The closest I've come to anything like this, is every now and then, when I'm in bed. It either happens after I close my eyes, but right before I start dosing off, or it would happen not long after I'd dosed off, but wake back up, then close my eyes again. Anyway, while my eyes are closed (while not fully sleep), I'd begin seeing the most demonic looking cartooinsh images that would come too mind. I would have to stay up awhile, then fall back to sleep later after my mind was clear. This don't happen alot. As a matter of fact, I can count on one hand how many times I've experience this...well, maybe two hands. I didn't know other people experienced this, until I read it one day.