« Making Sense with Sam Harris

#247 — Constructing Minds

2021-04-21 | 🔗

In this episode of the podcast, Sam Harris speaks with Lisa Feldman Barrett about the origins and function of the human brain. They discuss how brains evolved, the myth of the “triune brain,” the brain’s network organization, the predictive nature of perception and action, the construction of emotion, concepts as prescriptions for action, culture as an operating system, and other topics.

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This is an unofficial transcript meant for reference. Accuracy is not guaranteed.
Looking to make your search bar cast This is SAM Harris just a note to say that if you're hearing this, you are not currently on our subscriber feed and we'll only be hearing the first part of this conversation in order to access full episodes of the making sense, podcast you'll need to subscribe at SAM Harris Org. There you'll find our private rss feed to add to your favorite podcaster, along with other subscriber only content. We don't run ads on the podcast and therefore it's made possible entirely through the support of our subscribers. So if you enjoyed we're doing here, please consider becoming, as always, everyone money to be the reason why someone can't get access to the past
you can't afford a subscription there's an option at San Aristotle or to request a free account and we grant a hundred per cent of those requests. No question: tens. Ok, some housekeeping today, I have a new podcast to announce a single episode which we will be dropping. I believe, Friday of this week, if all goes according to plan, so look for it in your feed on the twenty third of April. The title of this episode is engineering the apocalypse and it was produced. My friend Rob Reed. Who is a caste and author also a tech entrepreneur. I met rob at the TED conference some years ago and then he started his own podcast, the after on podcast
Any interviewed. May I think, for the first episode there I fell is probably the best interview anyone had ever done of me. So we heard that here on making sense completely title with E F IRAN interview anyone the intervening years Rob has gotten very, interested in existential risk and, in particular, the risk posed by advances in synthetic biology. Which were very will lead to an engineered pandemic, but everything he says in this podcast is relevant to a naturally occurring pandemic like the one we are currently suffering anyway. This is a deeply researched. And by turns Heroin and hopeful look advances advances in synthetic biology? It's broken into four chapters, which are separated by interstitial conversations that,
have with rob anyway. I thought the job he did was fantastic pandemic preparedness has to be a huge priority for us going forward and dumb This is our best efforts to argue that it really must be covered has been a dress rehearsal for something far worse and as such, it has been pretty much an unremitting it'd disaster. We may have lost sight of this, given how successful or vaccine production has been, how the roll out has wrapped up but our response to cover it, Particular our failure to organise a globally coherent response was just a terrifying failure: terrifying, given how much worse a pandemic can be and how much worse is likely to be if it ever consciously engineered. So anyway, this upcoming podcast will be dropped as a single.
Episode. That's nearly four hours in length and again the title is engineering, the apocalypse and, needless to say, your release in that as yet another PS aim, which is to say the whole thing, will be freely available. But of course, if you find this work valuable, the waiter support it is too subscribe. And Aristotle work and to coincide with the release of this podcast, the waking up nation will be given to significant grants to relevant organizations that are working on the front lines of pandemic preparedness, as many of you know from my conversations with
the philosopher: will mechanical I've been thinking more about how to effectively do some good in the world? In addition to just talking about what is good to do so, we formed the waking up foundation for that purpose, and at least ten percent of the corporate profits of waking up go. There asked as a minimum of ten percent of my own income and the foundation works as a pass through to other organizations, so a hundred percent of the funds leave it and go elsewhere, and so these next nations are focused on this problem of pandemic preparedness in this vein, were supporting the centre for communicable disease dynamics at Harvard University, which focuses on improving our methods of understanding the data around infectious disease, and it engages policy makers to improve their decision making, which often leaves a lot to be desired, and the second organization is the coalition for epidemic preparedness innovations.
The cepi whose whose mission is to accelerate the development of technology technology, their funding, new platforms we can develop vaccines even more quickly than we did for Covid, and really do it just in time in response to a a novel pathogen, which is precisely what we're likely to face in the case of a synthetically engineer pandemic. Now neither of these organizations are set up to take small individual donations, but if you're a philanthropist, and you want to come along with us in helping to improve our pandemic preparedness and was certainly encourage you to support these organizations once again. Its assent for communicable disease dynamics at Harvard University and the coalition for epidemic preparedness, innovations and I should say that the waking up is get in great advice on this front from Natalie Cargo of long view philander.
This is an organization that advises individuals and foundations who want to deploy significant funds solve long term problems, and I was introduced to now. Lay through Wilma Castle and I've been extremely. Impressed with the research that they've done at long view and the clarity of their advice, all of which is given free of charge. Long view is independent. We funded. So if you're running a foundation or you're a wealthy person who wants free advice about how to give most effectively. I highly recommend that you get in touch with the people at Longview DOT Org Again, this is not a recommendation for small donors. I believe in to be giving away at least a million dollars a year before long view can help guide you but for those of you who are in the philanthropy space, I recommend you get in touch, but it nor in individual donor, and you want a ride along with me. We will be,
detailing all the orgs. We support at the waking up foundation once that website is launched, and on that point I want- The making sense audience has been fantastically generous in the past on the occasions were, have discussed specific nonprofits on this podcast. The people who run them always come back astonished at the result. To give you just a couple of snapshots here, Give well dot org reach out recently to say that, just by my mentioning their organization a few times on the spot cast, this is the group. Does exhaustive research on the effectiveness of charities and recommends what they consider to be the most effective ones in several categories, mind discussing their work, a few times once with will mechanical resulted in you guys donating one point.
A million dollars through them directly and pledges another one point: eight million in recurring donation. So as three point six million through the end of this year, and Wilma Castles organization, given what we can, which was started by Toby ORD, who has also been in the past, has told me that, in response to my discuss, in their pledge is the place to give a minimum of ten percent of one's lifetime earnings to the most effective charities. Would you Do it any level, whether you're, making thirty thousand a year or thirty billion. I am told that my discussing this path, with will caused hundreds of you to take this pledge yourselves. And after waking up became the first company to take the pledge. Ten more companies soon followed now, how much money to the most effective charities this represents, but
it. Surely many many millions of dollars, I believe, given what we can just past the two billion dollar mark in lifetime earnings that have been pledged anyway. My point in mentioning this isn't to brag about the influence of this punk asked, but rather to convey my gratitude and astonishment frankly, I just amazing to see the knock on effects of discussing this things anyway. I will keep you informed about this, but turned this just to let you know that over waken up and here at making sense, we have transit, and into doing more then just talk about specific problems, we're marshalling our own resources to try to do some good directly ourselves. Ok,.
Today, speaking with LISA Feldman bear it. Who is one of the most cited scientists in the world for her research in psychology and neuroscience she's, a professor at northeastern Universe, with appointments at Mass General Hospital and Harvard Medical School, LISA was order. A Guggenheim fellowship in Neuroscience in twenty nineteen Andrews, a member, the American Academy of Arts and sciences. And the Royal society of Canada and she's the author, most recently of a very enjoyable book, seven and a half lessons about the brain and recover a few of those lessons in today's pond ass. We talk about how the human brain evolved the myth of
Try Une brain, which has been all too influential. We discuss how the brain is organized into networks, the predictive nature of perception and action, the construction of emotion, concepts as prescriptions for action, culture has an operating system and many other topics and now that further delay. I bring you LISA Feldman Barrett
I am here with LISA Feldman Barrett LISA Thanks, rejoined me it's my pleasure, so you ve written this wonderful little primer on the brain, seven and a half lessons about the brain, which I think will be the focus of our discussion. Although a properly wander to other topics, but damn I just stir among our listeners to know that this is a m marvellously accessible book and a short one is only four hundred and thirty pages or so, and I you know with, we need more of this kind of thing. It said, there's this some awful property of the brain and am neuroscience generally, which is when you get into the details. It becomes.
Just a catalogue of anatomical names that her were certainly not written by by writers, the especially ones who wanted to write books for a general audience, and it becomes this blizzard of chronic challenges for a reader and eat. You have managed to avoid all of that and still deliver a very interesting discussion about the brain and the mind. So, congratulations. Thank you. So much so we jump in. Perhaps you can summarize your background, intellectually, what kinds of questions have you focused on as a scientist? Well, I
you know I started my training as a clinical psychologist and then very quickly went through a series of retraining in physiology and then in Marseilles and more recently in engineering learning, some thing about systems theory and, in addition, area and development, all aspects of neurosciences. So the questions I really think about now relate to your hat, and how is the brain? How is your brain in constant conversation with your body and the other brains and bodies who know that surround you? How is it conjuring the features of your mind? How does it control you're the internal systems of your body at the same time? Is it controlling your behavior and giving your memories and thoughts and feelings and so on, and that may sound, like you know too big of a question to answer, but I
say I'm really interested in understanding a systems, level kind of approach to to brain function, and that encompasses a lot of things. So I have a large a largest lab and we have a lot of different research projects going on. So it's really hard when someone asks me. So what are you? What is your newest research project? Don't like? Well, we have like, probably forty of them, going so far this it's hard to summarize in one sentence you kindly professor is well right. Do spend some time teaching us at all research. At the moment, I know, we're talking covered, landed at that and one of the carbon pandemics or nothing seems normal. But what is your general lifelike? As professor yeah so I run a lab which has twenty five full time. People in it
and then usually, we have not yet covered, but usually at other times. We have about a hundred hundred and fifty undergraduate researchers at researchers in the laboratory in any given year and the lavish spread out across two different places. So I have personnel at a tune from places graduate students, post, docs and so on will start to fellows. I teach one course a year for undergraduates its allowed course and then occasionally. I will also teach formally teach graduate seminars But I also run a weekly or now biweekly I'm an are that I've been running for but eight or nine years, that I dont get in credit, for we just do it out of the love of doing it with engineers and computer scientists and other scientists and psychologists
so I and another, and my colleague and engineering we run this seminar for Oliver keeps so it's about twenty five people who attend the seminars and has been going on, like I said, for it for quite a number of years, and then I also run other reading groups that people attend on particular topics depending on what were interested in so, for example, fur. On predictive processing or on energetic switches at the word that we used to refer to brain metabolism and the other waited the brain is regulating the metabolic functions of the body, So one of the things you do throughout this book, especially at the outset, is A few myths and bad metaphors with relied on to understand the brain or WAR
seem to understand. The brain and dumb seems like a very useful thing to do. Perhaps we should just start where you start with the larger context of evolution and what we think we understand about the evolution of the human brain. What are in, and perhaps this is a good place to part company with Palma clean. So how do you think about the brain? In evolutionary terms? I love this question. My think this is one of the most fun questions really it occurred to me at some one point like: why are we even have a brain? It's it's a really expensive organ right that three pound blob of meat between your ears costs you about twenty percent of your entire metabolic budget. So it's pretty. Spencer Andrews Point out, depending on what you do with it and cost you much more than that, It certainly again, especially social media, certainly can lead us,
we right and so I'm very fortunate in that I've been we meeting really weekly with Barbara Family, who is an evolutionary environmental, neuroscientist and she's. Basically, you know these her words she's, like downloading all of her knowledge into my brain, which really means that she repeats herself frequently and has to explain things often more than one time, and this is pretty pretty young not make about permanently pretty heavy stuff. It's pretty complicated, you know I had to learn, embryology and you know barely understand what I'm reading, but I understand a little bit now. At least the really cool thing I think, is that if you go back you know five hundred and fifty million years ago to a time in the earth, history called the carrion animals didn't half brains, and I was really interested
to try to understand why you know why did brains evolve, and SAM. You know you ve never really answered why question very easily and evolution, but certainly can answer one question so like what is the brains most important job? What is a brain will be good for and you can look, at the evolutionary when the English restoring that that molecular geneticists and anatomists, and so on. The ecologists have have crafted and it's a really cool and interesting drama, and it. What it suggests is that your brains, most important job, isn't thinking or seeing or even feeling. So these are characteristics. These are features that the brain performs,
continued, but they're not actually the brains most important job. Its most important job is regulating the systems of your body, your heart, your lungs, your immune system. Here you know and a consistent and so on, and of course we don't experience every delight, were you know every drama in our lives. This way we down experience every kind. Were used to get before covered every insult that we bear. We know we don't experience things these way this way, but this actually what is going on under the hood and when your brain thinks and decides and seas and hears and feels its doing this in the service of the regulation of your body, and that turns out to be a really important
I would add one peace here. I know you are not recovery. Put it this way your book, but it does strike me that, just by the the logic of evolution, The motor behaviour is in some ways primary here, because you can't move if you can't do anything with a brain, if there's no way that it can influence, see, differential success of an organism in in the contest for made sir or survival. Then there would be no evolutionary pressure in this direction, so it seems to presuppose an ability to do something with respect to the environment. I don't think it's a bright line between that story in the story of regulating the internal state to the body with it will get to that. But don't you see an ability to actually act in some way as being the necessary contacts for that
evolutionary pressure. Absolutely in fact really. You know, I guess I'm very persuaded by motor neuroscience and certainly in philosophy. The idea that motor motor action is primary and everything all sensory processing is in the service of motor and I think, that's absolutely right. The one thing I would say, though, is that you know in invertebrates certain all vertebrates, certainly and in in I would maybe hazard to say all animals who have whims that move or parts that move. There is usually an internal set of systems that support that movement. Now, invertebrates, you know like us, that's you know according ask your system and respiratory system and so on,
you know not all animals have the kind of viscera that we have that vertebrates out so invertebrates. You now have their own systems, but There is no extra movement of bodies without internal systems to support that and in modern neuroscience. As much as I respect that work- and I really do, I think, they're really ahead of the curve in certain ways they did and ignore the internal Sense of animals bodies, and I really think that that's an important part of the story that is missing so when I say you know that the brain is right in the body I really mean ever The thing motor about the body that would include what we call visceral motor, which means the beating of your heart and the contraction of your lungs and so on. But it also means the movement of yours. Eleanor Motor system them your muscles monetary movements of your muscles, and, in fact, if you look at
example, primary motive for tax in he Brain and Lecoq brain it has this remoter mass maps in it and some of them regions that are considered to be in house services asian regions for the motor system are actually primary cortical controllers, a visceral motor regulation, regulation of the viscera of your lungs, in your heart. So, and so, your brain, the internal systems of your body, the losers, though the neurons are controlling interest, if your body and the girls that are controlling your skeletal motor system, the you know you're voluntary Muslim. We are really intertwined. That's not well documented motor, neuroscience work, but it's present in the anatomy. You can just see it. It's there,
we'll talk about emotion, but I tend to think about emotion now as a kind of covert behaviour. Writer, the line between emotion and action- that is, some commonsensical, I think, can break down. If you follow that framing but tell us was not leaped emotion, just yet the evolutionary story we have told ourselves for a long time has been no summarised by this. Concept given to us by Palmer Queen of the Une brain, and I use of people refer to there. Their lizard brain our they think of a step, wise evolution from reptiles, two mammals generally and then to primates as having been climbed up from the brain stem to the cortex. What's wrong with this picture? Well, what's wrong with that picture is that it doesn't really matter the best available scientific evidence for how brains about
I mean if you look at a lizard brain and say, manual brain like like see, em a rat were a road and brain say, and you will the monkey braided human brain now, they look different to the naked eye, It looks like the rat diversity. It looks like it will say the lizard doesnt really have much of a cerebral cortex it. It looks like the round has you maybe a little bit of of old cortex and that the monkey and the human have quite a bit and the human having you now substantially more than the monkey. That's how it looks to the naked eye This led Palmer, clean others. You, I did by, I think, certain cultural beliefs to describe
brain evolution in in much the way that you just described it. Although your description and slightly more lyrical man, maybe what Maclean Rob. But you know the idea, a lizard brain is mostly has parts for instincts freezing and fighting and fleeing and calculating which you know neuroscientist make make of funny jokingly. They refer to it as the four hours. That's no humor for you and then layer on top of that evolved. What's called a limp dick system, Limburg, meaning border bordering this. You know why these lizard parts for emotion- and then what leg and then what about? On top of that is the cerebral, cortex, The need for tax, the new part of the cortex, which you only in what are referred to as higher
mammals like us, and the idea is that You know your lizard brain contains your instincts. Your olympic system contains your emotions and then these are these, make up your inner beast and they are called we in battle with the more rational side of yourself, which resides in Europe through because so your brain is a battleground between your inner beast and your rational self. For control of you heavier and the idea is that you know when you were cortex winds and you behave rationally, you're a moral person and your healthy and if you're in a beast wines,
to control your behavior, then you're either immoral, because you didn't try hard enough or you're sick because it didn't work on it that there's something wrong with your with your rational cortex and the problem with this, It makes a lot of sense in terms of our stories that we tell ourselves about what it means to be moral and responsible for behaviour and its use very consistent with western views of the south. The problem is that it doesn't actually have the evidence that, when you pier into neurons and you get a molecular structure in particular. Do you know that the genes that guide the formation and function of of those neurons you, you see a really really different story? The story is that really all mammals, Hoover whose brazen ever been studied, actually their brains, follow. This
same developmental plan the neurons surely. There are no new neurons, really no new Nora types and remarkably, the stages of development, and I'm talking about your embryological development forward. The stages of development in in all of these mammal brains, but have been studied different species proceeds in exactly the same order, pretty much it what's. What changes is the duration of each stage and there's this really interesting observation that George Street her though the neurobiology us made about brains in his book and brain of Lucian by the way absolute book. If anyone wants a primer on in a brain of illusion, it's it's a really fantastic. Button. You know she says, brains, reorganizes, they grow larger, and so we can look like there are new structures there. Just me,
as there are more of certain neuron types, but actually the in others: nothing new in terms of the neurons, it's just there. They look like their reorganising. They look like there are miraculously new parts there, but there are really no new parts is just that certain types of neurons have- certain stages in development of gone on for longer, and so there are certain types of neurons there's just more of them and if you go back even further and you look at other animals other vertebrates, you see that many of them have. So really striking similarities to them. Two mammalian brain. So, for example, birds, don't have a stable cortex, but they certainly have neurons are the same as the neurons that make up our cerebral cortex and that seems to prefer some very similar functions to what our super court at the various functions are cortex perform. So basically there is no. You know
lizard brain, you don't have an ancient beasts lurking side. Your brain and the only animal who has a little brain is a lizard. Are there any exceptions that I've thought that term VON economy neurons were an exception that they were just? They were present in great apes agenda? I think cetaceans and elephants, and a few other, your charismatic vertebrates, but were not found in in reptiles, her birds or so VON economy under answer very contentious hurrying there, there are some anatomists who will tell you that animal neurons are not a special class of neurons they're, just really big honking pyramidal says so you find them in large friend animals, because you know as raise get bigger. Sometimes the neurons also get bigger, and you know one thing that happened
example in large brain animals would often happens is that there are certain parts of the quartet in particular that as they grow. What an evolutionary, but also in development, what happens is not that they develop more neurons, but they develop fewer neurons that get much bigger and they have much more connectivity. And the reason for that is the reason for that of the functional consequence of that is that we something I explain in as seven which is that it means that the animals brain can summarize information much more efficiently and maybe even do some abstraction, meaning can find similarities in things that look and feel and smell and tastes different, find functional similarity. So this is abstraction. This is what we call abstraction right, and
That's really you don't baby. What these very large pyramidal neurons are forbidden. There The not too distant and some nursing as you will get one I'm? On neurons able? These are just ordinary big? You know Are there not there's nothing really special about them and you find them in animals who have large brains relative to their body size? So what is the appropriate picture of the structure of what we have in their if it's, not this cartoon of dissent from reptiles? What pick of complexity and end here now leading the witness network complexity. We should we have in our heads I'm going to ask you a question, but I just want to take one step back for a minute and say that you know we.
Live in a world where we see objects, and we we see boundaries between objects. At you know like here is a book. Here's a purse, here's a computer, here's a glass whatever, and so we have a tendency to think about things in terms of objects instead of in terms of relationships. Between features and so for a really long time, people have thought about the brain ass having these distinct parts. You know like there's this group of neurons called the major language, performs emotion and there's this other group. You know called the bees ganglia, which forms you don't movement and then there's the southern part called the cerebral cortex and the prefrontal part of that really performs decision. Making or rationality would have you and that's just mean our people, who still pulled that view in and it certainly, people are built a whole careers on such notions and and been very successful, but
I think there's also a growing understanding that that's really not how the brain works. It's not how the brain is structured. There are no objects here. There are no amendments the organs in your brain? That's just not we the way, that's just not the best way to understand the announced, we were the function and that instead we should be understanding, neurons in terms of their relationships to one another and the features that they compute, and so there really didn't. Listen take many forms in published papers there are signs, but one, that's very part. Look at the moment. Is to think about the brain thing about you: on as a large dynamically fluctuating network, and so, if you think about
You know, instead of thinking about neural signals as being passed from one region to the other, like a baton in a race you can think about neural activity and the patterns that are created more like weather. Or something where you know many many many neurons are participating in. Peering an event that has a set of features and some of those features are, you know very close to the data that you get from your sensory surfaces, like you're Ratner in your cochlea and all the sensory, all the sensors and inside your body, you know, like a line for example, were color like the color read your experience of the collar red is a feature that your brain computed doesn't attacked, as you know, and its computing it using
information from not one color detector. If you know what a so called cones ingenuity of three new comes in the cells in your retina that register three different ranges of wavelengths of light, and you need all three to see read were green, were any color, and so your brain computes these features, and it it also computes features like like seeing a face. It competes features like threat, it competes features like novelty, it competes features all kinds of feed, and in given advance your brain is sort of computing sequences of events and in computing an event would its duties. Computing features in the service of right waiting, the body regulating action and the all the vizir all the changes that will support that action, and so do you think about it. Is your brain is a single structure
with you and twenty eight billion neurons give or take, and it can take on trillions of patterns and these patterns are, you know helped along by the chemical bath that surrounds these neurons, so you're neurons are bathed in a chemical system and an it's just treat your brain is basically danger agree along a trajectory from one pattern to another pattern, to another pillar, to another pattern and trying to understand what launches those patterns. What maintains those patterns? What features your brain is, you is computing, that's really goal of understanding, brain function, Yoda also just point out that the methods we use to understand brain function like increasingly functional neuro imaging, can also give ay a false picture. Of the module airily of the brain,
therefore the mind, because he either way to just by the nature of the tool that we look at the data in terms of these pretty pictures of certain regions of the brain, so called lighting up in response to stimuli or tasks, and I can give a sense to not to actual neuroscientist generally, but perhaps in a more subtle way. I can even corrupt their thinking, but it's early He says to the general public that this is a question of other areas of the brain actually not doing anything went. They're, not part of the illuminated map of in a what is most active during a certain functions, so you can just give this. This false picture of separate organs in the brain that are I'll be connected are really independently responsible for an emotion like discussed, say or a certain kind of
perceptual task and you just can't visualize the network behavior and the fluctuating network behavior in the in the waiting between nodes in the network as easily as you can just aggregate the data by subtracting in a Tuesday to the brain and showing one hundred and twenty one wear. These for more active and then in the other? Yes, I know, I think I mostly with you, but I will I would probably just pushed back. Maybe a little bit on a couple of points one. I would say it's not the father of Brain imaging techniques, it really the fault of the analysis, techniques that we use and the sample size as we have, though I would say that Whenever I hear everything has its problems for sure it's, it has limitations in terms of its temporal. We know resolution and also even some spatial resolution issues
really it has. It has much more to do with the kinds of designs that scientists use and the kinds of analytic techniques that they use and I'll. Give you a really good example. There is a where I think of as a brilliant Elliot Paper that was published in the proceedings of the National Academy in two thousand twelve. The first author is Gonzalez Castillo. And it's this really nice paper where they, you know, compare the sort of standard Me, no experimental design really for a very, very simple task: Which is why I believe it was a visual visual perception, tat, maybe vigil orientation. I think it was, And the very very straightforward house of visual attention task and When you run, you know some subjects,
you you have- maybe you know forty fifty two hundred trials were trial. As you know, you show something unexpected to the subject in their name. You know they have to make a judgment of whether you analyzer pointing in the left direction on the right track what have you what you see in the end, the waiting offices is done, the way that choices, analytic choices are made to separate signal from noise and someone, you see, a couple of islands of that of of increasing activity that are depicted brain image as like spots that light up like the library, UNICEF, and it's important to really understand here- that these women, is that we see in magazines and internal articles and so on are curated by scientists. They don't just pop The data on their own there made contingent that
images are contingent on a bunch of analytic decisions that are made now. If you expect that There are I ll ends of activity because you know different parts of your brain are responsible for different, specific psychological functions and that's what you expecting you designed your study that way, and you ve only you know, tested your subjects on fifty hundred trials and you threshold others make decisions about signal versus no, in particular ways. What you get are a couple of islands of activity. However, with this paper show, is that if you run four hundred trials for each subjects, so you bring them back from multiple scanning sessions. And you analyze the day, in a slightly different way by instead Assuming that every of the brain, has better that, though the shape of the the response is the same.
Aim and instead of assuming that you model, you know this the very ability and how the different parts are responding. What you see is that eighty five percent of the brain shows an increase in activity. That means eighty five percent of the brain, is showing a change to make a very, very simple decision that is considered yet. So the point is that if you're part of your studies are designed in a way that is underpowered you're not come to realize that you're making at what we would call it take to error, which is that you're missing a lot of important activity, that's their because you know your expecting to see blogs and what you get our blogs. And so, if we expect is islands activity, you perform your studies. You know something I used to call blob ideology, which is that you know you identified his blood,
Actually, I think people to realise that these these images are really curated by humans who have a sort of assumptions. I ll just give you one really quick. Example in that, as you know, when people started looking at networks in the brain, so this is some regions that are have correlated with where the brain Bonds is correlated so the young. If you take a brain and divided up into lots of little cubes called axles and say you look for sets of boxes that have a similar change in blood flow during an experiment and he called out a network and internet you know this actually does reveal something about the underlying structure of the brain. But when you look at the way that scientists mostly study these networks there, they look like Lego blocks like they're, completely unrelated to each other and, like, like you, know, pieces of a puzzle and put them all together and
Break, but you know that's a decision, those computational decisions that are made on personnel in it. You don't choices that are guided by certain, if you do the analysis slightly differently, which is what we did so we took in almost a thousand subjects, and we, instead of asking musing, out of standard way of looking for signal and noise. We said: okay, anything which replicates from one subject to another is signal by definition and anything which doesn't is noise, and so, let's just try to power ass. You know, networks in the brain. By doing this, and what we found was tat. We found that the sort of networks the people often talk about, but they're, really they overlap tonight they're, not disconnected. There actually overlap in the overlap in in particular region of the brain, which are known to be their call, Hobbs, are rich club, Hobbs, meaning densely connected regions that are responsible for
Really coordinating activity across the whole brain there call you know these risks has recalled the backbone of neural communication in the brain. There's really nice paper by less foreign and abandoned evils, warns eddies vending evil and sports in two thousand thirteen in the Journal of Neuroscience, and so My point is that these images that you see the beautiful and awe inspiring. Their curated by humans, who have a set of assumptions
yeah and its also easy to see the temptation to think in those terms, because when we have something like a hundred and seventy years of neurology attesting to the fact that highly focal lesions brain damage can lead to very specific deficits again, this can be understood in network terms. But it is in fact descriptive really true that you can have a small region of the brain damage and that can dissect out eight a very specific mental capacity in a language user and ability to recognise, faces or or even to recognise, specific classes of objects. Like me, no tools, verses animals, and that's that does give you this sort of Jigsaw Puzzle, like Lake alike, intuition about the
modulation the mind yeah you're right, but even there is more complicated than it first appears right because when you damage part damage tissue, you don't really know whether what you ve damaged the critical part. You know to the function that evil those are the neurons in damage or what are called fibres pass it in Europe means you know, axons that run through that area, which are really important, and I just learned about this really does on that I I just this is the kind of stuff. I just love honestly, where you know you can lose. If you damage one part of your primary visual, where tax this is an animals, L, a blade. Apart of the primary visual cortex- and animal will lose the ability to see and so on,
especially you think, are well ok. This this region must be super important to seeing and it is important, except that you can recover some of that function by a second lesion in the superior Kaliko s in the membrane, others, information that could make it from your. But now to your primary visual cortex, but he's being suppressed by the collective us. Right in irregular fat in regular, typical brain, though you can recover function buy me a second lesion, and so it's just things like that, right that The key word here is another example, another you know example, which I find it absolutely fascinating. I find it slightly horrifying is a person, but because what happens to the animals, but that is a scientist- is really fascinating. So they took these rats and Train them to run on a wheel and recorded dry
they from neurons in visual cortex premier visual cortex, and then they a blade the damage the retinas destroy the retina of these animals. So they can't see And the one neurons primary visual, cortex, neurons, quiet and down and then over twenty four hours they ramp up again start firing at normal rights. So what's causing these neurons to fire. Where you put the rat back on the wheel and its neurons. The pattern of firing looks really similar to what it was like when the animal was cited. So what is it exactly? That's driving the activity in these neurons. And the answer probably is regions of the anterior singular cortex which have direct connections to the one, and the reason why this is interesting is
this these this region of the brain, is a primary regulator of the systems of your body. Both it is applied Harry Motor Area were the vista of your body and its an association region for your skeletal motor system and what these, what this activity is. Essentially, what you can think about is R r, a seventh visual predictions that are coming from past. Experience from that. You know that the motor that these micro regions are array What's u to reinstate, and so it's just it's just trickier sound. Then you know every it. If you start to just garden, the little bit modular already starts to fall apart. You here. Why did we found me seminar? You can teach it s one one day, blade in brain stem nuclei so as to recovery properly
the world, but I really want it. Recommended people try them home, it's not not boys. So, let's talk about. Prediction and justice. This uncanny, Sir, I'm stands were all in which very few people realise than those of us who realize it, I think rarely think about, which is why we have this venerable philosophical thought experiment of the brain in the vat- and this is a kind of them device to think about many things and in in the philosophy of mind, but rarely has pointed out that we, we really our brains and vats already, the vat is our skull. And we do not have direct contact with the physical environment. Much less reality itself
in any straightforward way is not like our senses or windows through which were peering or hearing norm. Sensing directly there's a very active and even anticipatory and to use your term predictive activity that is producing a visionary experience, a dream like experience, of the world. They may it's exactly like a dream, except for the ways in which in the waken state are envisioning of the world, is constrained by sensory input and in two different degree. So how do you think about the situation where, in here I just a system logically existential early? We are- and this is a phrase used at some point- the book we are. Experience in a kind of controlled hallucination it I'd say that nothing is vertical or nothing is that no statement about the world as it is
is better than any other know you nor more conversion with facts that we could enter subjectively find credible. But you know it is much more like the matrix than we give it credit for most of the time, and so that's I can perhaps back in. Yet you going in the direction of how you think about the mind as eight and the brain ass, a predictive computational system and not one that merely passively encountering me the world as it is. Why didn't you just did a beautiful job, describing it in very poetic turns actually a dream like calling the brains, you know we're describing the brains function as conjuring drew. A dream like state, is actually something good, just came across in this really wonderful book by Carlo Valley. It's in its new book called Helga Land
I don't think it's available. Yet in the? U S, I had to order it from the UK, and I and you know, he's really he what he's doing is explaining his understanding of quantum mechanics for a civilian like me, and I'm not, I don't, I'm not a physicist but you know, and with with very very little mouth and and then you know, as often seems to happen, everyone wants to take a shot at explaining what the brain does and you know what consciousness his doesn't matter. If you trained, as you know, the physicists,
I would have you, everyone takes their shot and then his shot, you know he's describing trying to describe prediction based on you know, I'm imagining what he what he read from the literature and visual neuroscience, where a lot of this work has taken place. I think, though, there's much there's a lot more work, which is very consistent with you know your description, there's a really really nice paper that was written actually, which was my review. I was reviewed this paper actually for
brain sciences, which suddenly a really great journal, and this is what alerted me to this growing literature, as was backlog in two thousand and ten. I think. Maybe she doesn't eleven. This growing literature on what's called predict, decoding or predictive processing its paper by Anti Clark, philosopher philosopher, but also you know, just rights, beautifully about very intuitively and beautifully about. Brain as predictive organ and but you don't want from me- and I don't know about you, but I am like inherently skeptical person. I really I dont even believe my on data necessarily ITALY. A really long time before I don't jump on bandwagon typically, and I also really don't I mean scientist I think in general. Wouldn't you agree, we don't really like to use the F word. You know fact: that's a really scary words. We try to avoid it.
And by you know, if you look in the literature get anatomy and you look at any number of literatures in neuroscience, and you look at signal, processing, literatures and engineering, and so on. What you see is that exactly the same disguise worry, is being made over and over and over again by literatures, they don't talk to each other, and I found this really compelling, and that is this idea, that your brain is trapped in a dark, silent box called your skull and it is constantly
receiving sense data from the world. You know, through its sensory surfaces, you're right now, you're cochlear, whatever and also in inside your body. So it's it's the world to your brain, is everything outside of the skull and is receiving these. They send stated that has to make sense of unease. He's an inverse problem, because it these sense data are the facts. There, the outcomes of some something changes, but your brain doesn't have access those changes. It only has access to the outcomes, but the consequences of those changes. So how does it you know if your brain, if your brain is exe I was to allow bang. How does your brain know what that loud, Bang is. How does your brain know what to do about it? You know it you put, you would do something different if it were
as a Fleming door or dropped box or a gunshot, and similarly, Unifil attacking your chest. How did you know no. Are you re no waiting to tax the tug freak weather with what is it sensing attack? Whether that's you know anxiety were you know that there is some uncertainty were that you just a big meal and you're having a will travel digesting. It were the beginnings of a heart attack. It has to gas and what does it used to guess you, the only other source of information that it has, which is past experience that it can re, implement, reinstate in its own wiring. So colloquially we recall that memory so when a brain remembers, when your brain remembers, when my brain remembers my brains,
Store memories and then call them up like files in files were basically remember. It is reassembling resembling the pass in the present for the purposes of of making sense of sense data and for a number of reasons, some of which are metabolic your brains, doing this. Predictably, it's not waiting to receive the input. And then try to make sense of it, and there are lots of ways to demonstrate this two people, sometimes when I
having talks in all use of baseball example and kind of walk people through the timing of the baseball example. You know baseball couldn't exist as a sport. No actual ball related sport to exist. If we had reactive brains, do just isn't physically enough time for, in order for a better to wait to see a ball before he swing and actually hit the ball, and there are lots of really lots of really cool interesting examples remedy life. But the point is that, metaphorically speaking, it's much cheaper for the brain to use past experience and to gas. What's gonna happen next, where the gas is not some abstraction, it's actually your brain, changing the firing of its own neurons to prepare you to see and hear and smell, and
and do something in the next moment, and then it checks those predictions against the incoming sense data from the body in from the world. Scientists call this, you know running a model of the world, but really what your brain is doing is its running a model of your body and it. The model of your body in the world. But it only knows the world by virtue of the sense data that it gets from the sensory surfaces of your body. So essentially, every feature that your brain compete it's in computing in relation to your body. In a petition
for a moment in time, in a particular context, your location relative to or related to that particular shape of your ear and the particular distance of your two eyes from one another and the particular state. You're mitochondria and so on and so forth. Its all relative. That doesnt mean some kind of postmodernism morass, but what it does mean is that
We really have to realise that everything that we experience we experience from a particular perspective and there is nothing really called objectivity. The best we can hope for according to the historian of Science, Naomi or ask us, is that a bunch of people with their own subjectivity. You know with different histories and different backgrounds and different experiences in the world that they can come to consensus over a scientific set of observations. And now
the cloud is close to objective fact is: we can get, and it's a pretty it's pretty darn good. It's worked out pretty pretty well for us, you know, but the idea that there are universal facts that can be objectively adjudicated by being rational or something has just done. It's a fiction that interesting we, the brain, stem themselves, even though your brains are completely incapable of doing such things. There is no true objectivity is not the same thing as saying that is not possible to be wrong, rain, we no longer young overshort, and it's also not saying that anything is possible. Right, though I mean sometimes when I say well there's more than one, you know There is more than one you know when it right up,
But you know very ability is the norm right that in many places in biology and in psychology there's much more variation than we often acknowledge. Work would like, but that doesn't mean that anything is possible. You know it means that there is just more than one stability and similarly, I would say: look you know we can all agree right that we're gonna have ground glass for dinner, but that doesn't necessarily translate into the objective reality that we can actually glass write it is it really matter what way we could all agree that Covid nineteen factious and that we don't have to wear masks? But you know the virus doesn't care about that? Being viruses, don't care about anything, but really all of virus needs. Is it wet set up with night sweats out of lungs? It doesn't. It doesn't matter what you without prisons brain believes. But there are many many, but I think that there are many many cases where
what we believe really matters to what we experience, but even if you wanna take a leaf out of the equation, the what you experience what you're reality is how you sphere in the world is very much relational. It's in relation to the body that you have an! U dont experience yourself. That way. I certainly I mean I can't tell you what you experience. I own experience myself that way wasn't as scientists in somebody just told me that I am not sure that I would believe it actually, but it is. That is the best available evidence that year, your brain is constantly cultivating your past for the purposes of predicting your future, which will become your present here,
if we can make this concrete for people, because if this is really ground upon which the scientific framing of what's going on, can unlock the kind of psychological freedom to just change one's sense of what one is as a as a subject in the world and tat, I think, can relieve certain kinds of suffering the simplest gauges to take. This predict give peace which can sound spooky. You take something like a a voluntary motor action, looks like I can decide to reach and pick up a cup on my desk, and this is does relate to this controversy that that I keep resurrection for my cell phone reality or lack thereof of free will and if you know how far down that rapid
I've gone, but our yes, I've enjoyed I've enjoyed them. I guess fault following you down there So we can talk about that of its interests you buy them. People have a sense that they are subjects that have this capacity to freely initiate behaviour and that's different and I would certainly agree that voluntary behavior is different from involuntary behavior, but I just don't think we need for the concept of free will to differentiate the two. So one way there different is when I'm doing something you know of my own volition, can pick it up it cup. That feels a certain way and feels that way because their certain implicit processes that we we know must be going on nerve physiologically there that do follow this kind of predictive mapping of thing. So when I'm reaching
and I'm not consciously aware of it, but at, but I can be made consciously aware of it. Certainly when anything goes wrong So I am not aware that I'm a prediction machine when I'm reaching to grasp this cup, but if I reached and my fingers pass through it right if it was a holiday I'm a cop and not a real one or if it felt you know squishy if it was. Made of rubber, and I wasn't expecting that all of those occasions of surprise are built on some set of. Expectations that I wasn't aware of having until I became disillusioned. So I was not aware of expecting solidity, Of course I was everything about the grasping behaviour. My hand was anticipated. In a certain way and you can make those that predictive programme consciously fell
certainly in the moment and which has violated, but it is just simply neurologically the case that we are, comparing in order the only way to detect a non he's in the environment is to have this background mom when going on of, what's likely to happen in each moment, based on what I am. What I'm doing now, and what I'm doing next and and and this question of what to do next, really does cover so much of what we're about as mines were constantly deciding what to do next on some level, o, absolutely there's so much to say, there's so much to unpack of it. That's interesting about what you just said. I mean. First of all, I would say it seems to me that
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Transcript generated on 2021-05-22.