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lukeprog comments on Human consciousness as a tractable scientific problem - Less Wrong
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Perhaps, though some - including Dennett - think that the hard problem will end up being solved by solving the easy problems. I tend to take this 'deflationary' view about the problems of consciousness.
Maybe it's antisocial to keep asking these sorts of questions, I hope not. Do either of you have any idea where I can find a less-wrongian friendly description of this "hard problem". Everything I've read that tries to describe it in the past is full of snippets like "something that it's like to be" and "subjective qualitative" and other such things I have no ability to understand...
It's kind of supposed to be hard to explain, but...hmmmm...maybe something like "why is there a subjectively perceived difference between sleepwalking through your life and being awake?"
If we imagine a sort of "perfect sleepwalker" who, while sleepwalking, could hold conversations, go to work, write poetry, and do anything else that people do while awake exactly as waking people do it - even to the point where if we ask her "Are you awake?" she answers "Yes." - then it might be necessarily impossible for us outsiders to distinguish her sleep from her waking.
But we feel an intuitive believe that she should be able to do so easily. If she's awake, she can notice her awakeness and all the sensations she's feeling and experiences she's having. If she's sleeping, then it doesn't even make sense to "experience" not being awake, because there's no one "at home" to do the experiencing.
An equivalent interpretation of the problem revolves around qualia. Suppose that your experience of "red" was everyone else's experience of "blue". You would never be able to confirm this by talking to other people - you would say things like "blue is the color of the sky and the sea and short-wavelength light" and they would agree with you, but you would be thinking of red when you said it, and everyone else would be thinking of blue. This "experience of blue" which is separate from statements about blue or concepts surrounding blue is the "quale" (plural "qualia") of blue.
Intuition tells us one difference between the sleepwalker and the awake person is that if you ask the sleepwalker what color a stop sign is, the light rays would hit her eyes, go through a chain of neurons in her brain, and produce the response "it's red". The same thing would happen in the awake person, but she'd also have the conscious visual experience qualia thing where she "sees" a certain color in her "mind's eye".
The hard problem is whether there's a difference between awake people with qualia and perfect sleepwalkers (aka "p-zombies") without qualia, and, if so, what causes that difference.
Is the answer even relevant ?
As far as I understand, there currently exists no "qualia-detector", and building one may be impossible in principle. Thus, in the absence of any ability to detect qualia, and given the way you'd set up your thought experiment about the sleepwalker, there's absolutely no way to tell a perfect sleepwalker from an awake person. As far as everyone -- including the potential sleepwalker -- is concerned, the two cases are completely functionally equivalent. Thus, it doesn't matter who has qualia and who doesn't, since these qualia do not affect anything that we can detect. They are kind of like souls or Saganesque teapots that way.
It certainly matters to the subject! I sure wouldn't want to lose my ability to experience regardless of whether others can ever notice (or whether it's possible).
Your objection here strikes me a little bit like behaviorism. Yes, there are valuable things to be gotten most of the time from such an approach, but behaviorism suffered from an unwillingness to acknowledge that people had thoughts. After all, thoughts didn't demonstrate themselves in behavior beyond being talked about, in which case it was the talk that was part of the scientific domain, not the thinking. The thing is, I know I think, and my strong impression is that others talk about "thoughts" for the same reason I do: they think. The fact that behaviorism didn't have a clear empirical approach to exploring these subjective experiences tagged "thoughts" didn't mean that they were uninteresting or irrelevant. This was the main reason why we switched away from behaviorism in the second half of the 20th century.
(Quick note: Yes, I know that not all behaviorism was like this. Some behaviorists simply said that they didn't want to make claims about what thinking entailed because they didn't know how to approach the matter empirically. However, it was common if not dominant among behaviorists to take the "If we can't study it then it doesn't exist or doesn't matter" approach.)
In exactly the same way, quale-type experience seems to be present for me, and my own impression is that everything I talk about in terms of empiricism gets filtered through qualia. There are no data that transmit information to my mind that I am aware of without that awareness taking on qualia. I'm under the strong impression that others experience the world similarly. The fact that we don't know what that means in reductionistic terms doesn't mean that it's irrelevant or that qualia don't exist. It just means that we don't know how to approach the question unambiguously as yet.
But according to the though experiment you'd set up, you wouldn't notice:
Granted, you go on to say,
But that to me seems like a contradiction. We asked the sleepwalker if she was awake, and she said "Yes", after all. If she could in fact determine that she was sleeping, she'd say "No". Which brings me to your next point:
As far as I understand, a hardcore behaviorist would actually claim that humans have no internal state and are basic reflex agents; that's obviously silly, so that is not my position. Instead, I actually agree almost completely with everything you'd said above.
You think thoughts, and your thoughts affect your actions. Unlike a simple reflex agent, you are able to actually think about your thoughts; this ability affects your actions even further. For example, when someone asks you, "are you awake ?", you can think about it for a moment, and say "Yes, probably", or "Most likely, not". You can also hold a lively discourse on the subject of your own thoughts. Thus, your actions -- including your speech -- are, in fact, evidence for your consciousness. A perfect sleepwalker, then, would have to perfectly emulate being conscious, as well; and I'm willing to stick my neck out and say that a perfect emulation of X is, in fact, X.
You say that you are "under the strong impression that others experience the world similarly" to yourself -- well, why is that ? I would argue that your "strong impression" is actually based on evidence (well, that, and possibly some biologically programmed response, but mostly evidence). You converse with others and they respond in certain ways that are consistent with the hypothesis that they, like yourself, are conscious. Sure, they could be perfect sleepwalkers, but that is a less parsimonious hypothesis.
Thus, again, I see no need for dualistic assumptions of any kind, which includes qualia. Besides, dualism doesn't actually explain anything, it just replaces one mystery with another, because now you have to explain how it is that qualia do what they do -- in the total absence of any empirical evidence, as well as any possibility of acquiring such. Well, ok, you don't have to explain it (I'm not the boss of you), but then you're stuck with a kind of mental elan vital that gets you nowhere.
P.S.: For what it's worth (which admittedly isn't much), I personally recall having both kinds of dreams: the kind where I knew I was dreaming, and the kind that seemed so real that, upon waking, it took me some time to figure out whether or not the events in the dream had actually occurred. Thus, I have no trouble imagining a perfect sleepwalker who would answer "No" when you asked her whether she was dreaming or not.
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I think you're confusing me and Yvain. I'll take that as a complement, though!
I agree with pretty much everything you've said here - but it's posed as though to stand as an argument against what I think, so I'm a little bit concerned that we're not talking about the same thing. For instance, you say:
I agree, dualism is unnecessary as far as we know. It's hard for me to conceive of a type of evidence that would ever suggest that we need dualism.
However, the existence of qualia does not immediately require dualism. The term "qualia" just points to the experiences we have that currently seem to sit on the "other side" of the hard problem of consciousness with respect to our current empirical knowledge. Presumably, we will eventually find a reductionist answer to the hard problem of consciousness. In the meantime, though, we still need a way of talking about the phenomenon in question. Qualia don't play the same role in this question that vis vitalis did with vitalism; it isn't that we're trying to answer the hard problem by saying "subjective experience is made up of qualia", but instead we're trying to describe how subjective experience presents itself to us. We see red, and this experience of redness seems to have a certain character to it, so we tag it with the descriptor of being the quale of red. The question is, how is it that there is a conscious experience induced by neurons firing in response to stimulation of the optic nerve? We know how visual perception works, but as far as I know we don't very well know how the quale of red appears from that. It's a statement of the question, not a phlogiston-class proclamation masquerading as an answer.
Does that clarify where I'm coming from on this? It's not dualism (or at least I'm pretty darn sure it's not!); it's just naming a confusion in as much detail as possible.
Oops, I think you may be right, I'm sorry and/or you're welcome. Heh.
Anyway, oddly enough, I understand the details of your argument, but I don't see the big picture that you're presenting. You reject the proposal that qualia are dualistic in nature, so we're definitely on the same page here. But then you ask,
I agree that this is a hard question (seeing as it hasn't been fully answered yet), but I don't see this question as categorically different from questions such as "how is our blood flow regulated ?" or "how does visual perception work in humans ?". Presumably, a sleepwalker's brain, or a robot's circuitry, or a zombie's... er... goo or whatever it is zombies have, would implement this functionality in different ways than normal human brains do; and we could tell whether the sleepwalker/robot/zombie implements this functionality or not by talking to them (as you have pointed out in your thought experiment).
So, would you agree that the question "how does consciousness work" is no different from "how does blood flow work" ? If not (as I suspect is the case), then what's the difference ?
By the way, when people talk about qualia, they usually claim that we all share the same ones. Thus, for example, when I see something that I experience as "red", and you see something else (or maybe even the same object) that you experience as "red", we are both using the same exact quale to experience that stuff with. There's pretty much nowhere to go from this premise other than toward dualism, which is why I'd originally assumed you were going toward that route. But now I think that you'd reject the premise just as I do -- is that correct ?
Ah, then perhaps I'm more confused than I thought! I still haven't identified the source of my confusion, though.
Er... Yes and no. I agree that eventually we should be able to find an answer that sounds as reduced as an answer to "How does blood flow work?" does. But from where we currently stand, they seem to be really, incredibly fundamentally different questions - as long as you understand the question "How does consciousness work?" to be in the hard sense rather than in the easy one.
I think you get near to the crux of the matter in this statement:
Yes, presumably that's the case, and eventually we'll nail that down. But from what we can currently tell, there doesn't seem to be even an in-principle plausible mechanism for adding qualia to a computer's way of processing things. A computer receives input, does some well-defined manipulations, and offers output. Where do qualia come into play? How is it we get the subjective impression of there being a "someone" who is "watching" what's going on in the Cartesian theater? The very concept is internally inconsistent (e.g., how does the homunculus experience?), but the point is the same: there doesn't seem to be any plausible way that we have currently thought of to get from neurons firing to qualia.
I guess the categorical difference is that when asking about blood flow, there's someone who experiences the question and the data and the subsequent answer; but when asking about consciousness, it's the very process of being able to understand the question in the first place that we're asking about. I'm not sure that's entirely equivalent to the hard problem, though.
You might find it helpful to read the Wikipedia page on the hard problem. That might help to explain some of the nuances better than I've been able to thus far. (In particular, it helps to point out that by "hard problem" I don't mean "a challenging problem" but rather "a problem whose potential to be answered even in theory seems in question.")
Again, I think that was Yvain.
Ok, that makes sense. I understand now that this is what you believe, but I still don't see why. You say:
This, to me, sounds like a circular argument at worst, and a circular analogy (if there is such a thing) at best. You are trying to illustrate your belief that qualia are categorically different from visual perception (just f.ex.), by introducing a computer which possesses visual perception but not qualia, because, due to the qualia being so different from visual perception, there is no way to grant qualia to the computer even in principle. So, "qualia are hard because qualia are hard", which is a tautology. Your next paragraph makes a lot more sense to me:
I think that, if you go this route, you arrive at a kind of solipsism. You know for a fact that you personally have a consciousness, but you don't know this about anyone else, myself included. You can only infer that other beings are conscious based on their behavior. Ok, to be fair, the fact that they are biologically human and therefore possess the same kind of a brain that you do can count as supporting evidence; but I don't know if you want to go that route (Searle does, AFAIK). Anyway, let's assume that your main criterion for judging whether anyone else besides yourself is conscious is their behavior (if that's not the case, I can offer some arguments for why it should be), and that you reject the solipsistic proposition that you are the only conscious being around (ditto). In this case, a perfect sleepwalker or a qualia-less computer that perfectly simulates having qualia, etc., is actually less parsimonious than the alternative, and therefore the concept of qualia buys you nothing (assuming that dualism is false, as always). And then, the "hard question" becomes one of those "mysterious questions" to which you could give a "mysterious answer", as per the Sequences.
I'd actually read that page earlier, and it (along with associated links) seemed to imply that either dualism offers the best answer to the "hard question", or the "hard question" is meaningless as per Dennet -- which is why I took the time to slam dualism in my previous posts.
Darn, again, I'm sorry. But nevertheless, I think it's a good thought experiment.
How well established is it that they are equivalent? The second, qualia version seems much less mysterious to me.
ETA: I completely forgot that you wrote an article on that, sorry. There were two people in the comments whose comments seemed to suggest that they lack a "mind's eye", Garth and Blueberry.
Note that you are using potentially confusing analogies and therefore terminology here. Some people, e.g. my dad, are unable to see anything with their "mind's eye". Indeed, those people don't even know what you mean by that. If you ask them if they are able to imagine a beautiful sunset then they think that you are asking them if they could describe or paint a sunset (database query), they do not understand that you ask them to simulate a beautiful sunset visually and experience it with their "mind's eye" as if dreaming. My dad can only experience visual images if they actually happen live, but he has visual dreams when asleep. That's how I figured this out in the first place, by asking if he is able to deliberately cause dream-like sensory experiences that do not correlate with the outside world (he can't, it is all "black"). I asked others and there are quite a few people who are not capable of "daydreaming" (my mom is). I don't know how else to call this but a lack of a certain type of consciousness.
I find David Chalmers's explanation of what is meant by "qualia" and "subjective experience" and "something its like to be" the easiest to understand. For example, read the first chapter of <i>The Conscious Mind</i>.
The Knowledge Argument above refers to the fictional story of Mary the color scientist. She was raised in a black and white environment and never saw color. But she read textbooks on color theory (printed in black and white, of course.) The question is, when she finally experiences the color blue, how is that different from the previous knowledge she had about what the color blue would be like? That different extra aspect to the actual experience is what we refer to as qualia, and how such an experience can be caused by physical processes is (in Chalmers's terminology that has now been widely adopted) the Hard Problem.
That's a really clear description! Thanks for summarizing it.
I suspect it's highly relevant that if someone were to actually grow up in a grayscale environment, they wouldn't be capable of experiencing blue. Even if the optic nerve had somehow retained the ability to transmit data from cones, the brain simply would not be wired for blue-processing. I'm pretty sure her brain would interpret a colored world the way a black-and-white television would. (This is my understanding of neuroscience, by the way, not my stab at philosophy.)
I haven't taken the time to think carefully about the implications of this. It just seems suspicious to me that one of the clearest descriptions of qualia I've encountered involves a process that's neurologically implausible to enact.
Results of gene therapy for color blindness suggest otherwise. Maybe those monkeys and mice cannot experience colors, but they react as if they can.
I'm really want to try this myself. Infrared sensitive opsin in a retina, isn't it wonderful?
Does this article help? The knowledge argument is a famous argument that tries to pump the intuition about the existence of qualia, which are the source of the 'hard problem' of consciousness.
Thanks for the link but it still doesn't make sense to me (I've tried to understand what this qualia thing a few times before and I am still baffled about what it is and why everyone other than me thinks it's real).
I can't find the source but I recall reading the following interesting point: different people might possess different degrees of qualia, perhaps ranging down to none, and that perhaps some or all of the debate could be explained by this fact. So maybe it's just your brain. You've read the qualia wikipedia article I assume? It's a pretty obvious concept for most people- whether or not it is 'real'. Perhaps you recall wondering as a child if when other people saw something green they saw the same color you did: "Maybe what you see when you look at things called 'green' is what I see when I look at things called 'orange'. How would we know?'" The aspect of color that cannot be communicated and generates this worry is the qualia of 'greenness',
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Yeah. Except you're not the physically impossible kind since you're actually reporting your lack of qualia- and I'm not sure you actually lack qualia entirely- it's just very weak in you. +1 For Less Wrong neurodiversity. Would you be offended if I prodded you with questions about how you think? (Heck, I sort of think you should just start a discussion post called "I'm a zombie AMA".)
Yes quite happy to answering anything. In fact I sort of preemptively started already! I don't think I'm knowledgeable enough to make an AMA worthwhile for the people asking though.
If I get to anything too private, feel free to tell me to frack off.
Do you know your IQ? Have you been diagnosed with any condition listed in the DSM?
Are there any cognitive tasks that you find yourself notably worse than average (especially compared to those with similar IQs)? What about tasks that you find yourself to be notably better than average?
Can you got into detail about this:
What games/experiments?
Would you say you have a good sense of humor? Can you reliably read someone's emotions from non-verbal cues? Do you have empathy for others that are suffering? Does music evoke emotions in you? Ever been in love?
Let's say you are in a situation which could lead to either excitement or anxiety. When you learn that you are anxious and not excited does that information just come to you verbally? Do you read physical signs of your body? For most people the way we know whether we are excited or anxious is that these emotions feel different- their qualia are different (or at least that is how we report learning about our emotional state... I'm not entirely sure that story is right).
Is this a good zombie test? I have to consciously search my body for hints to tell those apart.
By the way, I'd be interested in your opinion on my comment here, are you able to deliberately cause dream-like, simulated sensory experiences that do not correlate with the outside world?
I am able to simulate sensory input, i.e. dream deliberately, enter my personal Matrix (Holodeck). I can see, hear, feel and smell without the presence of light, sound, tactile or olfactory sensory input. That is, I do not need to undergo certain conditions to consciously experience them. They do not have to happen live, I can imagine them, simulate them. I can replay previous and create new sensory experiences in my mind, i.e. perceive them with my minds eye. I can pursue and experience activities inside my head without any environmental circumstances, i.e. all I need is my body. I can walk through a park, see and hear children playing, feel and smell the air, while being weightlessness in a totally dark and quiet zero gravity environment. Can you do that?
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Well, "the philosophical zombie is a hypothetical person whose behavior is indistinguishable from an ordinary person, but who lacks conscious experience." That's nonsensical, but you could however lack conscious experience while acting differently, e.g. not being able to comprehend the concept of qualia.
Excellent point.
Maybe it's better to start from obvious things. Color experience, for example. Can you tell which light of traffic lights is illuminated while you are not using position of light and you aren't asking himself which color it is? Is there something in your perception of different lights that allows you to tell that they are different?
The cones in the eye detect three different aspects of light (redness, greenness, blueness) and these are sent to the brain in three different fibers. By this mechanism we see there's nothing magic going on in telling the difference between two colors. I guess the rods (which detect variation in brightness) are more relevant to the question of which light is on though.
I doubt that you think about rods and cones when you are deciding if it's safe to cross the road. The question is: is there something in your perception of illuminated traffic light, that allows you to say that it is red or green or yellow? Or maybe you just know that it is green or yellow, but you can't see any differences but position and luminosity?
I don't understand what the question is getting at. You're right that I don't think about cones when I check which color a light is, but this is the mechanism by which it enters my brain: since different lights enter my brain in different ways it is no surprise I can differentiate between them.
I am getting there. There's a phenomenon called blindsight type 1. Try to imagine that you have "color blindsight", i.e. you can't differentiate between colors, but you can guess above chance what color it is. In this condition you lack qualia of colors.
Not to be dismissive of a chunk of philosophy, but your post is akin to "I've tried to understand elan vital, but I keep running into problems integrating it with my biology course".
Materialists should be able to answer "why do people think they have qualia" without it being a mystery.
Even the most strident eliminative materialists understand what is meant by qualia. You don't have to integrate a concept into your theory to understand what it means.
It's hard to understand because it's confused.