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Why isn’t their a scientific explanation for consciousness yet? What is consciousness in physical not descriptive terms?
Posted: 05 November 2008 01:01 PM   [ Ignore ]   [ # 31 ]
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mckenzievmd - 05 November 2008 11:59 AM

On a technical basis, I’m not sure your point about shape vision holds. There is an awful lot of processing at multiple levels in the CNS which “constructs” the perception of shape. Sure, there is a “real” shape out there, and our perceptions bear a predictable, meaningful relationship to it, but things like edge-enhancement, preferential recognition of lines at certain orientations based on prior exposure, a preference for recognition of certain shapes over others, and so on make our internal representations less direct than I think most people realize. It is literally possible to not see something that one is predisposed to ignore for some reason, just as a frog doesn’t see an object not in motion. This doesn’t invalidate your general point, which I take to be that qualia are subjective representations but, as they are based on real phenomena, they are not arbitrary and they are limited by the properties of the phenomena they represent, but I think it is important to recognize that our perceptions, even of very simple things like shapes and colors, are a lot less reliable than we generally believe.

Well, I agree with all that you’ve said; I’m aware of the multi-level processing that goes on to recover shape from shading and motion, etc. What I’m saying is that under the vast majority of circumstances perceived shape is isomorphic to the real shape as perceived by any visual detector put at that angle and distance. There is an argument that colors are, in some sense, not in the environment; what is in the environment are wavelengths of light which correspond to colors, but color experience is partly constituted by color interrelations—e.g., the fact that there are three primary colors. This notion of a “primary color” has nothing to do with the environment, nothing to do with wavelengths of light in and of themselves. It has to do with cones in the retina, an artifact of visual processing. So far as I know there is no similar problem with shape and shading.

To put it another way, our experiences are extremely faithful to what exists around us. We don’t generally make mistakes about objects in our environment. This is because of our senses. It is true that there are some artifacts of processing that remain (e.g., the phenomenon of having three primary colors), but these are comparatively rare. It is misleading to pretend that somehow our senses are globally misconstruing or creating the information with which we are presented. They are information conduits, not information sources.

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Posted: 05 November 2008 01:39 PM   [ Ignore ]   [ # 32 ]
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I don’t think we have any substantive disagreement. I certainly concur with “our experiences are extremely faithful to what exists around us.”  I’m not entirely sure how you prove “perceived shape is isomorphic to the real shape as perceived by any visual detector put at that angle and distance.” Obviously, the shape we perceive in a two-dimensional representation of an object is an extrapolation from the real object. We know it’s a cube, for example, even though it can’t really be a cube in two dimensions. And I sort of feel the evidence from art history and child development suggests that perception of three-dimensional shapes is learned, or at least heavily influenced by development (both innate and as influenced by experience). You can cripple the system by denying it input at critical phases.


None of this undermines your assertion about the reliable relationship between perception and reality, but it does suggest that a more accurate description of the details of this relationship would be more nuanced and include the fact that our perceptions only correspond to reality in certain ways, namely those of importance in survival and selection in the past. Doubtless, we perceive shape differently from bats, dolphins, and triangle soldiers (assuming you’ve read Flatland). There are probably aspects of the real objects we fail to perceive that could have salience under different conditions. For example, humans are excellent at assessing relative size, weight, temperature, etc. We are not great at assessing absolute values of these without a great deal of training. Perhaps under different evolutionary circumstances, we would be able to perceive the “longness” of something to a much higher degree of accuracy. And yet maybe the angle of orientation of the object would be irrelevant, so we would have poor ability to discriminate this (we might know exactly how big something was but not if it was directly in front of us or off to the side, above or below the plane of our head, whatever). SO in a sense, which qualities of a real object we perceive and to what degree is relative to our natural history, and our perceptions are “true” only to the extent that we are talking about certain lmited elements of an objects overall characteristics.

Anyway, not a crucial distinction, just something I find interesting. As you know, I’m convinced that many of our judgement errors are tied to an excessive, unwarranted confidence in our perception, judgement, memory, and so forth, so I’m always looking for places to point out the limitations to these.

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Posted: 05 November 2008 01:52 PM   [ Ignore ]   [ # 33 ]
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mckenzievmd - 05 November 2008 01:39 PM

I’m not entirely sure how you prove “perceived shape is isomorphic to the real shape as perceived by any visual detector put at that angle and distance.” Obviously, the shape we perceive in a two-dimensional representation of an object is an extrapolation from the real object. We know it’s a cube, for example, even though it can’t really be a cube in two dimensions.

Well, I’d say it can be proven mathematically. That is, if you take the two dimensional image of an object, and compare it to an image that you construct (say) by feeling the object blindfolded, constructing one with the same shape, and then putting it at the same distance and orientation and taking a black-and-white photograph, the two images will be isomorphic.

(Actually, though, we do see objects in three-dimensions. This is both because of stereo vision and because the brain is wired to recover shape from motion and shading).

mckenzievmd - 05 November 2008 01:39 PM

None of this undermines your assertion about the reliable relationship between perception and reality, but it does suggest that a more accurate description of the details of this relationship would be more nuanced and include the fact that our perceptions only correspond to reality in certain ways, namely those of importance in survival and selection in the past.

Absolutely. I actually did my dissertation on some of this. But for an informal discussion I’m leaving out the stuff about fitness and biological selection. Clearly, the senses function as information conduits about the state of the external world. That is why they increased fitness in our ancestors, and why they are around today.

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Posted: 05 November 2008 01:58 PM   [ Ignore ]   [ # 34 ]
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That sounds like an interesting read! Did you publish any of it?

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Posted: 05 November 2008 02:01 PM   [ Ignore ]   [ # 35 ]
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mckenzievmd - 05 November 2008 01:58 PM

That sounds like an interesting read! Did you publish any of it?

Well, only insofar as every dissertation is “published” ... otherwise, no. (It’s also very technical, lots of inside-baseball philosophical jargon and argumentation).

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Posted: 06 November 2008 04:47 AM   [ Ignore ]   [ # 36 ]
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Chris Crawford - 31 October 2008 01:47 PM

I have an easy answer for you, but you may not like it: I deny the existence of consciousness. Let me explain: I think that the term is simply too messy to have any explanatory utility. In other words, it doesn’t help us understand the operation of the human mind. I believe that “consciousness” is merely the modern term for “soul”: some sort of mysterious force that animates the human brain.

If you simply drop the idea of consciousness, then understanding the brain becomes simpler. There are still lots of mysteries, but at least they involve concepts that you can define and work with.

Scientifically you may be right, but no one can live that way. It’s another version of absolute materialism.

Of what practical value is this observation, even if it’s true? The only value I can see is that we entertain the possibility that we may never know what consciousness is, and indeed the question may be meaningless. On the other hand, I think the effort to find an answer is worthwhile.

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Posted: 06 November 2008 03:45 PM   [ Ignore ]   [ # 37 ]
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I have been thinking about qualia and the my red quale is your blue quale argument. It is convenient to pick colors because people don’t usually have extreme repulsions to colors, preferences for color is almost completely cultural. If you think about something like food where food that tastes good is pretty much universally enjoyed once you get over the taboo/fear and develop a pallet for it. When I eat a cheese burger it tastes good, if someone’s quale for a cheese burger was like my quale for rotten eggs then that person would literally be repulsed by cheese burgers. So how could someone arguing for qualia explain that. Another example we know that elevated saratonin levels are associated people feeling happy if someones happy quale was inverted and they would then feel depressed when they had elevated saratonin levels. It seems like quales are directly correlated to our brain states, and that they are relational to our experiences.

That still leaves the question of why quales are like they are. It brings me right back to my original question of what is it about the brain that makes a quale the way it is. It is obvious that a our brains make the quales and quales are governmened by the same natural laws as everything else.

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Posted: 09 November 2008 10:41 AM   [ Ignore ]   [ # 38 ]
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dougsmith - 05 November 2008 10:59 AM

Well, in a sense yes, but we must keep metaphysics and epistemology separate. I would prefer to say that the two states (let’s say of Descartes being awake by the fire or Descartes asleep in his bed dreaming of a fire) are epistemically indistinguishable. We can be fooled. But they are metaphysically distinct possibilities. It is not correct to say that you see your visual qualia. What you see are external objects, but without epistemic certainty. Those objects are presented to you in a certain way, qualitatively. The qualia modify the experience of the external.

Let’s also recall that the standard visual qualia are colors. But there is more to vision than color. There is shape and shading, for example. Is there really a “quale” to a shape which is different from the shape itself? I don’t think so. Shapes are presented directly, as are phenomena like light intensity. The odd thing about color is that the visual spectrum with its three primary colors depends upon the number of cones we have in our eyes. There is no similar issue with shape or shading. Similar sorts of arguments could be made about the other senses, I think.

Hi Doug,

I think there might be a quale to a shape , I’m not sure, but I take the point that the relationship between the shape we see and the colour we see and objective reality differs. However, the shape we see is not the same shape that exists in objective reality. So if you and I were at opposite ends of a very long oblong table, I would see a table starting out wide and getting narrower and narrow, where as you would see something different, the end that looks narrow to me would look wide to you and visa versa.

Actually, of course, the table is the same width all the way along but we definately don’t see that, which is why artists are taught to “paint what you see”

Stephen

[ Edited: 09 November 2008 10:50 AM by StephenLawrence ]
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Posted: 09 November 2008 11:54 AM   [ Ignore ]   [ # 39 ]
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StephenLawrence - 09 November 2008 10:41 AM

Hi Doug,

I think there might be a quale to a shape , I’m not sure, but I take the point that the relationship between the shape we see and the colour we see and objective reality differs. However, the shape we see is not the same shape that exists in objective reality. So if you and I were at opposite ends of a very long oblong table, I would see a table starting out wide and getting narrower and narrow, where as you would see something different, the end that looks narrow to me would look wide to you and visa versa.

Actually, of course, the table is the same width all the way along but we definitely don’t see that, which is why artists are taught to “paint what you see”

Stephen

Your brain is not representing the table in your mind, your brain is representing the light coming off of the table. The table gets smaller because of the geometric relationship between the angle and distance of the light coming off the table into your eye.

If both people sat at the same spot at the end of the table with a pain of glass between them and the table, they could both trace the shape of the table on to the glass. Furthermore the shapes would be identical unless one of the observers had a brain abnormality that affect their vision/vision processing.

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Posted: 09 November 2008 12:58 PM   [ Ignore ]   [ # 40 ]
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Your brain is not representing the table in your mind, your brain is representing the light coming off of the table

I’m not sure I agree. Your brain is processing the data from the light but using it to construct a representation of an object, which can then be reliably interacted with on the basis of the properties deduced by the brain. Not sure it matters to the overall issue, but I think it’s important to keep in mind that our sensory and cognitive systems are in the business of creating representations of real things so we can interact with them.

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Posted: 09 November 2008 04:57 PM   [ Ignore ]   [ # 41 ]
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mckenzievmd - 09 November 2008 12:58 PM

Your brain is not representing the table in your mind, your brain is representing the light coming off of the table

I’m not sure I agree. Your brain is processing the data from the light but using it to construct a representation of an object, which can then be reliably interacted with on the basis of the properties deduced by the brain. Not sure it matters to the overall issue, but I think it’s important to keep in mind that our sensory and cognitive systems are in the business of creating representations of real things so we can interact with them.

Point taken, should have said your mind doesn’t make it get smaller it is the nature of the light reflecting off of the table that causes things to have depth.

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Posted: 09 November 2008 05:38 PM   [ Ignore ]   [ # 42 ]
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StephenLawrence - 09 November 2008 10:41 AM

I think there might be a quale to a shape , I’m not sure, but I take the point that the relationship between the shape we see and the colour we see and objective reality differs. However, the shape we see is not the same shape that exists in objective reality. So if you and I were at opposite ends of a very long oblong table, I would see a table starting out wide and getting narrower and narrow, where as you would see something different, the end that looks narrow to me would look wide to you and visa versa.

Actually, of course, the table is the same width all the way along but we definately don’t see that, which is why artists are taught to “paint what you see”

I took account of that in my answers before. If you take the orientation and distance and modify the shape by the mathematics of perspective, the shape is mathematically correct.

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Posted: 09 November 2008 11:25 PM   [ Ignore ]   [ # 43 ]
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mckenzievmd - 09 November 2008 12:58 PM

Your brain is not representing the table in your mind, your brain is representing the light coming off of the table

I’m not sure I agree. Your brain is processing the data from the light but using it to construct a representation of an object, which can then be reliably interacted with on the basis of the properties deduced by the brain. Not sure it matters to the overall issue, but I think it’s important to keep in mind that our sensory and cognitive systems are in the business of creating representations of real things so we can interact with them.

Hi Brennen,

There seem to be two views amongst those discussing this.

1)Is that what we see is objective reality, as expressed by Doug and 2) is that what we see usually is a faithfull representation or image, as expressed by you Wes and a similar idea by Dan. When speaking to Wes he was saying that he couldn’t see the philosophical problem. Well the problem is simple, neither, views work and we don’t seem to have another.

The problem with the faithful representation idea is that it is meaningless to us. You may have the feeling it means something to you but I believe if you try to imagine it you can’t.

Lets say I make a scale model of a building. You could look out of the window at the building then look at my model and understand what I mean by it being a faithful representation. It’s not the same size but it’s made to scale, it’s not in the same place, the building is over there and it’s over here but we know the relationship between the space it’s in and the space the building is in. It’s a similar colour but is made of different stuff and we know the relationship between the different stuff.

But we can’t say anything about the relationship between our faithfull representation and what it represents because we don’t have that information. We would need to see the object itself to have the information.

So for instance if we are looking at a faithfull representation of an object, we see it in a space but this can’t be the space that the object is in, as the object itself is there and not our representation. So where is the faithful representation and what is the relationship between the space it is in and the space the object is in?

Stephen

[ Edited: 10 November 2008 12:18 AM by StephenLawrence ]
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Posted: 09 November 2008 11:45 PM   [ Ignore ]   [ # 44 ]
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dougsmith - 05 November 2008 10:59 AM

Well, in a sense yes, but we must keep metaphysics and epistemology separate. I would prefer to say that the two states (let’s say of Descartes being awake by the fire or Descartes asleep in his bed dreaming of a fire) are epistemically indistinguishable. We can be fooled. But they are metaphysically distinct possibilities. It is not correct to say that you see your visual qualia. What you see are external objects, but without epistemic certainty. Those objects are presented to you in a certain way, qualitatively. The qualia modify the experience of the external.

Ok so let’s look at a more concrete example.

Here is an optical illusion supplied by Choco on another thread and a following quote from Choco

brain_shadow.jpg

“A and B are the same color.  No matter what you do, you can only see A and B as different colors.”

I think what Choco means is that the two squares are the same in objective reality but that we see two squares which are different colours (different shades of grey )

So here we have a case where our epistemology is that the two square are objectively the same but still what is it that we see? Surely it’s true that we see one square which is lighter than the other. Yes again it’s fakery but still what we see is there, it doesn’t disappear with the knowledge that it is fakery.

If we watch the fakery of a magician sawing a lady in half, we don’t really see a lady sawn in half we assume we do but are mistaken. But this is not true of the two squares, we do really see one lighter than the other, don’t we?

Stephen

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Posted: 09 November 2008 11:48 PM   [ Ignore ]   [ # 45 ]
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dougsmith - 09 November 2008 05:38 PM
StephenLawrence - 09 November 2008 10:41 AM

I think there might be a quale to a shape , I’m not sure, but I take the point that the relationship between the shape we see and the colour we see and objective reality differs. However, the shape we see is not the same shape that exists in objective reality. So if you and I were at opposite ends of a very long oblong table, I would see a table starting out wide and getting narrower and narrow, where as you would see something different, the end that looks narrow to me would look wide to you and visa versa.

Actually, of course, the table is the same width all the way along but we definately don’t see that, which is why artists are taught to “paint what you see”

I took account of that in my answers before. If you take the orientation and distance and modify the shape by the mathematics of perspective, the shape is mathematically correct.

Yes I’ve read there are mathematical rules that this follows but still the table doesn’t really get smaller as it gets further away and it’s still the case that we don’t see an oblong table despite the fact that in objective reality the table is an oblong.

Stephen

[ Edited: 10 November 2008 12:01 AM by StephenLawrence ]
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