Christof Koch is an American neuroscientist, best known for his work on the neural basis of consciousness. He is the President and Chief Scientific Officer of the Allen Institute for Brain Science in Seattle, and from 1986 to 2013 he was a professor at California Institute of Technology (Caltech). Koch has published extensively, and his most recent book is Consciousness: Confessions of a Romantic Reductionist.
What follows is an interview between Christof Koch and Byron Reese, publisher of GigaOm, and author of the new book The Fourth Age: Smart Robots, Conscious Computers, and the Future of Humanity. They discuss artificial intelligence, consciousness and the brain.
Byron Reese: So people often say, “We don’t know what consciousness is,” but that’s not really true. We know exactly what it is. The debate is around how it comes about, correct?
Christof Koch: Correct.
So, what is it?
It’s my experience, it’s the feeling of life itself, it’s my pain my pleasure my hopes, my aspirations, my fears, all of that is consciousness.
And it’s described as the last major scientific question that we know neither how to ask nor what the answer would look like, but I assume you disagree with that?
I disagree with some of that, it’s one of the two or three big questions, being: Why is there anything at all? What’s the origin of life, and yes how does consciousness arrive out of matter?
And what would that answer look like, because people often point to some part of the brain or some aspect of it and say, “that’s where it comes from,” but how would you put into words why it comes about?
It’s a very good question. So, having the answer which bits and pieces of the brain are important for consciousness is critical to understand what happens in emergency room when you have the patient who is heavily brain damaged, but you have no idea whether she is actually there, was anybody home. It’s going to be of immense practical importance and clinical importance for babies or for anencephalic babies, or at the end of life, but of course that doesn’t answer the question. What is it about this particular bit, piece of the brain that gives rise to consciousness, and so finding what we need, we need a fundamental theory of consciousness that tells us what type of physical system, whether evolved or artificial, what type of physical system under what conditions can give rise to feelings, because those feelings aren’t there. If you look at the fundamental theories of physics, quantum mechanics and general relativity, there’s no consciousness there. If you look at the periodic table of chemistry, there’s no consciousness there. If you look at the endless ATGC chart of our genes, there’s no consciousness there. Yet every morning we wake up to a world full of sounds and sights and smells and pains and pleasures. So that’s the challenge: how the physics ultimately give rise to conscious sensations.
Or, some might say, “whether physics give rise to it?”
Well, physics does give rise to it in the sense that my brain is a piece of furniture of the universe. It’s subject to the same physical laws as everything else. There isn’t a magical type of law that only applies to brains but doesn’t apply to anything else, so somehow physical systems, or at least a subset of physical system gives rise to consciousness. The classical answer, at least in the West, was forever, for a very very long time, there’s a special substance, the thinking substance, res cognitans, or people today call it the soul, and only certain types of systems have it and only humans have the soul, and the soul somehow mediates the mind. But of course we [say], sort of logically, that’s not very coherent, there’s no empirical evidence for it… how would this soul interact with the brain, where’s the soul supposed to be, where does it come from, where’s it going to, it’s all incoherent, although of course the majority of people still believe in some version of this. But as scientists, as philosophers we know better. There isn’t any such soul, so it comes back to the question, “What is it about the physics of the world that gives rise to feelings, to sensations, to experience?”
Well, I want to tackle that head on in just a moment, but, let’s start with you, because you’ve been dealing with this question for a long time, and it’s fair to say, your understanding of it has evolved over time. Can you walk through, like the very first time you thought about this? As far back as you remember, and then what you thought and what the early theories you offered up, and how you have evolved those over time?
Sure, so I grew up in a devout Roman Catholic family, and I was devout and then of course you grow up to believe there’s this soul, the real Christof, is sort of this spirit that’s hovering over the waters of my brain, and every now and then, that soul touches the waters of my brain, makes me do things, and then when I’m thinking about, for instance, whether I should sin or not, this absolute freedom to choose one or the other and then my soul does one thing or the other, but then, this was on Sundays. Then during the day and the rest of the week, I taught science, I thought about the world in scientific terms, and then you’re left… well wait a minute, you begin to think about more detail and that just can’t work. Because, most importantly, where is the soul? How does it interact with a brain, and so then you begin to think about scientific solutions. And then I encountered, years later, Francis Crick, the co-discoverer of DNA, and he and I started up this very fruitful collaboration, where we wanted to take the problem of consciousness away from purely philosophy where it’s vested over the past 2,000 years, which is great you’ve had some of the smartest people of humanity, but they haven’t really advanced the field that much, to take it into an empirical operation that we scientists can work on. And so we came up with this idea of the neuronal colleagues of consciousness. It’s a fairly obvious thing; it’s the idea is that, whenever I’m conscious of something, whether it’s your face for instance, I see your face or hear your voice, or I have a pain or I have a memory, there must be some mechanism in my brain, we know it’s not the heart, we know it’s in the brain, there must be some mechanism in the brain that’s responsible for that. And it’s a 2-way communication between this mechanism and my feelings in the sense that I artificially activate this neuronal colleague of consciousness or abbreviated as NCC. If I trigger it for example, by an electrode that I put into the brain, and say doing brain surgery, I should get that person, even though there isn’t anybody out there, but I still see a face. Or conversely, if this part of the brain gets removed by a stroke or a virus or a bullet or something, I shouldn’t be able to have this person anymore.
Now also this is a big scientific empirical program that’s going on in many places throughout the world, where people are trying to look for these neural colleagues of consciousness in the brain. But then of course, somebody pointed out to me, he asked me a very simple question, said, “Well in principle, if your program has run its course and then 50 years later we know exactly that every time you activate these neurons in this particular mode, projecting to this other part of the brain, you become conscious.” How’s that different from the cards cranial gland, because famously 80 years ago, they said well the place where the brain needs to have this spooky stuff, this cognitive stuff, is the cranial gland, and today we all laugh at it, right? Well how is that different from saying, “well it’s made up of 5 neons that oscillate at 40 hertz?” It’s just much more detailed, because ultimately it seems like magic. Why should activity in these neurons give rise to conscious sensation, and at that point, I really thought, well what we need, we need a fundamental theory that tells us, independent of which mechanism, tells us what is it about any one mechanism that can give rise to consciousness? And so here we are, 20 years later.
And so talk about IIT?
So the most promising theory of consciousness in my personal opinion, and in the opinion of many of the observers of the field, is this integrated information theory, due to this Italian-American psychiatrist and neuroscientist, Giulio Tononi. And it starts by saying, “Well what is a conscious experience? A conscious experience exists for itself – in other words it doesn’t depend on anybody else, doesn’t depend on my parents or you or any observer – it just exists for itself. It has particular properties, it’s very definite, either I have a conscious experience or I don’t have a conscious experience. It’s one, it’s only one at any given point in time, and it has parts, like, if I look out at the world, I can see you over here, over there something else, and there’s an above and below and a close by and a far away, and all those notions of space and other sensory qualities. And so then let’s look for a physical mechanism, or first an abstract mathematical formulation of such a magnitude that instantiates these key properties of consciousness. And so the theory says that ultimately, consciousness is its causal power of the system upon itself.
So let me unpack that a little bit. Well firstly, let me repeat it. So the idea is that consciousness ultimately is the ability of any system, like my brain, to influence its immediate future, and to be influenced by its imminent past, it has causal power. Not upon others, that’s what physics has. If I have an electric charge, I’ve attraction or repulsion of other things, but it’s power upon itself. The brain’s a very complex system, and its current state, influences its previous state and its past state influences its current state. And the claim is that any system that has internal causal power, feels like something from the inside. Physics tells us how objects appear from the outside, and this thing, intrinsic cause-effect power, tells us what it feels to be that system from the inside. So physics describes the world from the outside perspective, from the third person perspective of an observer. Integrated information cause and effect power tells me what it is to be a system from the inside, and the theory has this number called phi, that tells you how conscious the system is, how much intrinsic cause and effect power it has, how irreducible it is, that’s another way of looking at it. Consciousness is a property of a whole, and how much that whole is a whole, how much it is reducible, that’s quantified by this number phi. If phi is zero, you don’t exist, there’s no consciousness, the system doesn’t exist as a whole. The bigger the phi, the more conscious the system is, and the theory delivers, at least in principle for any system, whether it’s a brain or computer chip or a molehill, an ant, anything else, it says, in principle you can determine, it gives a recipe algorithm, how you can determine for a particular system, in a particular state, whether it’s conscious and how much it’s conscious by computing the phi. So that’s where we are today.
So it’s a form of panpsychism?
One of its consequences of integrated information is, that it says consciousness is much more widespread than we’d like to believe. It is probably present in most of metazoa, most animals, it may even be present even very simple system like a bacterium may feel like something, that’s what it says, that a single paramecium for instance, right, a single protozoa, single bacteria is already a very complicated system, vastly more complicated than anybody’s every simulated, right? We don’t have a single simulation today, in the world, of a single cell at the molecular level, but it’s way too complex for us to do right now, but the theory says yes, even this simple system feels like a tiny bit…
What about non-biological systems though?
In principle the theory is agnostic. It just talks about causal power, so any system that has causal power upon itself, is in principle, conscious.
So is the sun conscious?
Well, okay so that’s a very good question. The sun is not conscious I believe, at the level of the sun, because, so consciousness really requires… It says that the system has to be integrated and highly differentiated as a whole; so the system has to be able to influence its whole. The sun is so big that it’s very difficult to understand how propagations within the sun would exceed any time more than a few millimeters, given the magnetic hypo dynamics of the corona atmosphere of the sun. So any system, you can always ask the question, is that as a whole conscious, as many people have asked in the West and in Eastern tradition. The sun is unlikely to be conscious, just like, for example a sand hill, is very unlikely to be conscious, because if you look at the individual sand particles, they only interact with each other over very, very short distances. You don’t have two sand particles that ever, let’s say, an inch apart, they don’t interact anymore, only very, very weakly. Just like, for instance, you and me, you’re conscious, I’m conscious, there isn’t something that’s right now, that feels to be a Byron-Christof, although we do interact, right, we clearly talk to each other, but your brain has a particular amount of integrated information. My brain has a particular amount of integrated information. There is a tiny bit of integrated information among us, but the theory says, the only systems that are conscious, are local maximum. It’s like many physical systems, it has this extreme on principle, it said, “only a system that has maximum cause-effect power is conscious.” Therefore, the integrated information within my brain is much more tightly integrated given the massive interconnection within my brain, and the very few bits that we exchange sort of every second, given the speed of verbal communication. So that’s why you’re conscious, I’m conscious, but there isn’t an uber consciousness, there isn’t a gestalt that sort of consists of you and me.
But, do you have a sense, if you were a betting man, that while you extend this order of consciousness to all of these systems, are humans somehow more conscious than an ant?
Yes, there’s no question…
So what is it about humans, in fact, could you name something that hypothetically could be more conscious than a human?
Yes, in principle you can imagine other physical systems…
No, I mean something in the real world? And what is it about us, back to this, “What’s special about us that gives us supercharged consciousness? Because our brain isn’t that much different than an ape brain…
But it’s bigger.
Right, but only by percent.
Well by a factor of three. But just size… in terms of local interactions, we haven’t done enough microanatomy, to be able to see… is a little grain of ape brain really fundamentally different from a little bit and piece of human brain? Certainly by size…
But then the Beluga whale would be more conscious than us?
Well, so that is one of the challenges, we look at brains of some mammalian, that made it back to the sea, their brain is indeed bigger than us and it may be, it’s very difficult to know right now, but it may be that at some sense, they may be more conscious of their environment than us, but they haven’t developed the ability to talk about it in the way we have, so it’s very difficult for us to test that right now. But that’s not impossible. But it’s an important question, ultimately you can test.
It just, it feels like you have a world full of all these objects…
These conscious entities, yes indeed. The universe is partly filled with conscious entities.
But somehow we appear, and I understand your caveat that that might not actually be the case, but we appear to be the most conscious thing.
Well because we are eloquent.
And other animals, by and large are not nearly as eloquent. My dog, I can communicate with my dog, but only in a limited way, you know I know the position of his back, how he wags his tail, his ears etc., but it’s low grade… and also my dog doesn’t have an affect representation of Charles Darwin, or evolution or god or something like that. So yes, by and large, it appears to be, at least on planet earth, that it’s not unlikely that we are the most, homo sapiensis the most conscious creature around. We live in a world with other conscious entities. Now this is not the usual belief. The majority of the planet’s population believes that there are lots of other conscious minds. It’s only really in the West, that we have this belief in human exceptionalism, and somehow we are radically different from anything else in nature. It’s not a universal belief.
No, but I guess one would say, if you compare our DNA to an ape, as an example, the amount that’s different is very small.
And of the stuff that’s different, a bunch of that may not manifest itself. It may not do anything, and that the amount of code different between us and an ape is trivially small, and yet, an ape isn’t 99% as conscious as I am, or at least it doesn’t feel that way to me.
We remember the code that’s in our DNA, which is only 30 MBs, if you compress it, not a lot, and as you pointed out, it’s more or less the same in an ape, in fact it’s more or less the same in some mammals. But let’s not totally confuse the amount of information in the blueprint, with the actual information in the final organism as a whole.
I’ve heard an older interview of yours where you were asked if the internet was conscious. And you said, “it may have some amount of consciousness,” would you update that answer?
Well, in the meantime, the internet has got a whole lot more complex of course, I don’t see any behavioral evidence of consciousness. So, it has a very different architecture, it’s not point to point, it has packet switching, so it’s quite different from the way our brain is, so it’s not easy to actually estimate how conscious it is. Right now, I’d probably say it’s not very, based on what I know about it today, but I may be wrong, and it certainly could change in the future. Because if you think about it, certainly in terms of its component, the internet has vastly more transistors, the internet taken as whole, it has 10 billion nodes… each of those nodes has 10 to 11 transistors, so if you look at it as a whole, it’s bigger than a single human brain, but it’s wired up and interconnected on many different ways, and connectivity, — this is what integrated information tells us: the way components are wired up really makes all the difference, so if you take the same components, but you wire them up randomly or even the wrong ways you might get very little consciousness, it really matters.
What about the Gaia hypothesis, do you think that the Earth and all of its systems, if they function as a whole, if they are self-regulating to some degree, then it’s influencing itself and so could the Earth as a whole be conscious, and all of its living systems?
Unlikely, for the same reason, integrated information says always consciousness, it’s local maximum of intrinsic cause and effect power. In fact, this criticism has been made by an American philosopher John Searle. He said, “Well, IT seems to predict that all Americans, that America is conscious as a whole, there are 310 million Americans, each one of them is conscious, at least when they’re not sleeping etc. And therefore, how do you rule out that there isn’t America as a conscious entity? Well the theory has a very simple principle, local cause-effect maximum, you’re conscious, I’m conscious, but unless I do some interesting technology, we can return to that point in a little bit, there isn’t anything what it is like to be unique, right now there isn’t… There are four of us in this room, there isn’t a group consciousness, there isn’t anything that feels like to be the group of the four of us sitting around here, nor is there anything like to be America.
So, what would be your criticism of the old Chinese nation problem, where is says, “you take a country like China, one billion plus people and you give everybody a phone book, and they can call each other and relay messages to each other, and that eventually…”
Okay, let’s get to something much more concrete, I find more interesting… Let’s take a technology, let’s call it bridging, brain bridging, okay? Let’s say brain bridging allows me directly with some future technology to wire up some of my neurons to some of your neurons. Okay, so let’s do that in the visual thing. So now my visual brain has access to some of what you see, so for instance I now see a ghostly image of what I see across the usual world, and now I sort of ghostly super-impose, I see a little bit of what you see, right now you’re looking at me, so I see me ghostly reflected. However, the theory says, until the integrated information between the system or your brain/my brain, and the spring bridging, increases the above integrated information with my brain or within your brain. There’s still you, and there’s still me. You are still a conscious entity with your own memory and I’m still a conscious entity, Christof. Now, I keep on increasing the bandwidth of this brain bridge. At some point the theory makes a very clear prediction: when the integrated information in this new system, that has now 2 brains exceeds the integrated information in either your or my brain, at that point I will die, Christof will die, Byron will die and there will be a new entity, a new single entity that consists of you and me. It’ll be a single thing, it’ll be a single mind that has some of your memories and some of my memories, it’ll have 2 brains, 4 hemispheres, 4 eyes, 4 ears.
And you know what, the inverse has happened in surgery, it’s called split brain, because in split brain what I do, I take a normal brain, I mean they’re not normal, they’re not healthy, but for the sake of argument, let’s assume it’s a normal brain, I cut it in the midline where there are 200 million fibers across the corpus callosum that link the 200 million fibers that link the left brain with the right brain, I cut it, and what’s the empirical evidence? I have two minds inside one skull, so here I’m just saying, “Well let’s just do it using technology, we built a sort of artificial corpus callosum between your brain and my brain.” And so, in principle, there will be this technology, that allows us, maybe even in large groups, to merge, we can take all these four people here, we can interconnect us using this brain bridging, and then there will truly be a single mind. Now that’s a cool prediction. And you can probably start doing that in mice in the next 10 years or so. It’s a very specific prediction of the theory. That’s the advantage, once you go from philosophy to very concrete theories, you can test them and then you can think about technology to implement and test them.
Think about two lovers, think about Tristan and Isolde, right? Who sing in Tristan and Isolde opera… they don’t want to be Tristan/ Isolde anymore, they want to be this single entity, right, so in the act of love-making, you’re still, that’s the tragedy of our life, you’re still always you, and she’s always she, no matter how close you are, even though your bodies interpenetrate, you’re still you and she’s still her, but with this technology, you would overcome that, there would be only a single mind. Now I don’t know how it would feel, you might also get all sorts of pathologies, because your brain has always been your brain, and my brain always my brain and suddenly there’s this new thing, you could probably get what you get in split brain, that one body does something different from the other body, these conflicts that you see in split brain, after the operation, this so called “alien hand syndrome”… But at least conceptually, this is what the theory predicts.
I’ll ask you one more hypothetical on things whether they’re conscious or not, what about plants, how would you apply IIT to a tree?
It’s a very good question. I don’t know the answer. I’ve thought a little bit about it, of course there are now people who claim that plants, flowers and trees have much more complex information processing going on, at a slower scale. They clearly didn’t evolve to move around, they clearly don’t act on the timescale of seconds. It may well be possible that at least some non-animal organisms like plants, also that it feels like something to be them, that’s what consciousness is, it feels like something to be you, we can’t rule it out. Now our intuition says, “Well that’s ridiculous,” but our intuition also says, “The planet can’t be round, because people obviously would fall off,” people have used this argument for hundreds of years, but the person on the antipode is going to fall off the planet. So we know planets can’t be round, “we know whales are fish, they smell like fish, they’re in the water, they’re not mammals.” So we’ve all sorts of intuition that then science tells us, well actually these intuitions are wrong.
So let’s think through the ethical implications of that, if people are conscious, and because people are conscious they can feel pain, and because they can feel pain, we deem that they have certain rights. You can’t abuse animals because, of course up until recently people didn’t believe animals necessarily could feel pain, up until the nineties. And so, we say “no, no,” you can’t abuse animals, because animals can feel pain. Well according to you, everything can… well not everything, but almost everything can feel pain. Does that (a) imply everything has some right not to be hurt, does a tree have some right not to be cut down; and part (b), does it not undermine the very notion of human rights, because if we’re just another conscious thing, and everything else, and whales may be more so and fish may be, and this may be and that may be, then there really isn’t anything wrong with torturing people or what have you, because everything’s conscious, of course everything.
Okay the first point, I don’t know, having consciousness doesn’t automatically imply that you have the capability to feel pain, to experience pain. Consciousness just, could maybe be all they have are pleasure centers, for them the entire life is just a ride of pleasures, just one orgasm after the other, so our theory of having consciousness is not the same as having conscious experience of pain. Pain is a subset of conscious experience. Second of all, even as humans, we have rights, but then of course, very often those rights clash. “Thou shall not kill.” But there’s capital punishment, and there’s abortion, and then there is homicide, and then there is war, where I can legally kill other people, right? So, these rights are always a tradeoff, as are other rights, and same thing with consciousness yes. It’s no question that certainly all mammals are conscious, right? Birds are conscious, most of the complex fish are conscious, and so one consequence is maybe we shouldn’t eat it. So ever since I had this realization, I don’t eat the flesh of creatures anymore, for that very reason. Now once again, it’s a tradeoff, okay, I’m not going to starve to death if there’s a piece of dead flesh, of steak that I could eat to survive, and so it is a trade off. But given that we have choices, I think we should act on those choices and yes, if it’s true, the moral circle becomes larger, but this has happened over the last 2,000 years. The moral circle of life, the people accorded special privileges, first only used to be Greek men, alright, and then we extended it to some other men around the periphery of the Mediterranean, and then we thought about women, and then we thought about African Americans, and Africans and people who look, at least superficially, very different from us. Right now, as you may well know, there’s a movement to accord at least great apes certain rights, because, yes they are our cousins, our distant cousins. And yes we shouldn’t hunt them and eat them for bush meat.
That’s maybe addressing a slightly different question I’m asking. I’m saying, if the circle eventually becomes everything, then the circle becomes meaningless right? If it’s like, “no, no, you can’t eat plants either, and then you can’t cut a sheet of paper or…”
No, no, because the theory says, not every object is conscious, most certainly not. A sheet of paper for example, the interactions…
Not a sheet of paper, I shouldn’t have said that one, but you extended it to plants…
A big question is, it’s the difference between having one cell that’s highly complex and conscious, versus is the plant a whole? That’s a question you have to ask. Is the tree, the oak tree, as a whole, is it conscious as a whole, or are there bits and pieces of it? That makes a big difference, I assume we don’t know, I haven’t looked at the structure, I don’t know.
Fair enough, but the argument is, you speed up the plant growing and finding sunlight, and it sure looks like animal movement…
Yeah but movement by itself, we know in patients, we know when you’re sleepwalking you can do all sorts of complex behavior, without the patient necessarily being conscious, so it’s a complicated question.
You made a really sweeping statement just a second ago, you said, “all mammals are conscious, and birds and fish.” How do you know that, or how do you have a high degree of confidence in that?
Very good question, so, two things have happened, historically over the last hundred years, (a) we’ve realized, the continuity of all brain structures, we believe it’s a brain that gives rise to consciousness, not the heart. If you look at the brains of all mammals, I mean I’ve done this at my institute, my institute has 330 people that are experts in the neuron anatomy of mouse brain and human brain, I’ve shown them, one after the other, cells, brain cells, they’ve come from a human brain and a mouse brain, each one a slide on the screen. And I asked them, I moved the scale bar because the human brain is roughly 3 times bigger in width than the mouse brain, I remove the scale, each one I asked, “tell me, guess.” And they had this photo app, they had this app on their phone, “is it human or mouse?” People were entranced. Why? Because the individual components are so similar across whether it’s a mouse, a dog, or monkey or a human, it all looks the same, we have more of it, but as you point out, whale has even more of it. So the hardware’s very similar. [Secondly,] behavior with the exception of speech, (but of course not all humans speak, there are people who are mute, there are babies, and early children that don’t speak, there are people in faith that don’t speak. But speech at least in normal human adults, is a difference from other creatures). But there are all these other complex behaviors: empathy, lying, there’s higher order theories, there’s complex bees for example, who’ve been shown to recognize individual beehive owners. Bees have this very complicated way how they choose their hybrid, you think how long it takes you to choose a house, you can look at how a bee colony sends out these scouts and they have this very complicated dance to try to find an agreement, so we realize there’s lots of complex behavior out there in the world. Thirdly, we’ve decided, at least scientists and philosophers have, that consciousness is probably not just at the apex of information processing. So it’s not just what it used to be, so high level awareness that I know I’m going to die and I can talk about it, but consciousness is also those low level things like seeing, like feeling, like having pain. And those state that the associated behavior and the associated underlying neural hardware that we find in many many many other creatures. And therefore today, most people who think about questions of consciousness, believe consciousness is much more widespread than we used to think.
Let’s talk a little bit about the brain and work that way. So let’s talk straight with the nematode worm… 302 neurons in its brain. We’ve spent 20 years trying to build a model of it, and even the people involved in it, say that that may not… they don’t know if they can do it. Do you think…
Embarrassing isn’t it?
Well is it, or is it not beautiful? That life, so my question to you is this, you just chose to say, “because our neuron looks like a mouse neuron, ergo, mice are conscious.”
No, no, no, it’s not quite that. Our brain is very similar to a mouse brain, our behavior is rather similar, and therefore it’s much more likely that they also have similar states, not identical, much less complex, but similar states of pain and pleasure and seeing and hearing that I have. I find no reason to… there’s no objective reason to think otherwise, because otherwise you have to say, “Well we have something special, but I don’t know what that special is. I don’t find it in the underlying hardware.” So, and this of course what Rene Descartes did famously, he said, “When your carriage hits a dog and the dog yells, it’s just a machine acting out, there’s no conscious sensation.” Clearly he wasn’t a dog owner, right? We believe, I mean, I don’t know a single dog owner who doesn’t believe his dog can be happy or excited or sad or depressed or in pain. Well those are all conscious sensations. Why do we say that? Well, because we interact with them, we live with them, we realize they have very complex behavior that’s not so different from ours. They can be jealous, they can be happy, same thing that your kids are jealous of each other sometimes, or happy, so we see the great similarities of cause and divide across species. We’re all nature’s children.
So, back to the nematode worm, our understanding of how 300, and I think 2 of them float off on their own, so how 300 neurons come together, and form complex behavior, such as finding food, finding a mate. I mean they’re the most successful creatures on the planet. 70% of all animals are nematode worms.
They out survive us.
Yeah, so my question is to you, first of all, could a neuron actually be as complicated as a super computer? Could it be operating on the Planck scale, with such incredible nuance to say… well I’ll leave the question there. Why is the nematode worm so intractable so far, and why do we not understand better how neurons operate, and could a neuron be as complicated as a super computer?
Right, okay so three very different questions, let’s start with neurons, any cell. As I mentioned before, right now we do not have a molecular level model of an entire cell. There’s not a single group that has such a model, just of a single cell, no matter what cell that is, nematode cell, human cell, some people are trying to do that. The Allen Institute for Cell Science is trying to do that, but we aren’t there yet, right? Why? Because we still don’t have the knowledge and the raw computational ability, but more important, the knowledge to try and model all of that, right? That’s just a practical limitation. We’re making progress, but it’s slow. You’re right very unbalancing for my science, brain science. We do not have a general-purpose model of a creature that only has 1000 cells, 302 of which are neurons. We’re getting there, I mean we understand many many things about the nematode, but we’re still not there yet, so, my science still has a long way to go. So it’s difficult, what else is new about the world, research is difficult. Look, per unit, per gram or pound, the brain is the most complex organ in the known universe. It’s the most complex piece of highly organized matter in the universe, right? And I think that’s related to the fact it’s also conscious, because it is so complex, it is also conscious, so yes it is a challenge to our current methods, we’re making progress but it is, and remains the biggest challenge we have in science.
It’s interesting though, because the argument I heard earlier, you said, “People used to say there’s something special about humans.” We don’t know what that is, dualism breaks down because of this problem. Therefore, there isn’t anything. Let’s look for a purely scientific answer… you come to some theory, but, and I’m in with all of that, but then, you say, “We look at a cell, we don’t understand how the cell works…”
Right, and therefore, and we’re fine knowing there are just certain things we don’t know about it.
But we didn’t take that about the specialness of humans. Look, there’s something special about us, everybody knows that, everybody knows that there’s a difference between a person and a paramecium, everybody knows. And we just don’t know what it is yet, and we’re fine with that for now, but you say, “No, no, we have now concluded there is nothing special about us, let’s go figure out an alternate explanation.”
Well depends what you mean “special” about us. Clearly there are many things that are special about us. As I said, we’re the only ones who are eloquent. I’ve never had a conversation with my dog, nor with a worm. We have, for example a capability of language, that’s enabled us to build these cultures and to build everything around us. So there’s no question we’re special. What you’re saying, we are special, or what people want to hear, that we are special, we somehow avoid the laws of science or we have something going above and beyond the laws of science. Anybody else in the universe has to follow the laws of physics, but somehow humans are exempt from them, they’re this special deal, they have this special deal called a soul. We don’t know what it is, we don’t know how it interacts with the rest of the world; but somehow, and that’s what makes us unique. Sure I can believe that, that’s a great belief, makes me special, but I don’t see any particular evidence for it. No, we are different in all sorts of ways, but we’re not different in that way, we are subject to the same laws of physics as any other thing inside the universe.
So you mention language. I’m just curious, this is a one-off question. You think it’s interesting that of all the animals that have learned to sign, that none have ever asked a question, does that have any meaning to it?
I don’t know.
Because that would imply perhaps, they’re not conscious, because they can’t conceive that there’s something that knows something that they don’t.
Well you say this as like a fact. So, you’re sure that no gorilla has ever asked a question to another gorilla?
Correct, the one potential exception is, Alex the grey parrot may have asked what color he was, maybe. Other than that, no gorilla has ever asked.
I’m not sure I would take that at face value, but even if it’s true, so let’s just say for the sake of argument, yes. We seem to have vastly more self-consciousness than other creatures. You know if the other creatures do have some simple level of self-consciousness, a dog has simple self-consciousness, my dog never smells his own poop, but he always spends a lot of time smelling other dog’s poop, so clearly he can make the difference, between self and somebody else. But yeah, my dog isn’t going to sit there and ask questions, because his brain just doesn’t have that sort of complexity.
Back to the notion “You and I don’t have anything between us that makes us one entity.” Do you think that a beehive, or an anthill that exhibits complex behavior in excess in any of them, do they have an emergent consciousness as a whole?
So that’s a very good question. I don’t know. Again you have to compare the complexity within a bee brain, so a bee is roughly one million neurons, their circuit density is 10 times higher than our circuit density because they evolved to fly, so they have to be on very tight weight mass constraints of the sorts that we aren’t as terrestrial animals, and nobody’s fully reconstructed a bee brain yet, although they’re doing it for flying. So question is, given the complexity of what’s in the bee strain and the communication, the wiggle dance they do to communicate, what’s the tradeoff there? I mean it’s a purely empirical question that can be asked. Right now my feeling is probably not, but I may well be wrong.
Do you know the wasps that do the shimmering thing, they make this big spinning pin wheel, and they spin so quickly there’s no wasp who says “oh he just flared his wings, therefore it’s my turn, and then the next one, that somehow…?
Look you have these beautiful, what are they called ruminations, there’s these beautiful, you can see it on the web, these movies of birds, and flocks of birds that execute these incredible flight maneuvers, highly highly synchronized. Are they one conscious entity? Again, you have to look at the brains and you have to look at the amount of communication among the individual organs. You can look at North Korean military parades, right? It’s amazing the precision with which you get 100,000 Koreans to do these highly choreographed [maneuvers]. But they’re not conscious as a whole because the information they exchange is much much lower than the massive information. Once again, you have 200 million fibers just between your left brain and your right brain, but those are all good questions that you could ask and that have answers once you have a fundamental theory of consciousness.
So let’s go from the brain to the mind. So, I’ve looked hard to find the definition of the mind that everybody can kind of agree on. And my working definition will be: it’s the set of attributes that we have, some abilities that we have, that don’t seem, at first glance, to be something that mere matter could do. Like, I have a sense of humor, my liver may not have a sense of humor, my liver may not be conscious the way my brain is. So, where do you think the mind, under that definition, where do you think all these abilities come from? Do you think they’re inherently emergent properties? Or are they just things we haven’t kind of sorted through? Where does a sense of humor come from when no individual cell has a sense of humor?
It’s a property of the whole, it’s the property of your brain as a whole, it’s not a property of individual cells, we know this is true of many… I take a car, I look at the many individual components of a car, they don’t drive, they don’t do the same what a car does, but you put all these things together as a whole, and then the whole can do things that the individual parts can’t.
Emergence, so do you believe that strong emergence exists? Do you believe you can always derive the behavior from, like if you studied cells long enough, you would say “I understand where a sense of humor comes from now?”
No, for that you need a theory of consciousness, if you’re really referring to the conscious mind, to the mind, as many aspects are unconscious. I think about the maiden name of my grandmother. I have no idea, how my brain, how my mind comes up with the name Shaw. I don’t know how it works, so that’s all unconscious. The conscious mind you need a theory of consciousness, you, not just a theory of cells, not just the physics of it, but you also need to explain how conscious mind that has a sense of humor, because that’s the property of a conscious mind. Or maybe doesn’t have a sense of humor, depending who it is, emerges from. Yeah, so it’s what you refer to as strong emergence.
And so strong emergence…
But it’s not magical you understand that?
Well that’s a word you’ve used a few times. And it’s because as you said at the very beginning, there’s nothing magic about us. But I think people who believe that strong emergence is possible believe it’s a scientific process. But, a lot of people say, “No, you can’t say that for something to take on properties that none of its components have, and you cannot derive those properties. Until eternity passes away, you can study those individual components and not figure out how that comes about.
Yes, you need to solve a problem that Aristotle was one of the first who wrote about it, the parts, the relations among the parts and the whole. Yes, you need a theory that describes what a whole is, the whole system. An integrated information theory is an example of such a theory that thinks about parts and how the parts come together to define a whole. Without such a theory, yes you would be lost, I agree with you, but it’s not magical. What I meant was that, once you have such a theory, then you can understand step-by-step. You can understand… you can predict which systems are whole and which systems are not whole. You can predict which system properties are essential for the wholeness and which ones are not. So in that sense, it’s a physical theory. It’s a lawful set of rules.
Well how can IIT be disprove it?
It can be disproved in a number of ways. So it says that the neural colleague of consciousness is the maxim of cause and effect. In principle it gives you a way exactly how to test it, how to measure it. In fact now there was this recent series of articles in neurological journals where people tested one implication of information theory and built a conscious meter, built a simple device where you probe the brain with these magnetic pulses, when you are asleep or anaesthetized or you go to an emergency room, critical care facility where you have people who may be in a vegetative state, or maybe in a more conscious state, maybe there’s a little bit of consciousness there, or maybe they are conscious but they can’t tell you because they’re so grievously injured. So integrated information derived a simple measure called perturbational complexity index, where you look at the EEG in response to these magnetic pulses where you can tell this patient is probably unconscious based on the response of his brain, and this person probably is likely to be conscious, so it’s one of the consequences. So there are ways you can test it. It is a scientific theory; it may be wrong. It is a scientific theory.
Did you read about the man in South Africa who was in a coma for some amount of time, then he woke up and he was still locked in, but he was completely awake? And the thing is that every day he was left at this facility, they assumed he wasn’t conscious. And so they played Barney all day long, and he came to abhor Barney, like so much he used all of his mental energy just to figure out what time it was every day, just so he would know when Barney was going to be over. And he said even to this day, he can look at a shadow on a wall and tell what time it is. So you believe that we’ll soon be able to put a device on somebody like that, saying “No, he’s fully awake, he’s fully abhorring Barney as we speak right now.”
I just came back the last two days I attended a meeting of emergency room medicine, coma and consciousness, and there we were for 2 days, we heard what is the current criteria, how can we judge these patients? They are very very difficult patients to treat because ultimately you’re never fully sure given the state of technology today. But yes in principle, and it looks like even in practice, at least according to these papers, the last test was 211 patients, that we might soon have such a conscious meter. There are several larger scale clinical trials trying to test this across a large clinical population. There are thousands of these patients worldwide, like Terry Schiavo was one of them, where it was controversial because there was this dispute between the parents and the then husband.
So, I’m curious about whether all these things are conscious, for two reasons. One we discussed, because it has, as you’ve said, implications for how you treat them. But the other one is, because if you don’t know if a tree’s conscious, you may not be able to know if a computer’s conscious, and so being able to figure out something as alien as the sun or Gaia or a tree or a porpoise is conscious, how would we know if a computer was? That’s the penultimate question I want to ask, how would you now if a computer was conscious?
Very good question, so first we need to make it perfectly clear because people always get this wrong: there is artificial intelligence, narrow or broad, and we’re slowly getting there, that is totally separate from the question of artificial consciousness. In other words you can perfectly well imagine a super computer, super human intelligence, but it absolutely feels like nothing. And so most of all the computers today are of that ilk, and most will agree with that statement. So, we have to dissociate intelligence from consciousness. Historically, until this unique moment in time, we’ve always lived in a situation where if you wanted something done, you wanted a ditch done, you wanted a war fought, you wanted your tax to be done, you employed a person and the person was conscious. But now we are living in this world where you might have things that dig ditches, fight wars and do taxes that are just algorithms. They’re not conscious. However, of course this does raise the question, under what conditions can you create artificial feelings. When is your iPhone actually going to feel like something? When is your iPhone actually going to see, as compared to taking a picture and putting a box around it and saying, “This is mum’s face,” which it can do today. So once again you need a theory of that. You can’t just go by the behavior because there’s no question, in the fullness of time, we will get all the movies and all the TV shows, Westworld,etc.
We’re going to live in a world where things behave like us. We will experience the world in 10 or 20 years where Siri talks to you in a voice that you cannot distinguish at all anymore from a human secretary. Instead he or she will have perfect poise, be perfectly calm, laugh at every one of your jokes. So how do we know she’s conscious? For that you need a fundamental theory, and this particular fundamental theory of integrated information says you cannot compute consciousness. Consciousness is not a special property of an algorithm, because your brain isn’t an algorithm. Your brain is a physical machine: it has exterior, it has cognitive powers, both on the outside, it can talk, it can move things about and it has intrinsic cause effect power, and that’s what consciousness is. So if you want human level consciousness, you have to build a machine in the likeness of man. You have to build what’s called a neuromorphic computer. You have to build a computer whose architecture at the level of the metal, at the level of the gate, mimics the architecture of the brain, and some people are trying to do that.
The Human Brain Project in Europe
For instance, let me give you an example that’s very easy for scientists. So I have a friend, she’s an astrophysicist, so she writes down the Einstein equations of general relativity, and she can predict on her laptop, on her computer there’s a black hole at the center of our galaxy. It’s a big black hole a billion solar masses that sucks up all the… it bends gravity so much that not even light can escape. But funny enough, she doesn’t get sucked into her laptop that runs that, why not? Why it’s simulating all correctly, all the effects of gravity, yet it doesn’t have any effect on its environment. Well isn’t that funny, why not? Because it doesn’t have the causal power of gravity. It can simulate, it can compute the effect the gravity has, but it can’t emulate it, can’t physically instantiate the cause and effect of gravity (same thing). Consciousness ultimately isn’t about the causal power, it’s not about simulation, it’s not about computation, and so unless you do that, you can build a zombie; you will be able to build zombies that claim they’re conscious, but they don’t feel like anything.
Well that is a great place to leave it. What a fascinating discussion, and I want to thank you for sharing your time.
Thank you very much, Byron. That was most enjoyable, and this is part of the IEEE Tech Fisherman series at South by Southwest.