A recent study of people who had near-death experiences (NDEs) found that those people were more likely to have had incidents where dreaming and wakefulness intertwined to some degree. I’ve had exactly that kind of “waking dream” experience myself, and I’ve found it to be a most unpleasant state. Despite—or maybe because—it’s such an uncomfortable occurrence, I’m very curious about what’s going on, so I’ve read a little bit about it. I learned that what happens is that for some reason you’re partly asleep (having dreams and unable to move due to the muscle paralysis that accompanies some stages of sleep) but also partly awake (which makes the dreams more like hallucinations, and the feeling of paralysis recognizable and, to me, terrifying). Because people who had NDEs were more likely to also have had this kind of odd sleep/waking experience, researchers want to figure out more about what is going on in the brain to trigger these experiences.
http://www.nature.com/news/2006/060410/full/060410-2.html
Hypnagogic hallucinations are the kind of wakeful dreams that you have as you’re falling asleep, and hypnopompic hallucinations happen as you’re awakening. I mostly have the former; they happen about an hour after I go to sleep. (I think there is a transition to a different type of sleep somewhere around an hour into the night, and maybe I sometimes don’t navigate the transition well.) This Wikipedia article mentions that creative types use the hypnagogic state to tap into their creativity, and I’d love to be able to experience it that way rather than as an unpleasant time when things happen that scare the bejabbers out of me. The Wikipedia article also mentions a possible connection with temporal lobe epilepsy, which I think is associated with both creativity and a tendency toward strong religious experiences. Hypnagogic hallucinations might explain why some people believe that they’ve seen religious apparitions or encountered aliens at night.
