Hidden Brain - One Head, Two Brains

Episode Date: May 4, 2021

Your brain is divided in two: a left hemisphere and a right hemisphere. In this 2019 episode of Hidden Brain, we dive into Iain McGilchrist's research on how the left and right hemispheres shape our perceptions. Iain argues that differences in the brain — and Western society's preference for what one hemisphere has to offer — have had enormous effects on our lives. If you like our work, please consider supporting it! See how you can help at support.hiddenbrain.org. To learn more about human behavior and ideas that can improve your life, subscribe to our newsletter at news.hiddenbrain.org

This is Hidden Brain, I'm Shankar Vedanta. If you type in the words left brain versus right brain on YouTube, it's not long before you'll find yourself in a vortex of weird claims and outlandish hype. With the left brain imbalance, the overall function of the brain is stunted so that the oldest part of the brain, the reptile brain, takes over on an instinctual level. Men, men need formulas, we need systems. It's a left brain by the way for men. Now the problem is, is that most people are either exclusively left brain or right brain. They're one or the other. For decades, pop psychology books and plenty of YouTube videos have made dramatic claims about people who are left-brained

and people who are right-brained. It got to the point that respectable scientists felt they had to steer clear of the study of hemispheric differences. This week on Hidden Brain, we follow the work of a researcher who went there. What he's found is much more nuanced and complex than the story on YouTube. His conclusions, though, might be even more dramatic. He argues that differences in the brain and Western society's preference for what one hemisphere has to offer have had enormous effects on our lives.

Ian McGilchrist is a psychiatrist. He has spent years studying the human brain through case studies of his patients and a detailed examination of scientific research. He has found himself fascinated by a question that is intrigued philosophers and scientists for centuries. Why is the human brain divided in half? How does each hemisphere shape our perceptions? Ian's book on this topic has been on my radar for many years.

It's called The Master and his Emissary. Ian joined me for a chat in our studios in Washington DC. I asked him to start with a basic overview of what the two hemispheres do. In motor terms, it's fairly straightforward that the left hemisphere controls the right side of the body and receives messages from it and vice versa. But in terms of psychological life, they have quite different kinds of roles. They have quite different dispositions, and I believe evolutionarily they are, if you like, addressing different questions. If you look at the last 20 or 30 years, and there's been a lot of work or speculation really looking at how these two hemispheres might operate when it comes to perception, when it comes to behavior. You argue in the book that there has been many over simplifications of how the two hemispheres work and what their different roles are. What does that look like? What does this world of over simplification look like?

Well, the conventional model is something that's sprang up probably in the 60s and 70s and had some life into the 80s and even into the 90s. And is now probably mainly at home in middle management programs and pop psychology books. And I was told when I got involved in this area, don't touch it, it's toxic, don't even go there. And basically that was that the left hemisphere is logical and verbal, and that the right hemisphere is kind of moody and possibly creative. But all of this turns out to be much more complicated and some of its plain wrong. When we look at the evolution of the brain, not just among humans but other species, do

we find a similar division in other species? We certainly do. This is not something that was invented by human beings. It's there in all mammals, amphibians, reptiles, fish, insects, nematode worms, which have been there like one of them has 302 neurons, but it's working asymmetrically. And in fact, the oldest creature that we know of that has a neural net of any kind is called Nematostellavec-Tensis. It's 700 million years old. It's thought of as the origin of neural networks. Guess what? The neural network is asymmetrical. And so in some ways, this does prompt the question,

why would you have the brain be divided? I mean, it does beg the question. It suddenly begs the question, particularly if you buy which I emphatically don't, the idea that the brain is a computer because of it is. Surely it's a fast waste of computing power to have this brain divided into two bits. If you go to an antique store, you might find posters showing a human head with a brain divided like a map. Reason is in one quadrant, emotion in another. Memories over here,

emotion in another. Memories over here. Imagination there. For a long time the popular representations of hemispheric differences focused on what different parts of the brain do. Ian says what really distinguishes the hemispheres is not what they do but how they do the same things differently. The reason that we got things wrong in my view is that we were looking at simply the functions as we saw them and divided them up in much the way that we would if we thought about a machine this part of the machine does this this part of the machine does that and if you instead of using the machine model use the model of this is part of a human being a person you would ask a slightly

different question which is not just what does it do, but how does it do it? And that turns out to be a profoundly important question when looking at the hemispheres, because they are both involved in doing everything. But there is a difference. It's that quite consistent, each hemisphere does all these things in a totally different way, with a different kind of spirit towards a different end, if you like to put it that way. Ian believes the brain is divided into two hemispheres, so that it can produce two different views of reality. One of the hemispheres, the right, focuses on the big picture.

The left focuses on details. Both are essential. If you can't see the big picture, you don't understand what you're doing. If you can't home in on the details, you can't accomplish the simplest tasks. This fundamental difference in orientation turns out to have profound consequences for everything the two hemispheres do. Ian uses the example of learning a piece of music to explain how this works. Imagine you are attracted to a piece of music and you try playing it as a whole and you love it.

But you realise that there are bits that you are not getting right. So you know you need to practice your fingering at bar 18. And when you are taking it apart you realise, oh here we move into the subdominal and at this point we are moving back to the dominant. You understand a whole lot of details which are fine. You need to do the work and you need to do the analysis. But when you come to play the piece you must put all that out of your mind, otherwise you won't be able to play it all. The right hemisphere takes in the hole at the start. The left hemisphere unpacks that and enriches it, but then that work being done it needs to be taken back into the whole picture which only the right hemisphere can do. And it seems to me that this is not just, of course, when you're learning a piece of music,

you have examples in the book of numerous cases, including in the animal world, when a bird is trying to pick up a grain of corn, it actually needs to be doing two different things at once. All living creatures need to be able to attend the world in two different ways, which require quite different attention at the same time, and this is simply not possible unless they can work relatively independently. On the one hand, in order to manipulate the world to get food, to pick up a tweak, to build an est, you need a very precise targeted attention on a detail, in order to be able to achieve that and be ahead of your competition. But if you're only doing that, if you're a bird just concentrating on the little seed,

you'll become somebody else's lunch while you're getting your own, because you need at the same time to be paying the precise opposite kind of attention, not piecemeal, fragmented and entirely detailed, but sustained broad and vigilant for predators and for other members of your species. Decades ago, scientists discovered that the two hemispheres are connected by a bundle of nerve fibers. They named it the Corpus Colossum. The Corpus Colossum is often described as a bridge that it passes information back and forth between the hemispheres. But it turns out it is much more like a traffic signal.

In order to collaborate, you need to both work together and work separately. If a surgeon collaborates with the scrubb nurse, they don't both try and do the same job. They have distinct roles. And the culprits calosum enables both separation, mainly, I believe, separation, but also connection. I mean, that's extraordinary, isn't it? When you think about this, it really looks like we actually have two different brains inside our head. Certainly, the first people to look at, split brain patients, thought that there were two

distinct people there. And they would talk to one another. I mean, these are very famous names in the history of neurology, neuropsychology. They would talk about the two hemispheres as two people. Ian's book has a lot of science in it, but it's also a commentary on modern industrial societies. The title of the book comes from a parable, a myth about a wise spiritual master who rules over a land.

The master appoints an emissary. He's a smart messenger. His job is to carry the master's instructions to the far corners of the land. And this emissary was bright enough, but not quite bright enough to know what it was he didn't know. And he thought, I know everything. And he thought, what does the master know, sitting back there, seraphically smiling, well, I do all the hard work.

And so he adopted the master's cloak, pretended to be the master. And because he didn't know what he didn't know, the result was that the community fell apart, essentially. Ian argues that the right hemisphere of the brain is supposed to play the role of the wise master of our mental kingdom. The left hemisphere is supposed to be the emissary. Ian says we have grown infatuated with the skills of the emissary.

We prize the details but scorn the big picture. He makes an analogy about the relationship between the hemispheres. I want to emphasize that I resist very strongly the idea that the brain is a computer. It's just nothing like a computer, actually. But in this one limited sense, the left hemisphere is a little bit like a very, very smart computer. So you know what the data you've collected mean, but you haven't yet been able to analyze them.

You put them into a machine that is just very clever at carrying out a routine. It doesn't understand. And then it spews out a result, which it also doesn't understand, but you then take back into the world where the data come from and go, I see. So, that is the relationship. Your left hemisphere is busy processing things to make sure they're consistent and unpacked. Be it all right, hemisphere is seeing everything. I'm suggesting that we have arrived at a place, not for the first time in the West,

where we have slipped into listening only to what it is that the left hemisphere can tell us and discounting what the right hemisphere could have told us. And in your analogy here, the right hemisphere is the master, the left hemisphere is the emissary. In my interpretation of that myth, that's right, yeah. Coming up, we look more closely at Ian's view that we're living in a left hemisphere world, and we dive into the ways the left and right hemispheres produce different accounts of reality.

I'm Shankar Vedantam, and you're listening to Hidden Brain. This is NPR. This is Hidden Brain, I'm Shankar Vedantam. In 1997, PBS aired a documentary about a patient named Joe. He had epilepsy. I was having seizures my every day, so I was so nice. Two or three a day. Joe's doctor's device at treatment that sounded more sci-fi than like a real medical procedure. A surgeon literally split his brain in two. The surgeon sliced the corpus callosum, the nerve fibers that connect the left and right

hemispheres. In Joe's case, the surgery accomplished what the doctors hoped. His seizures stopped. I know the left hemisphere and right hemisphere now are working independent of each other, but you don't notice it. Now you just kind of adapt to it. It doesn't. You don't have any feeling of feeling different than it did before. Psychiatrist Ian McGilchrist says many other patients with epilepsy have been helped by this procedure. So by simply separating the two hemispheres, so that an electrical storm, if you like, in one hemisphere, couldn't cross over and invade the other.

They were able, actually, to carry on a remarkably normal life. So this was a life-saving procedure. But it also had the consequence that by clever experimentation, you could deliver information to one hemisphere at a time and find out what that hemisphere knew and had to say about it. These experiments showed the left and right hemisphere approach everyday tasks very differently. The left focuses on narrow details, the right on general vigilance. To use a basketball analogy, the left hemisphere is focused on the mechanics of dunking the basketball. The right on where all the players are, the current situation in the game. One sees the small picture, the other the big picture.

You see something similar when it comes to language. Language has many components. One of them is attending to the tone of voice in which I say something. For example, I can say, yes, or I can say, yes, I can intone that in probably a dozen different ways with quite different meanings. So, for example, I say, it's a bit hot in here. You're using your right hemisphere, no, that what I mean is, could you have the door open, could be put on the air conditioning. But your left hemisphere is wondering meanwhile why I'm supplying this quite unnecessary meteorological

information. So it's really focused on sort of the granular detail. Yes. And because of this all kinds of things happen, because of its narrow focus it doesn't see anything that isn't explicit. It only sees what's right in the center of the focus of attention. And it doesn't understand things that are not said. Often that's as important as what is said. The way in which it is said, my facial expression, my body language, all of this is lost, as well as the interpretation in the whole picture. One of the important differences you point out is sort of understanding the role of metaphor in language, for example, which is that the left hemisphere really is incapable of understanding what metaphor is or how it

works. Yes, and that's no small thing because as some philosophers have pointed out, metaphor is how we understand everything and they point out that actually particularly scientific and philosophical understanding is mediated by metaphors. In other words the only way we can understand something is in terms of something else that we think we already understand and it's making the analogy which is what a metaphor does that enables us to go, I see, I get it. Now if you think that metaphor is just one of those dispensable decorations that you could add to meaning, it's kind of nice, but probably a distraction from the real meaning. You've got it upside down, because if you

don't understand the matter, you haven't understood the meaning. Literal meaning, however, it's a peripheral diminished version of the richness of metaphorical understanding. And what we know is the right hemisphere understands, those implicit meanings, those connections of meanings, what we call connotations, as well as just denotations, it understands imagery, it understands humor, it understands all of that. Do the hemispheres differ in how they think about time, their orientation towards the future and their orientation towards the past? Well, that's an interesting question, and not in a clear, cut way, although the left hemisphere

is tending to look for the next opportunity, so it's very gold-driven, but very short-term gold-driven. It wants to grasp things that are within reach. Remember the left hemisphere is what controls our right hand with which we grasp things that are within reach. So it has a very direct linear idea of a target and let's go and get it. Is some of this played out in sort of the relationship they have with tradition with history as you say? In some ways if I'm primarily focused on what's right in front of me, I don't really need to know what the last 2,000 years of history have taught me. I think that's certainly right. Time can be seen rather

like the flow of a river, which isn't made up of slices or chunks of river that are then put together. We as personalities in time are cultures in time are like this flow. The left hand is if you can't deal with anything that is moving, it fixes things. It likes things to be fixed because then you can grab them. You can't grasp your prey, you can't pick up something unless you can at least immobilize it for that second while you're interacting with it. So it doesn't like flow and motion which are, in my view, basic to not just life, but actually to the cosmos. So instead, it sees lots of little punk-tate moments, little slices of

time and things have to be put together by adding them up. I mean, it's almost like a form of calculus, you know, of taking slices and then trying to integrate them together. You're absolutely right and calculus is an attempt actually to achieve something which is indivisible by dividing it into slices. The two hemispheres even appear to have different value systems. The left hemisphere prefers to reduce moral questions to arithmetic. For example, if you, and this experiment has been done, if you disable temporally the right temporary parietal junction which you can do with a painless procedure and ask people to solve moral problems, they give quite bizarre answers to them based on entirely utilitarian understanding of them.

An example is a woman is having coffee with her friend. She puts what she thinks is sugar in her friend's coffee, but it's in fact poison in the friend dies. Scenario 2, a woman is having coffee with her friend who she hates. She wants to poison her, and she puts what she thinks is poison in the coffee, but it's sugar, and the friend lives. Which was the morally worse scenario? Now, all of us using our intact brains say, well, the one in which she intended to kill her friend. But no, if you disable the right hemisphere, the good old left hemisphere says, well, obviously, the one in which she died, the consequences what matters. So, values

are not well appreciated, I think, by the left hemisphere. One of the most striking differences between the hemispheres is how they relate to each other. With its big picture view of the world, the right hemisphere can see what the left hemisphere is doing. See the value that it produces. But the left hemisphere, with its narrow view of reality, doesn't recognize the value of the right. In other words, the left hemisphere not only sees a narrow view of the world, it believes that the narrow view that it sees is all there is to see.

Ian explains this through one exchange between a physician and a patient who experienced right hemisphere brain damage, her left hemisphere is still intact. The patient has a strange belief about her own arm. We asked a couple of producers to read the exchange. Whose arm is this? It's not mine. Who's is it?

It's my mother's. How on earth does it happen to be here? I don't know. I found it in my bed. How long has it been there? Since the first day, feel. It's warmer than mine. The other day, too, when the weather was colder, it was warmer than mine.

I asked Ian how the patient could be unaware of her own arm, and why she came up with this odd way to explain the presence of the arm attached to her. Well, what we're seeing is a phenomenon called denial, which is a feature of the way the left hemisphere works. So, if you have a left hemisphere stroke, so you're right hemisphere still functioning, you're very aware of what deficits you have. If you have a right hemisphere stroke, you are completely unaware of the being anything wrong. So if you have a paralyzed left arm, which is often a consequence of right hemisphere stroke, more often than not, you will deny

that there's any problem with it. If asked to move it, you will say there, but it didn't move. If, on the other hand, I bring it in front of you and say, whose arm is this? Can you move it? They say, oh, that's not bring it in front of you and say, whose arm is this? Can you move it? They say, oh, that's not mine. That belongs to you, doctor, or to the patient in the next bed, or as in this cut, my mother.

It's extraordinary, because these are not people who are in any way mad. They don't have a psychosis, but they're simply incapable of understanding that there is something wrong here that involves them. When we look at patients who have damage not now to the right hemisphere but to the left hemisphere, do we see a pattern in terms of how they behave, what deficits they have, what they're able to do? Yes, it's really fascinating because the consequences are so obvious.

You can't speak. And sometimes you can't appreciate the structure of a sentence that's being said to you. The other thing that happens is you can't use your right hand, which is a bit of a bummer if that's your important hand. But effectively the structure of reality is not changed. That's why it is easier to rehabilitate somebody after a left hemisphere is straight enough for a right. The left hemisphere is the one that sees body parts, whereas the right hemisphere is the one that sees the body as a whole. It has something called the body image, which is not just a visual image, but an integrated image from all senses of the body. But I've been looking at all the interesting neuropsychiatric syndromes,

many of them described by Oliver Sachs, which follow brain damage, and all these quite extraordinary delusional hallucinating syndromes that most people can hardly believe can happen to a human being, happen either only or very largely after damage to the right hemisphere, not after damage to the left. So the succinct answer is the left hemisphere is to do with functioning and utilizing, reading, writing and grasping, and it doesn't really deal with the structure of reality, whereas the right hemisphere does. What about emotion? Are there emotions that tend to lateralise more to one hemisphere than the other? Broadly speaking, the right hemisphere is more emotionally literate. It reads emotional expression and it gives emotional

expressivity to a greater extent than the left, but it's not a simple matter. And some emotions to do with particularly understanding and other person's point of view, what it feels like to be that person, are very profoundly connected with the right hemisphere. However, there are some emotions that are more particularly associated with the left hemisphere, perhaps the most striking one, is anger, which happens to be the most lateralized of all emotions, and it lateralizes to the left hemisphere.

So I think it's that the left hemisphere always has an immediate task that wishes to accomplish, and if it encounters any opposition, it's dismissive and it becomes enraged. I mean, that's a simplification, but I think it works. And after a right hemisphere stroke, the range of emotions open to somebody is limited. It's mainly irritability and anger.

You obviously have an interest in music. We've talked a little bit about learning a piece of music. I'm wondering if you can bring to mind a favourite piece of music that you return to every so often and describe to me what that would sound like if I only had my left hemisphere hearing it and I only had my right hemisphere hearing it. Okay. Well part of the second movement of the Bach violin concerto would be a good place. It's a particularly beautiful piece. And it involves the intertwining of two violins accompanied by an orchestra. So there is definitely something going on at all levels.

For most of us, understanding and appreciating a melody, understanding and appreciating harmony, and understanding and appreciating complex rhythm is all served by the right hemisphere. And the bit that the left hemisphere gets is regular beat. One observation is that if you look at a score of a piece of music, if you read music at all, you see individual notes. It encourages you to think that there are separate notes. And so when we then listen to a piece of music, we think we're hearing

separate notes. Actually, we're not. We're hearing an absolutely seamless flow, in which we remember the notes that have just happened. And we already anticipate where the notes are going to come next. So in the absence of a right hemisphere we would be hearing much more point-like, punctate sounds whereas in the right hemisphere while it's getting the flow, the melody, the overall picture. And to an extent we need both, but for music it really is mainly the right hemisphere and there's a condition called amusia in which you either can't make sense of music, or you cease to understand it.

And that usually happens following a right hemisphere stroke. So it's totally interesting when you're analyzing something, you're trying to take it apart, and you can analyze a great symphony, and you can analyze it by looking at the different instruments that are playing, but you can also analyze it acoustically. You can say here are the different frequencies and the different wavelengths and here's the tempo and the beat and so forth. But really what you're pointing out is that that is not music. Music is actually the connections between them. It's what happens between the notes. It does indeed. And I sometimes give an analogy of, you know, a scientific approach to what

is music and a conventional scientific approach will be, we'll let's drill down and see what it's made of. And after eight years of expensive electron microscopy, I can inform you that music is made up of notes. What is a note? A note is a simple tone. What does it mean? Actually, it means nothing. Well, let's take another one. That was a navelat. Let's take a B. Doesn't mean anything. Now, if you put 35,000 of these together, you've got the Barthiumein

Amas. Where does it come from? Well, it can't come from the notes because you've established that they don't mean anything. So it must be something else, but all the rest is gaps. It's the gaps between the notes, the gaps that make melody, the gaps that make harmony and so on. But the gaps are just as it were silence, they don't mean anything either. So if you put lots of things together that don't mean anything, with lots of gaps that don't mean anything either. So if you put lots of things together that don't mean anything, with lots of gaps that don't mean anything, you get something that means everything. How did that happen? That's what I call betweenness. So it's the notes and the gaps, plus whatever happens when they're all added together

something new emerges. That is an idea from complexity theory. It's also an idea that is in haggle for those who are interested in the history of philosophy. So computer scientists and people of study complexity theory would call these emergent phenomena. That's right. The only thing that is about emergent phenomena is that by labeling them emergent phenomena, we think we've somehow explained them, but we haven't. We just kick the cam down the road because how the Dickens do they emerge? That's the

question that's interesting. That's not explicable. There's another domain where what matters is not sort of the individual details, but what happens in between and the picture you're painting, one hemisphere seeing the big picture, the other seeing only what is literal, what is right picture you're painting, one hemisphere seeing the big picture, the other seeing only what is literal, what is right in front of it. This has effects on things such as the world of humor. Understanding a joke requires some appreciation of the implicit, what is not being said, as well as what is being said. Here's a clip from the TV show, The Big Bang Theory, which you might not be familiar with in Britain. The character Sheldon Cooper is a caricature of the left-brain scientist.

They're Penny, how was work? Great! I hope I'm a waitress at the cheesecake factory for my whole life! Was that sarcasm? No. Was that sarcasm? Yes. Was that sarcasm? Stop it! What do hemispheric differences tell us about humor? Yeah, I love that um Well the fact is that in order to understand humor you have to be doing an awful lot of things You have to be drawing on experience you have to be understanding what's not said and you have to be making connections That are not normally made. All of this is

far better done by the right frontal cortex. And if you show cartoons to people with right hemisphere damage, they ask entirely inappropriate questions and make entirely inappropriate deductions about what they're seeing. So humour is another example of something very human and very important that the left hemisphere doesn't get. Humor is an example of something else which is the ability to understand the implicit in poetry. You can't really understand poetry by paraphrasing it. Any more than you can explain a joke and expect it still to be funny. And that's very close to my heart because I used to work in the area of English literature. And in brief,

I left it partly because I loved poetry too much and it seemed to me that these entirely implicit, unique, embodied creatures, the poems, were being turned into explicit, general, and entirely abstract entities. So I thought this was a destructive process. I wrote a book called Against Criticism and went off to study medicine and become a psychiatrist. So this would be, give me the 600-wards summary of Macbeth and as in assuming you basically have understood Macbeth. That's it. Yeah, yeah, yeah, yeah. Or yes, there are six points you need to know about Jane Austen and they are, whatever it is, you know. And being able to translate a poem, reduce it to some incredibly banal ideas that you could have found somewhere else. You know, you take a wonderful poem by Hardy that he wrote after his wife died.

And to me, the times and flinching rigor in mindless route has ruled from sight the substance now, one phantom figure remains on the slope, as when that night saw us a light. I look and see it there, shrinking, shrinking. I look back at it amid the rain for the very last time. For my sand is sinking and I shall traverse all loves to main, never again. I mean I can never read those poems 1912 to 13 without tears. But if you ask me what do they say, I'd say it's very sad when somebody you're close to dies and you sometimes have regrets. That is not going to wash. Ian has a broad thesis about the brain, but also a broad thesis about how these differences

might affect our daily lives. Increasingly he argues, we live in a world that prizes what the left hemisphere offers and has contempt for what the right hemisphere brings to the table. When we come back, I ask Ian about what happens when the emissary usurps the master. I'm Shankar Vedantam and you're listening to Hidden Brain. This is NPR. This is Hidden Brain, I'm Shankar Vedantam. Ian McGill-Christ is the author of the Master and his Emissary, a book about the divided

brain. He uses research drawn from patients who have brain damage to one hemisphere or the other, and patients who suffer from serious mental disorders. Ian argues that the left and right hemispheres of the brain have competing visions of reality, and that increasingly we live in a world dominated by the left hemisphere. I asked Ian to imagine a world where all of us only had one hemisphere, the right. What kind of a world would that produce? The right hemisphere, if it were really without the left hemisphere, would see a lot of connections between things and would see a broad picture.

But it might not be so good at focusing on details. Emotionally the timbre might be somewhat melancholic and sad because I think it's one of the aspects I'm afraid of the right hemisphere's realism and sympathy, a capacity for empathy, that it does feel suffering. We would not be able to make calculations in the same way. Most arithmetic calculations are made by the left hemisphere. So we would be good at coming up with the ideas, we might not be good at actually sort of carrying out the nuts and bolts and getting it working as a machine.

Now, let's run the opposite thought experiment. What if all of us just had only a left hemisphere, what would that world look like? Well, obviously we would lose sight of the big picture, that's the thing I've emphasized throughout. There would be an emphasis on the details instead. There would be a great emphasis on predictability, organisability, anonymity, categorisation, loss of the unique, and an ability to break things down into parts but not really see what the hole is like. There be a need for total control because the left hemisphere is somewhat paranoid. After a right hemisphere damage people often develop a paranoia.

And that's because we can't understand quite what's going on and one needs their water control it. Anger would become the key note in public discourse, everything would become black and white. And that's because when you can't understand quite what's going on and one needs their thought to control it. Anger would become the key note in public discourse, everything would become black and white. The left hand is the only need to be decisive because don't forget, it's the one that's catching the prey. It's no good going, well yeah, it could be a rabbit, but it might not be. It's going to go, I'm going to go for it.

So it likes black and white, it doesn't like shades of meaning. So in this world, we would lose the capacity to see grades of difference. We would misunderstand everything that is implicit and metaphorical and have to make rules about how to achieve it. And it's your contention in some ways that the world that we have come to live in is a world that increasingly looks like that latter picture. I think what I observe is an over emphasis on predetermined systems of algorithms. The sense of social alienation, the way in which we live

divorced from the natural world, which is a very new phenomenon. The insistence on extreme positions, which is what the left hand is for understands, not a nuanced argument about the pros and cons of every single thing. Meaning comes out of living in a consistent culture where there is a sense of connection with one's past and not just one's own past but the past of the people who made you who you are, with the other people in the society to which you belong and to the world at large,

the natural world and things that are just simply beyond our can, the transcendental. These are very important things at the right hemisphere is much better equipped to understand, and I feel that the loss of them in modern life is grievous. One of the unusual things about Ian's book is that it has detailed passages about neuroscience followed by discussions about thousands of years of art and music and literature. Ian argues that we have come to live in a world that prizes details over the big picture, what is literal, or what is metaphorical.

He then tries to show how these changes play out in culture. One criticism of his book by other scientists is that it steps off the ledge of science when it ventures into polemics about art and culture. I asked Ian what he made of that criticism. Well, I'd event how you look at it if you look at it with your left hemisphere. It makes sense. If you look at it with your left hemisphere, it makes sense. If you look at it with your right hemisphere, it's nonsense. I mean, I think what it shows, and it's made typically by a certain kind of scientist who is not generally somebody who's interested in the big picture. Now, in the past, scientists couldn't leave school without having

read quite a lot of history, literature, and even doing a bit of philosophy. Nowadays, it's possible to be crammed with technical information and leave them going to an entirely technical scientific subject. So in the past, scientists tend to take a humanistic view. They saw the import of their work in a broad context of human life. But if you spend all your life looking down a microscope at a tiny detail and hardly even know much about what's going on in the next cubicle to you. Then somebody coming along and saying, this has something to do with human life is very odd. But if you actually think that researching on the brain has got to have human implications, because excuse me, the brain

is something that makes it possible to be human being, then you know, it's bound to have human implications, because excuse me, the brain is something that makes it possible to be human being. Then it's bound to have implications. So I just think it's a feeling of discomfort as they would put its strain off the field. So let me push back on you just a little bit, because I think there's an interesting rhetorical trick here. You're essentially saying that some of the people who criticize you are criticizing you because they're overly reliant on their left hemisphere. That

does come a little close to basically saying that if you criticize my idea, there's something wrong with your brain and that essentially seals you off from criticism, doesn't it? Well, no, I don't think it does. I know it looks like that and I do accept that there's no way round that because I, what I'm really pointing out is that I think that if you do take an arrow view, you will object to it. If you don't take an arrow view, you won't. But it's perfectly possible to criticise my thesis coherently. For example, you could take any one of the contensions in many areas across the board to do with say the appreciation of metaphor or creativity

or facial recognition, and you know there are at least 20 of these. And you could say, now I look at the research, I find all these things and you don't take them into account at all, you're wrong mate. And then I have to go, okay, or can I point you to this and I think that I can make it go here. This is a sensible, rational conversation, but just to go, if you talk about things I don't know about, I'm going to tell you you're not welcome in the club. But that's not good enough. So the book is in some ways a criticism of our increasing love and reliance on models. But as I was reading the book, I did

notice that you yourself have built a very complex and compelling model here. Have you ever wondered whether you yourself might be captive to your left hemisphere and you potentially now can see the problems with your own model? That's a very good point. It's not, I'm not critical of models actually, in themselves, I'm critical of particular models, because in fact we can't understand anything, this is one of my basic points, except by having a model with which we compare it, so that is always a limitation. We don't move from a world in which we have models, to a better one, in which we don't. We move from a bad model to a better one image we don't. We move from a bad model to a better one. So every model has its limitations, but some form simply a better fit, and that is what the progress of science

is. It's always what I would call a Gestalt. Does this Gestalt, which is an overall appreciation of our whole, rather than nitpicking it little details, does this generally speaking answer better to the picture of reality I have and does it answer some questions that were not answered under the old model? So that is a perfectly good question to ask. I'm not blind to the problems of it. I'm open to and desirous of dialogue with people about its virtues and its vices. And if there are vices and they undoubtedly have to be, then I appreciate being able to alter my model to incorporate this new information.

So that is how science progresses. We talked a little bit about some of the critics that you've had, but I also had a question about some of your admirers. I mean, your book has had a considerable amount of success. It's been very well received, but I do wonder whether some of the people who like the book, like it in some ways because it allows them to say, you know, the reason I'm not successful at work is because, you know, I'm a right brain person stuck in this workplace with all these left brain technocrats. And it's really a way to sort of bring back the left brain right brain person stuck in this workplace with all these left brain technocrats and it's really a way to sort of bring back the left brain

right brain pop psychology this time with FMRI studies. Do you worry about that? I think what I'm saying could be obviously misused by people who want to deceive themselves. But I do also think it may open their eyes to something that is real. For example, I have cheated many patients who come into the consultation and immediately put down a mobile phone, a pager, and a third electronic appliance. And I can sense already what's wrong with them.

And many of my patients, I say to them at the end, you know, it's not that there's pathology in you, it's that there's pathology in the workplace, in the corporation for which you work, and perhaps in the society to which you belong. And so I don't want you to approximate yourself more and more to what is demanded of you, because it is inhuman, it is dehumanizing, and they wonder you're feeling a bit depressed. And to be fair, what most people say to me, and I get people writing me from all walks of life all the time saying, you describe what I'm experiencing at work. What they say is not, you've suddenly explained, you know, what I don't like about my job. What they say is, you've given me a whole new view of my life. Some people say you've improved my marriage. You've made me enjoy my work better. And you've confirmed to me, this is a very common thing.

You have confirmed to me something that I knew at some level, but I just didn't have the language to express. You have helped me articulate it. One of the things that's really important to mention again is that even though so much of your work is a corrective to our over-aliance on the left hemisphere, you are cautious to separate yourself from those who would say the worlds of science and reason are expendable. That those worlds don't actually give us anything of value. Oh, absolutely the opposite.

Absolutely the opposite. I love science. Since a child, I was captivated by science. I depend on science in my work, and I depend on scientific discoveries for my life. The argument in my book, as people have pointed out, is sequential, analytic and rational. In fact, people say, it's quite a left-hand, it's a book. And I say, good, I hope I use both my hemispheres in writing this book, because if not, it wouldn't be a very good one. So we need both. And what I feel is that science

and reason depend on a balance of these things. There is a distinction to be made between rationality by which I mean the mindless following out of rationalistic procedures. And what I would call reason, which since there are naysaws, has been exalted as the mark of a truly educated person, which is to make balanced, informed judgments, but not just informed by data, but informed by an understanding in the whole context of a living being belonging to a vibrant society of what this actually means. In other words, judgment.

Judgment has been taken out of our intellectual world and replaced by something a machine can do. And that may look good to a certain kind of way of thinking, but I think it's a disaster. The right emissary sees the need of the left. That's in the image of the master and the emissary, the master knowing the need for the emissary, the emissary not knowing the value of the Master and the Emistry, the Master knowing the need for the Emistry, the Emistry not knowing the value of the Master. And if I may use a quotation from Einstein, I think this gives us the full picture. He said that the rational mind is a faithful servant. The intuitive mind is a precious gift. We live in a society that honors the servant, but has forgotten the gift.

Ian McGill-Cris is the author of the Master and his Emissary, the divided brain and the making of the Western world. A new documentary about his book has just been made. It's called The divided Brain. Ian, thank you for joining me today on Hidden Brain. It's been a huge pleasure, thank you. This episode was produced by Raina Cohen and edited by Tara Boyle and Jenny Schmidt.

Our team includes Parth Shah, Thomas Liu and Laura Quarral. MFA Agawu performed the Debussy piece. Kevin Beasley read the Thomas Hardy poem. Alex Curley and Lauren Landau performed the scene of the doctorate patient. I'm Shankar Vitaanatham. See you next week.