Brain Decoder has a good short piece on the hallucinations which come with sleep paralysis, and the cultural priming thereof. As a narcoleptic who experiences sleep paralysis multiple times a week, I feel I can speak with some authority on this matter. There are, in my experience, four levels of sleep paralysis:
1. Fuck it, I can’t move.
2. I can’t move, and ordinary but inconvenient things are happening.
3. I can’t move, and WTF is going on?
4. The Terror.
Level one is simply the paralysis, which is annoying and frustrating enough in itself, but lacks any hallucinatory content. Level Four—which you really, really do not want to experience—also lacks detailed hallucinatory content: it is simply the paralysis accompanied by a sensation of blind terror, lacking cause or meaning.
But the interesting levels with respect to hallucination are two and three; and whilst level three certainly manifests culturally-ingrained concepts, level two is equally interesting because of the incredible specificity of the hallucinations: specific not only to what I consider plausible, but actually to the particular circumstances of the attack.
It’s worth pointing out here that the hallucinations associated with sleep paralysis are almost always discomfort-inducing to some level. This annoys me, partly because it’s frightening, and partly because the one thing really, really good at getting under my own skin and playing on my particular fears is my own brain, which is exactly the organ doing the hallucination. As posted many times here, I don’t believe in free will, souls, non-material sources of consciousness, or any of that bull. The brain is simply a thought-crunching machine and in my case one with a structural fault in it; but it does irritate me that this fault seems to make it determined to put the willies up itself. Dumb brain.
The level three hallucinations, in which my brain seems set to deliberately induce full-blown fear, not only track cultural norms, but my credence thereof. When I was younger, and a more credulous individual, they were frequently supernaturalist, as described in Brain Decoder’s post. Nowadays, they very rarely are; indeed the fact that I still have any demons sitting on me (or worse) rather vexes the sternly intransigent atheist in me, as it would seem to be evidence that somewhere deep down I still can give a level of acceptance to these nonsenses. However they are, by and large, outside the paranormal but implausible for the actual circumstances.
Physical attack, alas, crops up regularly, rather horribly occasionally extending to rape. It’s worth noting that the one muscle which contracts rather than relaxes as you sleep is your anal sphincter, for reasons which it does not take a genius to work out. Occasionally, in the oddly prolonged process of falling asleep that is one of my many parasomnias, I feel this happening (you don’t want to experience this, either). Given the presumptions that the hallucinations of sleep paralysis are in part your brain’s attempt to explain to itself the peculiarity of its current experiences, it is worth noting that a common explanation for alien abduction experiences is sleep paralysis (again, a regrettably prevalent cultural trope; but one I have never experienced because I quite simply have never been close to believing that They Are Here). A much joked-about feature of the alien abduction experience is their great fondness for anal probes; and in this I see a direct corollary with my hallucinated rapes: in both cases I think it is the brain trying to explain to itself the really unwelcome sensation currently going on in the butt area.
Level two hallucinations, however, are equally astonishing: not for their linkage to cultural tropes, but to the dull and prosaic, to the ordinary detail of life around me. They seem carefully and precisely calibrated by my rebelling brain into fooling itself into irritation and worry, but highly short of heart-pumping fear. Because, at this level, my brain is working for maximum credibility, they are almost always auditory or tactile. I can’t move, my eyes are usually shut, and if I happen to be able to force them open (the paralysis is not always total) I often do not have my glasses on and, when I do, the control does not seem to extend to being able to focus. But it is incredible what my brain can achieve with this.
I’ve posted before on related matters, notably the sheer ordinariness of the level two hallucinations, and how perfectly they fit my circumstances. I’ve woken up paralysed in an airport to hear the last call for my plane only to find when I finally break out of it that they’re not yet even boarding. I’ve heard delivery men come and go from my house, only to find them turning up half an hour later. And, in the most icky but (in retrospect, at least) amusing instance, I’ve had an over-affectionate but somewhat incontinent cat fart noisily on me (possibly genuinely), and follow through. I lay there, immobile feeling in detail the discontents of Bear’s accident oozing into my jeans; as always, to come round and find a clean and perfectly happy feline curled up on me purring innocently away.
One particularly interesting feature is when I try to speak. As stated, I have some minimal control sometimes, and I often try to speak to get those around me to shake me out of it. This rarely succeeds, because the resultant vocalisation is incoherent: I lack the fine control needed to produce understandable speech. Yet to my ears, the speech sounds a bit slurry, but basically fine. It has taken me many years of people insisting to me that I was merely making inarticulate grunts indistinguishable from ordinary sleep sounds to accept how inaccurate my perception of my own voice in this circumstance is: my brain is hallucinating comprehensiblity where there is none.
As I said in my previous post, all this gives me great doubt when considering the naive realist idea that, in normal functioning, the brain simply manifests perception data directly as percepts pre-cognitively. That is, the idea that our experience of the world is a simple trajectory of sense data to full and accurate mental representation thereof to cognitive processes thereupon does not seem to match my experience. I believe that our brains are somewhat lazy: they do not process all and every sense datum and produce a perfectly representative percept before getting to work on thinking about that percept. They make up a great deal of the percept, using rules of thumb but also existing cognitive categories, even fairly high-level ones such as cultural tropes and knowledge of current circumstance. They start thinking about the content of the mental representation as they are constructing it and their specific credences and beliefs are input to our perception, not simply posterior to it.
Interesting stuff, having a malfunctioning brain. Though now I have the benefit of these insights, it’s quite welcome to start functioning properly any time it likes.