Henry Markham, Ray Kurzweil and the Artificial Brain

A Popular Fairy Tale

Comparing human brains to computers has become something of an industry lately. Like nuclear fusion, an emergent silicon mind seems to be always just around he next corner. The poster boy for this idea is Ray Kurzweil. If you want to watch a movie imagining precisely this vision, take a look at Transcendence. Transcendence is a tolerably good movie but brain capture fails in the movie for truly stupid reasons (plot spoiler) because it apparently fails to capture the "soul" and not due to any fundamental difficulty involved in creating a mind in a machine.

The monstrously expensive and spectacular failure of the Blue Brain project was conceived by Henry Markham. You can view his version of this fairy tale on TED. [1]

So How Big a Computer Do We Need?

The 19 million volumes in the US Library of Congress represent about 10 trillion characters - 10,000,000,000,000 characters. To make the analogy even approximately apt, we need to imagine each character in each book being a tiny, super-powerful computer with an operating system of millions of lines of code. As long as each of these tiny computers is 1,000 times faster than any computer we could ever build, and as long as the computers can communicate with each other at better than internet speed, we are getting into sight of the computational power of the human brain.

The Super Computer Between Your Ears

Let's take a look at how your brain "computes".

The neuron's closest analogue in a computer is the CPU chip (central processing unit), not the memory. Your computer may have terabytes of memory on board but that's almost irrelevant. Bits in memory are "dead". They only become useful when run through the CPU for processing. So we are talking about 100 billion CPU's -- one each per neuron. That's more than the number of CPU's on the planet at the moment. Per brain.

But this isn't quite right either. The neuron has complex behavior based on its genetic "programming", inputs, outputs and a bath of mostly unknown enzymes. Like every cell in the body, the neuron is as complex as a jumbo jet. You could probably model it with reasonable success with a complex program of some sort. So we basically have 100 billion PC's. That's full-scale computers consisting of on or more CPU's, a big chunk of memory (Terabytes),  and a few million lines of code. Each.

Synapse Simulation

But wait!

Active, dynamic "thinking" in the brain is not controlled the neuron. It's about how one neuron is influences another. Each connection is mediated by a synapse. There are about 100 trillion of these in your head. Each synapse connects an "upstream" neuron U with a "downstream" neuron D. Whether or not the connection U,D exists is a dynamic property of the brain. Connections are being formed and broken all the time. What's more, the strength of the connection varies due to processes like "thinking" and "experience". For example, the speed of connection depends on the existence of the myelin sheath around the axon - something that's built up or torn down depending on the dynamic "usefulness" of the connection. These connections are not "dumb" wires - each connection needs to be simulated, probably with a rather simple program, but there are trillions of them.

To make matters more interesting, the synapse is not just a dumb connector. Whether or not it will transmit a signal from U to D depends of a lot of things including the concentration and gradient of dozens of neurotransmitters in the synaptic cleft, the number of receptors for each type of neurotransmitter molecule (ready to pick up a signal from U to D) and the properties of the transmitting "upstream" part of the synapse (axial terminator). All these things are dynamic, changing thousands of times per second. Each factor depends on the others in complex ways.

Simulating all this for a synapse may be feasible, but you'd need 100 trillion powerful PC's to do it. It's hard to imagine how you would connect all these computers together but fortunately for our thought experiment, the connections are not that fast by electronic standards. The number of connections is mind boggling but we don't need to worry about the speed of the connections.

Simulating Synaptic Receptors

Optimistic authors tend to assume that such PC's would have no trouble simulating a synapse in real time (comparing the switching speed of computers to the signalling speed of neurons)  but the speed comparison needs to look at the speed of the chemical processes at the synapse, thousands of which take place in the nanosecond range simultaneously. The problem is that chemical reactions take place on a the "pica" scale, thousands of times smaller and thousands of times faster than silicon logic. We need 100 trillion PC's a thousand times faster than than any computer can be. And then there is the elephant in the room: it is by no means obvious that protein reactions can be simulated. It's a work in progress (to put it mildly). Definitely a day's work on a super computer to simulate just one reaction.

Programming and the Problem of Dynamic Non-Linear Systems

And then we need to program all this! Programming turns out to be not just hard but impossible. It's easy to imagine that the same program might work for 100 trillion synapses, but it could take decades of research to figure out how to approximately model just one synapse. At best, such research would give us a system of a few hundred dynamic non-linear equations. "Solving" such a system to predict or model behavior is known to be impossible. Things like that start to get hard with just three simple equations. Systems of equations that model change through time are called "dynamic". If the variables involved depend on each other in a non-trivial way (rates of change for example), the system is "non-linear". Almost always unsolvable, in the sense that you can't find value of all the variables that satisfy the equations.

And Then There's the Issue of Measurement

Measuring the current state of any particular synapse in a human head is also impossible for Quantum Mechanical reasons, so you have the additional problem of deciding the initial conditions for a few hundred parameters in each of 100 trillion synapses. Finding the initial conditions involves solving a set of dynamic non-linear equations which is impossible.

But Let's Not Give Up Entirely

There is no way to do this, but perhaps we can imagine a start ...

Memory elements (bits) in computers are "dead" and need to be picked up by the CPU to be processed into new memory elements (bits). Like cars that spend 99% of their time parked, almost all the "bits" in the computer sit around waiting to be funnelled through the CPU.

On the other hand, in modern computers, random access memory is refreshed thousands of times per second (it's read out and written back automatically). We could imagine a system that made the write-back a function of more than just the bit being written back. That would be referred to as a massively parallel architecture, orders of magnitude more powerful than today's fastest super computers. But still not beyond he realm of imagination. That would make the memory a "thinking" machine, constantly "unpacking" ideas at thousands of times per second. For this to work, you'd need a way to represent "ideas" in a form that could be quickly and efficiently "unpacked" into new "ideas". I can imagine a structure involving hundreds of thousands of "concepts" (English words for example) where the memory function is to write back concept B if concept A is active and B is "strongly" related to A. That would make "B" active and concepts related to "B" would be activated on the next cycle. In this picture, "A is related to B" is our synapse.

The modern Graphics Processing Unit (GPU) is the kind of parallel processor we need but we need one a few billion times bigger (same size, more capacity), thousands of times faster and with the ability to program itself on the fly. Then all we need to do is figure out what an "idea" is ...

But Maybe We Can Design a Better Brain

The one thing that keeps the "strong AI" idea alive is that a human-designed brain may turn out to be many thousands of times more efficient than its meat counterpart. We shouldn't need to simulate the actual brain to produce the "mind". If this is so, we need to understand the architecture of the mind itself (independent of how it "runs" on meat). To put it kindly, this process is in its infancy. Most AI research uses brute force to solve practical problems and has no interest in how the human mind actually works. (Hofstader hardly attends AI conferences any more).

For now, we are stuck with the meat computer between our ears which apparently zips along much faster than 100 trillion super computers. If you ask me, the singularity is not as close as Ray Kurzweil imagines.

The Blue Brain Project

The Blue Brain project is an attempt to model a tiny brain based on actual data on the brain structure of a rat. It is not even an attempt to model the entire rat's brain - just a patch of its tiny neocortex.

Artist's conception-Fractal Cortical Column

The project shows the sweeping simplifications and assumptions that are required, along with the vast computer facilities to model even these assumptions. The project investigates an intermediary structure, larger than the neuron and smaller than brain modules such as the visual cortex. This is the "cortical column". There is no general definition of what, exactly, this "column" is, but the outer surfaces of the brain (neocortex) seem to have a consistent structure of vertically associated neurons in "vertical" columns (stacked inwards from the surface). The "wiring" within the column and between columns is not random (widely considered to be a fractal structure - each column being daughters of a single stem cell). It has long been recognized that the cortical column is promising both as a subject of study (how does it work, what does it do?) and a subject of computer modelling if you happen to own a super computer. 

The Blue Brain Project seems to be the ultimate evidence that Hofstader's line of investigation (at the "meme" level) is sadly far from the mainstream, even though his model of the mind is, so far, the most successful. "Blue Brain" is working on the reductionist assumption that understanding of the mind will "emerge" from a sufficiently detailed understanding of the "fundamental" aspects of the brain, just like Quantum Mechanics is supposed to be a "Theory of Everything". The hopelessness of this idea is illustrated by the goals of the project, which attempt to model a tiny patch of cortical columns based on the brain structure of a rat.

Literature on the cortical column seems to focus on brain processes at the very origin of perception (such as the visual cortex). The assumption that the same processes are involved in (for example) formation of new concepts is so far not justified by the research.

[1] Recent reports indicate that the Blue Brain project is not going well. Markram pitches the project is here as a TED project. He is stunningly naive about how his "top down" idea of how the brain works. He parades the reductionist assumptions of how this can be "unpacked" by simulating it all on the computer. His talk illustrates a popular technique of "brain talk". Markram talks as if "columns" are well defined, let alone understood, just as others talk about "neurons" as some kind of "explanation" of thought. He mentions "10 million synapses", somehow ignorant of he fact that there are 10 trillion. He lies about "having the math" to describe neurons with a "handful" of equations. He lies by creating the impression that having such equations amounts to solving them. He lies about attempting a "real time" simulation. His bottom line: "It's not impossible to build a human brain and we will do it in 10 years".

Hidden Assumptions About Consciousness

What, if anything, is "consciousness"?

This is a central question of Zen. I have recently taken a look at the more "Scientific" view on the question.

I just read Daniel Dennett's discussion of consciousness. There are lots of Dennett lectures online. He's articulate and entertaining.  Dennett is a philosopher so tends to dig himself into obscure debates about language, terminology and disputes with other philosophers. He borrows a lot of experimental results, but he's not really part of the Scientific culture. Sorry, philosophers, philosophy is not Science. As Robert Laughlin reminds us, scholars of the humanities talk about words; physicists talk about facts. Dennett is still well worth reading though.

Let me sketch out what I think he's talking about.

He seems to be arguing against the intuitive view of consciousness, best represented by what's called the Cartesian Theater. This pictures the mind as something sitting in a theater watching the world "through" the brain. The mind is something other than the brain, in other words, or possibly something very strange and wonderful "in" the brain, so far undiscovered.

The Cartesian Theater cannot be the way it is. It just leaves you asking how the "person" in the theater works, which is where you started. This is similar to the problem with the idea that God created the world. We are not supposed to ask where God came from. At least with respect to the mystery of how the world came to be, God doesn't help.

But what are the options with respect to consciousness? Dennett says, quite convincingly, that we can learn a lot about consciousness from the "outside", what he calls the 3rd person perspective. Submit the subject to experiments designed to probe the "inner workings" of consciousness, and record physical evidence, such as button pushes, speech acts of the subject and so on. In fact, you can learn a lot this way, but Dennett begs the question: what are you learning about? His hidden assumption seems to be that he is learning about what his opponents claim he's not learning about: what boils down to the mind, the soul or the self. Dennett loves to pepper his talks with interesting discoveries about the brain, which leaves the reader with the impression that the experimental discoveries about the "mind" are revealing what is really going on in the brain and nothing more.

Philosophers tend to carve up the Universe into camps and continually make the mistake of assuming that they have proven their own theory when they have discredited the (sometimes misrepresented) beliefs of the other camps. This is the fallacy of the excluded middle.

The discussion, as Dennett frames it, is that either (a) there is something about the "soul" that cannot be learned from 3rd person experiments on the brain or (b) we have no reason to think that such experiments will leave out anything important.

But does this cover all the possibilities? Isn't Dennett assuming that the results of his experiments give us data on the brain? If the "mind" and the "brain" are indeed different (which is, after all, the central issue), can we assume from the outset that our experiments involve only the brain of the subject and nothing else of importance? Shouldn't this be a hypothesis instead of an assumption?

Let me put on my system's analyst hat and look at one of the experiments Dennett presents so entertainingly and refers to every time he discusses consciousness. As a systems analyst (not a philosopher), I find his account crawling with entities that are so familiar as to be invisible to the casual listener. To put it simply, Dennett's accounts risk being considered as mere cartoons or "thought experiments".

• The whole idea is to somehow capture the "1st person" account of the subject and show how this spectacularly disagrees with what is "really" happening. Discrepancies reveal the "workings of the mind". The "1st person" account plus "3rd party" (experimenter) account of what is really happening is the "data" for Dennett's scientific study of consciousness.
• As is typical of psychological experiments, the "subject" is actually a statistical fiction. The "data" is about average responses, typical accounts etc. The goal of peeking inside one mind slips away (and, after all, this is what we want: insight into the feeling we all have of being unique - "me" - the 1st person perspective).
• What is referred to as "3rd person" or "observer accounts are obviously 1st person accounts from the experimenter. Or maybe these are averaged too. We somehow assume that the experimenter's point of view makes no difference, but this has been exposed as a huge mistake in Relativity and Quantum Mechanics. We are asked to assume it is irrelevant in studies of consciousness. To Dennett's credit, he allows the public to become subjects in on-line experiments and appreciate a bit of the "raw data" Dennett is talking about. But Dennett is still "talking over the shoulder" of the subject and immediately providing his interpretation of what is important and/or significant.
• The "apparatus", the context and the overall experimental conditions are assumed to be irrelevant. This is a standard procedure when we try to learn about Nature. As much as possible, isolate the system studied from all other influences. It makes sense if you are studying gravity, but if you are trying to find out if the "mind" is actually confined to the brain, it amounts to an unstated assumption or (better) a hypothesis. It is impossible to study a "mind" on its own. In fact the business of the mind is to reflect context. No context, no mind.

The whole idea of 1st person, 2nd person, 3rd person is a linguistic convenience and the kind of thing philosophers love to dispute over. But they certainly don't exclude the possibilities, especially when the subject of discussion is the human imagination or the "mind's eye". What I mean by "me" is the whole question.

• 1st person refers to the way I describe my own experience. It's the perspective that Dennett seems to regard as an illusion. He's not alone in this, but "illusion" over-states the issue. You can't get around the fact that it feels like something to be me, no matter how much you learn about what's happening in my brain to make me feel like that.
• 2nd person is "you", the reader of this post, for example. Speaking of "you" involves an assumption by "me", commonly referred to as a "theory of mind", that you have a mind like mine and experience the world more or less like I do.
• 3rd person is "they", not me or "you" but objects in the world. When these objects are human, "theory of mind" applies.

To my knowledge, this exhausts the possibilities built into language, although fine distinctions can be made about the gender, social status or personal relationship of the individuals involved. But there are lots of other "persons" that we talk about routinely.

• The "observer" in Relativity is a god-like entity whose only attribute seems to be a location in "space time". The observer mixes the attributes of "I" and "me", seeing the world from his unique perspective even though he/she is always referred to in the 3rd person. The Relativistic observer has been stripped of all human attributes or capabilities apart from those useful to the theory of Relativity itself. This "observer" is capable of visiting places and times that would be inaccessible to humans (such as inside a black hole or just after the Big Bang), so "theory of mind" hardly applies. The Relativistic observer really only "knows" things. He"observes" and measures.
• The "apparatus" is operated by a close relative of the Relativistic observer in Quantum Mechanics. This observer can "know" only what the apparatus (like a Geiger counter) tells him. In Quantum Mechanics, neither the observer nor the Universe exist separately. Einstein intuitively thought that the world had properties that didn't depend on observation but was proven wrong. This has left us with a huge problem, in particular, it has left us scratching our heads about what counts as an "observer" in Quantum Mechanics. Not surprisingly, different Relativistic Observers can get different results from straightforward Quantum experiments, such as counting the number of protons in a box.
• The story teller has a long tradition in human thought. We are so used to stories beginning "Once upon a time" that we forget to ask who is telling the story. The story teller adopts an omniscient point of view, knowing even the inner thoughts and motives of the humans in the story. Steeped in stories like this, it is easy for us to imagine God a celestial story teller, even though we know that all stories are ultimately told by a story teller from a 1st person perspective. Accounts of Scientific experiments often slip into this perspective as if God were taking notes, reading minds and revealing what is "really" going on.

The issue of "person" - human perspective - is right at the middle of the discussion of consciousness and we need to be very careful about who is who in the stories we hear about experiments supposedly "about" consciousness. Whose consciousness?

Milgram's Obedience Experiments

The point can be illustrated from a famous series of experiments conducted by Miligram, which claimed to provide a peek into one small aspect of the human mind, specifically our tendency to inflict cruel punishment on other humans when ordered to do so by authority figures.

Milgram's experiments and his analysis crawl with the same demons that inflict Dennett's. Milgram is tryies to sort out the effect of context on the subject's decision to be cruel. If so, his conclusions and extensive discussions about how subjects "feel" need to be set aside.

• Milgram's "discoveries" turn out to be heavily influenced by his interpretation. In other words, they are 1st person accounts of records of events, exactly in the spirit of Dennetts (in fact, Milgram's experiments are some of the first of this kind). Milgram cannot subtract himself from the experiment. Most obviously, Milgram was struggling to understand the Holocaust and how such cruelty could be inflicted by supposedly ordinary people. He imagined he got the answers to the questions he posed. Other questions were set aside. In this case, Milgram adopts the God-like "person" of the story teller.
• It turns out that it makes a big difference who the "subject" is. "Results" are actually statistical and convey information (if at all) for a rather small set of specific subjects. It makes no sense to speak of what, say, 100 people are thinking "on average", yet this is precisely what Milgram is trying to do.
• It makes a difference who the "tester" is (the person giving instructions). Varying the tester (by giving him a lab coat or not) makes a difference. This is an invisible 3rd party in Milgram's stories. Correctly interpreted, Milgram's results are about situations not just decisions.
• Culture and history make a difference. The "self" of individual subjects depends on where they were born and the culture they belong to.
• The physical setup (the Quantum "apparatus") makes a difference. To get results similar to Migram's you need to exactly replicate his experimental setup. That's standard Scientific practice, but the practice again emphasizes that the conclusions are about the specific situation, not about the inner workings of the mind.

It's reasonable to expect that a successful theory of consciousness, like any Scientific theory (Evolution, Relativity, Quantum Mechanics) will force us to abandon the "obvious" and draw us into new ways of thinking. It seems to me that consciousness poses an even bigger challenge than the problems tackled and overcome in the 20th century. Is it possible to glimpse what a new theory might look like? Maybe.

• Consciousness is accompanied by a non-local pattern of activity in the brain over time. Large areas of the brain are involved. It's clear that there is no single area "in control". This looks to me like a field phenomenon.  For example, in quantum mechanics, it makes little sense to talk about where particles are or imagine a bunch of tiny billiard balls whizzing around. The world is best described in terms of variations in a field over time. So my guess is that consciousness is a whole-brain kind of phenomenon. At least.
• In quantum mechanics, there is a mysterious process known as "collapse of the wave function". Quantum fields are wave-like probability distributions, which tell you the probability that an event will happen at any given time and location, should you introduce an apparatus to detect it. The events that the apparatus detects are actual, "real" events.  Is the experience of consciousness a similar "collapse" of the field-like activity in the brain? This idea is getting quite a lot of serious attention (Google it). The idea is that collective "chatter" between neurons "collapses" into a specific perception or "thought". Dennett's experiments illustrate the idea, where the perception magically seems to shift as the subject "sees" the same scene in a different way. I am skeptical about attempts of mystics to co-opt Quantum theory directly into a theory of mind. I think Quantum theory gives us clues about how a theory of mind might look like, but the "field" in question is quite a different sort of thing.
• It's worth asking about the boundaries of the "self" under examination. Quantum wave functions are "about" a system of particles and tell you about, say, the probability that an atom (a system of particles) will emit a photon  of a given wavelength. Psychological experiments involve a "subject" along with everyone and everything that has ever influenced the subject, including the specific setup surrounding the situation of the experiment. Is it correct to assume that the "brain" of the subject is identical to the "mind" that produces the data? The Zen way of looking at it would be to ask, is the "mind" not a product of the whole Universe? Are the distinctions the result of the way the brain works? Is the "illusion" a matter of feeling that the mind is exclusively happening to "me"?
• Robert B. Lauglin's "emergence" is probably a better paradigm to work with than Daneil Dennett's reductionism if only for the reason that emergence seems to be a better paradigm for everything. Reductionism in Science is on its way out.

ZOMBIES

There is an entirely different issue going on in Dennett's presentations. The idea of the "philosophical zombie".

Theoretically, a Zombie is physically identical to a human being but lacks a "mind". The Zombie will perform exactly the same as a real human in any experiment. Philosophers love to dream up ways that you could tell if the Zombie really has an "inner experience" or is just faking it. Of course, you can't by definition, but what the Hell, it's publish or perish.

This image gets a lot of popular exposure in movies about "strong AI" and in Ray Kursweil's idea that we could eventually migrate our "selves" entirely into a machine, leaving our biological bodies behind. This idea if fundamentally "dualistic", assuming that the "mind" is something other than the brain and could be implemented on an entirely different (presumably better) technology (Why not Heaven?). Both ideas depend on the widening experience of people with computers, which seem to be getting "smarter" all the time. Is it not just a matter of time before they become conscious?

As one who has lived with computers since they started to proliferate, my guess is that a computer, no matter how sophisticated, will have no more "inner experience" than a cuckoo clock. But this is not obvious to others and this keeps the zombie concept alive and well. Real AI research gives us a practical way to build "real" zombies and, as a byproduct, explore what it is to be human.

Kursweil's invites us to think seriously about zombies. The last thing Kursweil would admit to is Dualistic ideas(soul apart from brain), but that's exactly what he's assuming.

Kursweil's bottom line is that we could (a) build a computer that is functionally identical to a human mind (Zombie) and (b) we could migrate our biological mind into such a machine and thereby become an immortal non-Zombie and (c) if a machine thinks it's me, it's me. It should be noted that the movie "Singularity", based directly on Kursweil's idea, (a) and (b) are assumed but (c) is challenged as well as any serious idea may be discussed in a Hollywood movie. 

If we assume both (a) and (b) of Kursweil's Science Fiction, we are left with some questions. What do we do with my biological body after my mind has migrated to a better home? Presumably that body still thinks of itself as "me". Recycle? Scrap? Keep as backup? Once "I" am safely ensconced in my computer home, why not clone me? Would both clones be "me"? Check out Oblivion.

These are what Dennett refers to as "Imagination Pumps": questions that force us to think about old issues in new ways. Kursweil's zombies are ideal test subjects for Dennett's thought experiments. Whatever we figure out, it's certain to be a big surprise.

See also:

Zen and Outside-In Mind
Re-Thinking Mind and Soul
What, If Anything, Is Reality?
What, If Anything, Is the Self?

Emergence - A Different Universe - Robert B. Laughlin