Sense 3: Sleep Paralysis as Hypnagogic Hallucinations
There is not much justification for the use of the term "sleep paralysis" in the sense "hypnagogic hallucinations". However, LaBerge speaks of hypnagogic hallucinations as "the harbingers of REM sleep paralysis", so it's not unlikely that some people may have assumed they had to be the same phenomenon.
Hypnagogic states occur in the transition from wakefulness to sleep. By definition they are related to sleep stage 1, but they have also been known in some cases to occur in periods of reduced wakefulness before sleep. With respect to EEG, hypnagogic states are associated with a dropoff in alpha activity. Hypnic jerks (also known as sleep starts) occur in the hypnagogic states.[7]
There are also similar states in the transition from sleep to wakefulness called hypnopompic states. However, it's more difficult to tell hypnopompic states from dreams. Sometimes, for simplicity, hypnopompic states are also called hypnagogic.
In hypnagogic states people may experience hallucinations. Hallucinations, including hypnagogic ones, are experienced as if you had actually perceived them through your senses, and they may involve any and all of your senses.[7] The most common ones are:
- Visual HH, also known as hypnagogic imagery (HI), are typically faces, landscapes, geometric shapes.
- Auditory HH are typically roaring sounds, explosions, people shouting.
- Kinesthetic, vestibular, tactile HH are typically vibrations, the feeling of being electrocuted (sans the pain), a sense of extreme acceleration.
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Sense 3: Why Would LDers Want Sleep Paralysis as in Hypnagogic Hallucinations?
Whenever we fall asleep we pass through hypnagogic states. We are not usually aware of this, or at least we don't remember it. But LDers who want to WILD need to maintain awareness all the way into sleep, so it's highly likely that if they get any HH they will recall it because they were aware at the time.
Thus, wanting HH may make some sense for LDers. It's not that HH will buy them anything in itself (unless they like the HH for their own sake), but if they get HH it's a symptom that they have managed to keep themselves "awake" beyond the point where most people lose awareness. And that's a good sign, because it means that they may not be far away from entering a dream.
On the other hand this may cause problems too, because not everyone gets any significant HH, at least not every time they fall asleep. So if you think you should get these HH and then you don't maybe that will stop you in your efforts and discourage you from trying again.
The conclusion is that if you get HH it's an indication that you're on the right track, but if you don't get them it's
not an indication that you're on the wrong track. HH are a potential side effect of WILDing and absence of HH doesn't mean anything. BillyBob, author of several WILD guides on DV, explicitly recommends that you don't focus on HH, because that focus may actually prevent you from entering the dream.[9]
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"Hypnagogic states are transient states of decreased wakefulness characterized by short episodes of dreamlike sensory experience. These phenomena were first described by J. Müller (1826/1967) as "fantastic visual phenomena" (p. 20ff) occurring usually, but not exclusively, at sleep onset. Maury (1848) coined for them the term hypnagogic, from Greek hypnos (sleep) and agogo (I bring). Schacter (1976) described them as "dreamlets." Subjects usually report short visual percepts like faces, landscapes, and natural or social scenes that may or may not be related to previous daytime experience. These percepts may be of pseudohallucinatory (i.e., with preserved insight of unreality) or truly hallucinatory (i.e., experienced as if real) character. In contrast to dreams, hypnagogic experiences are usually rather static, without narrative content, and the subject is not involved as an actor (cf. Sleep and Dreaming section)."
