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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24/01/2009 by admin.

The Research Digest Blog had a posting (here) titled ‘A spontaneous experience of a sensed presence caught on EEG.

A patient who was being treated after a motor accident, had experiences of a presence when she was alone and happened to be having her EEG recorded when the episode happened.

“It began with a feeling of an electric shock in her right hand, was followed by her arms and hands feeling icy cold, then vibrations went through her body, before she experienced the feeling that a man was in the room with her, even though she was actually alone.
A look at the EEG scans showed that a burst of electrical activity, similar to that observed in an epileptic seizure, occurred in her left temporal lobe at approximately the same time that she reported the sensed presence on her right-hand side.
“Although over the last 20 years we have assessed hundreds of patients who reported the emergence of a sensed presence … this is the first time the reports of a strong ‘sensed presence’ and related sensations occurred ‘spontaneously’ while our screening electroencephalographic measurements were in progress,” said Persinger and his coauthor Sandra Tiller.”

 This seems to be another of those ‘fringe’ qualia (the ‘I am not alone’ feeling) that populate consciousness. We can only see that it is there when it is inappropriately there.

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05/01/2009 by admin.

It is the time of year again when Edge does its yearly question. This year it is, “what will change everything. What game-changing scientific ideas and developments do you expect to live to see?” Among the replies is one from V.S. Ramachandran. I am never disappointed in what Ramachandran has to say and I intend to have a few postings centered on his essay, Self Awareness: the Last Frontier. The Edge contributions are (here).

As well as self, Ramachandran has an insight into qualia.

“…The qualia problem is well known. Assume I am an intellectually highly advanced, color-blind martian. I study your brain and completely figure out down to every last detail what happens in your brain—all the physico-chemical events—when you see red light of wavelength 600 and say “red”. You know that my scientific description, although complete from my point of view, leaves out something ineffable and essentially non-communicable, namely your actual experience of redness. There is no way you can communicate the ineffable quality of redness to me short of hooking up your brain directly to mine without air waves intervening (Bill Hirstein and I call this the qualia-cable; it will work only if my color blindness is caused by missing receptor pigments in my eye, with brain circuitry for color being intact.) We can define qualia as that aspect of your experience that is left out by me—the color-blind Martian. I believe this problem will never be solved or will turn out (from an empirical standpoint) to be a pseudo-problem. Qualia and so-called “purely physical” events may be like two sides of a Moebius strip that look utterly different from our ant-like perspective but are in reality a single surface…So to understand qualia, we may need to transcend our ant-like view, as Einstein did in a different context. But how to go about it is anybody’s guess.”

One of the examples of the disruption of the normal ‘self’ is:

“A patient with a phantom arm simply watches a student volunteer’s arm being touched. Astonishingly the patient feels the touch in his phantom. The barrier between him and others has been dissolved.”     

Ramachandran discusses motor mirror neurons and then goes on to discuss other types of mirror neurons.

“There are also: “touch mirror neurons” that fire not only when your skin is touched but when you watch someone else touched. This raises an interesting question; how does the neuron know what the stimulus is? Why doesn’t the activity of these neurons lead you to literally experience the touch delivered to another person? There are two answers. First the tactile receptors in your skin tell the other touch neurons in the cortex (the non-mirror neurons) that they are not being touched and this null signal selectively vetos some of the outputs of mirror neurons. This would explain why our amputee experienced touch sensations when he watched our student being touched; the amputation had removed the vetoing. It is a sobering thought that the only barrier between you and others is your skin receptors! … I mention these to emphasize that despite all the pride that your self takes in its individuality and privacy, the only thing that separates you from me is a small subset of neural circuits in your frontal lobes interacting with mirror neurons. Damage these and you “lose your identity”—your sensory system starts blending with those of others. Like the proverbial Mary of philosopher’s thought experiments, you experience their qualia.”

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21/09/2008 by admin.

Francis Crick and Christof Koch in Cerebral Cortex1998, Consciousness and Neuroscience, make the following observation about philosophers of consciousness.

“There is, at the moment, no agreed philosophical answer to the problem of consciousness, except that most living philosophers are not Cartesian dualist — they do not believe in an immaterial soul which is distinct from the body. We suspect that the majority of neuroscientists do not believe in dualism, the most notable exception being the late Sir John Eccles (1994).

We shall not describe here the various opinions of philosophers, except to say that while philosophers have, in the past, raised interesting questions and pointed to possible conceptual confusions, they have had a very poor record, historically, at arriving at valid scientific answers. For this reason, neuroscientists should listen to the questions philosophers raise but should not be intimidated by their discussions. In recent years the amount of discussion about consciousness has reached absurd proportions compared to the amount of relevant experimentation.”

They suggest that in two areas philosophers have raised important questions that have not been tackled by neuroscientist.

“The Problem of Qualia

What is it that puzzles philosophers? Broadly speaking, it is qualia –the blueness of blue, the painfulness of pain, and so on. This is also the layman’s major puzzle….

The Problem of Meaning

How do other parts of the brain know that the firing of a neuron (or of a set of similar neurons) produces the conscious percept of, say, a face? …Put in other words, how is meaning generated by the brain?…”

But are these reasonable questions? I suspect that Eliezer Yudowsky from Overcoming Bias with his Bayesian outlook would call these ‘wrong questions’.

“Where the mind cuts against reality’s grain, it generates wrong questions - questions that cannot possibly be answered on their own terms, but only dissolved by understanding the cognitive algorithm that generates the perception of a question.

One good cue that you’re dealing with a “wrong question” is when you cannot even imagine any concrete, specific state of how-the-world-is that would answer the question.  When it doesn’t even seem possible to answer the question.

Take the Standard Definitional Dispute, for example, about the tree falling in a deserted forest.  Is there any way-the-world-could-be - any state of affairs - that corresponds to the word “sound” really meaning only acoustic vibrations, or really meaning only auditory experiences?”

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