Jun 14 2013

What is Unconscious?

I recently received this question:

I heard Seth Shostak mention in one of the “Big Picture Science” podcasts, that we are unconscious when we sleep.

I disagree. This is an altered state of consciousness.

Then.. you go further…

What about a COMA? Still not truly unconscious. People have memories after they wake up of people talking to them. They just don’t know where they come from.

What about NDE’s?

C’mon… if you were truly unconscious (regardless of scientific unmeasurability of brainwave activity) , you are still either having thoughts or remembering the thoughts before you wake up.

I contend that TRUE unconsciousness is ACTUAL death. (not clinical death – a decision made by instruments) The inability to think AT ALL in any capacity as if you had never been born.

Please discuss this? Am I wrong?

I do not believe in dualism. I trust that as I lay dying, I may have experiences that feel like fantastic dreams… but when I actually die… I am dead.

If I were unconscious while sleeping… How did my alarm clock wake me up? How did my snoring wife rouse me from non REM sleep?

Michael Goff (Aka, Evil Eye)

Thanks for the question. In short – this is wrong, or at least overly simplistic to the point of effectively being wrong. The primary problem is in dealing with consciousness as a binary state, and therefore any flicker of consciousness is not “unconscious.”

Consciousness is more of a continuum, and there are various states of consciousness. To answer what is unconscious, however, we need to first ask what does it mean to be conscious.

We don’t fully know, because we have yet to fully identify the neuroanatomical correlates to consciousness. Phenomenologically we define being conscious as being awake and aware of one’s surrounding and oneself. This is a high energy state, and requires a certain critical amount of brain function to maintain (we’re not exactly sure how much this is, but of note one hemisphere of the brain is capable of being conscious by itself, without the other half).

There are two general types of alterations in consciousness – diminished consciousness, and altered states of consciousness. These are not mutually exclusive, and often occur together.

Diminished consciousness results when brain function is impaired. The entire brain may be functionally impaired, or pieces of the brain may be damaged and prevented from contributing to consciousness. There is also the special case of brainstem function, which is necessary to maintain wakefullness. If the brainstem is sufficiently damaged, then even if the rest of the brain is completely intact, coma may result.

Impairments in consciousness occur on a spectrum from a little drowsy all the way to brain death. “Coma” describes a condition of significant impairment in consciousness, but does not define an absolute demarcation along the spectrum. People with impaired consciousness may have some retained consciousness, may be in a minimally conscious state, or may have no discernible consciousness (let’s call this latter condition “deep coma”).

In deep coma, people do not form memories, do not have any experiences, and do not display any evidence of consciousness – even far short of brain death. This state can be induced with medication, as is often done with general anesthesia. Anyone who has had full general anesthesia is aware of how complete the absence of consciousness can be – there often isn’t even the perception of the passage of any time.

Altered states of consciousness are a bit trickier to define. Generally these emerge when the manner in which the brain constructs our perceptions of reality and our conscious selves is altered. This can occur when a part of the brain that is vital to this construction is damage or suppressed, leading to out-of-body experiences, hallucinations, feeling separated from oneself or from reality.

The e-mailer brings up sleep – sleep actually represents various different stages of consciousness, which are all part of the normal functioning of the brain. There are four recognized stages of sleep, each with deeper suppression of brain function. Stage 1 is simple drowsiness, while stages 2-4 are progressively deeper. In stage 4 sleep it can be very difficult to arouse someone.

In these stages of sleep the brain is still able to respond to external stimuli, but I don’t think it is valid to argue that the brain is therefore conscious. That argument assumes that all brain function contributes to consciousness, but we know that it doesn’t. Many brain processes are subconscious. The brain can process and even respond to stimuli without conscious awareness.

Dreaming, or REM sleep, is another stage of sleep that is perhaps better understood as altered, rather than diminished, consciousness. The brain is very active in REM sleep, and we experience dreaming in which we can feel fully conscious. However, not all brain regions are contributing to dreaming consciousness the way they are in wakeful consciousness. Reality testing, for example, is not very active while dreaming, which is why our dreaming self can accept fantastical events that would not be accepted by our waking self.

Consciousness is a very interesting phenomenon and is still an area of active research and debate. We know that it results from brain function, that it takes a lot of brain function to maintain consciousness, and that the brain also does a large amount of subconscious processing. There are various forms of diminished or altered consciousness, both normal and pathological.

Although consciousness is a continuum, there are many states short of death that can be meaningfully described as “unconscious.”

14 responses so far

14 thoughts on “What is Unconscious?”

  1. I feel like this is mostly a semantic distinction. Dr. Novella is arguing that unconscious means a lack of self-awareness, whereas Michael Goff is arguing that unconscious means a lack of mental processes.

    I’m going to side with Dr. Novella here, but on language grounds more than anything else. Unconscious is a word, and if as a word its meaning is indistinguishable from dead, then it doesn’t do us much good. (I’m not arguing against the use of synonyms, because ideally synonyms convey similar, but not identical, meanings).

    I think the word unconscious is more useful from a communication standpoint if it refers to mental states in which we lack self-awareness, because I’m not sure there is another term out there that fully encompasses all those possible states.

  2. Don’t mention this to Cannotsay, but consciousness seems like a continuum to me. Full consciousness would have cognitive features such as:

    – sensation of flow and continuity of time
    – feeling of immersion in physical world; spatial awareness
    – access to short-term memory
    – access to long-term memory (many different types here)
    – ability to create new memories
    – ability to move/interact with physical world
    – causality continuity (Dr. N calls this “reality testing”; does the world behave as expected?)
    – ability to focus attention at will
    – ability to divide attention at will
    – ability to achieve goal-directed behavior, conduct long-term planning, prospective memory, etc.

    Sleep versus dreaming versus lucid dreaming versus hallucinogenic trip versus drunkenness, these states of mind seem to have access to some but not all of these cognitive features. Would be cool to see a matrix of rows and columns mapping all these out for different states of consciousness.

  3. steve12 says:

    One of the biggest problems is difficulty in operationalizing consciousness.

    E.g., I don’t think consciousness is tantamount to attention – but I fall into the trap of thinking of them this way all of the time. It’s hard to study something that is such a slippery concept to begin with!

    And most experiments define consciousness as that which the subject can report awareness of – but this has huge problems as well in that we are necessarily dealing with memory confounds. An easy example of this is a coma. If we ask someone whether they had experience during a coma, and they say no, there are (at least) 2 interpretations: 1. they were truly unconscious 2. they were conscious at the time but have no memory.

    This is even an issue with short times scales with experiments used to investigate consciousness. In masking experiments, critical images are shown very quickly and with distractor stimuli in close temporal proximity, yielding reports of non-awareness to the critical stimuli.

    It might be that the critical stim never reached consciousness because it was replaced to quickly in the perceptual memory buffer (the usual interpretation) or it could be that it indeed reached consciousness, however briefly, but was kept from being encoded in longer term stores.

  4. steve12, I agree conceptually that consciousness is not tantamount to attention. We know unconscious “awareness” occurs on some level (like the “cocktail party” effect where someone can hear their own name spoken by someone else, as if part of them were listening in to the other conversation the whole time).

    But it also seems that the attention literature is the closest thing we have to experimental studies on consciousness, and that if you wanted to really deeply study consciousness from an experimental perspective, attention is where it’s at. Do you get that impression as well?

  5. Your point about timescales is spot on. Just browse the literature on Benjamin Libet’s experiments for a flavor of the complexity of measuring awareness: http://en.wikipedia.org/wiki/Benjamin_Libet#Implications_of_Libet.27s_experiments

  6. steve12 says:

    The Libet stuff always freaks me out. It’s a cool experiment, but ultimately I think Dennett’s right. He’s the go to guy when I wanna feel rationale yet retain my high locus of control:

    Re: attention, I agree with you: it’s as close to an operationalization as we may have, but it’s not the same thing that I think most people mean when they wonder how consciousness works, or why we’re conscious. I could as easily say that working memory is consciousness. And this is setting aside that attention itself is not that easy to define, and is often confused with WM!

    I think there’s also some confusion re: the Q itself. If we want some grand answer as to how and why we experience qualia (with apologies to Dennett), I’m not sure we’re getting that from science. That’s more of a metaphysical question and I think this is part of the reason that consciousness is so hard to define scientifically: what we often (cerainly me, anyway) really want is not a scientific Q.

    So yeah – I do think investigating attention, WM, executive functions (a concept we’re all uncomfortable with!) etc. and finding the neural processes / substrate thereof will give us insight into consciousness and awareness, but I think this will be a neuroscientific reckoning more than a grand epiphany.

  7. BillyJoe7 says:

    It’s going to be difficult to prove one way or the other, but what are the odds that, between lapsing into a coma and dying, there wouldn’t be a point where you would be still alive but unconscious. And what are the odds that, whilst asleep, there wouldn’t be a time when you are not also unconscious. In fact, it doesn’t seem reasonable to think that unconsciousness and dead would necessarily be synonymous.

  8. SimonW says:

    Of course it is semantics.

    The word, like all words(?), means what people use it for. In my experience (and a neurologist may encounter different uses), “unconscious” is an “excuse” type phrase.

    So and so couldn’t defend themselves because they were unconscious.
    I was unconscious at the time and unable to …..

    So I’d suggest it often means lacking sufficient mental alertness to takes desirable actions, or to remember what happened, and in this sense is applied to many states of altered consciousness.

    Like all words it has more meanings. People talk about unconscious mind, meaning actions taken without the person being aware of them, and a whole host of sloppy or weird concepts that make little sense.

    Probably when being a skeptic it is a word to avoid precisely because the meaning of conscious itself is so vague. So if someone is asleep, or in a coma, or soporific due to drugs, say that.

  9. dottornomade says:

    According to Thomas Metzinger, consciousness can be modeled as a virtual organ, such as the immune system.

  10. Bill Openthalt says:

    @ dottornomade
    Most of the brain’s subsystems/functional parts can usefully be modeled as virtual organs.

  11. dottornomade says:

    Bill, that’s true, but the way Metzinger models consciousness is not trivial, IMHO. Plus it’s not like, say, modeling something with controlled/direct functions such as the cerebellum.

  12. Bill Openthalt says:

    @ dottornomade
    I didn’t mean to belittle Mertzinger’s ideas, which I largely agree with. In all likelihood, sef-consciousness is a module that originated with the need for extended communincation of internal state, which facilitates social cooperation. As such, I believe many social animals have a degree of self-awareness. The very developed self-awareness (and associated ability to communicate it through language) shown by humans is, in my opinion, what makes large societies possible. There’s some irony in the fact that what most represents our individuality is indispensible for social life.

  13. More debates! These are just awesome (loved the one with Don, too)

  14. stalphs says:

    Just to share!

    After much reading on Consciousness studies and related areas in the last 20 years, from NDE’s studies and the collection of NDE experiences of the dying, to the work of Roger Penrose/Stuart Hameroff on Orch-OR theory and quantum affect in biological systems, and related works on AI/Computation and the recent lectures of Peter Russell (eg) primacy of consciousness, to Studies on Meditation experiences, and ones own experience to travels to India, and Burma, to understanding Quantum Theory, Cosmology, Standard Model in Physics and so on…the following has become clear to me, or has become self evident conclusion from my understanding…

    Unconsciousness (minimal to zero awareness) either under anaesthetic, drugs, injury, coma etc, resulting in dreamless or in dreaming sleep, to being awake corresponding to a level of awarenesses we are familiar with, is all a property of living brain/person.

    Ironically, a dying brain, or a brain that has minimal activity (some drugs can cause this, and MRI scans support it), or because its dying, the “I” in me begins to have increased awareness, an increased presence and increased oneness with something we don’t fully understand.

    Its clear that the evidence supports a brain that acts like a valve on cosmic (outside of itself) input when its alive (presumably oxygenated with blood) , and that conciousness is non-local, and NOT produced totally in the brain, but a level of consciousness/awareness is manipulated (de-amplified) by the living brain.

    Too assume unconsciousness is 100% complete at death is not supported by any of the evidence.
    Its is exactly the opposite.
    Unconsciousness in any form that occurs, is only a property of a brain that is alive.

    Difficult stuff to put in words, and probably poor English….

    Furthermore, my experience has shown that resistance to this model of consciousness (when mounting evidence supports it) is mainly due to prejudice (a strong dogmatic atheists position, or anti-religious views, or even, believe it or not, job security at some academic institutions) and definitely resistance to this model occurs due to ones own lack of research into the subject matter before making a belief statement about the subject!

    Slowly a paradigm shift is occurring!
    The old over simplified paradigm: (classical materialist traditional view).. Consciousness only comes into existence with the evolution of complex nervous systems is slowly being replaced by
    The new over simplified paradigm: Consciousness is more fundamental then matter, space or time, and there is nothing but consciousness.

    We obviously don’t have all the answers, and this is only a baby step, but the I believe the paradigm shift will start to answer more and more questions, as the more you dig and dig the more this is evidence for this new paradigm.

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