23/06/2010 by admin.

Mark Changizi wrote a posting in PsychologyToday about colour qualia (here). He has some good thoughts about colour that stem from his research.

How do we know that your ‘red’ looks the same as my ‘red’? For all we know, your ‘red’ looks like my ‘blue’. In fact, for all we know your ‘red’ looks nothing like any of my colors at all! If colors are just internal labels, then as long as everything gets labeled, why should your brain and my brain use the same labels?…

However, I would suggest that most discussions of rearrangements of color qualia severely underestimate how much structure comes along with our color perceptions. Once one more fully appreciates the degree to which color qualia are linked to one another and to non-color qualia, it becomes much less plausible to single color qualia out as especially permutable…other qualia are deeply interconnected with hosts of other aspects of our perceptions. They are part of a complex structured network of qualia, and permuting just one small part of the network destroys the original shape and structure of the network - and when the network’s shape and structure is radically changed, the original meanings of the perceptions (and the qualia) within it are obliterated. But we’re beginning to know more about what colors are for, and as we learn more, color qualia are becoming more and more like other qualia in their non-permutability…

colors are part of a three dimensional space of colors, a space having certain well-known features. The space is spanned by a red-green axis, a yellow-blue axis, and a black-white axis. These three axes have opponent colors at opposite ends, and these extreme ends of the axes are pure or primary (i.e., not being built via a combination of other colors). All the colors we know of are a perceptual combination of these three axes. For example, burnt orange is built from roughly equal parts yellow and red, and is on the darker side of the black-white dimension…

Our primate color vision is peculiar in its cone sensitivities (with the M and L cones having sensitivities that are uncomfortably close), but these peculiar cone sensitivities are just right for sensing the peculiar spectral modulations hemoglobin in the skin undergoes as the blood varies in oxygenation. Also, the naked-faced and naked-rumped primates are the ones with color vision; those primates without color vision have your typical mammalian furry face…In essence, … our color-vision eyes are oximeters like those found in hospital rooms, giving us the power to read off the emotions, moods and health of those around us. On this new view of the origins of color vision, color is far from an arbitrary permutable labeling system. Our three-dimensional color space is steeped with links to emotions, moods, and physiological states, as well as potentially to behaviors. …

Furthermore, these associations are not arbitrary or learned. Rather, these links from color to our broader mental life are part of the very meanings of color - they are what color vision evolved for…The entirety of these links is, I submit, what determines the qualitative feel of the colors we see. If you and I largely share the same “perceptual network,” then we’ll have the same qualia. And if some other animal perceives some three-dimensional color space that differs radically in how it links to the other aspects of its mental life, then it won’t be like our color space. …its perceptions will be an orange of a different color.

The question now is not why colour? or is you red the same as my red? but why are colours so vivid and beautiful in our consciousness?.

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25/03/2010 by admin.

The MindHacks blog had a link to a interview of Nicholas Humphrey by Alan Saunders in Philosophers Zone (here). Here is another interesting observation from the recording. He is giving a possible reason for consciousness.

…What these experiments establish is a lot of other evidence which corroborates it, is that perception, the representation of things in the world, their characteristics, their physical characteristics, is going on independent of sensation. So that raises the huge question of, OK, well then what is sensation for? In the old days people didn’t need to ask that question because they said, ‘Well sensation is what gives the information for perception. You first have an image, your eye,you sensed that as a set of coloured sensations. You then build up your infer the existence of the objects out there in the world. We now know you don’t need that first step, you can go directly to perception. So, what is sensation for?

…Sensations have some very strange and wonderful properties, chief of which perhaps is their extraordinary thickness in time. Sensations are not instants, they’re not physical instants. Every sensation seems to last for more time than it actually occupies. And so instead of moving through life like a kind of point on a single trajectory, we move through it as a substantial entity. I’ve used the analogy we move through life as in a kind of time-ship which has both a prow and an after-end to it, and space inside to move around.

…So I’ve been trying to come up with a new story about why consciousness should matter and why it should have evolved. … the new line I’m taking is not to be looking for things which consciousness helps us to achieve. It doesn’t give us any particular new skills, it’s not like for example the wings of a bird enables the bird to fly. Your understanding English enables you to understand what I’m saying now. I don’t think consciousness enables us to do anything, what I think it does is it encourages us to do things which we wouldn’t do otherwise; to think about ourselves and relate to the world in ways which we wouldn’t do otherwise.

In other words, consciousness changes our psychology, not in the sense of giving us new cognitive skills, but changing our sense of what it is to be ourselves and what it is to live in the extraordinary world which consciousness delivers to us. Basically, it makes ourselves think of ourselves as being of hugely greater metaphysical significance (we don’t of course use that word ) but simply thinking of ourselves as mattering, of our lives as mattering, and indirectly of course, of other people’s lives as mattering because we have been privileged to have been given this miraculous phenomenon at the centre of our lives.

I have to say that this sounds like an interesting side effect of consciousness rather than a reason for its existence. However, it is worth thinking about.

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22/03/2010 by admin.

The MindHacks blog had a link to a interview of Nicholas Humphrey by Alan Saunders in Philosophers Zone (here). There are a number of interesting observations in the recording. Here is one about the separation of perception and sensation.

…The essential point to make is that seeing, hearing or touch or smelling for that matter, is not a single dimension, it hasn’t got just one dimension to it. It’s terribly important to distinguish perception from sensation. The perception of red means understanding, representing the effect about the world, that there is a traffic light out there and that it has a particular coloured light coming from it, or to take another example, that there’s a tree standing in the forest and that it’s quite a particular shape and position and so on. Those are facts about the world, and we use our eyes, use other senses, to get that kind of other information.

Sensation, by contrast, isn’t about what’s out there in the world, it’s about our own response to the stimulation falling on our sense organs… These two things, sensation and perception, are often confused and it’s been traditional in philosophy and certainly I think it’s most people’s view that actually perception depends on sensation. We only get to know that the traffic light is red because first of all we have a sensation. …

What I try to do in the beginning of the book is to show that actually and amazingly this isn’t the case. Perception proceeds independently of sensation; we don’t have to have the sensation in order to get to know what’s out there in the world. And I go through a lot of examples to make that case. Perhaps the most remarkable is the phenomenon of blind sight. It’s something I guess I was responsible for discovering many years ago when I was working, not with human beings but with monkeys.

As a student in Cambridge I had the opportunity to study a monkey who had the visual cortex at the back of her brain removed. My supervisor had done the experiment. He had established that this monkey was apparently quite blind … I had the chance to spend some time with this monkey, she was called Helen, and over literally a few days, sitting with her, playing with her, it became clear to me that she wasn’t actually as blind as she was meant to be. … But I realised there was something very strange about her vision. There must have been something wrong with her you could have guessed, because she didn’t have any visual cortex to see with, but what I became convinced of was that she didn’t believe that she could see. She didn’t seem to have the evidence in front of her eyes if I can put it like that, that she could see. Although every day she would demonstrate objectively that she could. She would run, climb a tree, she would pick up a bit of chocolate from the floor or whatever it may be, she’d come up and take my hand. Out of that work I began to speculate about the possibility of unconscious vision, visual perception occurring without the possibility, without I should say, the fact of sensation. So the subject wouldn’t understand why they could see or have any reasons to believe that they could see.

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08/02/2010 by admin.

Previously I looked at C. Here is the E in an AtoZ by P. Long in My Brain on My Mind. (here)

Easy Problem. Philosopher’s lingo for the problem in neuroscience of comprehending the neuronal correlates of consciousness. When you see red, what exactly are your neurons doing? When you remember your grandfather’s face, what are your neurons doing? It may be difficult to parse the answer but in principle we can do it. It’s easy. The Hard Problem is the mystery of subjective experience. When long light waves stimulate our neural pathways, why do we experience the color red? And what survival benefit caused our brains to develop, through eons of evolution, an ability to experience a “sense of self,” a self able to see itself as special or heroic or smart or not so smart—as, on occasion, a complete failure?

I am not going to discuss a sense of self here, as it seems self evident that a sense of self is useful.

It is not usually quoted as an example of the hard question. Usually we see colour mentioned. Why does the personal experience of colour seem unexplainable? or at least a different order of mystery from other things?

What is the function of colour? It is definitely not there so that we can know the wavelength of light. We do not need or want to know the wavelength of light and, further more, colour is not a reliable measure of wavelength The colours that we see are ‘corrected’ in so many ways and to such an extent that their mapping to the physical wavelength of light is very approximate. Forget wavelength.

What colour does is to help give us objects. Our experience is of a three-dimensional space that is populated with objects. Objects are created by our perception to have particular locations, sizes and surfaces. We understand the world in terms of its objects and the world at any point in time is just objects in space. We recognize them, remember them, categorize them, name them and so on. Our lives are easier if objects that are not actually shrinking or growing, keep their size no matter how much of our retina they take up. We do not want them to move unless they are mobile even though our eyes are flicking their image around on our retina. We do not want objects to suddenly disappear or appear unless they actually are intermittent. And we do not want the surface of an object to change unless it is actually chemically or physically changing. The light (and sound) that is reflected off (and the feel to touch or smell of) an object is important to recognizing that object – such as noticing the archetypal tiger in the long grass at twilight. What our perception creates is objects and they have surface as important property. Those surfaces have colour as part of their image. So colour is very useful in recognizing and remembering objects.

Why is colour so complex in its nature and so delightful to us? The more complex it is, the more we can differentiate between similar surfaces. As far as delighting us – all the aspects of all our senses delight us or disgust us as appropriate. We build a model of the world; we are aware of parts of that model when we are conscious; we remember that model as we live in it; what is important and memorable in the model at any time is what we attend to and remember.

We do not have an explanation for colour or other aspects of subjective experience, but when put in a biological context, it does not seem any harder than many other questions. When we compare it to other questions in biology, why assume it was somehow different and unsolvable?

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15/01/2010 by admin.

There is a site called Less Wrong that I visit (here) because occasionally there is an outstanding post there. I do not comment on the posts as a rule because it is something of a boys club of AI guys and I don’t feel that I belong. But last week there was a post that got me a little worked up and I commented. My efforts lost me some karma but never mind, I didn’t know I had been playing the Less Wrong game. Here is the comment:

“The local worldview reduces everything to some combination of physics, mathematics, and computer science, with the exact combination depending on the person. I think it is manifestly the case that this does not work for consciousness.”

No it doesn’t work because you have left out BIOLOGY. You cannot just jump from physics and algorithms to how brains function.

Here is the outline of a possible path:

1. We know that consciousness has an important function because it consumes a great deal of energy – that’s how evolution works.

2. Animals move – therefore they must have a model of where they are, where they are going etc. - like the old Swedish joke, ‘I cant yump when I got no place to stood’.

3. To make a model, animals need to sense the environment and translate the info into elements of the model (perception).

4. In order to use the model to plan and monitor motor action, they have to also model themselves – so the model is of the animal-in-the-world - the tree is not the real tree in reality but the modeled tree and the me in the model is not the real me in reality but the modeled me.

5. In order to make a good model that was useful it would have to be a unified global model of the animal in the world – all the parts of the model have to be brought together in order to create the best fit scenario and in order for various functions to use the information.

6. In order to make a good model that could be used to plan and valuate actions it would have to model the needs of the animal such as goals, motivations, emotions etc – the model has to have a theory of mind for the animal - so my thoughts in the model are not my real thoughts in reality but the modeled mind. When we introspect we are aware of our model of ourselves but not of ourselves in reality. Definitions can be a problem here – do we use the word ‘mind’ for cognition or for awareness? For we have trouble if we confuse these two things.

7. To make the model more useful it should be predictive to overcome the time it takes to construct the model – so if ‘now’ is t, then the model would be created from the information the brain has at t-x used to predict what reality will be after x duration where x is the time it takes to construct the model – this allows errors in motor actions to be monitored and corrected because the sensory data coming it does not match the model prediction – even the ‘now’ is a modeled now and not the now in reality.

8. So the biological criteria for a good model are unity, speed, accuracy and predictive power. The elements used to create the model must be easily manipulated in order to achieve these goals and must also be capable of being stored as memories, imagined, communicated etc. The qualia of the model will be anything and everything that is biologically possible and makes a good model. We have the data that the sense organs can measure and some effective ways of representing that information in the model.

So the question “Why red?” can be answered with “Why not – it works.” And the question “Where is the red?” can be answered by “In the structural elements of the model”. If someone has a better way to model the frequency of light, I have never heard of it.

If you cannot envisage this modeling as a sequential computer program that is because it isn’t one. It is a massively parallel assembly of overlapping feedback loops that involve most of the cortex, the thalamus, the basal ganglia and even points in the brain stem. It has more in common with analogue computers then digital ones.

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09/01/2010 by admin.

J. Hoffman in the New York Times writes in ”Taking mental snapshots to Plumb our inner selves’, about the work of R. Hurlburt (here), who is attempting to document the contents of consciousness. The method is to fit a person with a random beeper and instructions to record everything they are aware of when the beeper sounds. The people were later interviewed about each recorded moment of consciousness.

After hundreds of introspective interviews, Dr. Hurlburt still hesitates to generalize from his findings. But he has observed that the basic makeup of inner life varies substantially from person to person.

“My research says that there are a lot of people who don’t ever naturally form images, and then there are other people who form very florid, high-fidelity, Technicolor, moving images,” he said. Some people have inner lives dominated by speech, body sensations or emotions, he said, and yet others by “unsymbolized thinking” that can take the form of wordless questions like, “Should I have the ham sandwich or the roast beef?”

In a 2006 book, “Exploring Inner Experience,” Dr. Hurlburt suggests that these differences may be linked to personality and behavior. Inner speakers tend to be more confident, for example, and those who think in pictures tend to have trouble empathizing with others.

Many feel that this is not a very objective experiment. How do we know that people can or do report their conscious awareness in an isolated moment with accuracy, nothing added and nothing missed.

It may be that turning introspection into a science is as impractical as “trying to turn up the gas quickly enough to see how the darkness looks,” as William James wrote in 1890.

But Dr. Hurlburt remains hopeful. Maybe, he said, “it is possible with our modern technology to take a flash picture in the dark.”

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11/10/2009 by admin.

E. Thompson in the philosophical blog, Brains, posted on the ‘Hard-Problem’. (here) He looks at Chalmers’ ideas on consciousness and quotes a Chalmers definition:

“The really hard problem of consciousness is the problem of experience. When we think and perceive, there is a whir of information-processing, but there is also a subjective aspect. As Nagel (1974) has put it, there is something it is like to be a conscious organism. This subjective aspect is experience. When we see, for example, we experience visual sensations: the felt quality of redness, the experience of dark and light, the quality of depth in a visual field.”

Thompson pin points the weaknesses in Chalmers’ statement:

First, as suggested in the second sentence of the quote above, Chalmers assumes that experience cannot be a matter of information processing. If you read his book, he explicitly assumes (in the Introduction) that experience cannot be generated by information processing, neuronal activity, standard biology. Given that assumption, is it any surprise that he thinks experience is a really hard problem? … Chalmers has the stones to claim that those not working within this loaded conception of consciousness aren’t ‘taking consciousness seriously’

Of course, the biologists who are studying consciousness are taking it seriously and believe that ’standard biology’ can generate experience. They are not playing word games.

Thompson goes on to the use of the hard-problem idea by others:

Despite these seemingly obvious problems with his approach, I observed with dismay as the phrase “What about the hard problem?” spread like syphilis over the amateur philosophy of consciousness landscape. It became a kind of cognitive creativity sink, an easy knee-jerk response to any discussion of consciousness. Psychologists and neuroscientists are now required, by law, to address the “hard problem” in the first or final chapter of their books on consciousness. It’s a bit ridiculous.

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05/10/2009 by admin.

Science Daily (here) reports on a paper by S. Shevell, Color-Binding Errors during Rivalrous Suppression of Form. The work shows how the brain integrates the multiple features of an object, such as shape, color, location and velocity, into a unified whole.

“The brain’s neural mechanisms keep straight which color belongs to what object, so one doesn’t mistakenly see a blue flamingo in a pink lake. But what happens when a color loses the object to which it is linked? Research at the University of Chicago has demonstrated, for the first time, that instead of disappearing along with the lost object, the color latches onto a region of some other object in view – a finding that reveals a new basic property of sight.

The research shows that the brain processes the shape of an object and its color in two separate pathways and, though the object’s shape and color normally are linked, the neural representation of the color can survive alone. When that happens, the brain establishes a new link that binds the color to another visible shape.”

It is as if entities are stored in working memory with ‘tags’ to their attributes and these ‘tags’ can sometimes be lost, misplaced or (in synesthesia) be applied to inappropriate entities. However, there must be two sorts of ‘tag’: the vivid attributes of conscious sensory experience which presumably still have access to the primary sensory areas of the cortex, and the much less vivid attributes of memory and imagination where the primary sensory input is long gone or never was.

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22/06/2009 by admin.

Deric Bownds in Mindblog has a post on the book ‘The Ego Tunnel’ by T. Metzinger (here ). An excerpt on the ineffability of consciousness is included:

In between 430 and 650 nanometers, we can discriminate (make same/different judgments about) more than 150 different wavelengths, or different subjective shades of color. But, if asked to re-identify single colors with a high degree of accuracy, we can do so for fewer than 15. The same is true for other sensory experiences. We can discriminate about 1,400 steps of pitch difference across the audible frequency range, but we can recognize these steps as examples of only about 80 different pitches… Thus we are much better at discriminating perceptual values than we are at identifying or recognizing them.
Metzinger uses a simplest example of two similar shades of green to spell through the consequences of this situation (he calls them Green No. 24 and Green No. 25, nearest possible neighbors on the color chart, such that there’s no shade of green between them that you could discriminate). We can experience their difference, but are unable consciously to represent the sameness of Green No. 25 over time. We do not possess introspective identity criteria for this simplest state of consciousness, and we can not pinpoint a minimally sufficient neural correlate of Green No. 25 in the brain if we can not correctly identify the phenomenal aspect of Green No. 25 over time, in repeated trials in a controlled experimental setting. This is why it may be impossible to do what most hard scientists in consciousness research would like to do: show that Green No. 25 is identical with a state in your head.
These simple findings show that there is a depth in pure perception that cannot be grasped or invaded by thought or language. This ineffability problem arises for the simplest forms of sensory awareness, for the finest nuances of sight and touch, of smell and taste, and for those aspect of conscious hearing that underlie the magic and beauty of a musical experience. It almost certainly appears also for empathy, for emotional and intrinsically embodied forms of communication.

What is being said here? We know that experience is ineffable – we cannot describe it completely because language has a ‘coarser grain’ then experience. That is not a surprise. We can notice that two things experienced together are slightly different without being able to identify or recognize which one is experienced alone later. That means that memory too is more ‘coarse grained’ than experience and that too is not a surprise. What does it mean to ’show that Green No. 25 is identical with a state in your head’? (I hate talking about states of mind or brain so I will talk about processes.) There can still be a process that is identical to the experience of green25 and also a process that is identical to the memory of having experienced green25. It would in fact be surprising if these two processes did not differ in some ways.

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26/05/2009 by admin.

ScienceDaily has an item (here) about the work of M. McCloskey on a subject called AH reported in the book, Visual Reflections: A Perceptual Deficit and Its Implications. She had an unusual visual perception deficit that caused her to see objects in the wrong locations.

“When AH looks at an object, she sees it clearly and knows what it is, but she’s often dramatically wrong about where it is. For example, she may reach out to grasp a coffee cup that she sees on her left, but miss it completely because it is actually on her right. And when she sees an icon at the top of her computer screen, it may really be at the bottom of the screen….Studying AH has taught us about how the brain codes where things are — some parts of the visual brain use codes very much like the x and y coordinates we learned about in algebra class… They discovered that when an object was stationary and remained in view for a least a second or two, AH often would see it in the wrong place. However, if an object was shown to her very briefly, or if the object was put in motion, she was able to see its location accurately…. These results tell us that the visual system has separate pathways, one for perceiving stable, non-moving objects, and the other for objects that are moving or otherwise changing. AH’s pathway for stable objects is abnormal, but her pathway for moving or otherwise changing objects is normal…”

As well as saying something about how the brain handles location, it seems to say something about how the brain creates objects. There is an implication that objects are made up of a lot of separate aspects. It is not so much that there is binding of various properties like colour to an object but perhaps the object perception itself is nothing but its various bindings. A number of qualia bound together = object. Worth thinking about…

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