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Kurzweil vs Myer on Brain Complexity

by Steven Novella, Aug 23 2010

There is an interesting blog debate going on between PZ Myers and Ray Kurzweil about the complexity of the brain – a topic that I too blog about and so I thought I would offer my thoughts. The “debate” started with a talk by Kurzweil at the Singularity Summit, a press summary of which prompted this response from PZ Myers. Kurzweil then responded here, and Myers responded to his response here.

Futurism

You can read the exchange for all the details. I want to focus on just a couple of points – predicting our efforts to reverse engineer the brain, and the question of how complex the brain is.  Kurzweil has predicted in the past that we will reverse engineer the brain – model it's function in a computer, basically – by 2030. It was reported that in his talk he said 2020, but Kurzweil has clarified that this is not correct, he said 2030, sticking to his earlier predictions.

That's a minor (but interesting) point, and Myers points out that it was not the focus of his original criticism. I agree with Kurzweil on some basic principles. First, we do have an active research program that is using computer modeling to reverse engineer the brain. These efforts are progressing nicely, and I do think that eventually it will succeed. I also agree that some technologies progress at an exponential rate, and they surprise those who were making predictions based upon a linear progression. Kurzweil gives an excellent example of this – the genome project. This project started out very slow, and many though it was lagging behind predictions, but as technology improved the effort to decode the human genome accelerated geometrically and actually finished years ahead of schedule. Now we can decode the genome of other species in a fraction of the time, and the pace continues to accelerate.

So Kurzweil has a legitimate point here – information-based technologies are accelerating, and if you account for that acceleration you get a better handle on predicting its future course. I do think, however, that Kurzweil is cherry-picking a bit also, for some information-based technologies have fallen short of prediction, such as speech recognition (an area of his particular expertise). Recognizing human speech works, but the technology has seen diminishing, rather than accelerating, returns in terms of accuracy, and this has delayed it adoption – which is not nearly as much as Kurzweil predicted in the past.

I think the example of speech recognition represents a factor that Kurzweil, in my opinion, seems to underappreciate. While our information tools may get better at an accelerating rate, some problems become exponentially more difficult as you try to eek out incremental gains. In other words, it seems that for some technologies (to use symbolic figures) each 1% improvement is 10 times more difficult than the previous incremental improvement. This offsets our exponential progress. The complexity of the genome project was linear – decoding that last 10% was as difficult as the first 10%, so it was the perfect example for Kurzweil. But other problems, like understanding how the brain works, are not linear in complexity. As our knowledge of the brain deepens, we are getting to greater and greater levels of complexity.

Further, while I think Kurzweil's charicterization of technological progress is generally correct when you consider the broad brushstrokes of advancement, it is very difficult to apply them to any individual technology. There are hurdles, roadblocks, and breakthroughs with any individual technology or scientific problem that are impossible to predict.

On the point of predicting the future I am somewhat between Myers and Kurzweil. Kurzweil has some legitimate points to make, but I think he over applies them and cherry picks favorable examples. Myers also has some legitimate criticisms – Kurzweil does not quantify some problems (like how much of the brain we currently understand), and does not account for the fact that we do not know how much we do not know. There may be hidden layers of complexity of brain function we haven't tapped into yet. But I think that Myers overall is a bit harsh on Kurzweil and does not give partial credit where it is due.

Will we reverse engineer the brain by 2030? I guess we will have to wait and see. Kurzweil gives himself a bit of an out by saying that we will reverse engineer the “basic functions” of the brain – this is vague enough that you can declare victory at any point along the way. You might argue we understand the brain's basic functions now. I think we will succeed eventually, even to the point of being able to make an artificial brain, but I would not hazard a guess as to when.

Brain Complexity

The more interesting point of contention, and a real teaching point, is the question of how much we can infer about the complexity of the brain by looking at the genome? A separate question is whether or not you can reverse engineer the brain by examining the genome. Here both Myers and Kurzweil agree – you cannot. But Kurzweil says he never made that claim – it was misreported or misinterpreted. So we can put that aside – no one is arguing that the design of the brain is in the genome. You have to examine the brain to reverse engineer the brain.

But Kurzweil is still claiming that we can infer something about how much complexity is in the brain from the genome. He writes:

The amount of information in the genome (after lossless compression, which is feasible because of the massive redundancy in the genome) is about 50 million bytes (down from 800 million bytes in the uncompressed genome). It is true that the information in the genome goes through a complex route to create a brain, but the information in the genome constrains the amount of information in the brain prior to the brain’s interaction with its environment.

This is profoundly problematic, and reflects the fact that Kurzweil truly does not understand the process by which the brain develops. From a developmental point of view – there is no such thing as the brain prior to its interaction with the environment. First – is Kurzweil talking about a newborn infant's brain? Does he understand the significant differences between that brain and a fully developed adult brain?

I think, to be generous, Kurzweil is trying to differentiate the design of the brain from the information contained within it (our memories, etc,). This could be analogous to a computer vs the software, or reverse engineer a generic human brain vs duplicating PZ Myers' brain.

But that was never the point at all – the point Myers was making (which I also discussed this week on the SGU) is that the design of the brain is dependent upon interaction with the environment. Myers focused on brain proteins interacting with each other in a complex way, while I focused on the neurological functions of the brain.  The genome provides a set of processes by which brain design unfolds – but that program is dependent upon input from the brain's environment, which includes the body of which it is part. The basic systems within the brain develop and organize themselves in response to sensory input or use. Our visual cortex requires visual stimulation, binary vision requires seeing with both eyes, our motor system requires use against gravity, our language cortex requires exposure to language, etc.

The process of brain design being a combination of genetic rules laying out neurons and connections in a pattern that is dependent upon feedback from some kind of input adds complexity and information to the brain. So again – what is Kurzweil talking about when he refers to a brain prior to interaction with the environment? He seems not to understand the process of brain development, and therefore he overestimates the degree to which information in the genome constrains information in the brain – or he underestimates the increase in information that derives from this interactive development process. Therefore his basic premise – the brain is not so complex because the genome does not contain that much information – is flawed and invalid (which was Myers original criticism).

Kurzweil adds another line of reasoning to his argument, writing:

For example, the cerebellum (which has been modeled, simulated and tested) — the region responsible for part of our skill formation, like catching a fly ball — contains a module of four types of neurons. That module is repeated about ten billion times. The cortex, a region that only mammals have and that is responsible for our ability to think symbolically and in hierarchies of ideas, also has massive redundancy. It has a basic pattern-recognition module that is considerably more complex than the repeated module in the cerebellum, but that cortex module is repeated about a billion times. There is also information in the interconnections, but there is massive redundancy in the connection pattern as well.

Here again, Kurzweil is grossly underestimating the complexity of the brain based upon some faulty assumptions. I agree with his point that there are modules or patterns in the brain that are repeated billions of times. But they are not simply repeated. You cannot describe this aspect of brain design by simply describing one module then say – repeat 1 billion times. With each repetition there is a novel and meaningful pattern of interconnectedness to other brain regions and to the body. Kurzweil seems to recognize this when he says: “There is also information in the interconnections, but there is massive redundancy in the connection pattern as well.” But he seems to be brushing it off too easily. We cannot assume that the pattern of interconnectedness is a simply redundant pattern.

We also have to consider that the added levels of complexity from the pattern of interconnectedness likely varies from brain region to region. Kurzweil might have a point if you are talking only about the primary visual cortex, for example – where there is a literal grid of neurons that correspond to the visual fields. Here the patterns are somewhat simple and repeated, and it is therefore not surprising that our efforts to reverse engineer these brain regions have progressed the most. But this is the lowest hanging fruit, and should not be considered representative of other brain regions and functions.

If we move to brain regions that subsume our most complex abstract thought and planning, there is no simple somatotopic pattern of neurons whose function we can easily infer. We have no idea, for example, how a pattern of neuronal connections equals a specific word, and connects to our knowledge of how to say the word, how to spell it, what the word means in all it's complexity, memories of the word's use, and its relation to other words and parts of words. But most importantly – we really don't know yet how complex this problem even is, and so predicting how long it will take to solve the problem strikes me as utter folly.

Conclusion

I find the entire discussion between Myers and Kurzweil to be a fascinating topic, and an opportunity to explore various aspects of neurology in the context of a specific and interesting application – reverse engineering the brain. This amounts to an elaborate thought experiment, but those are a fun way to challenge our understanding of a topic.

Ultimately I come down closer to Myers' position – Kurzweil does not seem to understand the brain or brain development, at least in certain key aspects, and this dooms his arguments to failure. He would do well to take the criticisms going his way seriously, and also to check his ideas with some actual neuroscientists. Myers, on the other hand, came off too harsh, but that seems to be his style. Kurzweil is an interesting mix of provocative ideas, some interesting insights, but also some serious flaws that border on crankery. This makes him a very intriguing character that I would not casually dismiss, but also I would take everything he says with a skeptical grain of salt.

22 Responses to “Kurzweil vs Myer on Brain Complexity”

  1. I find this topic fascinating, as is the anti-aging work of Aubrey de Grey,who is as controversial as Kurzeweil. Aubrey will be speaking at DragonCon, but there was not time for his talk talk “Don’t Be TOO Skeptical”, where he discusses things like this.

    Therefore, Kylie Sturgess of The Token Skeptic, Swoopy of Skepticality, Desiree Schell of Skeptically Speaking, me (of Podcast Beyond Belief) and Barb Drescher of ICBS Everwhere, will interview Dr. de Grey on Friday, September 3rd at 9:30 am in Room 204 of the Hilton, the podcasting track room.

    I enjoyed your interview with him on SGU, and am interested in hearing his take on the Kurzweil vs. Myers debate.

  2. Max says:

    Some large software projects have been cancelled after over a decade of work because they weren’t documented properly and were too hard to reverse-engineer. I doubt that the brain is any easier to reverse-engineer.

    If Kurzweil expects to achieve immortality by uploading his brain to a computer, there are two little obstacles. First, even a perfect simulation of the brain won’t be conscious if it’s implemented on a standard computer that adds several numbers per clock cycle and stores the result in memory. Second, even if we make a perfect conscious copy of the brain, it would be a different person. The original would still die.

    • Richard Gant says:

      “Second, even if we make a perfect conscious copy of the brain, it would be a different person. The original would still die.”

      As I understand Kurzweil’s point from his books, it wouldn’t precisely be a case of uploading your brain and then getting rid of the meat. Instead, it would be a case of having the computer integrated with your brain. It would assist with brain functions and then begin taking over more and more of the brain functions as the organic component of the brain fails to perform. Eventually, he sees a point at which the functions of the brain are fully taken over by the computer. But, since there has not been any gap in continuity, the original entity does not cease to exist.

    • NightHiker says:

      “Second, even if we make a perfect conscious copy of the brain, it would be a different person. The original would still die.”

      It doesn’t matter. Unless you believe the definition of “person” includes the atoms in the brain. But considering atoms are pretty much interchangeable and are indeed replaced all the time, the very concept of “original” doesn’t make sense here. The “person” is the current arrangement of the atoms, not the atoms themselves, and the feeling of continuity we have from being conscious may very well be an illusion, like seeing motion from pictures changing 24 times per second. As long as the copy is indeed perfect we would retain the same feelings and awareness as if we were the original, whether it is destroyed or not. You would continue to be “you”, for all intents and purposes (though if the original person remains both would start to diverge from the time of the copy).

      • Max says:

        It’s like the illusion of moving a file from a memory card to your hard drive. You’re not really moving it, you’re copying it and deleting the original. This becomes clear when the original is write protected and doesn’t get deleted.
        Now imagine copying the brain, but failing to kill the original. They’re two separate persons, neither of whom wants to die.

      • NightHiker says:

        “Now imagine copying the brain, but failing to kill the original. They’re two separate persons, neither of whom wants to die.”

        If the procedure is not destructive, a person could desire to make a backup copy at any point, with the right to receive an automatic “restore” only in the event of death, voluntary or accidental. It’s one way to avoid the “doubles” dilemma (of course the whole scenario only arises from the premise we can produce a new body to hold the backup as well).

        Leaving the technological hurdles behind for a bit, I find the thought provoking situations such scenario would create to be fascinating.

  3. Max says:

    Even if we consider a manmade object, knowing how it’s made doesn’t necessarily tell us how it works, and vice-versa.

    • BillG says:

      Likewise with quantum theory – we are confident it works but unsure how with paradoxes and such. Until we advance our understanding in the laws of physics any artificial intelligence will be primitive, eons from anything resembling the human brain.

      We shouldn’t easily assume “…eventually it will succeed.”

  4. Scott Young says:

    Interesting discussion for sure. The points to be examined themselves lead us deeper and deeper into complexities not generally appreciated. For example, the human genome is actually not completely sequenced. Extensive regions near the centromeres and telomeres are too difficult or impossible to sequence using current technologies. I still don’t know why this is glossed over. I like the point about environmental influence, even within the body. A “simple” example that is not well understood is the role of circulating hormones, not just steroids, in the fetal development of various social, sexual and other behaviors. Another is the two-way interactions between the brain and the periphery.

    I think I’ve heard Kurzwell say something about downloading a particular human’s “essence” into a machine (one of your brother’s fantasies!). This strikes me as particularly absurd; even if we could scan a brain at a molecular level, could any process (analog or digital) recreate that information distribution, including what was occurring just prior and after the scan.

  5. NightHiker says:

    While I think Kurzweil is at times betrayed by his wishful thinking regarding his fear of death, saying he’s just like Deepak Chopra may be as much of an exaggeration as his predictions (which are more like wild guesses) regarding the reverse engineering of the brain. Contrary to Chopra, Kurzweil at least contributed to interesting fields of practical research and development, and is talking about things that are theoretically possible, not some new age mumbo jumbo about quantum physics and some untapped mind power. He might underestimate some difficulties and may not even be aware of some of them, but he is, ultimately, right – reverse engineering the brain is a matter of “when”, not “if”, while Chopra will never be even close to that.

    Also, it seems to me there’s something to be said about Myers taking part of the software issue as a hardware one, and his analogy with Halo was completely unwarranted – it doesn’t look to me Kurzweil was talking about engineering any specific brain, but laying out the blank slate that could then be filled with the developmental part of the process – so he was indeed talking more about the “intel processor” side of the issue than any specific game or OS (even though he might’ve underestimated the difficulty of the issue).

    Also, Myers stance on some topics seem to indicate a view point that no rational mind can ever commit any value or judgement mistake, as if the only people who could deserve credit are those that never get anything wrong (of course he can’t really believe that, so it makes his attacks on this front seem gratuitous, just an exercise at being a dick (TM Phil Plait)).

    I think a more interesting criticism of Kurzweil’s ideas is in regard to the “why” instead of the when – as some comments on those threads stated, the only practical use of trying to reverse engineer the brain in such exact manner would be to “store” a brain state in case of a hardware failure (death) and reinstate it later. I am inclined to think that a fully operational, “conscious” model of a brain would not be feasible with our current way of building computational machines – I feel the physical architecture of the brain plays a role on that as well, so we would not only need to reverse engineer our brains, but also find a way to recreate them as a working, physical model. In other words, to work like a brain this model would have to be pretty much a… well, brain.

    So sure, Kurzweil might be falling prey to his faith in being able to cheat death, but he would not be the first example of a great rational mind to fall for such traps – Linus Pauling and vitamin C comes to mmind as a good example. Would anyone say Linus Pauling was just another Deepak Chopra of his time?

  6. MadScientist says:

    So we know the human genome, and some synthesis techniques are even useful for creating large(ish) chunks to splice with e. coli. The human genome still doesn’t allow us to synthesize humans. In fact all the hype from the early days of the genome project haven’t materialized, and even then we knew that there would be a huge task to figure out what various parts of the genome might do. Gee, it was going to cure all sorts of diseases in 10 years – a claim which had me laughing then and one which still gets me laughing. They were unscientific claims made about something which we did not know much about then – a case rather similar to Kurzweil’s.

    So let’s say the brain is reverse-engineered tomorrow – whatever that phrase is meant to mean (was the genome project a reverse engineering of humans?) Now you’re back to Myers’ statement that you can reverse engineer a CPU, but what then?

    These statements that Kurzweil make are only idle chatter; perhaps one day people will accomplish those things, but making these predictions is ridiculous at best nor are they new – this stuff has been in science fiction decades ago and the Trekkies have argued endlessly about the human brain and the teleporter and what it really means to be you.

    • MadScientist says:

      Oh, that “design of the brain” vs. memories thing is incorrect – Myers’ point is that you can take the thing apart but can you build something which functions like a brain? After all, how do you prove that your brain model is correct if it doesn’t do anything we expect of a brain? How do we demonstrate that information goes in, gets processed and filed away, and can be retrieved and manipulated?

  7. itzac says:

    I’ve long suspected a simulated brain, human or otherwise, would involve starting from an essentially blank slate and throwing piles of stimulation at it. Tilera (http://www.tilera.com/) makes hardware that I think would prove extremely useful in this endeavor, but I lack the expertise and resources to properly explore this idea.

    The idea that you can simulate a brain simply by reproducing a physical brain in a computer model is, in my opinion, naive on the part of both the neurologist and the computer scientist. We’re probably not so far off from AI, but I don’t think we’ll ever be able to copy a human mind.

    • Max says:

      A senior AI researcher told me we’ll never copy a human mind, but he’s a Creationist.

      On the other hand, there’s Stephen Thaler and his neural networks.
      http://www.imagination-engines.com
      He’s another futurist who wants to be immortal.
      http://www.initsimage.org

      • Nick says:

        Stephen Thaler will be mortal. Humanity doesn’t remember anyone who doesn’t give it something back. If he would release the source code of his Creativity Machine under GPL he could enter the competition.

      • Anon says:

        There is no competition. Anyone who wants to be “immortal” should become it. Who are you to determine whether he will be mortal or not? The future is based upon freedom and mutual respect, not primitive competition, hatred and self-righteousness towards others on how they should or should not live.

        Have you actually read some of Mr. Thaler’s material or are you just one of those persons who condemn everything without first looking into it? He plans to use his technology to bring about world prosperity.

        It would be great to see him releasing the source codes but get real – the current system IS based upon money and competition, which is sad, but he needs a great deal of money in order to advance this AI.

        If it where open source I bet hardly anyone would notice let alone knowing how to really use or upscale it but maybe he will do it some time in the future after the system transformed?

  8. Brian says:

    Something that must be taken into account is that the functional components of our genetic code were well understood for many many years before we decoded our genome. The same cannot be said of the brain. I would argue that one must clearly understand the building blocks before modeling is possible. We have yet even get the blocks right (see recent discoveries regarding chemicals and memory). Though one might hope that the basic building blocks are few and it will then be our task to organize them synthetically, but the future is a big unknown in this area.

    As mentioned above, a functionally correct brain does not mimic human thought patterns unless it is stimulated in a way that a human is from birth (or sooner). The structure of the brain evolves over time as the senses feed it information about the environment. This maturation process will be a huge science all it’s own once the time arrives.

  9. Scott Young says:

    Interesting discussion for sure. The points to be examined themselves lead us deeper and deeper into complexities not generally appreciated. For example, the human genome is actually not completely sequenced. Extensive regions near the centromeres and telomeres are too difficult or impossible to sequence using current technologies. I still don’t know why this is glossed over. I like the point about environmental influence, even within the body. A “simple” example that is not well understood is the role of circulating hormones, not just steroids, in the fetal development of various social, sexual and other behaviors. Another is the two-way interactions between the brain and the periphery.

    I think I’ve heard Kurzwell say something about downloading a particular human’s “essence” into a machine (one of your brother’s fantasies!). This strikes me as particularly absurd; even if we could scan a brain at a molecular level, could any process (analog or digital) recreate that information distribution, including what was occurring just prior and after the scan.

  10. epicurus says:

    I don’t understand what ‘principles of operation of the brain’ means. What Kurzweil is predicting is rather vague? If you can reverse engineer the brain, does that mean you can construct and simulate it? That means artificial intelligence (AI).

    Computer scientists have been trying to build AI for 60 years. They succeeded in building a computer that can beat Kasparov in chess but not smart enough to outsmart a cockroach. If they succeed in building a computer as smart as a cockroach, I would be open to the idea of human-level AI in a few decades.

  11. Petrucio says:

    Something I received today, totally relevant to this discussion:
    http://en.wikipedia.org/wiki/NOMFET

  12. donjoe says:

    1. You and Myers are both forgetting that Kurzweil thinks like an engineer more than a scientist. In his mind, the goals are always practical and as far as the brain’s complexity is concerned, it’s not really that part of the complexity that is outside the brain (in its environment) that seems to pose the bigger engineering challenge right now, but the inside – the essence of the brain itself. That’s why Kurzweil only focuses on the genome part of the complexity – the rest is “just” chemical soup + randomness, it doesn’t sound like a big engineering obstacle.

    2. “Eek” is not the same thing as “eke”. Look it up. :)

  13. Dr Johnty says:

    As far as Ray Kurzweil and his theories go I can understand why others often fail to see where he is coming from. I find almost everything that Ray proposes hinges on the concept of exponential growth in technology. I often discussed this with professional colleagues and even they could not really grasp the concept. The reason for this is that the mind cannot conceive the concept of exponential growth in the same way that you cannot really perceive how large 1 billion is unless you convert it into something you can conceive. The best way to do this is to keep in mind that at an average rate of counting you would reach 1 million in 17 days but 1 billion would take you 32 years! We have the same problem with linear versus exponential growth. When I realised how hard it was to explain the concept I decided to draw up a list and it consists of the dates at which major discoveries arose. This list is on my site at http://drjohnty.com/Exponential_Growth.html I think that when anyone looks at this list it is clear that Ray is most likely very much on the right track. If the pattern is continued as Ray suggests and indeed continually accelarates as history confirms then we are set for a degree of progress during course of this century which will be on a scale never before seen in history. My conclusion is that even if the trends are not repeated and progress slows to only 20/25% of that suggested by the calculations on exponential growth the developments in technology will still be so staggering as to be inconceivable from where we stand currently. In other words I believe as Ray does that it is inevitable and nothing will prevent the singularity the only quesion is whether it arises in 2045 as Ray believes or maybe as late as 2095 but whenever it arises I cannot see it will not arise somewhere in the course of this century.