Tuesday, March 27, 2007

A universal consciousness?

In Hinduism, there is this concept of brahman that refers to an all pervading consciousness. The individual souls (atman) are part of this brahman, and upon death, the atmans merge with the brahman.

Till a few years ago, I used to ridicule this concept. To me a unit of consciousness (you may call it "soul") was indivisible and also non-unifiable. Although I was plain aware of the fact that severing the corpus callosum in humans could lead to two individual consciousness in the same person, I still had problems reconciling that. But now, when I think about it, I do not think it is any more mysterious than the creation of a new consciousness when a woman gets pregnant. Physicalism is at the root of both and does have a bearing on consciousness, including creation, destruction, bifurcation, and unification of existing ones.

If bifurcation is possible, so should unification. I would say, re-attaching the nerve cells of the corpus callosum (at least in theory) should merge the two conscious streams back to one.

So does this mean consciousness is not conserved? Can a consciousness be destroyed without being conserved (as in rebirth) or getting unified with another stream? And what about ethics? If a consciousness is going to get permanently destroyed (as in death), does it matter if it is made to undergo a painless death or a painful one? Why do we care?

Fairly profound questions. But here is my take. I think that each conscious entity is nothing more than a physical console for a master consciousness on the "other" side. The "master consciousness", however, is not some omniscient supreme being. On the other hand, it is very limited in its epistemological capabilities. Its function is to provide instantaneous, memoryless qualia, nothing more. In other words, phenomenal consciousness. It interfaces itself to a console (a conscious entity) through some QM processes in the brain. Apart from feeling physical qualia (through the console), it can also undergo emotional qualia (like anger, grief, and so on), but even these processes are largely determined by the physical processes in the brain. Memories of past events, even behavior (access consciousness) are all stored locally in the physical brain. The master consciousness has no memory or personality other than that of the console it is currently plugged into.

This means that if there are two persons having two master consciousnesses, they can exchange them suddenly and they would not even know it. In fact, there could be a single master consciousness operating behind two individuals in a time multiplexed manner, similar to a multi-user operating system.

Now this would lead to an interesting ethical paradox. Let us suppose there are two people A and B. Suppose A harms B in some way. Now ethics would demand that A suffers some retribution because of that. But as soon as A harms B, let us assume that the master consciousnesses behind these two get switched. Now, in the interest of fairness, who would have to undergo punishment? A or B?

For a judge in the same physical world, there would be nothing in the behavior of either A or B that would give away the switching! In fact, there may be no theoretical way of distinguishing the change from a purely physical point of view. So it would be logical for A to undergo the punishment, as would be self-evident had no such switching taken place.

But given that the consciousnesses of A and B have switched, wouldn't punishing A now cause more suffering for the consciousness that was originally in B, while letting the other go scot-free? Although A would continue to believe that he is the one who harmed B, in reality its the other way round! So while A might still resign to whatever punishment he receives (because epistemologically his identity is that of A), in reality the consciousness that was sinned against is also getting punished for the same!

In dealing with ethics, I would like to think of joy/suffering undergone by any "master consciousness" as a scalar quantity. For example, in my life, I could keep a score of the pleasures and pains (both physical and emotional) and could tally the total over some period to give the "net" pleasure or pain I experienced. Although this is simplistic (for example, how does one assign weights to the various experiences?), I want to illustrate some points.

For example, do I assign points to my experiences in my dreams and treat them on par with the waking state? In my dream, I might get beaten by muggers, my loved one might be diagnosed with cancer, and so on, so I sure do suffer. But when I wake up, I feel relieved that it was all just a dream. But does that realization negate the subtotal in my dream? The answer is no. When I was dreaming, the pain (both physical and emotional) that I felt were every bit as real as they would have been in the waking state. Just realizing after waking up that it was all a dream does NOT make the suffering go away. If that were the case, it should not make any difference to me whether I get nightmares or pleasant dreams. In fact, there would be no need to wish "sweet dreams" to anyone then.

What if one has no memory of the bad dream on waking up? In this case too, it doesn't erase the suffering he underwent during the dream. Of course, if one remembers the dream, then thinking about it may cause more suffering, but this is a secondary effect. This is similar to reliving a tragic event or grieving over a loss after a long time since it happened. If a person undergoes a tragic or painful event, but suffers amnesia after that which removes the memory of the event completely from his mind, it still doesn't affect the fact that the person had the painful experience. What the amnesia does is, it prevents the event from having an effect on the pain score afterwards.

Now let's do this thought experiment. Imagine that for every misdeed a person commits during his waking state, the person suffers a negative consequence in his dream the same night. So if he beats someone up in the waking state, in his dream he gets beaten up by someone else! This might seem something like divine justice! If this happens a few times, the person would form the association and might stop beating people up! What a deterrence!

But let's add a twist to this scenario. Let's assume he gets beaten up in the dreams just like before, but has no memory of the dreams once he wakes up. In this case, he cannot form an association and might continue beating people up. But still he is brought to justice the same night every time that happens! Also let us assume that in his dream, he doesn't recollect that he had beaten someone up during the day, and therefore cannot link his being beaten up to what he did in the waking state. Some might call this unfair (since if someone is being punished, they would argue that the person needs to know for what), but I don't think so. Justice is when the consciousness undergoes some unpleasantness (like pain or grief), and no reason needs to be assigned. As long as the pleasure/pain score is altered in whatever manner to cause accountability, justice is being served. Of course, when someone knows why he is being punished, it may change his behavior which prevents him from getting himself into trouble in the future, but that's a separate issue.

In Hinduism, there is this concept of karma, which is akin to a score sheet for misdeeds. It is said that when someone gets reborn, the karma of his past lives would have an effect on his well-being or happiness in this life. Some people, even if they believe in rebirth, are not comfortable with the idea of someone getting punished for something they did in a past life of which they have no recall, for the same reasons as the thought experiment. But I think that if we just think of matters of justice, it is quite sensible. Actually, think of a scenario where between "rebirths", there is a transient state where they are aware of all the lives they have lived till then. In that case, they can sure form associations between their wrongdoings in one life and suffering in another, so not only is justice done, but there is also an opportunity for introspection. Of course, the same soul, on entering a new body, will lose all the wisdom since as I said, memories and identity are tied to the console once interfacing with the console. The console could be a human in one "birth" and an insect in the next one. And because I feel the person does not need to be made aware of why he is being punished for misdeeds of his previous birth, it is quite alright for the "person" undergoing the punishment to be an insect (since the only thing that matters is the ability to suffer pain qualia). This actually agrees with the rebirth aspect of Hinduism where one can be reborn as any other species.

But what if one consciousness commits some misdeed and unifies with another innocent one? Then how can justice be done? Is punishing the unified entity also entail punishing the innocent one to some extent?

I have no answer to this. This is a troubling question. It would be better to avoid this question in the first place if that could be possible. And here is where I am going to reach out for Occam's razor. The whole issue of retributive ethics can be completely avoided if we assume that ALL consciousnesses behind ALL consoles are effectively one and the same!

In this case, there is no question of justice, as the perpetrator and victim are one and the same! There is no need for retribution at the local level (console A vs console B). In fact there is no retribution at all! In reality we do not observe any kind of retributive justice in real life - evolution has always been predator vs. prey, society has seen tyrants who go scot free and so on. But in the grand scale, if we make the assumption that ALL conscious beings are ultimately the same, we need not look for local tit-for-tat justice in the first place!

For those who are unconvinced by the idea of a "dumb" soul behind a console that embodies the personality, think of yourself in dreams. When we wake up, a lot of the happenings in dreams make no sense whatsoever. But in the dream, even though our sensory experiences are quite realistic, mentally we appear to be greatly challenged in not being able to make out the inconsistencies which seem obvious in the waking state. This is because the soul is dumb (and able to only perceive physical qualia and basic mental ones). However congnitively and ethically, it is very challenged, and relies wholly on the physical aspect (the brain) for those. There are brain regions for empathy, criminal behavior and so on, its not the soul that is good or bad, contrary to what most religions say.

Of course, with the point made earlier, the whole question of ethics breaks down. Which is good since it appears to be a needless complication anyway.

The question is of course, how the consoles interface with this universal consciousness. Are QM processes responsible? I think so. If we find out, we could create our own non-biological consoles that can tap into this consciousness to experience any kind of qualia. We can even unify these with ourselves, so we get to share in the experiences.

May the Force be with us.

Saturday, March 24, 2007

The inverted spectrum problem (part 3)

In the previous post, I had asserted that the colors perceived by humans when the actual paths corresponding to different cone cells could be exact. But I also think there might be cases of mild and severe color inversions where the above may not hold true.

Let me explain why. In humans, there are 3 kinds of cones which correspond to blue, green and red (roughly speaking). Actually, it is not that for each monochromatic light, only one type of cone gets activated. All three types can get activated, but each type of cone is more sensitive to some wavelengths than others. The portion of the brain responsible for color perception decodes the information from the three types of cones to determine the actual hue perceived by the consciousness.

Human vision is trichromatic, meaning that the color perceived is a point in 3 dimensional color space. Typically we take red, green, and blue to be orthogonal components and any hue can be represented by a point in this space. If we normalize the intensity, all hues are on the positive octant of the unit sphere with origin at 0.

Note that the wavelength to color mapping is not one to one. Purple is a combination of red and blue (at opposite ends of the spectrum), but a monochromatic light having an average of red and blue wavelengths appears green and not purple.

There is nothing in theory that requires vision to be trichromatic. In fact, many birds have four types of cones, making their vision possibly tetrachromatic. It is quite likely that they perceive hues which cannot even be imagined by us (that is, outside of the qualia space of humans). In fact, the "white" perceived by birds might be different from our white and something that we cannot even imagine.

Now, it is true indeed that for a variety of reasons we consider red, green, and blue to be the primary colors. This has got to do printing, and CRT and LCD screens. In a monitor, there are R, G and B pixels and other colors and intensities are got by illuminating these at various levels.

But in principle, if we consider the color space to be 3-D, ANY set of three mutually orthogonal directions would do. But the main question is, is there a preferred set of reference hues which lead to invariance between different humans to exact precision? In other words, are there eigenhues that have a simple mathematical relationship so that all humans perceive the same color along these axes exactly? (It may turn out that these eigenhues may not even be orthogonal on the color sphere, but I suspect they would. Also, I think there would be an overdetermination with respect to the white point, which I believe would also exact for two individuals.)

Now, I wish to stress that these eigenhue axes are intrinsic to the "projector" of the Cartesian theater. Actual stimulation of the retinas of two individuals corresponding to these eigenhue axes will not lead to the same results because of the variability in the cone responses from individual to individual. I am talking about something a lot more fundamental.

Now lets take the case of color blindness. There are many types of color blindnesses and most have to do with the front end (the cones themselves). In some cases, the brain itself might be involved (as in the case of achromatopsia), where the subject sees only in black and white.

There is also evidence of some women having a fourth type of cone which allows them to differentiate hues better than other humans. This condition has been mistakenly quoted as tetrachromaticity, but unless the brain itself is wired for 4-D color space as opposed to 3-D, one cannot call it that (and there is no reason to believe that these women have such a radically different brain organization). They still would perceive the same range of hues as other normal humans, although the mapping to the actual visual spectral composition might be slightly different. (Actually, to tell the truth, I myself have not come across any content on the web establishing that birds indeed do have a 4-D color space, but I suspect this to be the case.)

So, we have seen that mix-ups can happen at the front end (the rods and cones), and the processing unit (the brain). What about the back end (the Cartesian projector)?

Now this question sure leads us to Cartesian dualism and the mind-body problem! But that doesn't mean we should get scared away and not attempt at conjecturing such conditions. We do know that our subjective experiences do depend on physical phenomena in the brain. After all, drugs like LSD can alter visual qualia and so no one can deny that there is a physical basis for our subjective experiences.

I think the color pathways offer an unique opportunity for a lot of such experiments compared to other senses like sound, touch, smell, etc. The reason is, assuming a 3-D color space for humans, there should be a great deal of identical brain processing for the three pathways except at the end of the chain, namely the colors of the lenses of the Cartesian projector. Note that these colors would be the eigenhues which I discussed earlier. An analogy can be found in the case of real life component video amplifiers. The component signals (R, G and B) undergo the same kind of processing in any cable chain and the amps can be exchanged as long as the inputs and outputs still correspond to one another.

Now we know why the front end (the cones) have different color sensitivity profiles. It has nothing to do with the mind-body problem and is in the purely physical realm. It has to do with the pigments photopsins and rhodopsins in the cone cells.

But what about the color lenses of the Cartesian projector? Now this is a totally different ball game! But I believe that the color lenses are due to simpler molecules (than photopsins and rhodopsins) and the quantum-mechanical wavefunctions of the excited states of these molecules correspond to the color perceived in qualia space. Well, I have not attempted to describe what QM has to do with perceived qualia, but I am certainly not Pinker to dismiss the consciousness-QM connection here. But at the same time, I am not sure if Penrose's argument is right here either.

So what does this imply? For one, I feel that there is a very restricted family of these molecules able to "project" on to the Cartesian screen. There should be three such in humans with possibly a fourth in the case of birds and other lower forms of life. Since I feel that these molecules aren't even proteins (which might have different allele-variants), but something much simpler, I feel that the hues of these would be the same for any two humans, because their eigenstates would be the same. These molecules would fail in their function with even the slightest mutation, and it is possible that some cases of brain achromatopsia might have to do with mutant forms of these molecules, rather than the wiring in the brain itself.

If my theory is right, this provides a new twist to the color inversion problem! For if, for the moment, we assume that the brain pathways themselves are the same for the three eigenhues, what would happen if these molecules get switched? Then we could indeed expect some people to be born with the classic "inverted spectrum" condition! I call this the "severe color inversion syndrome", since the subject indeed sees red different from a normal person. (Actually there would be many forms of this depending on which eigenhues get switched, but I lump them together for now. On top of that, there might also be color anomalies resulting from cone defects, but I do not want to discuss such complications which are unnecessary to the basic understanding.)

Now what happens if both the inputs and the outputs of the amps (read brain pathways) get switched together? If the amps are identical, it shouldn't matter. But I feel there might be minor differences in the amps themselves. I would term this condition "mild color inversion syndrome". This condition, if it exists, should not be discernible as easily as the severe one, even with subjective tests.

I think that most inversion syndrome conditions (if they indeed exist) would be the mild type. This is because, I think, any mutation that causes the eigenhue molecules to get switched also strongly causes the amp inputs to get switched. Perhaps because there might be a shared protein in the synthesis of both the eigenhue molecule and the "input selector". Evolution would have favored such a scenario.

I also think it is possible for a much rarer condition (which I term "alien color inversion syndrome") in which one of the normal eigenhue molecules in the human is replaced by the fourth one present in birds. I don't know of the possibility of this. But in that case, the colors perceived by someone from this condition would have no correspondence with that of normal people!

Monday, March 19, 2007

The inverted spectrum problem (contd)

In the last post, I had suggested that there might be minor variations in the colors perceived between two individuals, and the same might hold true of sound also. But let me elaborate on this a bit further.

I do believe that the absolute pitches heard by any two individuals might be off by a note or two. The reason is not because of any metaphysical mind-body interface, but might have to do with the mechanics of the inner ear itself. The part of the basilar membrane that vibrated with a particular pitch is very dependent on the mechanics of the ear which is subject to genotypic and phenotypic variations and also due to aging itself. So it is quite possible that a standard deviation of one or two notes is possible. There is no way the brain can calibrate out this source of error in the physical frequency<-> pitch qualia correspondence. But fortunately, this doesn't typically lead to any discernible changes in subjective preferences or sound pattern recognition. This might be one of the reasons pitches have geometric progression and a song played in a different base key still evokes the same subjective experiences and melody. Some forms of music (esp. Indian music) have no concept of absolute pitch, and the base note could depend on the performer.

But when we come to sight, I feel the match would be much closer, at least theoretically. If we take the human eye, it's got rods and cones. The rods respond to brightness while the three types of cones respond to red, green and blue colors. Of course, a red light might also stimulate the green cones, although only slightly. When they are equally stimulated, the resultant qualia is white. It might be argued as above that the actual hue perceived by two different individuals can differ because of the dynamics of the rod/cone activation which could show variations between individuals. It is possible for this to be the case.

But at a more fundamental level, the qualia correspondences may be much tighter, indeed exact. Let me explain this. How many of us have not experienced a bright flash when we had bumped our heads against something? Although very fleeting, it is of an absolute white, at least for me. My assumption here is that it is because of stimulation of the visual cortex, but only of the part that processes rod, and not cone information.

I now make the conjecture that any two people see the exact same white when only the "white" (read rod, not white matter) part of the brain is activated.

And similarly, if we could separately simulate the red, green and blue pathways, the color experiences corresponding to these stimulations would have an exact match between any two normal people (by normal, I mean those who don't have pathological problems like color blindness or genetic miswiring in the brain. In those cases, the differences in perception would not be a minor hue variation, but something really more drastic than that). Of course, this is just a conjecture, but I wish to call it "Shankar's color perception conjecture".

So one might ask, if in the case of sound, there could be minor variations, why not in the case of colors? The answer to this question is, in the case of sound, there is a continuum of auditory nerves for different frequencies, while for colors there are only three different types. In sound, the brain does not really know whether the nerve responsible for a pitch of 1KHz is indeed triggered by a sound of 1KHz, because there is no way of calibration. But in the case of color perception, there are only three different types of cones, and the distinction is clear.

Now, since this is only a conjecture, I'm not going to try to prove as to why two different people will have the same qualia when only a particular color pathway inside the brain gets activated. Well for now, I will assume Cartesian dualism, and then I believe that the color qualia are caused by the equivalent of mathematical eigenstates in qualia space. The qualia perceived will therefore be exact to mathematical precision, much the same way two different molecules of the same structure would have the same spectral lines.

Ok, I hope you didn't take the last paragraph too seriously :) For we have a long way to go before we can even perform these kind of experiments. But in the end, if this conjecture turns out to be true, I hope people remember the name of the conjecture :)

Sunday, March 18, 2007

The color inversion problem

The basic argument of the subjectivists is that there is no way to prove or disprove whether two people see red the same way. One could have the colors inverted with respect to the other, and yet they would behave identically. Either of them, or a third person cannot establish whether both of them see colors the same way.

In theory this argument sounds plausible. However, circumstantially, there is a compelling reason to believe any two people see colors in pretty much the same manner (except for some pathological cases like color blindness).

For example, take the sense of smell. If one has an inverted spectrum of smell, then behavioral preference would give it away. A person will avoid perfumes and instead prefer staying near rotting carcasses. He would have no use for bathroom fresheners.

It is also true of other sensations like sound. If one has the sense of pitch reversed, it is hard for that person to appreciate a piece that others consider melodic and vice versa. Now it is possible that people can still differ in pitch perception by a shift of a note or two, and this would not make any noticeable difference to the subjective preferences. In fact, pitch shifting is sometimes done to facilitate playing an instrument in a different key or to accomodate the voice of a singer.

Coming back to color inversion - it is probably not without reason that red is associated with anger, blue with coolness etc. It may be argued that since red is the color of blood and blue is the color of the sea, such associations came to be established. So, if someone sees blood as blue, he would associate blue with anger (although he would call it red, so he would still be correct), it is argued.

But my own feeling is that color inversion is not as neutral as it is made out to be. Smell inversion is an extreme case of non-neutrality. But someone who sees red as blue and vice versa from birth would make different subjective preferences in art, etc. Subjective preferences may not be transparent to such inversion of inner experiences. This doesn't hold true of just sight, but all qualia, although in varying degrees.

And if we assume that qualia is genetically determined by evolutionary reasons, then those reasons would dictate that two members of the same species have the same qualia states for a given stimulus. For example, if an animal feels a tickling sensation if bitten by an ant instead of pain, the animal would deliberately seek out ant hills, with detrimental results.

And lets say there is a species of fly that feeds on nectar. It is reasonable to assume that the fragrance of a flower presents a certain (likable) qualia to the fly. Now lets take a mutant form that feeds on carrion. It is highly likely that carrion presents the same qualia to this mutant form that flowers did to the original species, otherwise this fly wouldn't get attracted to carrion. This is mandated by selection pressure due to evolution.

And therefore I believe that two normal humans would have more or less the same color perception. By "more or less", I mean up to minor variations. Like, if I wear tinted sunglasses, I get used to it in no time. My brain adjusts the parameters to a certain level so that red is still what I consider red, although it could be different from the actual hue when I don't wear those glasses. This amount of variation is allowed since it is not detrimental to me from a behavioral standpoint - like when I'm driving, I still make out the traffic lights correctly.

Saturday, March 17, 2007

Zombies and qualia

I was mulling the p-zombie problem. For example, can we really have a world with only zombies which cannot be distinguished from sentient people? Although this might lead to the awkward situation that these zombies (in keeping up with real people) would discuss qualia related issues (like the color inversion problem) and the hard problem in general, although they would be lost as to as to why they discuss them. There would seem to be an internal contradiction which they themselves would make out (and presumably let us real humans know).

But seriously, there has to be a reason why evolution favored qualia. I have a feeling that feeling qualia makes a material difference to the behavior (and therefore survival) of an organism. And it leads to the postulate that there are behavior patterns that result because of qualia being perceived, and which would not occur given just pure functionalism. Note that the survival fitness of any life form depends not on the qualia perceived per se, but what it decides to do with it. Whatever be the decisions taken because of qualia being perceived, it needs to be translated back to physical behaviour. So there are broadly two pathways, sensory and motor, which are quite analogous to the real life case of the nervous system.

If a low form of life has purely reflexive instincts, qualia may not matter much. For example, an insect is not expected to be engaged in any high level thought. If it flies near a candle flame, maybe the heat can activate a reflexive behavior that causes the insect to beat its wings in a different manner instantly that causes it to avoid the flame. The insect need not even "feel" pain. We ourselves are capable of reflex action in avoiding a hot object or sharp knife, and only the spinal cord is involved in such cases. We do not make a conscious decision to withdraw from the harmful stimulus. It is possible that this reflex action behavior present in higher animals is just the original mechanism of our ancestors with a more rudimentary nervous system.

But lets take the example of a human engaged in some high level activity like reading a book. While reflexive behavior might help in avoiding certain kind of stimuli (like a bee sting), for some other stimuli which are nevertheless harmful, although over a longer time scale, there needs to be some sort of a "distraction mechanism" to tell the person that this is of higher priority and needs immediate attention. The qualia of pain seems to fit the candidature very well here. Thus someone could still carry out normal activities with a mild headache, but as it grows in intensity, he would ignore other activities and call the hospital. In fact, when the pain becomes intense, it completely hijacks the command center of the brain, and facilitates summoning of medical help. This obviously has survival value, since the pain might signal an impending stroke. If it were not pain, in what other manner could the person be alerted to the impending medical emergency? Since the action to be taken here is calling up the emergency room (which is a very complicated process compared to withdrawing a finger from a hot object), reflexive behavior is inadequate and the person's consciousness needs to get involved here. If we assume that the person has only one consciousness, then the person has to first consciously perceive the medical condition.

So whats the manner by which a person's conscious self is alerted to an emergency condition? We have ruled out reflexive behavior. The gateways to a conscious mind are qualia of some form. It is possible that instead of pain, one other alternative is that the person suddenly "knows" that there is something wrong, and also realizes the seriousness of it without perceiving pain. Then it would result in the same action, namely calling up the hospital. In fact, in ischemic strokes, instead of pain, there might be a mental qualia (transient loss of consciousness or suddenly forgetting where one is) which signifies the same. But unless one knows beforehand that these can be the warning signs of a stroke, the person may not give it the same degree of priority and delay in getting help for himself, with disastrous consequences. On the other hand, a person with a severe headache does not need to know that this could be the warning sign of a stroke. He might summon help just to get rid of the headache since it has become unbearable. Thus pain in itself will "lead" the person to the right course of action without the person actually having to know what it is about. Another example is being barefoot on a hot surface on a sunny day. If he were to stand there for a long time, his soles would likely get burnt. But when the pain grows, the person would start moving to the shade, not because he consciously realizes that standing there any longer would damage his feet, but to mitigate the signal of pain itself.

Therefore, when some stimuli (internal or external) needs attention and a complex response that can be mediated only by conscious behavior, qualia are the gateways through which those stimuli can bring themselves to the attention of the conscious mind. So once an organism develops consciousness (for whatever reason), evolution would favor all important stimuli for which complex mind-mediated action to be needed to manifest themselves as appropriate qualia that leads to the correct behavior from an evolutionary standpoint. This would be a runaway situation once consciousness develops in a system.

I have only detailed why qualia might be helpful in conscious beings. I have not really hinted at why zombies are at a disadvantage compared to sentient beings. After all, by definition, zombies have the same behavior as the latter and should not be discriminated against in evolution.

In a subsequent blog I will discuss why zombies may not even be possible. In other words, beings that follow strict physicalism will be at a disadvantage compared to beings that have consciousness and qualia. And zombies (which by definition strictly follow physicalism) will lose out to conscious beings.

Friday, March 16, 2007

Multiplicity of consciousnesses in strong AI

I want to prove an important result in strong AI through a thought experiment. Let's take the postulate in strong AI that a computer running a simulation produces consciousness.

Now consider two such computers running the same program. Further lets assume that their clocks are synchronized (by either running them off the same clock or using atomic clocks synchronized at the beginning, so that the program execution is still synchronized at the end down to the last cycle).

Now the question is, does each computer produce a separate consciousness? Or do both produce only one together? If the computers are physically separate from each other, it would appear that if one produces consciousness, so should the other. There is nothing in Daniel Dennett's Consciousness Explained (which I take to be the poster child for strong AI advocacy) that suggests otherwise.

However, let me make an argument that both together, in fact, produce only one, if any at all. To this end, I will make the following assumption-

If P and P' are two different physical systems which are functionally equivalent, functionality being defined in the physical domain of the form that gives rise to consciousness according to the strong AI hypothesis, then tautologically, P and P' should not make any material difference to the nature of the consciousness(es) produced, in qualitative terms, or multiplicity.

Now let P be the system that has the two computers as described above. Now let P' correspond to the system where every node of the first computer is connected to every corresponding node of the second computer by a wire. Since the two computers are clock synchronized and executing the same program, at any given instant of time, the voltage difference across each wire is zero, hence the current is zero. This means the presence of the wires do not make any material difference to the operation of the combined system. Hence P and P' are functionally equivalent. But the presence of the wires reduces the number of computers executing the program to one from two (since the wires just make the logic transistors switching each node twice as big, as opposed to a single computer)! So according to the strong AI hypothesis, if each independent computer produces one conscious entity in P, then the system P' should produce only one, since P' is a single computer which just has bigger devices. So if P has two consciousnesses, then P' should have only one. But we have already asserted that P and P' are functionally equivalent. Hence the multiplicity of consciousnesses for P and P' has to be the same. This leads to a contradiction.

By induction, any number of clock-synchronized computers operating the same program can produce only one stream of consciousness, if at all.

Note - This is not a far-fetched thought experiment. In fact, being a chip designer myself, we talk of paralleling gates or individual devices as "fanout". In fact the sizes of the devices in the latest Pentium may be vastly different from earlier ones on different process technologies. I am sure that Daniel Dennett himself would agree that his theories would not depend on which version of the Pentium his programs run on.

Thursday, March 15, 2007

Am I a dualist?

Let me start the debate from my own point of view. Now, this should be the home base for any theory of consciousness. At least for me. And it might turn out that it is only for me. But that's besides the point right now.

I know I am conscious. I know I experience qualia. But what can I say of others around me? That is, assuming there are others around me for real!

A great many theories (especially in pop accounts) like "Weak AI", "Strong AI", "Multiple Drafts model", etc., don't however seem to pay attention to the fundamental question of what constitutes reality in the first place. All of these operate on the platform that -

1. I am conscious, and experience mental states like qualia (agreed, so far)
2. The world around me is real (whatever that means)
3. Other living beings around me in the world (in 2) seem similar to me (again in 2) physically and biologically and also behaviorally. (again, I would express my doubts here as to what "other" and "me" refer to in the first place, because of my inherent skepticism in 2)
4. Therefore by applying Occam's razor, I have to immediately extrapolate that the "others" are also conscious and can experience similar mental states to mine.
5. Now coming to the differences-
Weak AI - The mental states of the "others" (which I already believe in due to 4) cannot be attributed to any physical process in 2, but to something else not explainable by any phenomenon in 2.
Strong AI - The mental states of the "others" is a result of computation processes (happening in the physical world of 2) and are the same source of my own mental states.
Multiple drafts model - Its the same as strong AI, just with more technical details.

There is also Eliminativism which denies mental states and contradicts even 1 (which is incidentally, the only numbered statement I am in agreement with!). I do not take this seriously.

Unfortunately, in my opinion, strong AI, in its various flavors, is just eliminativism in disguise. This is incidentally the view espoused by famous computer scientists like Marvin Minsky, Douglas Hofstadter, or Hans Moravec. But well, this is my perception. Dennett's arguments on explaining consciousness explains zilch. Perhaps just an eyewash?

Well, whatever be the case, one thing is for sure - all these don't question the validity of 2, that there is an absolute reality independent of my consciousness.

I have coined the term the "Terra firma assumption" for this.

I do not know why computer scientists and psychologists make this assumption in the first place. This is retrograde.

Especially considering the fact that debates on monism/dualism/solipsism are much older and don't take 2 for granted. In my opinion these debates are perhaps more profound than the current debates (especially among AI scientists and behavioral psychologists). We need to question our notion of reality itself if we are to get anywhere.

With this I would like to conclude this post. Stay tuned.

Tuesday, March 13, 2007


My name is Shankar and I have created this blog to discuss consciousness, qualia, the mind-body problem and related issues. I am not a professional philosopher in any sense, and am not familiar with the latest papers/technical terms used in the philosophy community. However I think this allows me to view these issues from a fresh perspective. And really, one cannot say that established philosophers have a better picture than novices like me - the established ones themselves are split into many different camps that it is logically impossible for *all* of them to be better than me! Unlike physics where a novice cannot hope to make any significant contribution to current theories without a PhD in Physics and a fundamental understanding of the Standard Model or String theory, fortunately the field of consciousness and qualia is based more on ones intuition and subjective experiences. Thus it is within easier reach of earnest individuals like me who seek to find answers for personal as opposed to professional reasons.

Even though I am not familiar with all the various theories floating around, and all jargon, I want to present my own theories/thought experiments as well as contribute jargon of my own! It is quite possible that my exact arguments/theories have already been published, but I most likely will not know about it (since I don't have access to professional journals and rely mostly on what I read on the web). Of course, readers can leave comments on my blogs to bring to my attention any similarities/discrepancies.

I wish to stop here for now. I look forward to your interest in my subsequent posts. Thanks.