Thursday, April 22, 2010

Chalmers's Fading/Dancing Qualia and Self-Knowledge

David Chalmers defends what he calls a principle of organizational invariance according to which if a system has conscious experiences then any other system with the same fine-grained functional organization will have qualitatively identical experiences. His main arguments for this principle are his "Fading Qualia" and "Dancing Qualia" arguments.

Both arguments are reductios. Let's start with Fading Qualia. Suppose, contra the principle of organizational invariance, that there could be a fine-grained functional isomorph of you without conscious experience -- perhaps a robot (call him Stu) with a brain made of silicon chips instead of neurons. If this is possible, then it should also be possible to create a series of intermediate beings between You and Stu -- perhaps, for example, beings in which different proportions of the neurons are replaced by silicon chips. If You have a hundred billion neurons in your brain, then maybe we can imagine a hundred billion minus one intermediate cases, each with one less neuron and one more silicon chip. The question is: What kind of consciousness do these intermediate beings have? Chalmers argues that there is no satisfactory answer.

There seem to be two ways to go: Consciousness might suddenly disappear somewhere in the progression, say between fifty billion and one neurons and fifty billion. But that seems bizarre. How could the replacement of one neuron make the difference between consciousness and its absence? You and Fifty-Billion-and-One are having vivid visual experience of a basketball game, say, while poor Fifty-Billion is a complete experiential blank. Surely we don't want to accept that.

Seemingly more plausible is a second option: Consciousness slowly fades out between You and Stu. But then what does Fifty-Billion experience? Half of a visual field? An entire visual field, but hazy or in unsaturated color? Note that since You, Stu, and Fifty-Billion are all identical at the level of functional organization, you will all exhibit exactly the same outward behavior. You will all, when asked to introspect, presumably say something like "I am having vivid visual experience of a basketball game". Stu is wrong about this, of course, if it makes sense to attribute assertions to him at all; but he is just a silicon robot without consciousness, so maybe that's okay. But Fifty-Billion is not just a silicon robot. He has some consciousness. But he seems to be badly wrong about it. His visual experience is not, as he says, vivid and sharp, but rather indistinct, or incomplete, or unsaturated. And Chalmers suggests that it's absurd to attribute that kind of radical error to him. Thus Chalmers completes the reductio: There's an absurdity in assuming the denial of the principle of organizational invariance. You, Stu, and Fifty-Billion all have qualitatively identical conscious experience.

I object to the last move in this argument, to the idea that it is absurd that Fifty-Billion could make that kind of mistake. My reason is this: Many of us make exactly the same mistake in ordinary instances of introspection. Some people, for example, when asked how detailed their conscious experience is at any one moment, say that it is extremely rich -- full of precise detail through a wide visual field, and simultaneously full of auditory detail, tactile detail, and detail in other modalities. Others say that their experience is very sparse -- they only experience one or a few things at a time. On the sparse view, when one is attending to the visual environment, one has no experience of the feet in one's shoes; when one is attending to one part of the visual field, one has no experience of the areas outside of attention; etc. I have argued that this dispute does not turn merely on a disagreement about terminology, and does not reflect radical differences in different people's experiences, but rather is a real substantive, phenomenological dispute. One or both parties must therefore be radically wrong about their experience. This is at least, I think, not an absurd view, given the potential sources of error about the richness of experience, such as the refrigerator light illusion (the possibility that thinking about experience in some modality or region creates experience in that modality or region where none was before, causing us to mistakenly think it was there all along). And if it's not absurd to suppose that ordinary people could be mistaken about how rich and detailed their experience is, it's not absurd to suppose that Fifty-Billion could be mistaken.

Dancing Qualia is a variation of Fading Qualia. It requires two visual processing systems with the same functional organization but different associated visual phenomenology, and it requires the capacity for you to switch swiftly between these systems. Since the functional organization of the systems is the same, you won't report any difference in experience when you switch from one to the other, thereby implying that some of your reports will be mistaken -- implausibly mistaken, in Chalmers's view. Therefore, by reductio, the systems cannot really differ in their associated visual phenomenology.

But in cases of "change blindness" -- for example here -- people will fail to notice substantial changes in their visual experience. (Or at least this is true if experience is relatively rich.) Such failures aren't perhaps as severe as what might be created by a visual system switch, and, as Chalmers notes, many of them require that your attention not be on the object of change. However, not all change blindness cases seem to require lack of attention to the changed stimulus -- like when the person you are talking to changes after brief interruption without your noticing (though determining what exactly qualifies as a target of attention may be a difficult matter in such scenarios); and in any case consideration of such cases should, I think, loosen our commitment to the seeming absurdity of failing, especially in weird scenarios, to notice radical changes in experience.

Furthermore, the Dancing Qualia case seems problematically pre-built to frustrate our ability to notice differences, much like radically skeptical brain-in-a-vat scenarios are pre-built to frustrate the sensory abilities on which we depend by giving the same sensory input despite a large change in the far-side objects. The following model is too simplistic, but conveys the idea I have in mind here: Imagine that introspection works by means of an introspection module located near the front of the brain, which receives input from the visual cortex in the back of the brain. The back of the brain has been changed so that experience is radically different (on the assumption of the reductio), but changed only in such a way that the input from the back to the front of the brain is exactly the same. In such a case, it seems not at all absurd to suppose that introspection would fail to notice a difference, despite a real difference in experience. Thus, the Dancing Qualia reductio fails.


  1. Hi Eric,

    Fun post!

    I'm going to side with Chalmers on this one. One thing we need to be a bit more clear about here is what sort of absurdity is at the heart of FQ/DQ. I think he's pretty clear that the absurdity is not a full-blown contradiction or inconceivability. He'll grant that it's *logically possible* that qualia fade, dance etc despite functional invariance.

    So, the absurdity is something else. Perhaps something harder to pin down like *really really weird* or *ontologically ugly* or something. Given that the absurdity is *not* supposed to be a logical impossibility, I don't see that, for instance, the appeal to change blindness or the appeal to phenomenological disagreement cuts much ice.

    Here's why: in the case of say, changeblindness, we might still suppose that whatever it is that people sometimes fail to notice in their experience (assuming, for sake of argument, that it is something *in experience* that they fail to notice) is something that is functionally characterizable. It's open that what people notice when they aren't changeblind is something that's functionally characterizable. In Block terminology: it's something that is not impossible to have access consciousness of.

    The way the FQ/DQ thought experiments go, in contrast, what's introspectively inaccessible is, by hypothesis, impossibly accessed. And that strikes me as absurd, though, of course, in the not-a-logical-contradiction sense of "absurd".

    So anyway, I'd love to hear what you think about this. When you put the case explicitly in the weakened sense of "absurd", do you still think the FQ/DQ reductios can be shown to be failures?

  2. Thanks for the comment, Pete! I agree that Chalmers is quite explict that inconceivability isn't the issue. My understanding is that the argument turns on the implausibility of certain sorts of *introspective mistake*. And thus my objection turns on denying the implausibility of such introspective mistakes. There may be other reasons to endorse the principle of organizational invariance, but I don't mean to be addressing those.

    I don't see why it's implausible to suppose that there might be phenomenological changes that are impossible to access. As in the brain-in-a-vat scenarios and perception, the Dancing Qualia case is rigged to conceal changes that we are ordinarily sensitive to.

  3. Chalmers’ argument-as always! - is based on intuition: dancing/fading qualia are intuitively hard to admit. This is not a matter of fallibility of our introspective faculty. Whether or not our introspection may be mistaken, the f/d qualia are counterintuitive. Now, if one is going to argue that this is due to some changes which are introspectively undetectable, it may weaken our reliance on introspective data, but it is hard to see how could effect our intuitive judgment.
    Anyway, it seems that Chalmers’ argument is a restatement of supervenience, isn’t it?

  4. I find it interesting, Ayoob, that you, Pete, and I read the arguments so differently. I had thought it pretty explicit that the key move in both cases was the appeal to the implausibility of the required introspective error. I thought this made the argument importantly different from -- and in my view more interesting than -- the usual metaphysics-of-mind appeal to our intuitive judgments about the consciousness or not of various hypothetical beings.

  5. thanks Eric for your answer.
    it seems that even if we accept your interpretation, it seems that there are some vague points.
    If I get your argument correctly it leads to the conclusion that ‘Chalmers’ arguments are based on implausibility of introspective error, but introspective error is not implausible. Then Chalmers’ arguments fail.’
    Chalmers doesn’t seem to deny introspective error, fundamentally/ in principle. Then, it seems that we can admit three approaches about introspection:
    Introspection is generally reliable. This option supports Chalmers argument (I mean your interpretation of Chalmers’ argument).
    Introspection may be mistaken. This option remains neutral, because we can say this about reason and intuition too. Our intuitive and other kinds of argument could be mistaken too. In every special case, it should be assessed, whether it is reliable or not. (The idea that introspection is always misleading, seems extremely implausible, doesn’t it?)
    3. ‘Introspection in Stu case is systematically misleading.’ This one supports your argument; you need to show that Stu’s introspection is not acceptable because there are phenomenal changes that are not detectable. But, all you have done is that introspective data could be mistaken which is not enough. Now, the point is that why should we accept ‘3’? If there are introspectively undetectable data, why should it be just in Stu case, not in every ordinary case?
    And if these data are not detectable at all, even in ordinary human cases, doesn’t it make the argument useless? (The argument would be as: introspective error is not implausible, but not detectable at all!)
    Am I right?

  6. Thanks, Ayoob. Yes, my interpretation comes down to (3) -- though not so much in the Stu case as the Fifty Billion case. In my discussion of Dancing Qualia I express why we might expect introspection to be systematically misleading in such cases. Too put it too crudely, the input into the introspection module is the same, though the experience (ex hypothesi per reductio) is different.

  7. Hi, Lawrence Speke Mcleod here,

    If you created standards of richness of experience that some
    did not meet-- say, by giving less detailed descriptions or some such, than your standard
    would allow to be called rich---
    how do you prove that your standard is solely the correct standard? If people do not have a rich experience, this is so from your point of view, it seems to me.
    If a majority of folk agree with you---still, how does that invalidate another's different point of view?
    I am not being a relativist here
    just a realist. People differ.
    In reality there are different points of view.
    SOme think that consciousness is an entity, some an aspect of things, some an ability introspect.
    Some think it is a general term,
    a broad category that encompasses a bunch of different things.I subscribe to this and I suppose I have a nominalist take on it---as opposed to a realist take. I also think it unecessary to posit such a thing in the first place, as consciousness, to account somehow for what is. Existence itself ties all things together---we don't need consciousness to do it.
    In fact, one may consider consciousness just another thing that shows up, that exists---people claim it is there---and because it shows up, as a notion or a sense or what have you, it is indeed part of reality, of our world. Our world--reality-- is made up of things that show up, a category which encompasses everything. And this is the basic fact of life and the world, from my point of view. It is so basic it may seem tautologous or perhaps trivial---but my reply is that it is profoundly present and plain and really should be our philosophical starting point. The universality of consciousness, on the other hand may be denied without absurdity by a simple claim to have no such intuition. It would be most absurd to deny that consciousness has been touted as a central feature of our experience by many folk--that consciousness exists in that way. Consciousness showed up in some way, and that--its showing up-- is the true reality--an existence based reality. If it shows up--in whatever way, it is part of the world. The world is made of whatever shows up.
    If I am refuted in this, then I am confirmed in this assertion, since to refute me, a refutation must first show up.
    IN comparison with this basic reality, consciousness pales as a fundament of existence.
    What is significant about anything, generally, is that it shows up at all!
    So, from my point of view, if we are to pick some aspect that typifies existence, I would not choose consciousness as having the most fundamental significance at all.
    If the world disappeared at noon tomorrow--the whole shebang gone--
    all things, thoughts, the entire universe, gone, what would be left?
    Here's where I become a realist rather than a nominalist and say that existence would be left--that existence is something out of which all things, stuff, phenomena, are made, if you will, and it seems a physical fact to me
    that if suddenly there is nothing-----nothing exists-- there must be an existence for nothing to be made of, in order for nothing to exist. Isness, is.
    Chalmers' hard problem is solved
    from my point of view, by a realization that both brain and mind arise from existence---and therefore some translation of brain into mind---and the requisite mind/brain, physical/mental, material/non-material split, is not a necessary posit.
    I know that all this does not address the narrow issue of your post---but I think things take on a
    different aspect, and I hope a more profound one, if the widest possible view of things is considered.
    It may be useful to create one set of standards or concepts that create a point of view for some purpose-----but in the deepest sense the reality, I think, is that everything that shows up--including consciousness or no consciousness, different or opposing standards and the all in all--is the world---what other world could there be?

  8. Thanks for your comment, Lawrence. There's probably too much in there for me to take on right now!

  9. Lawrence, I like where you're going with your comment, but in the end I think you're moving in the same direction as Eric.

    Eric has always been careful not to exert some standard to pin down who, specifically, is mistaken about their conscious experiences. At most he only ascribes the ability to make mistakes based on one's inclusion within a community of individuals whose introspective reports disagree with each other.

    In Chalmers' fading qualia argument, however, Fifty-Billion's ability to make mistakes is based on the a priori assumption that his experiences are vague and indistinct, such that we can and must pin him down as mistaken when he reports that his experiences are clear and distinct.

    Withholding that a priori assumption, we may include Fifty-Billion (and Stu, for that matter) within our discordant introspective community and thereby ascribe to him the ability to make mistakes without ever having to pin him down.

    But then it remains undecided, contra Chalmers' conclusion, whether systems with the same fine-grained functional organization will have qualitatively identical experiences, just as it remains undecided who, specifically, is mistaken about their conscious experiences.

    * *

    Eric, your appeal to change blindness in your reply to the dancing qualia argument positively resonates with Badiou's concept of evental site, though syncing your thought with Badiou's strains the appropriateness of 'experience' (or 'phenomenology' or 'qualia') as an index for what is actually unpresented and unpresentable within the situation of consciousness.

  10. Thanks for pitching in with that, Badda! That expressed my view well. I should probably also spend more time reading Badiou, as you suggest! (I've always found myself perplexed, though, by work in the recent French tradition.)

  11. Unable to reach you with the email address: eschwitz at domain-
    I see extremely vivid images, usually of cartoons while awake with my eyes closed. Usually when I am trying to fall asleep. sometimes when under alot of stress I will wake up and watch cartoons on my bedroom wall. Just like on TV. Am I totally nuts???

  12. Anon May 3: It is not unusual for ordinary people to have vivid visual imagery with their eyes closed or right before or after sleep. Try a web search on hypnagogic imagery for more info.