Lisa Feldman Barrett is a neuroscientist, psychologist, and author. Please support this podcast by checking out our sponsors:
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EPISODE LINKS:
Seven and a Half Lessons About the Brain (book): https://amzn.to/2Sp5ar9
How Emotions Are Made (book): https://amzn.to/2GwAFg6
Lisa's Twitter: https://twitter.com/LFeldmanBarrett
Lisa's Website: https://lisafeldmanbarrett.com/

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OUTLINE:
0:00 - Introduction
2:45 - Are we alone in the universe?
4:13 - Life on Earth
9:05 - Collective intelligence of human brains
17:53 - Triune brain
24:03 - The predicting brain
31:58 - How the brain evolved
37:58 - Free will
46:51 - Is anything real?
59:23 - Dreams
1:05:11 - Emotions are human-constructed concepts
1:30:40 - Are women more emotional than men?
1:39:16 - Empathy
2:10:56 - Love
2:14:50 - Mortality
2:16:26 - Meaning of life

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The following is a conversation with Lisa Feldman Barrett, a professor of psychology at Northeastern University and 1 of the most brilliant and bold thinkers and scientists I've ever had the pleasure of speaking with.

She's the author of a book that revolutionized our understanding of emotion in the brain called How Emotions Are Made and she's coming out with a new book called 7 and a Half Lessons About the Brain that you can and should pre-order now.

I got a chance to read it already and it's 1 of the best short whirlwind introductions to the human brain I've ever read.

It comes out on November 17th, but again, if there's anybody worth supporting, it's Lisa, so please do pre-order the book now.

Lisa and I agreed to speak once again around the time of the book release, especially because we felt that this first conversation is good to release now, since we talk about the divisive time we're living through in the United States leading up to the election.

And she gives me a whole new way to think about it from a neuroscience perspective that is ultimately inspiring of empathy, compassion, and love.

Quick mention of each sponsor, followed by some thoughts related to this episode.

First sponsor is Athletic Greens, the all-in-one drink that I start every day with to cover all my nutritional bases that I don't otherwise get through my diet naturally.

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Please check out these sponsors in the description to get a discount and to support this podcast.

As a side note, let me say that the bold, first principles way that Lisa approaches our study of the brain is something that has inspired me ever since I learned about her work.

And In fact, I invited her to speak at the AGI series I organized at MIT several years ago.

But as a little twist, instead of a lecture, we did a conversation in front of the class.

I think that was 1 of the early moments that led me to start this very podcast.

It was scary and gratifying, which is exactly what life is all about.

And it's kind of funny how life turns on little moments like these, that at the time don't seem to be anything out of the ordinary.

If you enjoy this thing, subscribe on YouTube, review it with 5 Stars and Apple Podcasts, follow us on Spotify, support on Patreon, or connect with me on Twitter at Lex Friedman.

And now, here's my conversation with Lisa Feldman Barrett.

Since we'll talk a lot about the brain today, do you think, let's ask the craziest question, do you think there is other intelligent life out there in the universe?

Honestly, I've been asking myself lately if there's intelligent life on this planet.

You know, I have to think probabilities suggest yes, and also secretly I think I just hope that's true.

It would be really, I know scientists aren't supposed to have hopes and dreams, but I think it would be really cool, and I also think it would be really sad if it wasn't the case.

If we really were alone, that would be, that would seem profoundly sad, I think.

Yeah, no, you know, I take a lot of comfort in curiosity.

It's a great resource for dealing with stress.

So I'm learning all about mushrooms and octopuses and all kinds of stuff.

And so for me, this counts, I think, in the realm of awe.

But also I think I'm somebody who cultivates awe deliberately on purpose to feel like a speck.

You know, I find it a relief occasionally.

To feel small in a profoundly large and interesting universe.

So, maybe to dig more technically on the question of intelligence.

Do you think it's difficult for intelligent life to arise like it did on Earth?

From everything you've written and studied about the brain, how magical of a thing is it in terms of the odds it takes to arise?

Yeah, so, you know, magic is just, don't get me wrong, I mean, I like a magic show as much as the next person.

But, you know, magic is just a bunch of stuff that we don't really understand how it works yet.

So I would say from what I understand, there are some major steps in the course of evolution that at the beginning of life, the step from single cell to multicellular organisms, things like that, which are really not known.

I think for me, the question is not so much what's the likelihood that it would happen again as much as what are the steps and how long would it take?

And if it were to happen again on Earth, would we end up with the same menu of life forms that we currently have now?

And I think the answer is probably no, right?

There's just so much about evolution that is stochastic and driven by chance.

But the question is whether that menu would be equally delicious, meaning like there'd be rich complexity of the kind of, like would we get dolphins and humans or whoever else falls in that category of weirdly intelligent, seemingly intelligent, however we define that?

Well, I think that has to be true if you just look at the range of creatures who've gone extinct.

I mean, if you look at the range of creatures that are on the earth now, it's incredible.

And it's sort of tried to say that, but it actually is really incredible.

Particularly I don't know, I mean, There are animals that seem really ordinary until you watch them closely and then they become miraculous, like certain types of birds which do very miraculous things, build bowers and do dances and all these really funky things that are hard to explain with a standard evolutionary story, although people have them.

I haven't quite, maybe you know much better, but it doesn't seem to fit evolutionary arguments well.

So I think you're talking about the evolution of beauty, the book that was written recently by was it from, what is his name?

It's very controversial though because he's making an argument that the question about birds and some other animals is why would they engage in such metabolically costly displays when it doesn't improve their fitness at all?

And the answer that he gives is the answer that Darwin gave, which is sexual selection, not natural selection.

But selection can occur for all kinds of reasons.

There could be artificial selection, which is when we breed animals, which is actually how Darwin, that observation helped Darwin come to the idea of natural selection.

RF And then there's sexual selection meaning and the argument that I think his name is from makes is that the selection pressure is the pleasure of female birds.

Which as a woman and as someone who studies affect, that's a great answer.

I actually think there probably is natural, I think there is an aspect of natural selection to it which he maybe hasn't considered.

But you were saying, the reason we brought up birds is the life we got now seems to be quite incredible.

Yeah, so you peek into the ocean, peek into the sky, there are miraculous creatures, look at creatures who've gone extinct, And in science fiction stories, you couldn't dream up something as interesting.

So my guess is that intelligent life evolves in many different ways, even on this planet.

There's not 1 brain that gives you intelligence.

There are lots of different brain structures that can give you intelligence.

So my guess is that the menagerie might not look exactly the way that it looks now, but it would certainly be as interesting.

But if we look at the human brain versus the brains, or whatever you call them, the mechanisms of intelligence in our ancestors, even early ancestors, that you write about, for example, in your new book.

What's the difference between the fanciest brain we got, which is the human brain, and the ancestor brains that it came from?

Yeah, I think it depends on how far back you wanna go.

You go all the way back, right, in your book.

So what's the interesting comparison, would you say?

Well, first of all, I wouldn't say that the human brain is the fanciest brain we've got.

I mean, an octopus brain is pretty different and pretty fancy, and they can do some pretty amazing things that we cannot do.

You know, we can't grow back limbs, we can't change color and texture, we can't comport ourselves and squeeze ourselves into a little crevice.

These are like superhero abilities that we invent in stories, right?

And so the human brain is certainly, we can certainly do some things that other animals can't do that seem pretty impressive to us.

But I would say that there are a number of animal brains which seem pretty impressive to me that can do interesting things and really impressive things that we can't do.

I mean, with your work on how emotions are made and so on.

You kind of repaint the view of the brain as less glamorous, I suppose, than you would otherwise think.

Or like, I guess you draw a thread that connects all brains together in terms of homeostasis and all that kind of stuff.

Yeah, I wouldn't say that the human brain is any less miraculous than anybody else would say.

I just think that there are other brain structures which are also miraculous.

And I also think that there are a number of things about the human brain which we share with other vertebrates, other animals with backbones, but that we share these miraculous things.

And we can also do some things with our brains together, working together that other animals can't do, or at least we haven't discovered their ability to do it.

I mean, that's 1 of the things you write about.

What's, how do you make sense of the fact, like the book Sapiens, and the fact that we're able to kind of connect, like network our brains together, like you write about.

Is that like some kind of feature that's built into there?

What I would say is that our ability to coordinate with each other is not unique to humans.

There are lots of animals who can do that.

But what we do with that coordination is unique because of some of the structural features in our brains.

And it's not that other animals don't have those structural features, it's we have them in abundance.

So, you know, the human brain is not larger than you would expect it to be for a primate of our size.

If you took a chimpanzee and you grew it to the size of a human, that chimpanzee would have a brain that was the size of a human brain.

So there's nothing special about our brain in terms of its size.

There's nothing special about our brain in terms of the basic blueprint that builds our brain from an embryo is the basic blueprint that builds all mammalian brains and maybe even all vertebrate brains.

It's just that because of its size and particularly because of the size of the cerebral cortex, which is a part that people mistakenly attribute to rationality.

Isn't that where all the clever stuff happens?

And I will also say that lots of clever stuff happens in animals who don't have a cerebral cortex.

But because of the size of the cerebral cortex And because of some of the features that are enhanced by that size, that gives us the capacity to do things like build civilizations and coordinate with each other, not just to manipulate the physical world, but to add to it in very profound ways.

Like, you know, other animals can cooperate with each other and use tools.

We draw a line in the sand, and we make countries, and we even, then we create, you know, we create citizens and immigrants.

But also ideas, I mean, the countries are centered around the concept of ideas.

Well, what do you think a citizen is and an immigrant?

Those are ideas that we impose on reality and make them real.

And then they have very, very serious and real effects, physical effects on people.

What do you think about the idea that a bunch of people have written about, Dawkins with memes, which is like ideas are breeding.

Like we're just like the canvas for ideas to breed in our brains.

So this kind of network that you talk about of brains is just a little canvas for ideas to then compete against each other and so on.

I think as a rhetorical tool, it's cool to think that way.

So I think it was Michael Pollan, I don't remember if it was in the Botany of Desire, but it was in 1 of his early books on botany and gardening where he wrote about plants utilizing humans for their own evolutionary purposes, which is kind of interesting.

You can think about a human gut in a sense as a propagation device for the seeds of tomatoes and what have you, so it's kind of cool.

So I think rhetorically it's an interesting device, but ideas are, as far as I know, invented by humans, propagated by humans.

So I don't think they're separate from human brains in any way, although it is interesting to think about it that way.

Well, of course, the ideas that are using your brain to communicate and write excellent books, and they basically pick you, Lisa, as an effective communicator, and thereby are winning.

To think that there's particular aspects of your brain that are conducive to certain sets of ideas and maybe those ideas will win out.

Yeah, I think the way that I would say it really though is that there are many species of animals that influence each other's nervous systems, that regulate each other's nervous systems.

They do it by, you know, So termites and ants and bees, for example, use chemical scents.

Mammals like rodents use scent, and they also use hearing, audition, and that little bit of vision.

Primates, non-human primates, add vision, right?

Humans, as far as I know, are the only species that use ideas and words to regulate each other, right?

I can text something to someone halfway around the world.

And I can have an effect on their nervous system.

And ideas, the ideas that we communicate with words, I mean words are in a sense a way for us to do mental telepathy with each other, right?

I mean I'm not the first person to say that obviously, but how do I control your heart rate?

With words, it's because those words are communicating ideas.

So you also write, I think, let's go back to the brain.

You write that Plato gave us the idea that the human brain has 3 brains in it, 3 forces, which is kind of a compelling notion.

First of all, what are the 3 parts of the brain and why do you disagree?

So Plato's description of the psyche, which for the moment we'll just assume is the same as a mind.

There are some scholars who would say, you know, a soul, a psyche, a mind, those aren't actually all the same thing in ancient Greece, but we'll just for now gloss over that.

So Plato's idea was that, and it was a description of really about moral behavior and moral responsibility in humans.

So the idea was that, you know, the human psyche can be described with a metaphor of 2 horses and a charioteer.

So 1 horse for instincts, like feeding and fighting and fleeing and reproduction.

They also printed a B word and it was really, yeah.

Well, we should learn something from England.

And then the other horse represents emotions, and then the charioteer represents rationality, which controls the 2 beasts, right?

And Fast forward a couple of centuries, and in the middle of the 20th century, there was a very popular view of brain evolution which suggested that you have this reptilian core, like an inner lizard brain for instincts, and then wrapped around that, layer on top of that, evolved a limbic system in mammals.

So the novelty was in a mammalian brain, which bestowed mammals with, gave them emotions, the capacity for emotions.

And then on top of that, evolved a cerebral cortex, which in largely in primates, but very large in humans.

And it's not that I personally disagree, It's that as far back as the 1960s, but really by the 1970s, it was shown pretty clearly with evidence from molecular genetics, so peering into cells in the brain to look at the molecular makeup of genes, that the brain did not evolve that way.

And the irony is that the idea of the three-layered brain with an inner lizard that hijacks your behavior and causes you to do and say things that you would otherwise not or maybe that you will regret later.

That idea became very popular, was popularized by Carl Sagan in the Dragons of Eden, which won a Pulitzer Prize in 1977 when it was already known pretty much in evolutionary neuroscience that the whole narrative was a myth.

So, well, the narrative is on the way it evolved, but do you, I mean, again, it's that problem of it being a useful tool of conversation, to say like, there's a lizard brain, and there's a, like, if I get overly emotional on Twitter, that was the lizard brain and so on.

I don't think it's accurate, and therefore I don't think it's useful.

You know, I think that, the way I think about philosophy and science is that they are useful tools for living.

And in order to be useful tools for living, they have to help you make good decisions.

The triune brain, as it's called, this three-layer brain, the idea that your brain is like an already baked cake and the cortex, cerebral cortex, just layered on top like icing.

That idea is the foundation of the law in most Western countries.

It sort of fits our intuitions about how we work.

But it also, in addition to being wrong, it lets people off the hook for nasty behavior.

And it also suggests that emotions can't be a source of wisdom, which they often are.

In fact, you would not want to be around someone who didn't have emotions.

I mean, that's not someone you want to really have that person deciding your outcome.

So I guess my, and I could sort of go on and on and on, but my point is that I don't think, I don't think it's a useful narrative in the end.

What's the more accurate view of the brain that we should use when we're thinking about it?

I'll answer that in a second, but I'll say that even our notion of what an instinct is or what a reflex is, it's not quite right, right?

So if you look at evidence from ecology, for example, and you look at animals in their ecological context, what you can see is that even things which are reflexes are very context-sensitive.

The brains of those animals are executing so-called instinctual actions in a very, very context-sensitive way.

And so, you know, even when a physician, you know, takes the, you know, it's like the idea of your patellar reflex where they hit your patellar tendon on your knee and you kick, the force with which you kick and so on is influenced by all kinds of things.

And so I think a better way is a way that to think about how brains work is the way that matches our best understanding, our best scientific understanding, which I think is really cool because it's really counterintuitive.

So how I came to this view, and I'm certainly not the only 1 who holds this view, I was reading work on neuroanatomy and the view that I'm about to tell you was strongly suggested by that.

And then I was reading work in signal processing, like by electrical engineering.

And similarly, the work suggested that, the research suggested that the brain worked this way.

And I'll just say that I was reading across multiple literatures and they were who don't speak to each other and they were all pointing in this direction.

And so far, although some of the details are still up for grabs, the general gist I think is I've not come across anything yet which really violates, and I'm looking.

So the way to describe it is to say that your brain doesn't react to things in the world.

It's not, to us it feels like our eyes are windows on the world.

We see things, we hear things, we react to them.

In psychology we call this stimulus response.

And I might react very automatically, system 1.

But I also might execute some control where I maybe stop myself from saying something or doing something and in a more reflective way, execute a different action, right, that system too.

The way the brain works though, is it's predicting all the time.

It's constantly talking to itself, constantly talking to your body, and it's constantly predicting what's going on in the body and what's going on in the world and making predictions and the information from your body and from the world really confirm or correct those predictions.

So fundamentally the thing that the brain does most of the time is just predict, like talking to itself and predicting stuff about the world, not like this dumb thing that just senses and responds.

Yeah, so the way to think about it is like this.

You know, your brain is trapped in a dark, silent box.

Which is your skull, and the only information that it receives from your body and from the world, right, is through the senses, through the sense organs, your eyes, your ears, and you have sensory data that comes from your body that you're largely unaware of to your brain, which we call interoceptive as opposed to exteroceptive, which is the world around you.

But your brain is receiving sense data continuously, which are the effect of some set of causes.

Your brain doesn't know the cause of these sense data, it's only receiving the effects of those causes which are the data themselves.

And so your brain has to solve what philosophers call an inverse inference problem.

How do you know when you only receive the effects of something, how do you know what caused those effects?

So when there's a flash of light or a change in air pressure or a tug somewhere in your body, how does your brain know what caused those events so that it knows what to do next to keep you alive and well?

And the answer is that your brain has 1 other source of information available to it, which is your past experience.

It can reconstitute in its wiring past experiences, and it can combine those past experiences in novel ways.

And so we have lots of names for this in psychology.

We call it memory, we call it perceptual inference, we call it simulation.

It's also, we call it concepts or conceptual knowledge.

Basically, if we were to stop the world right now, stop time, your brain is in a state and it's representing what it believes is going on in your body and in the world, and it's predicting what will happen next based on past experience, probabilistically what's most likely to happen.

And it begins to prepare your action, and it begins to prepare your experience.

So it's anticipating the sense data it's going to receive.

And then when those data come in, they either confirm that prediction and your action executes, because the plan's already been made, Or there's some sense data that your brain didn't predict that's unexpected and your brain takes it in, we say encodes it, we have a fancy name for that, we call it learning.

Your brain learns and it updates its storehouse of knowledge, which we call an internal model, and so that you can predict better next time.

And it turns out that predicting and correcting, predicting and correcting, is a much more metabolically efficient way to run a system than constantly reacting all the time.

Because if you're constantly reacting, it means you have no, you can't anticipate in any way what's gonna happen.

And so the amount of uncertainty that you have to deal with is overwhelming to a nervous system.

A reflex is when your brain doesn't check against the sense data.

That the potential cost to you is so great, maybe because your life is threatened, that your brain makes the prediction and executes the action without checking.

Yeah, so but prediction's still at the core.

I wonder, from almost an AI perspective, but just computationally, is the brain just mostly a prediction machine then?

Like is the perception just a nice little feature added on top, like the integration of new perceptual information?

I wonder how big of an impressive system is that relative to just the big predictor, model constructor.

Well, I think that we can look to evolution for that, for 1 answer, which is that when you go back 550 million years, give or take, the world was populated by creatures, really ruled by creatures without brains.

And that's a biological statement, not a political statement.

no, I'm not talking about dinosaurs, honey.

I'm talking way back, further back than that.

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Lisa Feldman Barrett: Counterintuitive Ideas About How the Brain Works | Lex Fridman Podcast #129