it.

I really don't think it has anything to do with demons, jsut you spirit seperating from your body for a short bit. Maybe that's what happens when you wake up too. Your spirit still hasn't quite arrived back from the river of dreams, so you're only partially reconnected.