JoshuaZ comments on Book Review: The Root of Thought - Less Wrong

47 Post author: Yvain 22 July 2010 08:58AM

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Comment author: JoshuaZ 23 July 2010 12:20:12AM * 4 points [-]

The real issue is not the "presence of qualia", it's what qualia should map to in the underlying physics. Saying that e.g. the color blue is an incredibly complex pattern in the classical physical system corresponding to the human visual cortex--which actually differs physically from human to human--is just not a tenable position.

So how is this at all distinct than the fact that words like "good" or "puppy" have complicated mappings onto our brain structure? These present just as much of a difficulty as qualia. And just because we can't precisely map those now doesn't make those positions untenable. Why posit new physical laws for a set of phenomena that we understand better and better with no sign of stopping? If we ran into some apparent wall in understanding how these function then after a while it might make sense to look at new physics that might explain things. But as it is now, we've been making steady progress on these issues for about a hundred years. We now can use electromagnetic stimulation to make people experience specific classes of feelings, and we can use electrodes more directly to trigger direct responses. We can see emotions and sensations actively in the brain by fMRI and other methods. There's no need for spooky suppositions.

Comment author: bogus comment score below threshold [+] (41 children)

Comment author: JoshuaZ 23 July 2010 01:57:53AM 6 points [-]

It's different because we know for certain that the mapping of words such as "good" and "puppy" onto our basic phenomenology is culturally dependent, learned throughout our childhood, etc. We can say no such thing about the mapping between physics and subjective experience.

I'm missing something here. How does the fact that this correlation isn't as culturally dependent imply something spooky is going on?

It's not because we can't precisely map them; it's because the possiblity of there even being a mapping is so weird and complicated that spooky, exotic physics looks good by comparison.

Again, I don't follow your logic. What would be weird and complicated about such a mapping?

Basically you would be forced to argue that the mapping between classical physics and subjective perceptions was picked by an optimizing agent, which is far more spooky.)

Why? What need is there for an optimizing agent? What do you think this optimizing agent would have done? I'm not sure what you are trying to say here but it almost seems to some sort of argument that if one wants to reject theism one needs spooky physics. I don't know how to respond to that.

We can see macroscopic correlates of emotions and sensations in an fMRI. Ths does not mean that the emotion and sensation is the same thing as the change in fMRI. (In fact, all fMRI does is measure changes in blood flow.)

You might notice that I said "fMRI and other methods." We can for example, use deep brain stimulation to directly stimulate emotions (this is in fact a cutting edge treatment for people with severe depression and is being investigated for use in treating other illnesses). We can see which parts of the brain are being used for what emotions and sensations and we can stimulate those regions to duplicate those emotions and sensations.

More generally, it seems like you may be confusing the map with the territory. A blank or poorly drawn area of a map doesn't tell us about the territory. It is true that repeated failure to get a good map of an area of territory can tell us that our mapping method has a problem or that another section of our map has issues. That's essentially what happened with Copernicus and Kepler; the repeated failures to get accurate models of the heavens forced a redrawing of fundamental sections of the map. But in order to justify that, one needs to have repeated problems over a long period of time with trying to get a good map of an area. If your map keeps getting more and more precise, that's not useful. Finally, a question if you don't mind: what hypothetical evidence would convince you that qualia can be explained by our current laws of physics?

Comment author: bogus 23 July 2010 03:39:31AM -2 points [-]

We can for example, use deep brain stimulation to directly stimulate emotions

We can stimulate emotions, yet we are nowhere near a satisfactory explanation of why each emotion has the psychological effects it does. It's quite clear that we can only play with the brain at a very coarse level.

Finally, a question if you don't mind: what hypothetical evidence would convince you that qualia can be explained by our current laws of physics?

Reliable brain simulation would be solid evidence here. Others have pointed out that we probably won't be able to revive cryopreserved patients without a thorough understanding of brain physics.

Comment author: JoshuaZ 23 July 2010 03:47:39AM 3 points [-]

We can stimulate emotions, yet we are nowhere near a satisfactory explanation of why each emotion has the psychological effects it does. It's quite clear that we can only play with the brain at a very coarse level.

Sure, but who cares? The point is that our ability to do this has been steadily improving and there's no indication that any part of our coarse play has turned up any evidence of any special physics at work.

Comment author: WrongBot 23 July 2010 01:20:47AM 5 points [-]

We can say no such thing about the mapping between physics and subjective experience.

The wavelength of light maps pretty straightforwardly onto our perception of color. We can trace the activation of cones in our eyes to patterns of neuron firing in the optic nerve to neurons firing in the visual cortex. "Redness" isn't magic. "Redness" is a particular configuration (or, more properly, a set of configurations) of neurons. The only reason it seems special to you is because you are experiencing the algorithm from the inside. Consciousness is what thinking feels like, not magic.

Comment author: saturn 23 July 2010 09:12:48AM 1 point [-]

Sure... I'm with you until you get to the part where some (all?) configurations of matter have experiences from the inside, which nobody can detect or describe, and the only evidence that these "experiences" exist is that people say they can feel them... isn't this exactly the kind of thinking we ought to dismiss as crazy? But on the other hand, I think I feel experiences too!

Comment author: WrongBot 23 July 2010 09:23:01AM 3 points [-]

You're making this more mysterious than it needs to be. No matter what our experiences felt like, we'd still call them qualia. No matter how we used our senses to acquire information about the world, we'd still call that process experience.

Comment author: cousin_it 23 July 2010 09:26:16AM 1 point [-]

Are you claiming that any sufficiently complex agent will report a mysterious feeling of consciousness? That can't be right.

Comment author: WrongBot 23 July 2010 09:35:13AM 3 points [-]

I wouldn't feel comfortable making that claim until I'd tested it on a couple of non-human agents, and in any case I wouldn't call it mysterious.

Really all I have is the suspicion that consciousness is much more normal than people tend to think. The only thing I'm confident of is that explaining consciousness won't require magic or special exceptions to the laws of physics.

Comment author: prase 23 July 2010 11:05:02AM 0 points [-]

What sort of answer, do you think, will people accept as explanation of consciousness? I ask that because I suspect that however deep understanding of thought will not destroy all the feeling of mystery. Even after we become able to model human brains on computers and after we discover which parts of brain are responsible for each exact feeling, I can't imagine how this knowledge stops people wonder about qualia, zombies and Chinese rooms.

Comment author: RobinZ 23 July 2010 03:29:05PM 2 points [-]

What sort of answer, do you think, will people accept as explanation of consciousness? I ask that because I suspect that however deep understanding of thought will not destroy all the feeling of mystery.

I imagine Lord Kelvin felt similarly when he thought of the elan vital. It didn't work for that, and it didn't work for a very good reason: your ignorance of the realm of possibilities is not good evidence. An inability to come up with alternatives may be better support for a claim than showing that you have not yet been compelled to admit defeat, but it's still nearly worthless.

Comment author: prase 24 July 2010 03:04:12PM 1 point [-]

I didn't mean my question as a Kelvinian declaration that we will never understand. I was only curious whether WrongBot has some more specific idea what sort of answer can destroy the feeling of confusion when thinking about qualia. I am even not sure whether there is a question to be answered.

continue this thread »

Comment author: bogus 23 July 2010 01:42:11AM * -2 points [-]

"Redness" is a particular configuration (or, more properly, a set of configurations) of neurons.

You're missing the basic problem: 'neurons' are part of the map, not the territory. The territory is made up of quarks, spacetime and probability amplitudes. What's the set of configurations of quarks which feels from the inside like thinking or like the color red? How can you be so confident that no magic is involved in this "how it feels from the inside" business, while casually talking about configurations of neurons?

Comment author: WrongBot 23 July 2010 01:54:34AM * 7 points [-]

How can you be so confident that no magic is involved in this "how it feels from the inside" business, while casually talking about configurations of neurons?

I usually find Occam's Razor to be sufficient. You are misapplying reductionism: if consciousness maps to a set of configurations of neurons, and neurons map to quarks, spacetime, and probability amplitudes, then we have no need of mysteriously specific exceptions to physical laws. Indeed, such hypothetical and entirely unsupported exceptions have no explanatory power at all.

What's the set of configurations of quarks which feels from the inside like thinking or like the color red?

Why, the set of configurations of quarks which describe any member of the set of neurons which feel from the inside like thinking or like the color red, of course.

Comment author: JoshuaZ 23 July 2010 02:00:51AM 6 points [-]

You're missing the basic problem: 'neurons' are part of the map, not the territory. The territory is made up of quarks, spacetime and probability amplitudes.

No, he's not. Neurons are part of the territory. They are composed of other parts of the territory which are composed of quarks, spacetime, etc. But that doesn't make a neuron not part of the territory. Just because something is ontologically reducible doesn't mean it isn't part of the territory. It just means that you need to be very careful not to treat it is as ontologically fundamental when it isn't.

Comment author: bogus 23 July 2010 03:05:13AM * 0 points [-]

No, he's not. Neurons are part of the territory.

Fine, substitute "not ontologically fundamental" for "not part of the territory" if you must.

It just means that you need to be very careful not to treat it is as ontologically fundamental when it isn't.

The problem is that most philosophers who care about phenomenology at all would assign at least some ontologically foundational status to it, simply because it is foundational enough to you and anyone else with subjective experience. There is a reasonable argument to be made that "the way it feels from the inside" is just as fundamental as the basic physics of how the world works.

This does not imply that the two are necessarily related (for instance, P-zombies or robots can be unconscious yet physically talk about subjective experience). It does mean that Occam's razor should apply to "the way it feels from the inside", which tends to weigh against complex explanations like "configurations of neurons" and in favor of either exotic physics or a spooky superintelligence who can figure out how to run debugger sessions on our physical brains.

Comment author: JoshuaZ 23 July 2010 03:18:16AM 4 points [-]

The problem is that most philosophers who care about phenomenology at all would assign at least some ontologically foundational status to subjective experience, simply because it is foundational enough to you and anyone else with subjective experience.

Unfortunately, this is close to nonsense. Just because something strikes me as foundational to me doesn't give me any decent reason for thinking it has any such actually foundational status. Humans suck as introspection. We really, really suck at intuiting out the differences in how we process things unless things are going drastically wrong. For example, it isn't obvious to most humans that we use different sections of our brains to add and multiply. But, there's a lot of evidence for this. For example, fMRI scans show different areas lighting up, with areas corresponding to memory lighting up for multiplication and areas corresponding to reasoning lighting up for addition. Similarly, there are stroke victims who only lose the ability to do one or the other operation. And this is but one example of how humans fail. Relying on human feelings to get an idea about how anything in the world, especially our own mind, works is not a good idea.

It does mean that Occam's razor should apply to "the way it feels from the inside", which tends to weigh against complex explanations like "configurations of neurons" and in favor of either exotic physics or a spooky superintelligence who can figure out how to run debugger sessions on our physical brains.

I don't follow this logic at all. I'm not completely sure what you are trying to do here but it sounds suspiciously like the theistic argument that God is a simple hypothesis. Just because I can posit something as a single, irreducible entity does not make that thing simple. (Also, can you expand on what you mean by a spooky superintelligence running debugging sessions since I can't parse this is in any coherent way)

Comment author: bogus 23 July 2010 05:08:11AM -2 points [-]

Unfortunately, this is close to nonsense. Just because something strikes me as foundational to me doesn't give me any decent reason for thinking it has any such actually foundational status.

Small nitpick: I am not talking about what is foundational to the way our world works. I am only making the fairly trite obsevation that subjective experience/qualia is the only thing we can directly experience; it would be really, really strange if something so basic to us turned out to be dependent on complicated configurations of neurons and glial cells, as naive physicalists suggest.

Humans suck as introspection. We really, really suck at intuiting out the differences in how we process things unless things are going drastically wrong. For example, it isn't obvious to most humans that we use different sections of our brains to add and multiply.

What this is actually saying is that phenomenology (the stuff we can access by introspection) cannot directly map physical areas of the brain of the kind which might get damaged in a stroke. In itself, this is not evidence that humans "suck" at introspection; especially if our consciousness really is a quantum state with $bignum degrees of freedom, rather than a classical system with spatially separate subparts.

it sounds suspiciously like the theistic argument that God is a simple hypothesis.

God is not a simple hypothesis, but "this was affected by an optimization process which cares about X or something like it" is simpler than "this configuration which happens to be near-optimal for X arose by sheer luck". Which is pretty much what one would have to posit in order to explain our subjective experience of the extremely complicated physical systems we call "brains". There are other avenues such as the anthropic principle, but ISTM that at some point one would start to run into circularities.

Comment author: prase 23 July 2010 08:47:40AM 6 points [-]

it would be really, really strange if something so basic to us turned out to be dependent on complicated configurations of neurons and glial cells, as naive physicalists suggest.

What else can it depend on? Your original claim was that it has to do something with quantum superpositions, so can you tell, how these superpositions are going to explain qualia any better? Seems like you demand the explanation be black box without internal structure; this is contrary to what actual explanations are.

this configuration which happens to be near-optimal for X arose by sheer luck

The "naive physicalists" don't maintain anything like that. Evolution isn't sheer luck.

Comment author: bogus comment score below threshold [+] (5 children)

Comment author: RobinZ 23 July 2010 06:33:46AM 3 points [-]

Small nitpick: I am not talking about what is foundational to the way our world works. I am only making the fairly trite obsevation that subjective experience/qualia is the only thing we can directly experience; it would be really, really strange if something so basic to us turned out to be dependent on complicated configurations of neurons and glial cells, as naive physicalists suggest.

Do you question the consensus that you see using your eyes? Because the eye is a blatantly complicated mechanism directly in the middle of one of the direct experiences of the world you stake your theory on.

Comment author: bogus 23 July 2010 10:26:54AM * -2 points [-]

I'm not questioning the fact that complicated mechanisms are involved in creating your subjective experience; I question the physical description of that subjective experience as an incredibly complicated configuration in the brain. If your qualia are at all real in some sense, they should correspond to something far simpler than that on Occam's Razor grounds. Alternately, you might just be a P-zombie. But then you'd have serious problems experiencing how your brain feels from the inside, although your brain would definitely be talking about its internal experiences.

continue this thread »

Comment author: WrongBot 23 July 2010 03:20:19AM * 3 points [-]

There is a reasonable argument to be made that "the way it feels from the inside" is just as fundamental as the basic physics of how the world works.

Well, what is it, then?

The problem is that most philosophers who care about phenomenology at all would assign at least some ontologically foundational status to subjective experience, simply because it is foundational enough to you and anyone else with subjective experience.

Ahhhh, I see now. Subjective experience must be ontologically foundational because it feels foundational, subjectively. This seems oddly... circular.

It does mean that Occam's razor should apply to "the way it feels from the inside", which tends to weigh against complex explanations like "configurations of neurons" and in favor of either exotic physics or a spooky superintelligence who can figure out how to run debugger sessions on our physical brains.

Configurations of neurons are not complex. They are complicated, but they can still be explained by the same physics as everything else in the world. You are proposing a more complex universe. Or possibly a god. They are equally implausible without supporting evidence.

Comment author: bogus comment score below threshold [+] (5 children)

Comment author: JoshuaZ 23 July 2010 12:38:01PM * 2 points [-]

You are proposing a more complex universe.

Not really, since both subjective experience and quantum mechanics are part of our universe already.

No, you are proposing a more complicated universe. Quantum mechanical systems can be simulated on a classical computer given a source of randomness. The only caveat, is that if certain compsci conjectures are true then it actually takes more time or more memory for a classical system to simulate these runs than a quantum system would. If the complexity hierarchy exhibits partial collapse with say BQP being equal to P, then even this would in some sense not be true and we'd then have quantum computers as just classical machines with a source of random bits. Now, most comp sci people don't believe that, but the thrust of this argument just requires the fact that classical machines with randomness can simulate quantum machines given extra time and space. since that is the case, in order to assert that quantum mechanics has any chance of causing things like qualia and consciousness would require that there are fundamental gaps in our understanding of quantum mechanics. It would also likely violate many forms of the Church-Turing thesis. So you'd have to basic failings in our understanding of QM and theoretical comp sci for this sort of approach to be even have a chance at working.

Comment author: bogus 23 July 2010 12:53:26PM * -1 points [-]

Quantum mechanical systems can be simulated on a classical computer given a source of randomness.

This implies that unconscious classical systems can simulate a conscious being. But such a simulation of consciousness would not involve the systems in our physical world which can actually be "felt from the inside". In this theory, qualia and consciousness are not caused by quantum mechanics; they are what some extremely complex quantum states feel like.

The only caveat, is that if certain compsci conjectures are true then it actually takes more time or more memory

If quantum algorithms are at all useful, this is enough for evolution to favor quantum computation over classical.

continue this thread »

Comment author: prase 23 July 2010 10:26:14AM 2 points [-]

What's the set of configurations of quarks which feels from the inside like thinking or like the color red?

Do you demand the exact wave function?

How can you be so confident that no magic is involved in this "how it feels from the inside" business, while casually talking about configurations of neurons?

I was never much comfortable with "consciousness is how thinking feels from inside" explanation, since it hardly explains anything. However, the alternatives are non-explanations even more. Unless the hypothesis predicts something testable, it is useless. The position that no non-standard physics is involved is a kind of default which is held whenever there are no clear reasons to think otherwise, that's all.

JoshuaZ comments on Book Review: The Root of Thought - Less Wrong

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