Within Reason - #146 The Most Complicated Thing in the Universe: What is the Brain?

Episode Date: March 8, 2026

Matthew Cobb is a British zoologist and Emeritus professor of zoology at the University of Manchester.Get his book, The Idea of the Brain: A HistoryCloser to Truth's Map of Consciousness: loc.closertotruth.com/mapTIMESTAMPS:0:00 The Heart or the Head?4:13 Medicine in the Ancient World12:25 Why Don’t We Accept Evidence?18:34 From Ancient to Modern Understanding29:29 When Did We Reach a Consensus on the Brain?37:41 Electricity in the Brain39:58 Our Metaphors for the Brain44:15 Is the Brain Segmented or Whole?01:05:20 Why is Speech Governed by the Left Hemisphere?01:18:55 Why is the Brain Split Into Two Hemispheres?01:23:06 Where in the Brain Does Consciousness Originate?01:32:46 The Ladybug Robot01:35:08 Back to Consciousness01:45:27 What is a Neuron?01:56:04 Why is Smell Connected to Memory So Strongly?02:02:14 Do London Cab Drivers Have Larger Hippocampi?02:10:11 The Limits of MRI and CT Scans02:19:24 Will We Ever Be Able to See Consciousness in the Brain?

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Many promotions are available both in-store and online, though some may vary. Matthew Cobb, welcome to the show. Great to be here, Alex. Thanks for the invitation. Tell me, where is fancy bread? In the heart or in the head? Yeah, so for viewers who don't know, that's from Shakespeare. And it's one of the things that I thought was really interesting

that in one of these Shakespeare plays, there's one of these songs in the middle of it, bits you skip over at school, in which somebody sings, tell me where is fancy bread or in the heart or in the head. And what that encapsulates, is the beginning of a shift in European knowledge about where fancy imagination might lie.

Is it in the heart or is it in the head? And I thought it was really interesting that not only that Shakespeare knew that people were worrying about this and thinking about it, but also that he knew that the groundlings, the people who were standing up at his plays and would throw cabbages if they weren't happy, that they would get the joke as well.

They'd understand it. So it wasn't just him being clever. it actually reveals something about popular culture at the turn of the end of the 16th beginning of the 17th century. So what it reveals is something that humanity's kind of mused about for a long time is what is the seat of imagination and thought. And for most of the time, most of humanity has thought it's in the heart, as far as we can tell. Very few peoples around the world, none in fact thought it was in the head. It required a great deal of investigation and thinking for that to begin to become apparent in the 15th, 16th century. Yeah, I mean, this is the, that that quote is from the end of the first chapter of the idea of the brain, which is a book I picked up a few months ago now.

And I found this really interesting because it's intentionally kind of a history of our understanding of the brain. It's not a book of neuroscience. It's not a book of philosophy of mind. Would you consider it like a history book? Oh, yeah. Very much so. I mean, that's the subtitle is a history in English. I suppose so.

Yeah, I think it's great. And it opens with this sort of taking us back to the beginning, these sort of ancient thinkers who believe that the heart was, as you say, the seat of fancy or imagination. And in a way, I mean, you talk about how this is embedded into our language. We say things like, I'm heartbroken, where like brain broken doesn't really seem to imply the same thing or, you know, his heart isn't in it. And people will probably sort of understand that, but specifically speaking, like as a scientist of the time, what were the like motivations that people had, people like Aristotle had for thinking that the heart was where thought came from? Well, that's what it feels like.

Yeah. I mean, you might think that you're thinking in your head, but if you think about what you feel, you don't feel, if you feel excited, you're not excited up here. You're excited in your whole body, in your guts. If your heart starts to pound, if you're frightened or, you know, your gut start to squirm. If you're feeling passionate, it's not in your head. So, everyday experience, if you're just thinking about it, which is all that people have for most of the time, it would suggest strongly that there's something on here, not up here. And I mean, so it's a bit like the sun going around the earth. People thought that because that's what it looked like. And you'd have to be very, very odd, or to have made incredibly precise observations to realize that it's the earth that goes around the sun. And that's why it took us so long to figure that out. And it also took us a long, long time to work out that the heart is simply a very weird

kind of pump pushing the blood round the body. And also is, people also thought that because when they did do dissections, uh, or they looked at animals or whatever, then you've got the blood, which seems really important. And the brain just is this kind of mushy white stuff. So Aristotle, for example, thought it was a kind of radiator. Its sole function was for cooling the blood and that the really important stuff was going on in the heart and in the blood and all the rest of it. Yeah. I mean, it's understandable, right? Because it's not just that you feel it there, but also you can, you can kind of measure it.

You can put your heart on your chest and when your emotions change, your heart starts pounding faster, but your head doesn't sort of seem to do anything. No. And yet, at the time, there were ways to begin to understand human biology, like you say. You can dissect animals. You can perform experiments on animals. And what was the sort of extent of like empirical science work on thinking at this sort of time? Well, they did things like, well, if you get a sheep's head. then you can see that its eyeballs, it's got its eyeballs, and connected to its eyeballs are these threads,

which they called neurons, which just simply means thread, sinew, and that connects to the brain in some way. But there was no reason to think that there's anything, any kind of what we would call information, or there's any message, or there's any, the image is somehow going that down there into the brain. And if you did think that, then all you would notice was all the connections of the brain to the heart, and you say, well, there you go, it's the heart. So simple dissections and looking at anatomy could help, but they didn't really solve the question. I mean, some people did think this.

So some of the ancient Greeks who wrote under the name of Hippocrates, as well known as the father of medicine, they began to argue, well, no, the brain is really what it's about. And one of the reasons they were thinking about this was to do brain injuries, head injuries, or epilepsy, and they began to think, well, okay, maybe the brain is much more important than what Aristotle argues. The key experiment was done by a man who developed what passed for medicine for about 1500 years, Galen, who was born in Turkey, he was Greek citizen, he was Greek ethnically, but was a Roman citizen.

So he's working at the end of the first, beginning of the century, the common era. And he worked as a physician in the arenas. So he'd see a lot of damage being done to fighters who were gladiators who were, you know, getting damaged. And one of the things you know from medicine and even from sports injuries, so if you play a contact sport like rugby, that it's very easy to damage the voice because our voice is controlled, we'll maybe come on to this later on, is controlled by this front left heart part of the brain. And the neuron, the nerve that controls that, controls your voice box, goes all the way down, loops under your heart, and comes all the way back up here. So it's one of the examples we give us showing that the body isn't designed because it's just kind of crazy.

If you're going to design it, you just go straight down. And that's to do with our evolutionary origins and the origins of the nerve and all the rest of it. But the key point is if you play rugby and you get hit on the chest, then you can lose your voice. You can damage your voice because you're damaging this neuron. And one of the things that Galen noticed was that this could happen to gladiators. And so he became, he was convinced that the brain, you could see the connection between this part of the brain, in both a human, but also in animals, and the voice. And he did a rather gruesome experiment. So if you are of a nervous disposition, you should fast forward a minute or so.

So he got a pig. He wanted to prove his point. And so he did an experiment, which was really a kind of demonstration. It was a way of an argument with his opponents. So they got a pig, and of course there are no anaesthetics at this time, so it's pretty gruesome. They chain the pig down, they bind its snout so it can't bite you, and then they open it up. And the pig is very unhappy, as you can imagine. It's squealing, it's making a terrible racket through this muffled muzzle.

And Galen says to his opponent, who thinks that the heart is, control of all behaviour, including the production of the voice. He says, right, put your hand round the heart, which of course is pounding away. And the man puts his hand, holds the heart, so it can't move anymore. No blood pumping, but the pig carries on squealing. Galen then says, okay, right, so they flip the poor pig over, it's still conscious. They crack open its skull, which would have involved a chisel of some kind. And they bear the brain, the pig still make you a noise, and then Galen says to his opponent, right, push down on the brain. So it pushes down on the brain and instantly, of course, the poor pig becomes unconscious and no longer makes a noise.

So this was an experimental proof of a kind that the brain was involved in controlling the voice and it wasn't the heart. Despite this experiment being well known, didn't change anybody's mind. The vast majority of people, obviously, people who weren't educated carry on believing what it feels like. It's my heart if they thought about it at all. But most clever people who knew about Galen's experiment didn't actually end up saying, okay, well, the brain is the seat of thinking and emotion. It's gradually developed a bit in medieval times. You can find strange diagrams of people became very interesting what are called the ventricles of the brain.

Right. So the ventricles, these kind of fluid-filled areas inside the brain. And people thought that there are three main ventricles and that they were, memory was in one part, thought was in another. and I can't remember whatever. There's sort of these gaps, right? Yeah, absolutely. We know are filled with fluid, but they also seem like if the brain is just this inert matter,

they seem like these sort of spaces in which, you know, thought or... Yeah, and also they're full of liquid. And you've got to remember, well, how would you conceptualize thought at the time? And the main word they would use would be spirit, i. This is some kind of non-material, it's a movement of something like air, or like water. So if you've got a load of fluid-filled bits in your brain,

then maybe that's where you can actually imagine that thought or whatever is based. So that was a thread. But most, as I say, there was no decisive evidence. I think the key point that people need to realize is there never was. There isn't a, there's no brain-centric moment. There isn't a moment at which the apple falls from the tree

and Newton goes, aha, gravity. I mean, that didn't happen either. But there's no experiment that convinces everybody. Right. And I think in general in science, that's the case. It's very rarely at the time that people go, oh my God, this changes everything. What they do do is say, hmm, that's really interesting. But maybe it's not right.

And then within a few years, there's extra evidence and they end up saying, okay, we change our mind now. But that took centuries of work, mainly in Europe. And that really, it's only by the middle of the 18th century that all thinking, So physicians and philosophers and others agree that it's something to do with the brain in some mysterious way that thought is either emanating from the brain, it's produced by the brain, or if you are what's called a dualist, that is, you think that thought is an immaterial matter, as Descartes put it, which is rather hard to make sense of. but he thinks that thought is some, or the soul is, comes into the brain, it accesses the physical world through a particular gland called the pineal gland. And he was very certain of this because only humans, he said, have the panneal gland, but in fact, virtual mammals do.

So people who fairly soon showed that was wrong. But even Descartes, who had this dualist idea, he was convinced that it was the brain that was the key organ. Yeah. But in the face of experiments like Galen's, and it is such a shame that so many important scientific developments have come at the cost of some exquisite tortures to animals and indeed humans. I mean, you talk later in your memory chapter about the patient HM, which is what he went by, right, who underwent some horrible trauma in his life, but which gave rise to a great deal of scientific understanding. but in the face of such experiments, grotesque as they were, how would somebody who believed that the heart is the seat of consciousness and thinking see the heart have no effect

and pressing down on the brain have all the effect and then still say, no, no, I still think it's the heart. Like, did they have, do we have any records of how they responded to this? No, not as far as I know. I mean, the key point they would say is, well, they go back to that, that's what it feels like. So, okay, this is experiment on a pig, and maybe the voice is something different. So it's about voice. It's clearly not only about voice because the pig goes unconscious. But then you can make up all sorts of explanations.

Given there is no kind of coherent theory for what's going on, you can make, you know, ad hoc, as they're called, explanations are on the hoof to try and say, okay, we can explain that away. And, yeah, I think that this is what it feels like. That's the reason. That's the reason for all these linguistic fossils. It's not only in English. When I give talks about this in other countries, always send a slide,

I have a slide with all these phrases about, you know, sweetheart and the heart was in my mouth and all the rest of it and ask the locals to translate it into their language using colloquial phrases. And they've all got them. Everybody's, every culture has those phrases. Yeah, that is, I mean, that is interesting. And I think we need to remember that our intuitions,

having grown up in a world that's quite certain of the role of the brain and thought, like those intuitions are very deeply baked and hard to shake off. So like earlier when you said, well, hold on, like, you know, you can open up a brain and see that the eye is connected by this thread to the brain. So, like, surely it's to do with the brain, but again, we just intuitively assume that, oh, because a message gets sent down, because we're used to things like electricity and cables

and how if two things are connected with a metal wire, there's information travelling down. But, you know, an ancient person would look at this as no more relevant than the fact that a chandelier is like hanging off the ceiling. To imagine that somehow that could convey information would probably be as mysterious as that it would, you know, jump from the heart right up to the eyeball, you know. And so we've got to sort of shake those intuitions off to then sort of do the history of how we came to adopt those intuitions. And that was one of the most interesting thing about the book was working, what was trying to unlearn things. So part of the problem with the history of science. is that it looks like it's a series of progressive steps

because science is cumulative. So, you know, as Newton said, we stand on the shoulders of giants. That's true, but those giants themselves made all sorts of mistakes and errors just as we do. And, you know, understanding how we got to where we are, there was nothing inevitable about it. And the particular passage, the pathway,

the set of discoveries were not inevitable. So one of the things I used to tell my students was that, you know, you cannot, and I say it's at the beginning of the book, you're allowed to find past beliefs amusing. I mean, I can't forbid people from laughing sometimes because some of the people's beliefs are a bit odd. But you are not allowed to think they're stupid because people are very clever. They're no less clever than we are. They're just no less because, I mean, we only know this stuff because we've been told it. It's very little that any of us have discovered ourselves, right? You've read it in a book.

Somebody's told you. You've seen it on the internet. Okay. So the question then is, if people's or individuals or groups didn't understand something that we think is self-evident, why didn't they? And what did they think in its place? And that is part of the challenge. So it means removing all the vocabulary. So things like information and message.

Yeah. I couldn't use them. I forbade myself to use them until I got to the bits where people at the time were starting to think in those. So there's this, there's a kind of restriction on the vocabulary you can use in order to try and reconstruct the ideas that people had and be fair and faithful to them. We'll get back to the show in just a moment, but first, if you've been watching this show for some time now, you'll know that for ages I've been recommending a way to deal with bias

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ground. News forward slash AlexoC or by scanning the QR code that's on your screen. Use my link to get 40% off their unlimited access vantage plan. And with that said, back to the show. Yeah, it's a great fallacy. We all too easily say like, oh, those people back then, those, those silly, illiterate, stupid people who didn't know anything. It's like, maybe they didn't know as many things as we did, but they were just as intelligent. To the extent that if you picked one up and dropped them into the modern day, they could learn to do it. Absolutely. And, And it's like there's that sort of internet meme of like, you know, getting into time machine and being like, I'm going to go back and I'm going to amaze, you know, these, these medieval

peasants with the technology of the modern day. And so you get there and they're like, okay, so how did, you said a computer chip. So how does that work? And like, oh. Well, yeah. I've got absolutely no idea. It like wouldn't even remotely speed up the process. But, you know, there has been a very long history of this development from Galen squeezing the heart of a pig, up until, as you say, only in the past few hundred years when consensus began to develop about the brain's role, that's a long stretch of history, but what do we know about some of the important developments that took us from that ancient worldview to this more modern worldview? Like, were there any, I only said there are no sort of definitive moments,

but are there any sort of tipping points on the scale of like a few hundred years or moments? Well, there's kind of inflections rather than tipping points. I mean, it's an arc and so. So I think the key thing is the development of anatomy and anatomical studies. And this isn't, this happens, begins in the 15th century and becomes a pace that you can actually now dissect human bodies. And it's very hard to understand why that began. Because although it happened in ancient Greece, there's a long period in which even Arabic physicians who, you know, developed a whole area of medicine and anatomy and so on, they were

not dissecting human bodies. Yeah. And we don't know why. It's nothing about, it doesn't seem to be anything about religion. This is forbidden or whatever. It may well have been looked down upon. I guess it still is now. But there was no kind of legal or absolutely accepted legal or religious framework to stop

people doing that. But in the 14th, 15th century, physicians in Europe start to anatomized dead bodies and to describe what's in there. up until then, they had simply relied, and this is what was called scholasticism. So when the Europeans caught up, so the Arabic world had been, had translated ancient Greek manuscripts, while we were all kind of taking chunks out of each other in the dark ages, and had also developed maths, chemistry, medicine and so on. when that knowledge came into Europe in around the 12th century, there were translations into Latin and so on, then that's when things start to kick off for all sorts of reasons.

It coincides to the development of printing. So now you've got printed, you haven't just got manuscripts where you're referring to what Galen said and so it must be true, but now you can actually find out new knowledge. And this links as well with the, ultimately with the rise of Protestantism, which. says that, you know, we can get direct access to the Word of God by the Bible. We don't need a priest's most kind of extreme version of Protestantism, that I can read the Word of God and I can find it out. And there's a similarity, and some historians have argued there's actually a link between that approach, I much more direct access to knowledge, religious knowledge, religious belief, and scientific knowledge in a period that is roughly called the scientific revolution. Some historians get very cross and say there wasn't. There was no such

this. One guy called Stephen Shapen wrote a little book called The Scientific Revolution and it begins, there was no such thing as the scientific revolution and this is a book about it. Now, I think there was a scientific revolution, but it was a rather odd revolution. It went on for about 150, 200 years and in some senses were still in the middle of it. So it's a change in thought, which is partly saying that I can get, I don't need to rely on Galen anymore. what's jolly interesting, but I can actually myself investigate what's in the body. And one of the things that they did, Vesalius was the most important, one he produced fantastic eight-volume book of human anatomy with marvellous woodcuts.

And ultimately, let's say there are prints later on, so actually printed on metal, showing the human body, glorious detail. And he also anatomized the brain and showed that it was this really complicated structure. and that began to get people very interested in England in the 17th century, a man called Willis did similar dissections of the brain. And really what it's showing is, look, the heart by this stage had been shown to be a pump, as I said. And it's a weird kind of pump, but it's a pump.

And you know that the blood's just going round and round in a circle, and this bizarre thing is going pumping back and forth. So that's okay. But that really does suggest that it's probably not doing anything. thing more than that. Whereas the brain, whatever it is, is connected to all the sense organs. It's astonishingly complicated, even without using microscopes and whatever they could see, it's very very complicated to understand. And that increasingly led by the 18th century to people saying, okay, it's the brain. So I think it's anatomy, which is the key thing. There weren't really

experiments that people could do or anything, although, you know, people like Descartes were thinking about how it might all work. And they were starting to use metaphors to think about how, what might be going on. So one of the things that Descartes did was to one, so he's in the 17th century in about 1630 or so. He's wandering around in the public parks in Paris and there were these animatronic statues

which would be things like, you know, you'd be walking along and then this dragon would come out and go back in. It was all powered by hydraulics. So that was the height of technology at the time. You could have weights pushing water up and down and these things would move. And what's striking is that there had been similar devices in ancient Greece, either were operated by water or steam or air.

So there were little models that would move. But nobody actually, even back then, thought, well, maybe that's how we work. Whereas what Descartes said, well, okay, maybe there's some kind of pressure in our nerves. That's what causes changes to movement. He has this very famous picture you can find on the internet of this great big kind of man baby

whose foot is touching a fire and there's a kind of diagram of this line going up to the brain and back down again. And basically what Descartes saying is that you detect something on your foot, it burns, it goes up, and the pressure goes up and bounces back down and you move your knee. this was later developed as the idea that the whole system was reflecting back. That's where we get reflex from.

So it's the idea of, you know, this, whatever it is, is going up and coming down. Yeah. And it's not like, this might sound kind of familiar. It's like, oh, yeah, like, well, we do have nerves and information kind of is sent from the foot, up to the brain, about down again. But again, before an understanding of something like electricity, what would that look like? And so, oh, maybe it's like water or air or something. So it's sort of getting the right kind of idea is beginning to develop. But again, you have to remember that you don't have the like conceptual imagery of like neurons firing or electrical signals or anything that doesn't exist.

So you look at a hydraulic press and think, oh, maybe it's air. So a lot of people would think that they were like literally like air sort of being pumped through these nerves. And that's, again, quite a sensible assumption. If you pull apart a body and you see that there's kind of a really thin chew. connecting these two things? What else is going to be going up and down? Yeah. And on the other hand, it was fairly easy to demonstrate that it was wrong.

Right. His idea was that there would be this hydraulic pressure. And so one man who's 17th century mainly working on insects, he also studied frogs and movement. And so he just cut a nerve in the frog's leg and nothing came spirting out. Yeah. But he's still so, well, okay, well, maybe Descartes's right. maybe it's something like a vibration. He said, well, if you imagine you've got to plank of wood and you hit one end, then you can feel the vibration at the other.

Maybe that's what's going on. So, you know, you can see that without the kind of understanding that we would have about electricity or electrochemical changes, which is really what's going on in our neurons, it's very hard to conceptualize. So all these people are grasping using the technology of the time. And that really is when actually the book took form for me. So it took about five years to write it. And at the beginning, it was awful. It was really bad.

It was just one damn thing after another. And I couldn't make sense of it. And it was just going to be a really, really boring book. And then it suddenly occurred to me. It was around about this period, so I started at the beginning and carried on, that I thought, wait a minute, there's something interesting here about how our ideas about what the brain is doing, are changing with technology. And the book is really about the metaphors we've used.

So the analogies, the similarities we've pointed to at different points. And it's always to do the peak of technology. Yes. So, you know, Descartes, amazing. You've got hydraulics. That's fantastic. You know, us today, amazing. We've got computers or large language models.

That must be how it works. And I thought that, once I realized that, I remember sending an email to my editor saying, I've made a conceptual breakthrough, which sounds rather fancy. It was. It actually meant that now I had a framing, not only for what I had, I now had to go back and rewrite, but also for where I was going to go in the future. And I thought, okay, that's interesting. That makes sense. And it also makes it really exciting because then you think, and scientists do this, because they don't think about what they, you know, they use these words, code and information. They don't worry about where it comes from. It all seems natural to them. And if you say, look, this is bound to the technology of the time. You know different from Descartes thinking about hydraulics. they go, so you mean this might change in the future with new technology? And you go, yes, of course. And they go, that's amazing. So what is it?

My answer has always been, well, if I knew what the future technology is, I'd be very rich. I have no idea. Yeah. But we can just see that thinking is linked to the conceptions of machines in particular and power and forces, and that will change in the future. At Desjardin, our business is helping yours. We are here to support your business through every stage of growth, from your first pitch to your first acquisition.

Whether it's improving cash flow or exploring investment banking solutions, with Desjardin business, it's all under one roof. So join the more than 400,000 Canadian entrepreneurs who already count on us, and contact Desjardin today. We'd love to talk. Business. Yeah, I think it's extremely interesting. Like, I've heard that some people had compared, you know, the brain to like an intricate kind of harp or something.

Whatever sort of complex, whatever the most complex thing they could think of, the brain must be a little bit like that. And that should give us perhaps some pause in thinking like, okay, maybe saying the brain is like a computer or an AI system is kind of accurate in some ways. But we should remember that this is a metaphor. And we'll get on to this. but like, I mean, it's worth remembering that metaphors are not saying it's the same thing as, you know. And that's the mistake that has so often been repeated. And the only mistake that's repeated more than that is thinking that we are now somehow not making a mistake. But, okay, so I want to talk about sort of once we've established that the brain is the key sort of part of thought,

I want to talk about some of these more recent developments. but I kind of just want to ask like just to fill in this picture of exactly how we got there like it can't have just been Galen does an experiment in the ancient world and then it takes 2,000 like years for people to finally accept it must have been other stuff going on or was it really just a case of like I guess it was like the discovery you said like anatomy but like the discovery of nerves people noticed that they were up to the brain and I suppose the also the discovery that the heart is just kind of a pump this kind of stuff just so. just slowly grew a consensus that the brain is what matters here.

Yeah. And you said it was around about when that people finally were sort of on board? In the middle of the 18th century. Right. And that coincides with the next big breakthrough in thinking about how the universe works, but also how movement occurs. And that's the discovery of the electricity. Yes.

And very soon people were able to produce, show that electric shocks initially, was the initial way they'd do it, would produce movement. Yeah. And you could do this, for example, with a frog's muscle. And they'd generate electricity by, this initially would be static electricity. Yeah. So you get some, a bit like you, you know, when you're a kid and your dad, or now if you're dad, you get a balloon and you rub it on your jumper and it sticks on the wall.

Yeah, static electricity. So you can produce a charge by rubbing wool against amber, for example. There were people who were called electricians who would have this as a party piece. And they'd go around and you'd go in and you'd get a, for example, there was a show called The Electrified Boy where you get a hapless child and you'd winch them up to the ceiling. And then you'd electrify them with the static electricity and then you'd throw a load of feathers in the air. And of course all the feathers would stick on the poor child. So you could do things like this.

Which again, like would have been extraordinary to see. Yeah, absolutely. But like when this is like new, when this is hot off the press, incredible, incredible thing. People, it was very eerie. Interestingly, people also started to use it as an early form of therapy. So there were itinerant electricians who would go around the country and give you an electric shock. So they charge this thing up and then you really high charge and then you'd touch it and you'd get an electric shock.

And it might or might not help cure your mental health problems. So, for example, Marat, the French Revolutionary, before he went on to lead the French Revolution 1789, he was touring the United Kingdom, giving people electric shocks because he was a great believer in the power of this. So there was a link between movement, perhaps something to do with mental health that was kind of unclear, but the whole series of reports of how this might work that led people to think it wasn't just nonsense. and we're still not clear about the power of this kind of therapy which was developed substantially in the 20th century

and is making a bit of a comeback today. The key development, however, came with the development of what we call in English batteries. And this was to try and resolve an argument that was taking place as to whether there was electricity in an animal or whether it was simply responding to it. even if you're getting this response, you know, you put a, you generate an electric current

and you touch a muscle with it if it contracts, well, okay, but it'll do the same if you put a drop of acid on it. Yeah. So it might be an irritant. So people are thinking very hard and, you know, if they weren't happy with the idea, they'd try and find other explanations. And with the development of the batteries, which were developed as a bit of biomimicry. So Volta, who's where we get the word vault from, he was trying to develop something. They studied electric, electric fish, so fish that will give you a shock if you touch them. And they knew the organ that produced the electric shock and it had these kind of layers in it. And he decided to try and imitate this. And so he makes a layers of using cardboard and metal and acid. And he produces a pile of these things.

And this in the end would produce an electric current. Now, we in English call this a battery, but in every other language it's called, for example in French, it's called in PIL, still called a pile. The only word where we, only time we still talk about piles in this sense is talking about atomic power where we call it an atomic pile,

but that's because the guy who first developed it was Italian, so he was basically we should be called it in atomic battery. But it goes back to this, it's a piece of biomimicry as I say. Interesting, okay. And in the beginning of the 19th century, you can now store electricity. And you could do dramatic things like

One philosopher got, he got about 300 monks and got them all to hold hands. So you've got about 600 metres worth of monk. And he goes to one end and he connects them to this battery, which just releases the power. And the electricity, the current goes down and they all jump up one after another. And then you could do things, for example, I mean, in people would do, you could go to London stage and see shows in which people would bring on a cow's head. The poor old cow had just been slaughtered backstage. They'd bring on the cow's head and then put its electrodes on either side of its ears or whatever and its eyes would open. Its tongue would roll.

Yeah, I mean, that's terrifying, right? That would have, like the Royal Institution, is that where they used to do that? Well, this was, this would be done as just for fun, as theatre. So you could go to the Drury Lane and watch it. And there was a notorious private demonstration of this in London where 12 members of the Royal Society went in a man who'd killed his wife and child was, was hanged. And then they immediately took his body down. and put it in a room with these members of the Royal Society, and they did the same thing. And, of course, you know, you put electrodes on the body, and its eyes are going to open.

And so there's a famous engraving of all these scientists fleeing because this seems like... The eyes would open. Yeah, absolutely. And arms would move. Really? Yeah. So what we know, so some listeners may be thinking, hang on a minute, this sounds very familiar. In about 1815, so all this was done at the beginning of the 19th century, in 18th century,

In 1815, a young woman called, well, she was a teenager called Mary Godwin. She went to the Royal Institution, you just mentioned, which is this newly created centre for scientific communication, which still exists, a marvellous institution. And she saw some, or we think she saw, some similar demonstrations to the ones I described with the sheep's heads and all the rest of it. No humans were involved. There were only a couple of experiments like that because it was quite rightly seen as pretty foul. And so she saw this idea that you could actually resurrect, apparently resurrect life

using electricity. And then two or three years later, she'd run off with notorious poet and revolutionary Shelley. She had become Mary Shelley. And on their honeymoon, because there was a volcano in Indonesia, the weather was awful. So the weather, well's weather patterns changed. They were on holiday in Switzerland. It's raining all the time. So they sit around and they say, let's write ghost stories. And Mary Shelley writes Frankenstein on the basis of this idea of you can actually reanimate

life by sticking bits together. Incredible. Yeah. It's incredible, isn't it? I love those little historical footnotes more than like anything. It's that an etymology that come out on this podcast

that are my favorite things in the world. But when you talk about electricity, people might be thinking, I mean, I find it very difficult to remember that when we're talking about electricity as it was discovered, we're not talking about exactly like the kind of stuff that you find in like an iPhone or an iPad or something. It's hard to sort of explain exactly what's going on there.

But what do we mean by electricity when we're talking about like the brain or organisms and how it's affecting? Like what is this thing called electricity? Well, I mean electricity in a wire, you've got a solid wire. And the current is the movement to electrons down that. down that path, that from one end to another, because there's a difference in potential, so it's going to go from one end to the other. In neurons, and this took an awful long time to find out, and it was only really resolved in the, after the Second World War in the 1950s, you've got, it's electrochemicals.

We've got chemicals in our, in our, in our, in our neurons, in all our cells, and you get a difference in the same principle, you get a difference in the potential on either side of the membrane, i.e. the surface of the cell, and I, you get a difference in the cell, and I'm Our cells have got little, little pores in them. And when a neuron is activated, then there's this wave of changes, it's movement of ions of different chemicals in and out of the neuron. And that passes down in the same kind of way. So it's an electrochemical.

But, I mean, you know, you can, if you, as I've just described, if you use an electric electrode, it makes that happen. So it's effectively it's the same thing. It's just that it's fluid and moving rather than at an atomic level, of course, rather than like a tap. It's not like that. But this movement of ions, different charge forms of atoms in and out of our cells, every second, every millisecond.

Or, you know, what I'm doing now, that involves really, really complicated activities of all those neurons. Yeah, so it's a similar kind of process because electricity just being like loose electrons, electron, electricity, and then those electrons just sort of move down a wire and that's the, that's the thing that's moving down. It's something kind of similar going on in the brain. Okay. So there's the discovery of electricity, if it's existence, then there's the discovery that it seems to affect organisms. And then you said, well, some people thought maybe this was just a reaction. Then presumably at some point we managed to establish that, no, no, like that's what's actually happening in the brain. When does that happen? How does that happen? And like,

why is that important? Well, it happens partly by, again, by metaphor. Right. In that people drew maps of the nervous system. And by this stage, by about 1838, the telegraph had been invented. So you can send messages. And you have a map of the telegraph system of England, for example. And you've got the centre, sadly, is London.

and then emanating from it or going to it are all these literal wires that messages are being sent down. And two things are happening. One, the centre is telling the provinces what to do, but it's also receiving information. This word started to be used. It's receiving signals from the provinces saying what is going on. So people actually literally drew a parallel and said, this is actually what is happening in the brain. Our brain is some complicated kind of telegraph system. So it made a big leap, just as technology had,

in the transformation of the United Kingdom, of the whole of Europe and then the United States, with the development of the railways, which literally paralleled the telegraph system. They went down the side. That technological development was then used to try and understand what was going on in the brain. The brain must be doing something similar.

So people start to think about telegraphing and so on. and one particular chap who I discovered in writing the book who I hadn't heard of and very few people apart from a handful of historians of 19th century you know about the chap called Arthur Smee he came up with the idea that this was literally what was happening in the brain the brain worked like a telegraph system and therefore I can make a version of that I can actually construct it I can actually construct

something out of metal that will represent a concept. And he came up with an idea for the way that information or the way that signals from very simple inputs from sensory perception could then be combined. And this is all very vague. But if you show those diagrams to somebody who works on large language models, they get really excited.

They say, look, that's just the kind of thing we draw to try and show how chat GPT can actually, respond to us in the way it does. It's all this complicated cross-cutting combinations. Now, Smee's device is very hard to make sense of, and he never built anything. He wasn't trying to build a computer, right? He's building a brain out of brass and screws.

And he hasn't, although he is thinking about electricity, and he even thinks he vents the fax machine, actually, because he says, look, if, what's, going on in the brain is we've got an eye and there are photoelectric cells. There are cells that are turning light into electricity and that's going down the wire into the brain. We could do that. Technologically, we could get some kind of device that would turn light into electricity. We could point it at a picture of the Tower of London and then send it down the wire to Edinburgh or whatever. Now, he never built it, but I mean, he was a completely cranky inventive. He was a completely cranky,

He also ended up working on inks and electrodes, which were later used in experiments to understand the brain. But the key point is that this metaphor of the telegraph system is really taken to heart by thinkers because they can now find a very powerful metaphor, not just for the organisation of the nervous system, but for what is going up and down them. It's messages, its information. and that immediately makes an intuitive sense. Yeah. Okay, so we sort of arrived at this realization that the brain is kind of working electrically, sending a kind of signal or information,

and that it's definitely the brain that's doing it. So then the next question that someone might have in trying to uncover the mystery of how we think is like, well, okay, we've got all kinds of thoughts, It's all kinds of different stuff going on. We've got memories, we've got emotions, we've got like behaviors that we do. We've got this one big brain that sort of does it all. But there's also this growing understanding that the brain is quite a complicated organ. And of course, the debate becomes, well, is there just this one great big brain doing everything?

Or is the brain like a sort of divvied up, you know, civil service of people all with their own little telehealth? to send out to different parts of the body. Well, that's what the, if you really took it to its end point, that's what the kind of informational 19th century Dickensian bureau system of thinking about thinking the brain would lead you to. And that is kind of where people ended up, but it depended what nationality were. So one thing that was very, very popular throughout the 19th century,

even into the 20th century, was what's called phrenology. That is that you can, the idea that you can feel the shape of your skull, that will tell you something about your personality. Because the theory went, the shape of the skull revealed the shape of these structures in the brain, and those structures in the brain were kind of the localization of different functions. This is the term that scientists and historians have used to kind of describe this debate, the localization of function. is this bit of the brain doing a particular thing.

And this was incredibly popular. I mean, you can think of a bit like horoscopes today. I mean, people might still say, well, I'm the querist rising, whatever. Okay, what are you? And, you know, without take it too seriously. But Queen Victoria took it very seriously. Yes. She had a children phrenologised.

Karl Marx, the German Revolutionary, he took it very seriously. He would feel somebody's head, a new comrade, to see, are they trustworthy? Are they on the right line? And I recently discovered, I've just finished a biography, writing a biography of Francis Crick. When he was a child, Francis Crick was phrenologized by a traveling phrenologist who amazingly said, yes, your son's, said to his mother, your son's head is really interesting.

You know, maybe I should come back again and do it again. So I mean, this is clearly nonsense, right? Because, you know, your skull's really thick and all the blumps on it do not correspond to organs in the brain. But it was a very, very popular. and what it led to was kind of a pushback from, in particular the scientists, and said, well, this is garbage. And the French scientists in particular for two reasons.

Firstly, they said, well, if we look at the brain, it's divided in two, and those two halves are mirrored. So it's kind of perfect in that sense, because you've got two identical halves. Secondly, Descartes said that thought is unitary. Thought is one thing. Therefore, the brain cannot be composed. of lots of different bits. And this is, you know, nonsense, but this is the kind of argument.

And a poor chap called Broca, who was very Cartesian, let you see, a follower of Descartes, good Frenchman, he ended up against his will. Actually, what he went through is, many scientists have found this, you've got a view, and then the data push you somewhere you don't want to be. And the experiments you do and everything you do to try and prove these findings, wrong, it'd go in the other way and you end up trapped. It's horrible feeling, but it's also quite exciting. So Descartes was, Broca was convinced that there was no localisation of function.

But he was working in a Parisian hospital and he noticed that there were, he had patients who had strokes and who therefore lost the power of speech and, or their speech was severely reduced. And he then started dissecting their brains. And he found that whenever one of his patients had lost the ability to speak, then there would be damage, lesions in the front left part of the brain. And his eventual conclusion was there is localisation of function that speech is controlled by the front left part of the brain, which we now call Broca's area. This is a production of speech. So back to Gayle, it's quite interesting. This is the same thing. And poor Brocker is in a double bind, firstly, because he's just shown that Descartes was wrong.

He can't have that. Secondly, Descartes's doubly wrong because now the brain is not symmetrical. You can't tell by looking at it with the techniques there at the time. But this part of the brain is doing something different from this part. This part does not control your front right part of your brain does not control speech. It's this part here. So now it's getting very exciting. It seems that there is localisation of function.

Some functions are very specifically in particular places. Yes. Which would have in some way supported the phrenologists. Absolutely. Except they never had speech here. It would always be things like love or, you know, it's all about emotions or intelligence. All good things were distributed in your brain. Yeah, yeah, yeah, yeah.

I mean, you're right that, I mean, it's amazing how popular the viewers, but you say that Charles Dickens is one person who may not have been impressed, impressed with this because in great expectations. The criminal Magwitch explains that he was subject to a phrenological examination before providing a simpler explanation of his behavior. He says, they measured my head, they had better measured my stomach.

Which is, you know, probably true. I mean, we do now know that, you know, judges are more likely to send someone to jail if they're hungry, for example,

which is quite an investing phenomenon. But, but, but, Now, it's a weird hodgepodge, isn't it? Because it's like, some people thought that the brain was responsible for, like, different parts of the brain were responsible for different stuff. And they therefore, maybe reasonably thought they could probably feel it through the skull. And it's like, well, they were more right than they could have known about the sort of different brain regions being responsible for different things.

But that other part about the skull anatomy is like, is like total nonsense. And it's amazing how sort of sometimes on the nose and sometimes not. Although the extent to which the brain is a unified entity versus a sort of specialized system of individual part is still quite like hotly contested. Oh yeah, very much so. I mean, I don't, part of the problem is scientists in particular, those who are studying in particular area will tend to kind of have a very condensed, short version, you know, kind of elevator pitch to explain things to public. So this part of the brain controls this or this. and the answer I mean so that's localisation of function

and really you're back with this series of organs just like in phrenology nobody really thinks that or very few people think that I mean scientists and neuroscientists do but it's a kind of shorthand they would use but I think the public does end up with this idea that we've got these bits of my brain

and oh we've got a left brain and right brain we can talk about that later on and I'm a left brain person I'm a right brain person and whilst there are asymmetries like in speech I mean the brain is both unified and distributed and consciousness, and all the various other perceptual things that we know

about are both localized and distributed. And the localisation, certainly animal studies, show us that the localisation of memories or whatever or perceptions, and this is where it gets really weird. You can identify a set of, for example, if you teach an animal that a particular part of the cage with a particular shape on it is somewhere they're going to get food, then they learn, you've got a representation of, say, the set of stripes that are on the wall, and you can record from cells that show that they fire every time it sees these stripes. If you carry on recording from those cells over the next month, then some of them, a large proportionate will stop firing because in fact the scientists call this representational drift.

So you've got a representation, but it's moving in time. So a different set of neurons are now doing the same thing. So the same task is sort of just like moved in the brain. There'll be some that are still involved. But my guess is that if you left it long enough, then a whole different. I mean, you know, this is in a very small scale. It's probably still the same region that's doing it. I can imagine like the scientists who first discovers this

finally thinking they're beginning to nail down localisation and then they're watching it move and they're like, hmm, yeah, not so sure about that. So this representational drift is a very neat kind of phrase but in fact it's just kind of these, oh my God. But I mean maybe back in the, let's move back to the 19th century because this is when they start to record, they do two things.

They record from electrodes. invented by Arthur Smey, very fine electrodes using batteries that he's developed as well, that mean that you can record from different regions, say, of a monkey's brain. And you talk about animal experimentation. Interestingly enough, it was public outcry against some of these, the claimed activity of some of these experimenters that led to the UK's introduction of very stringent restrictions on what you can do with animals and experiments. Yeah, absolutely.

So there's always, you know, this has been a long, long argument. Many countries don't care so much. But you've got to remember in the UK, we have a royal society for the prevention of cruelty to animals. Quite right. But we do not have a royal society. We have a national society for the prevention of cruelty to children. The RSPCA was founded in the 1830s. The NSPCC was founded in the 1870s.

So you're happy to shove children up? chimneys, but not to do bad things to animals. So, yeah. That's quite incredible. I mean, that just shows you the British attitudes. But, I mean, I think most scientists work in the UK are very happy with our very strict controls there are on animal experimentation. Anyway, the key point is that you could record from or stimulate different parts of the brain put electrodes in and you would stimulate the monkey's brain and you would be able to show that different parts of the brain were involved. in producing movement

or in apparently producing the perception of sound. So the monkey's ear, if you put areas in one particular, electrodes in one particular area, then the monkey's ear would twitch. And there's also a very famous accident that happened where a,

I've completely forgotten his name. That's okay. We'll take a minute. It doesn't matter. We can leave it in. What's his name? Everybody knows his name. Who are you talking about?

guy who gets the, the, the, oh, um, um, I didn't write this down, you see.

Oh, no, I've got this, I've got this. And if I don't say, I mean, it's, it's, it's,

it's, there's a P in there? See, this is interesting about when you're trying to remember things. It shows you how things are encoded, right? Do you know what?

It's a, you know, you can see the shape of the word, or you know it's got a P in it. And that shows you that, the thing or the name that you're trying to remember. is tagged with all sorts of different bits to it, which you use for retrieving it.

It's there and there somewhere. I think about this all the time. I'm like, one of my favorite things to do when I'm like reflect. It's less about brain science and more about, it's almost like meditation where I say to people like, you know the TV show Friends. Like you could name all of the five characters from Friends, right? And I'm like, don't actually focus on. Don't do it right now.

You know that you could. And yet those names are not actually like present in your head. So they're like there, but they're not there. until you like focus your attention over there. You shine the spotlight on that part of the brain. It's also interesting how like, it's that classic thing where if I asked you to name every book you'd ever read, you'd probably get to about 10 and then start forgetting, right? But if I went the other way, if I listed off every single book that you've read, you could tell

me instantly whether you'd read it or not. It's like memory kind of works in one way, but not the other. But yeah, there's a guy who got a pole through his head. It was a big tamping rod. So he's working on a railway cutting and you drill a hole and you put the charge in and you put the tamp it in and then you fire in the hole and you run like hell. Anyway, it went off and this tamping rod goes right through his. Don't tell me, don't tell me.

Don't tell me. I'm going to remember. I'm going to remember. I think this is great. It's got an experiment in real life. It's perfect. Of course, of course, you know, fans of the show will know that I talked about this with Robert Sopolsky. So if you don't know either at home, then you obviously haven't been paying close enough attention either.

But yeah, so he's working on the railway and this pole sort of gets like ejected and just like goes straight through his head in a way that if you looked at it, you'd probably think it killed him. Yeah. His skull is, his skeleton is still on display in American medical school. Yeah. And it does look like you could never recover. from that. And he did recover. And this is where it gets murky. So if you read neuroscience books, classic book, they say, you know, he was, he was no long a gauge. Phineas Gage. Phineas Gage. We got there. How about that?

Thank you. Yeah. Yeah. That's incredible. Yeah. It's like something lit up. It's like, it's so hard to explain. But I got there by thinking because the phrase was, Gage was not gauge. That's what was written down. And so I knew, then I was thinking about that And I got the Gage and you got the Phineas. And the rest. Which has got a P, but it doesn't sound like it. Yeah, exactly. So he's right.

When Alex popped his head over and he went to start telling him and he went, and I went, don't tell me. And I'm thinking, Fred, Phineas. Phineas. Phineas Gage. Yeah. So the classic story will tell you that Phineas Gage, Gage was not Gage. His personality was changed.

It became from being affable and pleasant. It became surly. He became changes in his personality. In fact, all this is very difficult to prove. And there's very, There's no evidence of this at the time. It's all kind of retrospective. What is clear is that he did go on to, he ended up, he was, he made a fairly complete recovery.

He became a stagecoach driver in Chile. I can't remember all the details. But the idea was, and this corresponded with some of the animal experimentation, that there's, in terms of your, your will and your confidence and your, your control over your emotions that the front part of the brain is extremely important. So we're back to the localisation idea. I mean, in terms of getting over the idea of localisation, then I think speech is the best one, because this is historically, it's the first, it is very clear.

You can do it, you can see, I wouldn't do this, but you can see experiments on YouTube where people get big electromagnets and they're in a scientific situation. And they're speaking away, and they put this. electro-magic and magnet here and they can't speak here. Take it away and they're fine. Yeah, because they sort of send, I don't know what it is. They're actually sending.

It's just electromatic, it's just very strong magnetic field. And you're talking like literally, like as you're speaking now, they would just place this device on someone's head and they would start just being able to speak. It's just slurs and you can't. Basically, you're, this strong, uh, electromagnetic field is just screwing up all your neurons. I mean, it's temporary. I still wouldn't do it. Yeah. I'd love to try that. Because presumably the person who's speaking is still cognizant of what they're trying to say. Yeah, but it just doesn't come out. It just like doesn't work.

I suppose it would probably be comparable to like being paralyzed or something where like you're trying to move your arm and it just sort of doesn't go. Or maybe it's what people feel when they have a stroke. Yeah. So, yeah, viewers, if, you know, you feel your face, somebody's face slips and they start slurring their speech, then that two are very important signs of one particularly kind of stroke. Make sure you get to a physician as soon as possible. scientists putting a big sort of electric blot on their head. Then I think we can exclude that. Then you might be okay.

So the interesting thing is that is really solid information, localisation of speech. Yep. And then after I wrote the book, about two, three years ago, paper appeared, which was co-produced, as they put it, between some scientists who were doing MRI scans and a woman who was in her 30s. This was in America. She was a secretary. She'd had a college degree and everything. and she wrote to them and said, they put an advert saying,

can you do, we want to scan people's brains. And she said, I think you might want to scan my brain because people have told me it's quite interesting. So I said, okay, fine, come in.

She sat in the scanner and they look at her brain and the whole left-hand side of her brain is just black, it's just empty. There is nothing there at all. She only has the right-hand side of her brain. As in like physically it's not there.

Physically, it is absent. There's a big hole. I mean, it's a, you know, It's a big fluid filled hole in her brain. Right. But as in so sorry, but like as in there was like a brain there and it was just, it had like a chasm in it?

Yeah. Well, her skull's still there. But it's just if you were. But the brain matter itself. The actual matter was just completely absent. Wow. So, I mean, she knew this because, I mean, when she was a child, what they think happened was that before she was born, she had a stroke. So already when she was in the, in the uterus, she had a stroke.

And the whole side of that left hand side of the brain did not develop. Now, what's interesting is that she's perfectly normal. You would not know if she hadn't at one point in her life had a scan. She would not know there was anything the matter with her. There isn't anything the matter functionally. So what's happened is the right side of the brain. It's what scientists called, well, it's plasticity. That is the same, you know, different brain functions can emerge in different areas.

So what that tells us is. although the ability to speak is clearly determined by this structure in normally developed adults, in children and in if you've been damaged at that stage, then you can actually overcome that. There are some cases of adults as well who've had very severe strokes, nevertheless, recovering virtually complete function. We don't quite understand how that happens beyond to say, well, it's plasticity. That's pretty rare, unfortunately. But this woman, and it shows you, so there's nothing that,

Or rather, there's something about being in a spoken environment, having words and language can be written language, can be sign language, doesn't have to be heard, leads to the development of language processing in the brain. Right. We know this from terrible things that happened in the kind of 18th century. It's a film about Casper Hauser. So he's one of these wild children who's been discovered, who's never spoke, never heard human speak, or children who have been locked up by foul parents.

And there's what's called a critical period. If you don't learn language before round about your late, just before your teens, your grasp of language is never going to be very good. Your brain can do it, but not quite the same way. And this relates to why children, you know, children who've got parents from different nationality to the country they're living in speak two languages or more

with absolute ease. You can learn to speak, all sorts of languages when you're a child. When you're older, it's much tougher. Oh, yeah, for sure. So this plasticity is partly a developmental thing. So that's what happened in the case of this woman. So the answer is speech localized. Yes, it really is localized to the left hand, front hand side of the brain, except.

Yeah. So, you know, it sort of doesn't have to be exactly. Yeah. But it has to be. It's only, you're only going to get that if you are given that speech. function. You've got to have it around. It's something about the environment is making the brain try and make sense of it and then produce a response to it in the same kind. So I say this can be sign language. If you're deaf, it doesn't have to be spoken language. But it confuses me a little

bit to think that like, okay, so if somebody doesn't have a right hemisphere, or a left hemisphere, rather, the right hemisphere can kind of take over that job, implying that, you know, brain function could be localized in different sort of areas of the brain. If that's the case, then why is it that, like, with people who have sort of healthy functional brains, they all develop, you know, the front left side of their brains as the area of speech? Like, why isn't it that, you know, you know, Johnny over here has it in the back, right, and he has it in the front or whatever?

I have no idea, nobody else does. I would say because. Yeah. Because we're still, we're still, well, to put it lightly, we're still pretty perplexed, the functioning of the brain. Yeah, I mean, this is about language, it's about speech production. Yeah. So it's not about language comprehension.

That is, there are the parts of the brain that do that. But speech production is very much controlled by this front left part of the brain. And, I mean, if we can talk now, if you want, about the amazing, astonishing, mind-blowing stuff that was done in the 1960s about speech production. well, and the brain. Yeah. So these are experiments which originally done on CATs. So what you've got to realize is that your visual field is you've got your retiners, which is what detecting the light.

And basically the left-hand side of both retinas go to the right-hand side of the brain. So basically that means what you see over there is processed here. And then the right-hand side, left-hand, which is... detect the left hand part of the visual field, go there. Yeah. So the opposite to what you kind of might expect. Yeah. But they're separated.

So if you do a very careful experiment and you only show an image that can be seen by the left-hand side of the brain, then it's only processed over here. Now, they were trying to understand how the brain integrates all this information. and they're working on cats in the 1950s and because cats are very visual animals so they've got a nice big visual cortex for all this is a process that you can record from and they discovered that

if they taught the cat say that an image in the left-hand right left-hand part of the visual system was so processed over here on the right-hand side of the brain if you showed that but you cut the brain in two,

then only the right-hand side of the brain was aware of that information. The left-hand side of the brain, if you then tested it by showing the same image in the other visual field, it didn't respond. It's not been it before. It had no idea what that meant. So the meaning, because you'd given it some food or something,

was not being transferred across the two sides of the brain. Okay, that's pretty weird, but things got weirder because they then were working with humans. And these are patients, right? So you've got to remember these incredibly generous people. These are patients who suffer from appalling epilepsy and have had operation. They're going to have an operation.

They're going to separate the two sides of the brain because epilepsy is kind of an electrical storm in the brain. And one of the ways of stopping an incredibly bad epileptic, fit, a very crude way, is to stop the message from spreading, stop the storm. Fulm full of spreads. Slice the brain into. You cut it into. And in normal life, these people were absolutely fine.

They just got on with their lives and they didn't have as much epilepsy and all the rest of it. So then the experiment is in particular a young research called Mike Gatsaniga said, well, what if we did an experiment like we did with the cats? And they discovered exactly the same thing. That is that if they showed something in this side of the visual field, then it went to the right side of the brain, that side, it went to that side of the brain. So, of course, you can ask, you can say to the patient, you can show them something over there and say, what do you see?

And they'll say, oh, you show me a picture of a cow. But if you show it over there and you say to the patient, what can you see? I can't see anything. Because it's this side of the brain that's responding. Yeah. And it hasn't had that. bit of information, it can't see it. So that...

Because the side of the brain that's responding is the left brain, because that's doing the speech. That's controlled speech. But the side of the brain that saw the thing is the right hand brain. So that's pretty weird. Yeah. That's pretty weird. But then things got weirder because they then thought, well, they noticed things would happen.

So, for example, with one patient, one woman patient, they showed her left-hand side, so seen by the right brain. a picture of a nude woman. And they say to the patient, what can you see? And he goes, you haven't shown me anything. But then she, as far as a woman patient, she started laughing. And they go, well, why are you laughing?

And she said, well, you've got a funny machine. So she didn't know that the side of the brain that's talking to you does not know that this side has seen something rude in this case. to me, she blushed and everything, so he had a full response. It was embarrassing to her. But if you talk to this side of the brain, is there anything you can get an order, a spoken response from,

then you getting... I don't know. I don't know. Some explanation. There's something happening to my body. My body's saying something. Wow. I don't know what it is.

So I make stuff up. And they did loads and those of experts. It's interesting, isn't it? Because they don't say, you know, oh, I don't know. They will make up an explanation. Well, you would do. I mean, if you're saying, you know,

you're suddenly doing something, you've got to find something to say, right? Yeah, right. I mean, why am I laughing? I don't know. It's funny. Yeah. So they did loads and loads of experiments and they found out that although, so you basically, what's happened is, we know that the brain somehow produces consciousness.

Yeah. What's happened is they've cut the brain in two. Yeah. And now they've got two presences, minds, whatever word you want to. And they're different. Because one can speak, because it can control speech. The other can't, but it can say move, understand language, so it can move things around on a board.

Yeah, draw pictures. Yeah, absolutely. Respond to you in all sorts of ways. And it seemed as well that there were slightly, they've done some really interesting experiments recently. I mean, the great thing is these, the great and the sad thing is these experiments are coming to a natural end. Because this all happened.

Yeah. These operations are done in 1950s before they were adequate drugs. and these patients are now dying. And, of course, there's no way that anybody would do this as an experiment. I mean, this is just too awful. But some of the later experiments they've done more recently suggests that there are actually differences in ethical views. So if they present people with a scenario about somebody tripping up

and hitting somebody by accident, the left-hand side of the brain, the one that can speak, is much more likely to say, well, he did that deliberately. And the right-hand side of the brain will express the view that actually I understand what's gone on here. So there may be other much more subtle differences between the two sides of the brain that we don't understand. Or it may be, so here's the problem, right? We know that this is actually controlling language. But we've broken the brain in these poor people.

We've separated. It's a whole thing. And in some magical way, it has now produced two slightly different functional. is two slightly different minds, because that's what's happened. Neither one has any idea that the other one exists. Neither one has any conception that things were different beforehand. They don't know. The left-hand brain can't tell you, oh yeah, I used to be much more sympathetic to people

who dropped things on my foot. It's not like that. They don't understand what's happened at all. And in normal everyday life, they just get on with things. Initially, they would have trouble putting on their trousers because their two arms were doing different things. things as they were trying to deal with everyday tasks, but very soon they kind of chilled the two sides of the brain. So part of the problem is this looks like, okay, you've got these two sides of the brain and, you know, this ethical aspect, so, okay, well, they clearly are more ethical view is stuck in the right hand side of the brain and a more kind of less empathetic view of human behavior or interpretations would be in the left-hand side of the brain.

But that's a mistake, and it's a logical mistake that has troubled both neuroscience and genetics. And it goes, it's a method that says, okay, if we break something and we change this particular thing in a system and something happens, then that element we've altered is controls this. Yeah. Whereas if you just think about it, well, wait a minute. So what I was taught when I was a student, this is back in the day, we did have transistor radios, but if you've got a radio or a circle, electric circuit and you've got a particular component. You could take, if you take one component out and now you get its terrible feedback. And you go, aha, this is the feedback suppressor because when I take it out, I get feedback.

If I put it in, I don't get feedback. But no, it's actually just part of a system. You've got a whole system. You've broken it and now it is malfunctioning. Gotcha. So although it's telling that malfunction tells you about the function of the system, it doesn't necessarily tell you something about that particular component. And this is something that has bedeviled neuroscience.

So people take out bits of animals, brain and behave differently. They say, aha, this is localisation of function, yeah. Whereas in fact, now it's not working properly. I mean, another way of thinking, if you think about a bicycle wheel, you're a whole set of spokes. And it is going to work really, really well. It's going to carry on. You take spoke out. It's going to be okay.

And another spoke. And you go, okay. And then there's going to come a point at which the wheel will fall apart or it will break on you and you fall off your bite. So there's a change from quantity to quality and it's a mistake to think, okay, well, you know, spoke number six. That was the one.

I mean, you need to, if you take out six spokes, then you get a problem. It doesn't, I mean, probably would make a difference as where they were, I guess, as well as to think about it, you know. But it's complicated and it's not a simple. And so, like, because in the face of, and I've spoken about these split brain patients a lot, like our listeners,

yeah, most of the people listening to this who've seen this show before will probably have heard of these experiments because I talk about it. I mean, they are extraordinary all the time. When I first, it was, it was I'm a girlchrist. You know, I read the Masters and Zemisory. And I, since that day, I have not stopped talking about it. It's like on my bingo card of things that I talk about all the time. But like the natural sort of reaction to this is to think, ah, well, okay, we can experimentally test in split brain patients and show that the sort of brains are sort of split in two. And that in healthy sort of functioning brains, where the corpus callosum is still in. You know, like they're communicating with each other, but the same thing's still going on. We just can't experimentally test it. But we have to be careful to say such a thing. That's almost certainly not the case. Right.

So the two sides are talking to each other all the time, forming a whole. Whatever consciousness is, it's emerging out of the whole brain. And the fact that it can emerge in a different way in the two halves of the brain is telling us something. But I don't know. Yeah. I mean. Because I was thinking the other day I was going to make a, a series of novel arguments against the existence of God, just like funny ones, a Christmas

video. And one of the ones I thought was like, well, if your brain is split into two hemispheres, both of which kind of have their individual, their own centres of consciousness and their own awareness of different things, and what if you, like, convinced one of them of Islam and one of them Christianity? You know, would that person get to go to heaven or not? And I don't think that religious traditions have sort of adequately accounted for that. But I suppose in a split brain patient, you could kind of do that. My guess is that religious scholars of all religions, if you pose them the problem, what's happened to the soul in these individuals, they would have an answer. I don't know what it would be.

Have you got two souls? Or have you got just got one that is slightly different? Or do we just go with the one that can speak and say the prayers or whatever? It could be comparable to someone who's like, you know, on Monday they're feeling pretty religious and then on Tuesday they're not. It's like, what happens to that person? They're kind of both of those people at once, even though it sort of changes a little bit over time. maybe it changes over space too. But it does,

I mean, it massively upsets like a lot of our understanding about, like, let's say personhood or the unity of the self, right? Because we've got, at least in these specific circumstances, people who,

for all intents and purposes, act like a single person. And yet there's sort of a little bit more going on. So, and yet when you connect them back up again, you know, the brain starts sort of, it's like completing a circuit

and the whole thing starts, working together again. And yeah, the brain is in two hemispheres, even without the split brain hemispheres, that the brain is built in sort of two parts. And there seems to be an evolutionary advantage to that because, you know, it happens across different animals. So then what is the relevance of this separation of two hemispheres in a brain that is connected up properly?

I mean, it's one of the, I mean, it's not just the brain, of course. We are symmetrical. Yeah. I mean, not entirely. So you've got one heart, not two, unless you're, you're, you're, you're not. unless you're from Gallifro. You've got one heart. You've got one liver.

So it's not entirely symmetrical, but we are bas-we-laterally symmetrical organisms. And one of the mysteries, one of the things we don't fully understand is that the evolution of bisymmetry, of symmetry, bilateral symmetry, occurs at the same time as what's called cephalization. Because if you think about it,

you are most definitely not symmetrical that way. You've got a head. From top to bottom, yeah. And you've got feet. That's interesting. And you've got a front and a back. Yeah. So in two of the key dimensions, you are most definitely not symmetrical.

And what happened around about, you know, 550 million years ago is that as, I mean, scientists can't define the brain, but let's just say it's a load of neurons. They tend, you've developed not only this, this cephalization, so the development of this putting neurons together, the brain, also goes with the development of a moment, also goes with the development of a moment. mouth and an an an anus, because that's the other thing you've got, it goes in one end, it comes out the other. And the sense organs are tending to be accumulating at one end, and this enables, and to be symmetrical, because it enables you to detect where food is coming from, or where a threat is coming from, because I'm here. And so, I can see that, or sense, the stronger sense, if the predators coming from over here, I can feel the vibrations in this neuron, the set of neurons more so than in this set of neurons.

Right. So then you tend to, in evolutionary terms, you end up with these neurons all kind of being stuck together. So the symmetry is probably, and it's a deep developmental, an evolutionary developmental thing that is going to be related to our various earliest origins as animals that are becoming bilaterally symmetrical and cephalized. And also with our, we have a spine, we're dorsal. We have a dorsal nerve cord, whereas if you are an octopus or a fly, then your nerve cord is ventral.

It's down your tummy. So there's a complete separation of the animal kingdom that occurred very early on with these two different ways of organising yourself. I mean, the big difference is that if you just think about it, I've got my throat here and my brain there. All my neurons are going down past the backside of my throat. Right. Whereas if you're an octopus or a slug, and that's all octopuses are. Apologies to Peter Goughby Smith, they're just smart slugs, you know. Or you're a fly or a bee.

Then you've got your brain here. And because your nerve cord is ventral, it's got to go round your throat. So basically, you have a brain that's kind of like a donut shake. It's got to go round your throat, basically. And then it goes down the front of your body. Yeah. So the short answer, I think that the symmetry is a concept. of those, those developmental steps that were taken deep, deep in animal history.

And that's why all animals have got symmetrical brain. And so then today, what does these symmetrical brains like do for us if, it seems like you're sort of saying most of the time in a healthy brain, the whole brain is active. And yet we can kind of localize like certain activities. and some of those localized activities will be on one side or the other. Like we've said a few times that, you know, the processing of spoken language, for example, is in the front left of the brain. But at the same time, you probably want to say, but that's too simplistic.

That's like an overview. But then what's the actual answer? You know, where is speech stored, if not there? Well, I mean, speech control of speech is stored, is there. That's to do with that. And that's why, if you have a stroke there, as Brock had discovered, you are likely to lose the power of speech. You still understand it.

You could write it, but you can't speak. So in that case, at least the left hemisphere could be said to do speech. Yeah. In the right hemisphere, they're not to, right? They're doing something else. And that is quite a division, even in a healthy functioning brain that's communicating with itself. I know it would be a fallacy perhaps to assume that in a healthy brain, like there are sort of two centres of consciousness, exactly. But do we have sort of good reasons to the contrary?

or should we remain sort of like agnostic? Like, could we look at that and say? No, there's any evidence for that at all. No. I mean, quite the opposite. That whatever consciousness is, it's emerging from the brain or parts of the brain as a whole. And even when you try and. So there's this argument about localization of function is still going on.

I mean, there's a, right. On the train down, I was reading a new big review all about how cognition is both distributed and localized. Yeah. And it changes over time. And I mean, one of the things that I tried to do in the book is, partly because, you know, so though I have a degree in psychology, I spent, I spent all my academic career studying insects. So took a kind of reductionist approach.

Let's see if we can understand simple systems. Yep. So, for example, a big study just came out looking at a tiny little worm called C. Elegans, which has got about 1,000 cells, 300 neurons. Wow. So its brain is about eight cells. So we know everything about these animals, absolutely everything. And they just did a huge study of looking at the recording from all the neurons, all 302 neurons,

whilst the animals were doing various things, wriggling about, turning, finding food, very, very simple things. And you might imagine, if you're building a robot, you say, okay, well, I can make it, you know, you could make a robot do that. You could get a robot that could detect a particular stimulus and then move to, a particular place where it can find that solution. And your computer would have functions hardwired into the components. But what the animal does is those neurons are doing all sorts of things and those things change. Their functions will change over time. Some of them are paying attention to past states. Some of them are just interested in what's happening at the minute. If you go back and test the animal again, it's going to be different sets of neurons,

even in such a simple thing. So it is really, really hard to understand how this is happening in our brains. Now, there is a counter-argument that is, I think it's quite interesting, somebody put to me the other day that, okay, so what you're saying is that identifying it kind of the atomic, the atom,

the particular level of neurons is going to be really hard. But do we need to do that? So climate change is a reality. We don't understand how every atom of air is moving about in the wind, where we deal with much larger scale problems. And I think that is, that's a good argument. And I think that large-scale studies of brain function,

and in particular, in humans, who are very interesting, obviously, to us and present the most complicated case, are absolutely valid. And I don't think that's not something that's worth doing or anything like that. But there is the weird thing about the brain. So consciousness, if it's anywhere, is thought to be in the outer layers of the brain and the cortex.

And in particular, there's bits at the back of the brain called the cerebellum, which, as far as we can tell, they're controlling movement and gait and all the rest of it. But they don't seem to be involved in consciousness. So we've got some neurons, I mean, bazillions of them, and not just the neurons, but we're not just the neurons, We all we talked about is neurons. You got to remember, they've got 80 billion neurons in our brains, but there are also things called astrocytes which envelop the neurons.

There's the chemicals that they're all flopping around in the hormones and all the rest. So it's a really complicated system. Yeah. But it's just the, those structures, some structures are producing thought somehow and others aren't. What's different?

I mean, I said I'd just finished writing this biography of France. Francis Crick, and one of the things that he was interested in was finding what he called the neural correlates of consciousness. Yes. Which is not the same as this is what consciousness is or where it is, but it's some, we can find a set of neurons that are responding whenever a particular thought or perception is taking place. Yeah, the neural correlates, so like what correlates in the neurons with the conscious experience. Yeah, absolutely. So that doesn't mean, I mean, it may be that, because it's a correlation, that is something else that they're both involved in. But it's a start.

And his questions are very useful. He said, well, where are these neurons? Is there anything special about them in terms of their structure or the genes they express? Or is there anything special about them in terms of how they're firing or how they're connected up? Those are the questions we need to answer. I think whilst the climate change argument is good, we can't get away from the fact that ultimately, whatever consciousness is, it is emerging from the properties of these incredibly complicated. neural networks that are in our brain and are communicating on the two sides. And you don't place much stock in the idea that, you know,

you know how the debate originally would have been about, are there certain parts of the brain that are responsible for certain behaviours like speech or the left-hand side of my sort of pinky finger or something? Is that different areas in the brain, a memory? Do you think there's a similar debate to be had about, like, are different parts of the brain responsible for different sort of parts of consciousness? Like, you know, there's the, there's your emotional self and your rational self and your, and your sleeping self, and maybe there's like different parts of the brain, or do you take,

what I suppose would be a more Cartesian view philosophically, that it's all like one thing? I think it would be terribly, terribly mealy-mouthed, well, a bit of one and a bit of the other. So, I mean, in this review, I was just talking about it was characterised you, the extreme position is, you know, cognition and ideas and thinking is everywhere, everything, everything, everywhere all at once. That's the extreme view. It's all going on, man. But I've already indicated it's not everywhere because the cerebellum doesn't seem to be involved. But it is, on the other hand, both distributed, I mean, all I can say is it's both distributed and localized, but the localisation is to say it's fuzzy. And where we can really identify localisation of perception,

it moves at a cellular level. And this is kind of mind-boggling. So I think what people have to realize is that simple neural networks remain a mystery to us. We might think that it should be relatively straightforward. And the example, but it isn't. The example I give is the work of Eve Marder. And she spent the whole of her career, still active, studying the lobster's stomach. And the lobster's stomach is a bag that has got lots of muscles in it, that grinds its food up. and there are around about 30 neurons controlling the activity of these muscles,

and the muscles do two rhythms. And Dr. Marla knows everything about those neurons. She can dissect them with both the scalples and chemistry and genetics. She can model their activity, and yet she cannot explain why the 13 neurons produce those two, rhythms and not other rhythms when models suggest that they should be able to do something else. She can't predict either what will happen if she takes out one of those ablates in the technical term.

You remove the act, stop one of those neurons being active, what happens to the rest? The network starts breaking down. Now, at one level, this isn't surprising. Physicists have something called the free body problem, whereby they can predict accurately using Newton's laws, the motion of two objects in space. then if, in randomly moving around each other, but then if you add a third one, it all gets chaotic and they can't predict what's going to happen. So we know that very simple systems can produce very odd kind of behaviours. So if we don't understand the lobster stomach, poor old

Dr. Marta can't, you know, figure it out. And that's not because she's, she's far cleverer than I am. And she had loads of researchers working with it. It really is a massive, massive problem. We can see some of this in an object that excited, in years after the First World War, as ideas about information and code started to emerge, long before the development of computers, it all emerges from messages being sent during the First World War, which is also when they start to use radio, of course, and had amplifiers, these which could amplify weak signals. people then start to record from neurons and start to say, ah, then it's not, you know, it's not just a message. It's a code that's going down the neuron.

There's information in there. Somebody's writing a popular book about behavior and so on. His man called Lottka, as many known as an ecologist. And he had a little wind-up, what in the UK we call it a ladybird, a ladybug in the US. And this shows an incredible emergent behaviour. I can, look, do you want to do, you could maybe record it, I've got a, I've got a, I've got a, I've got one with you. Yeah, so we need to put it on a leg. Oh, we're so.

And it moves a lot and it is amazing. I mean, I've done it in display. So when's this from? Well, this is a reproduction. So it's a repro, retro, there you go. Yeah, okay, I see. Because these were popular when? In the 1920s.

So it's entirely clockwork, right? You've got to remember, it's entirely clockwork where. There's nothing electronic in here. It's got those little wheels. I've just wound it up. Give it another wind. It's got these antennae that move at the front. Sure.

Is this big enough? Yeah, yeah, it's fine. Well, we'll see. Okay, I'm going to put it down, and it's going to go straight forward, and then we'll see what happens. Look at that. That is crazy.

So it looks purposes. Isn't that cool? And it really is quite an extraordinary kind of thing. Okay, shall I show you how it works? Yeah. the noise out a whole bit. So it's got a friction motor, the wind up motor. And this and this are the key thing. Okay. So this little wheel here, if you can see it in profile. Yep. That's a free wheel, and it's at an angle. And these little antennae keep the whole thing, I feel if you can,

you can see it in profile. You imagine this is not quite as deep. So normally, when the antennae are both down, it keeps this out of contact. So it just goes straight forward. But when the antenna drop like that they as it goes off then this comes into contact the little

free wheel comes into contact and because it's at an angle it will now turn the motion from a forward motion into a sideways motion I see so having to look at this down here

Alex is trying his best here as well yeah it's still rolling so what will happen is that antenna will sort of as it falls off the edge we'll call it to fall and it'll hit that wheel and that wheel

and that wheel will essentially steer it around. So wherever it goes, it will stay on the table. It's always going to turn the same direction. If it was angled at the other direction, it would go the other way. Yeah, that's pretty easy. Okay, so what did we just, I mean, that's pretty neat, a pretty cool, you know, Christmas or birthday present perhaps, but why is that relevant to brain science? Well, what it's showing is, one, you can get purposive, what looks like purposive behavior out of a very simple system.

Here we've got, I mean, there's no electrical communication or anything like that. It is simply the way it is organized, it's set up to be able to produce something. So, one thing people should take away from that is just because it looks like it's purposive, doesn't mean to say it is, and the same is true when you talk to chap GPT. Right. Right. Just because it's giving you some advice. I mean to say it understands anything.

Humans are very bad at being suspicious about things. We tend to assume, and we have to, right? This is part of what is called theory of mind. That is we have to assume that other human beings feel the same things and think the same way as we. I mean, they are basically human. I mean, clearly at times war, conflict, then we pretend they're not and we dehumanize them.

and so they are other and they must be killed or whatever. But in general, human society works on the basis that I assume that you're not a robot from Mars. You're not a figment of my imagination. I mean, I can't prove either of those things, of course. That is possible, but very unlikely, not terribly interesting at the end. So we assume that other humans behave that thing that way. We also assume our pets do. Everybody, you know, go, yeah, my dog.

Of course it's conscious, you know. But that's simply because you're projecting, I mean, it may be. But really, it's you projecting onto the animal. Same with, you know, when I was at work, I used to shout at the photocopier. Yeah. You know, so there's no point in there. No, Basil Faulty, thrashing the car.

Yeah, yeah, yeah, yeah, yeah. Because you treat it as a thinking object. So the key, the key point is that shows what appears to be purposive behavior. But then you've got to think about, well, what is happening there. Okay, I understand how it's set up. And what Lockear argued is that the whole device, It's the whole thing that functions. It needs to have all those parts.

And the device as a whole is somehow construing, he put it, construing the information from the little antennae. If you think about it as a functioning system, then that is the way it's working. But there's no actual transmission of information. It's simply an alteration of the structure. So whilst we can understand how that very simple robot works, understanding a real 30 neuron system in the lobster's stomach or a 302 neuron worm wriggling around for the moment that remains beyond this. But there's something about the organization of things, their structure, which enables particular functions to emerge.

And that is the same in the case of the brain and consciousness. but that is at the moment unknowable. Now, I don't think it is forever unknowable, but I mean, it's partly because I don't work in the area, so I'm not kind of despairing at trying to figure it out. And, I mean, opinions differ over this.

So, you know, studies of consciousness, when I was an undergraduate in the 1970s, I remember sitting around, and it's partly because Francis Crick had just stopped working on molecular biology and so on, had gone to America to work on neuroscience and he was going to study consciousness. And we knew this. And we kind of laughed and said, oh yeah, he's going to crack consciousness. Oh, yeah. And so we then said, well, what do we think consciousness is? And we said, well, it's some kind of

emergent property of the brain. And that's it. How could we study it? No idea. So I've never worked in this area. Crick was much more precise and more thoughtful than I was as a young man and came up with this idea of we can try and find the correlates of the neural correlates of consciousness. But he was very limited in what he was trying to do. He wanted to come up with a very precise hypothesis that could then be tested experimentally. And my impression of the field of consciousness studies in particular, although he helped me, make it a thing. He turned it into a popular, scientific, and acceptable, that's put it that, a respectable scientific activity, not simply something to be left to the

philosophers. They've been thinking about it for, you know, whatever is, 3,000 years and haven't got anywhere. Right, we can now work it out. Now, they haven't, and things have got really complicated. So the most recent article, I think, suggested there were over 250 different theories of consciousness. Yeah. which to me says you don't know what you studied. I know the guy from closer to truth. I forgot his name. It's like a TV show that's also on YouTube.

I think he and maybe some other people have just produced this like interactive map. And this is, I think probably more like philosophical theory in consciousness. But you can either see it as like a connective map or like as a big list. And it, yeah, I don't know if it's the same list that we're talking about here. I think it's like hundreds of them. And you can click on them all and there's, I'll link in it. I think it's awesome and it takes forever just to get through them. But it is also in a way a little bit depressing.

Yeah, but it shows we don't know what we're talking about, right? Because they can't agree what, I mean, most of those studies don't, I mean, the scientific versions don't try and say, okay, well, our version is better because we predict X and your theory doesn't predict that. That doesn't happen. They all kind of work in separation. It's the beginning of a change in that respect. But above all, their theories of everything, their theories,

try to explain everything all at once. And Crick, and I tend to follow him on this, his view was that that was the wrong way to go. We needed to do it very piecemeal and just try it getting there. Now, that having been said, his and his colleague, Christoph Koch, their search for neural correlates of consciousness,

in a way we found them. Okay, so one of the things that Koch did after Crick's death in conjunction with some neuroscientists, some neurosurgeons in Los Angeles, Ishak Fried, main researcher, they were again working on patients who had terrible epilepsy, so they were going to be operated on. They weren't having their brain split or anything. But these incredibly generous people said, yes, of course you can poke around in my brain

and record from my cells in my brain whilst I'm getting prepped for the op. So they're amazingly generous. Yeah, it's one. They always goes, wow. Anyway, so they're going to have an operation that's going to do various things to their brain to reduce their risk of epilepsy, very, very severe epilepsy. And what they did was to record from single cells in the brain and the visual processing areas.

And they would show them images. And they would show them a picture of the Sydney Opera House or of a differential equation or of Jennifer Aniston. And they would find cells that only responded to those very specific images. In the case of Jennifer Aniston, notoriously, there was one patient who had a cell that responded to Jennifer Aniston, but would not respond if there was Jennifer Adniston and Brad Pitt. So, you know, these were neural correlates of consciousness.

This was their visual. They were saying, okay, it's Brad Pitt. That's a Sydney Opera House. That's a differential equation. Yeah. And this single cell, one cell, is firing away. Now, this is a bit of a cheat, or it's not a cheat. It's a problem of optics.

So they've recorded, they're recording from single cells. Wow, that's amazing. Is that the only cell in their brain that represents Jennifer Aniston? Almost certainly not. What it will be is you can imagine, I mean, in a way, all it's saying is, well, our perceptions, the activity of neurons. That's all there is. You know, there's nothing else except neurons, you know. But what it goes against, I mean, clearly we cannot have a single cell for every possible thing we could remark.

Right. We could detect. Yeah. Our brains aren't big enough, you know, because we can see all sorts of things. I can see you, I can see the cameras, through the chair. You can see like Jennifer Aniston's left ear and, you know, like you can. I mean, Jennifer Aniston standing on ahead is that the same as Jennifer? You know, clearly, have we got two cells for that?

Right. You heard a left profile, left profile. It clearly is bonkers. And what there must be is you're going to have a set of neurons that would recognize blonde woman in her 30s. And then another set which would actually be much. more specific of actually Jennifer Aniston. And they were recording, by chance, from one of those cells. I mean, you know, that cell responded to Jennifer Anderson and nothing else, quite possibly.

It's part of this network. They wouldn't, you can't go to the same place in the different patients because our brains are so dense. And what that representational drift business I was talking about much earlier on suggests, if the same is true in humans as it is in mice, which my guess is it is, that if you were to leave that electrode in place and to come back a month later and show the picture of Jennifer Aniston, maybe that cell wouldn't fire. Not because the patient didn't know who Jennifer Aniston was, but because those thousand, say, cells had now moved on somewhere else in the brain. It's shifting for reasons we don't understand.

Yeah, that's incredible. Yeah, we've got neural corollips and then what? It hasn't actually, I mean, so Crick was. and cock, this was their big thing. I think they were real, this is the best approach, but we're kind of stuck. And that's really the theme of the book. And it struck me when I was, you know, they were all in the in the tens, 2010s, there were all these think pieces by neuroscientists saying,

we've got all these data from what I call connectomes, how neuron brains are wired together, all this other information. We can't make sense of it. We got too much data and not enough theory. to try and explain what should be going on. Right. I see. And, okay, I know it's a big topic and you've got a whole chapter on it,

but just as an overview, we've used the word neuron a few times, and people might sort of roughly know that that's what the brain's made out of. But what is a neuron? Well, it's a cell. It's a responsive cell with normally an input at one end and an output at the other end. And there's the dent. rights, as they're called, which are loads and loads of the input part, and then there's the cell body, which has got a nucleus, so enables it to function, and then you've got a long thing

called an axon, which sends the message on to the next part of the processing network. And these neurons, these specialized cells, are, they will interact with each other. So they've got, so, for example, in, one of the, again, to show how amazingly complex, simple organisms are. People have studied the cell wall of a maggot. So a maggot basically riggles along. And it's got a repeated nervous system in there which enables us to do this. And you've got little cells that say, I've stretched. They respond to stretching. So when the maggot pushes forward, these cell stretches. And it's basically telling the system, okay, I've stretched, don't go any further. We'll burst. We've got to now stop stretching and do the next kind of movement. And those single

cells that are simply saying I've stretched, not even to the maggots brain, but to a little circuit movement circuit, they have around about, they have about 130, connected to 132 other cells. And those connections are not like an electric circuit where it's just a plus or minus. They will have many, many neurotransmitters, because that's how the chemical electrical signal is transmitted from one cell to the other. through these chemical connections and we have lots of different

neurotransmitters in the same system that can do more than one thing so they can modulate the activity, turn the next neuron off and turn it on, excited or whatever. So it is not a series, it's not like a computer. I mean, it's so unlike a computer. It's not a digitally based system

in that if you shine light on a cell that can detect light, it doesn't just go, on and they go off. It will fire with greater intensity with more light. And things get even, they're even more complicated. It can show changes in the shape over time as well. Yeah.

So neurons are basically kind of connect, the connecting parts of the nervous system. And when they're in brains, they start, or when they're in connection networks, they start to do very complicated things that we, as I've tried to explain, we've found very hard to understand.

And somehow, some of those neurons in your brain right now are producing your perception, your thoughts. Yeah. And that intangible, weird, spooky thingness that's consciousness. And how that happens, I have no idea. And anybody who tells you that they have an idea is talking crap. When I finished the first draft of the book, I sent it to my editor. He goes, he sent back, he said, well, this is all very well.

Very clever. But how does the brain work? I said, well, we have no idea. And he said, we can't say that. Every book about the brain explains how it works. It's quantum this or it's what, it's computer, whatever. And I said, yeah, but all that's rubbish. I mean, that's just to sell books.

Maybe I said, you know, the USP, the unique selling point of my book, I tell the truth that we do not know. Yeah, it's the publisher thing, isn't it? like, you know, publishers are very keen on, like, like, in the world of philosophy, you know, publishers will sort of say, you know, it's a cool idea, but like, really love for you to just like do a chapter on like, you know, how to find meaning, you know, in your life and stuff. And you're sort of like, I'm not quite sure you understand the project. But, you know, I understand. You've got to sell books. And I think people are beginning to get a bit tired of that as well. I think if you walk into, you know, waterstones and you see all of the new books and they're all very certain. They're all very like, here are like 14 principles to follow that will fix all of your problems, or here is the explanation for this or that or whatever, like a comprehensive history of the world in like, you know, 18 screwdrivers or something. And it's cool. Hey, I'll buy that. That sounds great. Yeah.

It's interesting, right? And, but I think it needs to be presented as this is, you know, my theory, my idea. Yeah. And it needs to be tested against the evidence. And as a historian, right, which is the sort of cap that you're putting on with writing a, a. a text like this, it's not your job to say... Well, yeah, except I don't have... I mean, I don't have a dog in the fights, the many fights,

and I don't work on the brain, right? But I am or was until I retired, a neuroscientist, so I'm both. So I can see, and what I also wanted to do was not simply to tell the story and say, look, we've no idea, you know, let's go home, but quite the opposite, to actually sketch out these are the possible futures. Yeah. So I say sometimes say facetiously, the books divide into three. halves past, present and future.

And the future bit, again, I didn't want to write that. So there's a future is the final section where I try and predict what's going to happen, which is not something that scientists do, poor historians, right? But the publisher said, we really need that. You've got to say where are we going. So I said, okay, well,

you know, predictions are mug's game, especially about the future. But I'll try. And so it was actually, that was really interesting to try and think, well, what are we going, I mean, what are we going to discover? How could it be done? And I there lay out my own kind of prejudices, which I've outlined here, which tend to be more about understanding simple systems in the hope that something of the

principle of organisation can emerge, that we can then apply to more complicated things. In other words, I would largely personally put the problem of consciousness and how it works and how it emerges on the back burner until we've got some better idea. I mean, very famously, Christoph Koch had a bet with David Chalmers, who's the philosopher, who came up with the idea of the hard problem, i, what they're called Qualia, why I feel the work, what the feeling of consciousness is. And Scott very ambitiously, this is in 1998, I think,

bet him a case of fine wine that within 25 years we'd have solved this problem. He lost very graciously. But I mean, I, you know, my view, where I normally point to stuff I know about, So the maggot brain, I spent most of my career studying, as I say, tiny insects, maggots, very simple systems. We have the connectome of the maggot brain, which is about 5,000 neurons, something like that. If in a century we can predict everything that that can do and say, okay, we take out these neurons or alter their activity in this way, this is what the animal will do. and we understand everything about it, I will be amazed. And I think these, whilst many people think, well, okay, this is insects, we don't care

about that. What about the hard problem or wherever? I mean, the reality is that we aren't going to, and unless we can solve the other problems, I don't think we're going to be able to solve the big problem. And we've seen this. So this has happened repeatedly. Every kind of breakthrough we've made since the 1870s, been a huge breakthrough, say, in discovery of electrical activity in the brain and some localization of function.

And then people go, oh, my God, how are we ever going to figure out how consciousness emerges? My God, if it's not some mystical spirit, which is just a get-out, all right? If you think it is a material thing that is a consequence of neuronal activity, how are we going to explain that? Same thing happened in the 1950s when they developed the first EEG recordings. So you can record from the overall activity of the brain. And this looked fantastic, great insight. You could record from, or stimulate bits of the brain and you'd get people remembering things, most bizarre things like, oh, I can see my mother telling me off because I've put my duffel coat on upside down or whatever.

And most bizarre things. Or people could got earworms. They started singing along because they could hear a tune being played. Wilder Penfield. Yeah, that's right. Wilder Penfield. Sort of discovers this. Yeah.

And again, working patience and recording and stimulating. their brains and getting most, as they were being operated on for other reasons. These weren't experiments in that sense. One Plus one equals more of the greatest stories. Hulu on Disney Plus. Stories about survivors. The most dangerous planet. Family.

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It's like they relive. Yeah. Like, I can, I can hear a piano note in my head. I can, I can hear someone's voice. I can sort of remember what I did this morning. but to like actually sort of re-experience what I could make you do that I could make you do that I would have to know what the trigger was as it were right so I could do that the sense of smell so if you think of uh you think of Proust's a la Chesh deeuf deyte dee so in remembrance of

things Proust is the most used English translation it's a huge long book about experience and so on it begins with him saying you know I used to go to bed quite early and my mother would bring me a Madeleine, one of these nice biscuits, and she dunk it in the, in the, in the, in the, in the, in the, in the, in the, in the, in the, he'd eat and he, he can, he, he remembers this because he, he's doing this, and the smell and the taste of the food takes him back. And we've all had that, you know, you smell, I don't know, a particular food that your grandmother used to cook. And you're, you remember it like you're back there. She's up here, you're that high and the, you know, the counters at this height. You know, you're three years old. in the kitchen as she's cooked, something like that. So smell is in fact very able to produce these dreamlike, very realistic memories that are not the same as us struggling for the name of Phineas Gage or whatever. It's rather different. There's no tip of the tongue phenomenon. Bang, you are there, you can remember it.

Do we know why smell is so connected to memory? Well, as things, we're experiencing things, it seems that, I mean, again, this is partly because a lot of what we know comes from animal studies and then from a few patients. But we know that we are tagging events, key events, tend to get tagged with smells that are associated in the environment, but also with place. And we can manipulate this in animals. So, for example, you can make an animal remember a smell that it's never smelled. So if you know the particular set of neurons in a mouse's brain that are activated by stimulating the smell of aniseed or something, and then you will make it respond to that by stimulating those areas, activating them using optogenetics or whatever.

So you can actually reconstruct bits of memory that have never happened. Yeah, that's strange. I mean, it's in an animal. We can't do this in humans, but, you know, clearly, you know, science fiction is Philip K. Dix, you know, talked about this. We can remember it for you wholesale, you know, which just turned into a film and all the rest of it. Yeah. So memories, I mean, they can't be plugged in. You know, Elon Musk wants to get a, you know, get a language module and you stick it in.

And all of a sudden you can speak Italian or whatever. Or you can remember things that you, you know, about quantum physics you were never taught. That's not going to happen. Brain computer interfaces don't work that way, and I don't think ever will. But there is this tagging of events that are taking place and smell, partly because it's one of the oldest, there's the oldest sense. So it's the one that evolved. It's just detecting chemicals in the environment. Sure, yeah, of course.

So you can smell in water, fish smell. So we were smelling long before we had eyes, right? We're detecting chemical gradients in the environment and being moving, what we, you know, are long ago ancestors, you know, a little worm-like thing. So smell and memory are very closely linked. And in humans, memory is partly one of the gateways to it, the way that memory is then stored is through these structures called the hypothalamuses, which are deep down in our brain. and again, one of the things, the experiments that went wrong, this was studied by Wilder Penfield and Brenda Milner, who is astonishingly still alive,

and I think she published a lot. She's about 103. She's a Canadian psychologist. One of these patients called HM. Yep. That was, his real name is, because he's dead now, and so his name's been revealed, was Henry Mollison.

These patients were having an operation because they had terrible seizures and so on, and basically the surgeon who did it was a hacker. And, I mean, as he just kind of hacked around, and he drilled huge holes through the brain and destroyed, it was supposed to be simply taking out small areas and basically destroyed HM's memory system in that he could not form any new permanent memories after that day, pretty much. So what that meant was that he knew everything that happened up until he had the operation, but every day he lived it and knew.

He couldn't remember anything. So he, Brenda Milner worked with him for decades, did experiments on him trying to work out. His olfactory system was also damaged. He couldn't identify smells anymore. He found it very difficult to navigate, to read maps and so on. But she did all these tests on him, and every time she had to introduce herself. Yeah. Hello, Henri.

I'm here to do some experiments. Oh, that'd be great. Love to help you. Yeah. And of course she she knew that she knew him and he had no idea.

Now it's interesting that it doesn't seem to have been completely his isolation, a terrible, terrible isolation. Can you just imagine? You don't know anything from this event in 1952 or

1951 when the operation happened. But he did, he could later on, so for example, he knew about the Beatles, he mentioned them, he knew about landing on the moon. So the,

This awful, awful operation, botched operation, didn't completely destroy his memory, but you had to, you know, there are only very, very few things that escape the destruction of these two structures in his brain. And we're back to the problem of, what does this mean? Does it mean that the hippocampuses are the site of memory or rather that this, more likely it seems, this is the place through which memory. is then rooted. That jumps out at me. Yeah, it seems to be much more likely that it's the latter. Memories are distributed. So I've said earlier on, this perceptual drift is not happening in the hippocampus. It's happening elsewhere.

Perception and so on. Yeah, it's sort of like, and that original operation that you're talking about, wasn't it someone who, I mean, you were talking about a lobotomy, and this was at a time when it was a self-admittedly experimental sort of form of medicine. And this guy had been sort of trying to treat people with schizophrenia. and then this like Henry was having like epileptic seizures and he kind of just tried the same technique even though it was dubious in the schizophrenia case too and he just sort of destroys part of this this guy's this guy's brain and the idea that yeah the hippocampus is clearly

key to memory here but to think that that must mean that that's where memory is done or where it's stored, it's like maybe a bit like sort of, if I like plastered over the front door of a house and there's no way to get into the house anymore, I went like, oh, look, I can't get into the, into the living room anymore, you know, that the living room must be sort of stored in the, in the front door. It's like a sort of, yeah, a sort of, the wrong way of thinking about it, but we know that the hippocampus is incredibly important. And there's, again, doobie, I want to ask you about this, because I think it's dubious, but I'm not sure how dubious it is, the London cabies thing, like black cab drivers in London have bigger hippocampuses,

but they've not been able to replicate that test, right? Yeah, well, it hasn't been replicated. I don't know anybody's tried. So this is the issue. So in animals, the hippocampus is associated with place, identifying place. And there are these things called place cells, which very carefully, very dilitically, tell a rat or a mouse where it is in the environment. and events are tagged with that.

So if you find a bit of food in that corner, then those cells are really, really activated because that was great. Now, those cells have not been shown to exist in humans. Really? Now, we're not rodent. So part of the problem is you've got a model, an animal model you know so much about

and you then extrapolate because they're both mammals, but we don't know that they're places. They're in the hippocampus in animals, right? Absolutely, yeah. They were discovered by accident. They got a Nobel Prize for it. They did discover it. They're looking for somebody else.

Because it wasn't, I can't remember who it was or anything, but, you know, this experiment was, was trying to sort of measure a part of this, like, mouth or rat's brain. And then as the rats moving around, it's lighting up like crazy. And they're like, gosh, something crazy must be happening. And it turns out they just accidentally stuck it in the hippocampus. Yeah, well, they only knew that after they chopped the rat up. Yeah, yeah, right. Oh, where were we? Oh, we weren't there?

Okay, rats interesting. So maybe it's the happy campus. Yeah. But, I mean, clearly something similar is happening. We've got some way of encoding space. I mean, I have a very good sense of direction, and in general, I know where I am, and if I don't know where I am, I find it very disorienting.

I can, you know, in London, I know I go down, you know, Charing Cross Road, and I'm going to end up at Trafalgar Square. My wife, she comes out of the tube, she doesn't know it, you know, she has a very different sense, a direction to me. So the, we know that the hippocampus is involved in this kind of activity. And there is this claim from this study in London that taxi drivers who have to do what's called the knowledge. So if you get in a London cab, they're not going to use Satnav. You're going to say,

I want to go to Golders Green or whatever, and they will take you there. And they'll take by the quickest route and all the rest of it. Because they have to learn it. You've got to learn the name of every street in central London. You can watch them doing it on YouTube where they're doing the test and someone will sit there and go, okay, give me like Kingscross Station to, you know, somewhere in shoreditch and they sit there and they go right, you take a left down this street, right down that street, you know, follow it around to the, it's incredible. And still today, if I'm in a rush, it's a black cab in London every single time because they know, they know what's going on.

So London is quite unique. Most cities, like Manchester we have, you know, the taxi driver, but you either tell him where to go or he puts a postcode into his saturn. But taxi drivers in London have to do the knowledge. And so the claim was that by scanning their brain, they found that taxi drivers had larger hippocampi than you or I. Now, there are a number of problems. Firstly, with the arrow of causality.

Yeah, right. So maybe you can only pass the knowledge if you got a big hippocampus. They didn't do a developmental, didn't do before and after. Right, here's you. You don't know any street in London. Now you know them all. How your hippocampus has got bigger. So that's one problem.

Second problem is, you know, the hippocampus isn't very big. I mean, our brains aren't really very big. You know, they're kind of this part. And the happy campuses, I don't know, about that big. So is it... That size of wood, like a walnut? Yeah, a bit smaller and kind of elongated shape. Supposedly looks like a seahorse, which is a bit strange.

But anyway, they thought it looked like a seahorse, hence its name. But the scanning methods that, even now, the scanning methods are very, very noisy. So it's very difficult to be able to say, okay, you've actually. increased, you know, they may well have increased significantly in volume in the test, but whether that is a real, you know, you're relying on this very fuzzy measure. So I think most people are rather dubious about this. But we know that in rodents at least, there's this kind of almost like literal mapping of an environment in the hippocampus.

It's not just like, you know, you're walking around the environment and then you sort of write it down in a bit of code that's in hippocampus. It's like, I was trying to understand how this worked, because it took me a minute to figure out what was really going on here. But as far as I understand, if you sort of, you know, you measure like a particular neuron in the hippocampus and you just sort of stay locked on that neuron. And then you watch this route run around. Then if it passes by a particular area, the neuron will fire. And then it will keep running around. If it goes back to that area, it will fire again.

Back to that area, it will fire again. And it won't be the exact same position, but a sort of rough area, as if to suggest that what's happened. is literally just when you're in a particular area, a particular neuron just fires. And if you stay there, it's firing. And if you go somewhere else, that stops firing and another one stops firing. So you've got a map.

You've got a map of the world. You can sort of, if you look, if you imagine all of these neurons laid out inside of the hippocampus, like, they're like literally laid out physically in a way that corresponds with the physical environment, which I find quite incredible. Yeah, absolutely. And you can then also fool these rats because they can associate, the left-hand side of a room with this neuron firing,

and if you just artificially simulate that neuron, they think they're on the left-hand side of the room, which is kind of cruel. Again, it's so unfortunate that so much of this involves, you know, questionable treatment of animals, to say the least, but it does tell us something really interesting. But I didn't know that we didn't have evidence of places. Well, they haven't found them.

I mean, I guess the problem is how are you going to find them? Yeah, quite. So I'm not letting anybody go poking around in my hippocampus, and they're moving me around the room. Thank you very much. Yeah. So they're ethical, my guess is that we will have something similar, but that it's going to be much less developed because our ecology is very different.

Okay, so if you're a, if you're a mouse, you want to go around the edge of a room. You don't want to go around the middle. Sure. Right. Humans are going to be much more, you know, you might, you're going to wander all over, even a big space, right? I mean, if you knew there were big predators around, I don't know, you'd be changing your behavior a bit, but you don't have that.

instinctive response of, you know, keeping to corners or whatever. So the ecology is going to be what is driving brain structure because, and this was Darwin, one of the, you know, saying the problem about function and structure and how does it all work. Darwin worried about this. And then he said, you know, I don't care. I don't care how behavior and consciousness and all that stuff emerges from brains. All I need to know is that there's a link. Because natural selection can affect structures.

It can make giraffes necks grow longer or whatever. And it can affect brains because brains are just structures. And if you affect a brain, it's structure, you change behavior. And in fact, it's the other way. You can produce a particular behavior. So, you know, okay, you will be selected for if it's successful. And that part of the brain may grow bigger in the next generation because, you know, overall, the population has got more, more people with that particular

the size of the brain, you know, kind of selected for. So the, my suspicion would be that humans, for our particular ecology, we may not have as easily detectable a system of play cells as is the case in rodents. Some people are. But it'd be very odd, I think, if we had no way of, you know, identifying it. That's cool. It works in 3D space as well. Like if you measure a bat.

You do this, absolutely. Yeah. You map it onto the world. It creates sort of a sphere in the air of where those neurons would fire, which is incredible. Some people listening, I suppose, I mean, you know, in closing here, like, it's very clear that we know very little still. And there's so many questions to be answered. But some people might be thinking, you know, we've got technologies. Like you said, I'm not going to allow someone to go poking around in my brain.

Well, why would you have to? We've got these things like MRI scanners. I've heard of those. You sort of put a big sort of magnet around your head and can't you just sort of measure the brain activity? and then, you know, go in an MRI and then maybe like simulate the experience of moving around and just look for play cells, right? Like, it is true that these technologies have been quite revolutionary and changed a lot for us, but perhaps they don't do as much as people think that they can. I think that's the case. And I'll give you two reasons.

Firstly, there's a very big division between, in particular, FMRI, between researchers who use FMRI, who love it, and those who don't are extremely suspicious of it. And the people who use it are, you know, all good people. So I'm not, you know, I'm not dissing anybody here. But the system is very coarse. In particular, if you're taking the kind of approach that I'm interested in and I've been arguing for a much more cellular approach, then the tiniest vox cell, i.

3-dimensional pixel in one of these scans contains millions and millions of neurons and even more synapses. I mean, so you can't, all that these scans do is say something is happening here. Right. Because they measure oxygen levels. So if the cell is active or there's millions of cells in that Vox cell are active, you get, it lights up. Yeah. It doesn't actually light up, but that's what it scans are brights.

Because there's more oxygen in there. Because there's more blood flowing. That's all it is. It's metabolically active. So an fMRI scanner just measures blood flow in certain regions of the brain, essentially. Yeah. Or the metabolic activity. Yeah.

And so if it's active, it doesn't tell you whether those cells are on or off, and cells can be activated, they can be inhibited. So most sensory cells have what's called spontaneous activities, so they just kind of fire at random. If you activate them, they will often start firing very rapidly because they're excited. Some cells, if you activate them, will then turn off completely. So it's not binary, right? You've got negative response. You've got zero, if you want to put it this way, you've got one. 0, 0 is just firing randomly, and then minus 1, which is nothing there.

The smell cells that I've studied in the maggots nose, not in the human nose, they do exactly that. They will go on in all sorts of interesting ways. They will not change or they will go off for varying durations. And all those are significant in terms of how the brain's responding. So an fMRI scan, I guess we're back to the climate change thing. That's great for telling us the big weather. Okay, there's a storm coming, and that's pretty accurate.

right so we know when the hurricane is going to hit on the other hand uh it told me that it wasn't going to rain in london so i didn't bring a coat today i walked out of the station and there was water or it had been raining now so the weather the localized weather forecast was hopeless but the big picture is okay yeah so it's telling you different things i guess that's like you know it's like sort of if you're staring at the empire state building and you're sort of seeing which lights are turned on you can do that and that might be useful to some degree but it's not going to help you work out like the chemical composition of the perfume sat on a shelf in one of the rooms. You know, that requires a little bit more precision, I suppose.

Well, you need to go in and have a look. Yeah, yeah, quite a question. So this is a problem with the human brain. It's very difficult to do. So fMRI scans are problematic in that respect. And the other way, I think, is, and this is the most mind-bogglingly thing. So we talked a bit not that much about consciousness. So defining it is hellishly difficult.

There is no measure of it. So you cannot put somebody in a scanner. Let's say they're not responsive, you know, one of these locked in syndromes. Yeah. Where you don't know what's happening. You can't put them in a scanner and say, okay, they're conscious. We should look after them or they are not conscious. But, you know, if they're brain dead, then we know.

But you can't tell consciousness from, from, all we know about consciousness is it dissolves in halithane, which is what you have when you're doing, getting a general anesthetic. Yeah. It knocks it out. How that works, we don't know. So if anybody's going under the knife in the next few days, don't worry because they know exactly what to do. It's just that we don't understand the neural mechanisms.

We're getting there to understand the neural mechanisms of general anesthetics. It's not nothing, but, you know, be confident you're anesthetist. What if it doesn't get rid of consciousness? What if it just switches off memory? Don't, don't. No, this is too horrible. Okay, so this is one of the awful hypotheses is that, But yes, it doesn't work.

It just paralyzes you and that you don't remember anything. Yeah. I'm sure it's not like that. So you've been in agony for all that time and you don't recall it. I find that very unlikely. And also, even if that were the case, there are good philosophical reasons to think that that wouldn't matter when all is said and done. Well, it would matter to you at the time. But if you didn't remember, I mean, you'd be like HM, right?

You know, you had done the experiment the day before you had no idea. But I mean, I don't, I hope that's not true. Quite extraordinary. Yeah. I don't think that was a very fair thing. There may be people out there who are going to. No, I know. I know.

That is very, that is very unfair. Well, all I know is that everyone I've ever known who's undergone such a thing is actually found it kind of enjoyable. It's like a little experiment. Yeah, absolutely. They count. Yeah. And then you're out.

And then you wake up and you're back. Yeah. But I remember, I spoke to someone on this show the other day, Benardo Castro, who said, you know, when he was being an esotide, he wanted to kind of do an experiment. He was like, I'm going to try. try as as I can stay awake. And so he sort of,

he starts counting. He's like, you know, one, two, three, he's like four, he goes five. And then he says to the doctor like,

you know, is it going to, is it normal for it to take this long? And they go like, oh, we're nearly done. And he's like, what?

You know, it's amazing that I'd love to, yeah. Well, the anesthetists, I think, get used to people trying, thinking I can beat the system. But he just,

he didn't even, he, for him, perceive anything. A continual, sort of line of experience. It was kind of terror. And as a philosopher, he was like, the way that those two, that sort of big gap, you

could just take each end and stitch them together to a continual experience. Well, that's, I mean, that's partly what perception is, right? So we're not perceiving reality. Yeah. We're not, it's not unmediated. It feels like we got these holes in our eyes and everything's just coming and all our senses just getting this information. We know that's not the case.

Yeah. There's a delay. Yeah. There's a delay in perception, which is simply the, the delay in the activity of the neurons, they take a few hundred milliseconds. So in act, something happens, you hit your foot and then you will detect it. Those cells are going to take about 150, 200 milliseconds to respond. By the time it gets up here, it's a bit longer.

So something like, I mean, Helmholtz was the first neuropsychologist to work this out in the 19th century. He said, well, wait a minute. What about whales? If I tweak the tail of a whale, when does it finally work out that something's happened? His calculations suggested it was about a second and a half. So we're living in the past. And above all, those pasts aren't going to be identical for different sensory systems, but we're making sense of stuff.

Just like in perception, again, Helmholtz showed this. There are these people probably know about the blind spot. If you stare at a fixate at a particular point, then there's part of your visual field around here and here, which there's nothing there. And yet you don't feel that there's a big black hole. Your brain is just kind of, oh, well, It's like Photoshop, just blurring it in. Okay, right, we'll stamp that.

Okay, copy that, copy and paste. Can sense something out there. There are experiments you can do. Like, they're famously, you know, big, big sort of white screen, and they put a spot at the right area. And if you move it to the right distance, it just disappears. Yeah, you can't see things. And, but even then, it's not like you suddenly, oh, now I can see the big black hole.

It just fills in, it fills in white. Your brain just sort of lies to you. Yeah, absolutely. Well, I mean, what Helmholt said, which is incredibly smart for a guy in the 19th century, the brain is making hypotheses about the inductive hypotheses. It's looking at the world. It works out what probably should be there, and then it tells you that story. Most of the time, that's fine.

You know, you put yourself in a weird psychology experiment, and then you can detect it. But because you're moving your eyes around all the time, we don't know just the blind spot. And that's not the kind of thing that you can, like, test for, like you say, you can test for the neuronal activity, although I'm still not quite sure how that, like an MRI scanner, it's magnetic, right? I don't actually know how it measures the oxygen blood. I imagine that's extremely complicated. I don't know. I'm not enough of a physicist to be able to explain. However they do it, firstly, it measures only at a sort of zoomed out resolution.

Secondly, it's measuring brain activity. And consciousness is correlated with that, may be caused by it, you know, like, but there's no guarantee of that. And it's like the one thing in science that seems to resist measurement. But my final question for you then is I'm going to do the thing that the publisher asks you to do. But hopefully with a little bit more precision and a recognition that this is purely speculation, do you think it ever will be able to? Do you think you'll ever be able to look at a brain and see consciousness? Yes. But I say yes, but I've recognised that is almost an article of faith.

Yeah. But it's faith not in an old book or in some old belief, but it's a faith that we got this far already. Yes. That is the scientific method and scientific approaches. will get there in the end. I'm confident. I mean, but just remember,

physicists don't know what 90% of the universe is made off. Right. So we will understand that in the end, I hope. But these are massive problems

that have bedeviled us for millennia. And I think all we can do, I mean, I don't think people should despair, right? And despair can take the form of going,

hey, man, everything is conscious. You know, panpsychism is one. Very fashionable thing. Especially, you know, if you're interested in psychedelic drugs, which, you know, seem to change your perception. Well, they do change your perception. Yeah.

And understanding of reality, then you can think, okay, well, maybe everything. Maybe this chair's conscious. Yeah. But that actually is, you're not explaining anything. I'm not into that. That's the biggest criticism of the panpsychist world view is that it's a sort of panpsychism of the gaps. Yeah, absolutely. It's the same thing that people did with God.

I've had a few panpsychists on this show and I've been talking about that view and idealism a bunch. I get a lot of flack actually for having, I get excited about an idea and then I bring on a few people who talk about it and I get sort of accused of sort of going too hard on that worldview. So it's nice to have some sort of materialists on the show as well. I've made a conscious effort, if you will, to try to bring a variance of people on. But, you know, I'll leave the panseicus to speak for themselves. Well, yeah. I mean, you know, they could be right. So my view, I'm very, very confident we will, not in my lifetime, I'm sure.

of that, right? Because, I mean, that'll be whatever, 20, 30 years. That's no way we're going to make a breakthrough in that kind of time scale. Unless something very, very strange happens. So it's possible, you know, maybe large language models can, could be able to pull something out of this huge tsunami of data I mentioned. Maybe we'll all make, it'll all come clear. I mean, certainly that's the kind of thing people are trying to do to see can these machines see patterns that we can't. I still guess that that's, it's, we haven't got the right kind of data. to be able to do that. But that may well be an approach

that will happen this century. I mean, listeners and viewers, if they're still around, you know, in another 60-odd years, we may go, ha-ha, you see, we got there.

Yeah, things often come faster than you expect. But it may be that it takes millennia. Yeah. Yeah. You know. I don't know. What can we do?

I did a panel recently with Brian Cox. Oh, yeah. It was first time I'd met him, and there were some questions that were going to be on from the audience. And some of them were sort of about

panpsychic. and that's something. He, to say the least, wasn't really sort of feeling it. And I sort of tried to say, look, you know, like maybe it deserves a hearing, you know. I just remember saying to him like, look, you know, it is growing in popularity this few. And he said, he said, so is Nigel Farage, is what he said in results. Do you know, okay, touchy, fair enough. But I like, I understand why, I think it's, it's silly to ask scientists or indeed historians, things like, what will happen in the future? Because, you know, who knows? But I love asking just on like a speculative friendly level, what do you think? And I like what you said. It's sort of, it's not, it's not

faith in the books of the past. It's faith in the books of the future. Yeah, I think that's nice way of putting it. The last paragraph is my attempt to sum up what might happen. And it basically, I mean, the, nobody, no reviewers or nobody I've talked to has ever commented on this about, so I haven't spoken to the right, most learned people. But I stole it off Nietzsche. So I was reading a biography of Nietzsche, Nietzsche in one of his more craze moments is talking about the future and the philosophy of the future. And he just, because he was going a bit bonkers when he write it, he just kind of spews out all these possible alternatives, which is kind of idea, and partly to keep everybody on board, I listed all the various approaches that are

trying to understand how brains work and what consciousness might be, and then at the end, and this is what I stole from Nietzsche. You know, it's this, all this, all this. All this. All this. this, or this. And then the last word is, or, dot, dot, dot. So in other words, he left it open. And I just thought, how astonishingly bold to finish on saying, there's a, you know, make it up. You work it out. Yeah. You're going to find out what's happening. That was partly, as I said, the book is not just a history. It's also trying to point the way forward. And part of it was a, not a challenge, but a way of talking to my neuroscience colleagues and saying, well, okay, you know, if none of this fits,

if all of these various options that people have got at the moment aren't right, then what can you come up with? Yeah. And we'll see. We'll see. The book is the idea of the brain. It's, of course, linked in the description.

Matthew Cox. Excellent. Thanks for your time. Thank you very much. It's been great.