Even more on hallucination, this time with added Mariah Carey

I do worry sometimes that I might be psychic. It seems all too common that I post on a topic and then within hours someone else posts on exactly the same topic, usually irritatingly more concisely than I did.

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Mariah wishes you a happy and hallucinatory Christmas. (Image from Irishhips on DeviantArt, under Creative Commons licence.)

Yes, I know: confirmation bias. I post on things I’m interested in and I follow blogs on topics I’m interested in. I shouldn’t be surprised at serendipity throwing a few matched pairs my way. But, hey, if assigning active causation to coincidence is good enough for up to 98% of the world’s population, I might as well follow suit.

Anyway, after my little ramble about hallucination yesterday, the ever-entertaining I Fucking Love Science blog has linked to a deconstructed version of “All I Want For Christmas” in which many people actually hear Ms Carey’s dulcet tones. I certainly got a bit of it, especially where the word “you” would be sung. Nice evidence of the fact that the brain’s prior informational state directly impacts upon perception.

It also happens to be rather awesome, sounding distinctly as though Conlon Nancarrow had got to work on it.

More on hallucination

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.

On identity

As I’m playing catch-up, I’m afraid that for I you’re just going to get a quotation. It’s not even a particularly abstruse one, but it’s as close to being a credo as I get, and it’s pertinent to the previous two posts. I still remember when I first read it, and found that it exactly expressed what I had fumblingly and incoherently been reaching towards, and, though some of the phrasing may be a bit antiquated and it may need some fine-tuning of the concepts, I still love it.

It’s Hume, of course. All stand and uncover.

There are some philosophers who imagine we are every moment intimately conscious of what we call our SELF; that we feel its existence and its continuance in existence; and are certain, beyond the evidence of a demonstration, both of its perfect identity and simplicity. The strongest sensation, the most violent passion, say they, instead of distracting us from this view, only fix it the more intensely, and make us consider their influence on self either by their pain or pleasure. To attempt a further proof of this were to weaken its evidence; since no proof can be derived from any fact, of which we are so intimately conscious; nor is there any thing, of which we can be certain, if we doubt of this.

Unluckily all these positive assertions are contrary to that very experience, which is pleaded for them, nor have we any idea of self, after the manner it is here explained. For from what impression could this idea be derived? This question it is impossible to answer without a manifest contradiction and absurdity; and yet it is a question, which must necessarily be answered, if we would have the idea of self pass for clear and intelligible, it must be some one impression, that gives rise to every real idea. But self or person is not any one impression, but that to which our several impressions and ideas are supposed to have a reference. If any impression gives rise to the idea of self, that impression must continue invariably the same, through the whole course of our lives; since self is supposed to exist after that manner. But there is no impression constant and invariable. Pain and pleasure, grief and joy, passions and sensations succeed each other, and never all exist at the same time. It cannot, therefore, be from any of these impressions, or from any other, that the idea of self is derived; and consequently there is no such idea.

But further, what must become of all our particular perceptions upon this hypothesis? All these are different, and distinguishable, and separable from each other, and may be separately considered, and may exist separately, and have no deed of tiny thing to support their existence. After what manner, therefore, do they belong to self; and how are they connected with it? For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe any thing but the perception. When my perceptions are removed for any time, as by sound sleep; so long am I insensible of myself, and may truly be said not to exist. And were all my perceptions removed by death, and could I neither think, nor feel, nor see, nor love, nor hate after the dissolution of my body, I should be entirely annihilated, nor do I conceive what is farther requisite to make me a perfect non-entity. If any one, upon serious and unprejudiced reflection thinks he has a different notion of himself, I must confess I call reason no longer with him. All I can allow him is, that he may be in the right as well as I, and that we are essentially different in this particular. He may, perhaps, perceive something simple and continued, which he calls himself; though I am certain there is no such principle in me.

David Hume, A Treatise of Human Nature. Book 1, chapter 4, section 6. (Some minor edits for modern readability.)