Speaker 1: What are emotions? Are they something that happened to you?
Speaker 1: Or are they bodily signals that we interpret? Does everyone
Speaker 1: show emotions in the same way? Are there particular markers
Speaker 1: of the face or body that always mean anger or
Speaker 1: sadness or joy? And what does this have to do
Speaker 1: with Charles Darwin or the truth about facial expressions or
Speaker 1: the movie Inside Out. Welcome to enter Cosmos with me
Speaker 1: David Eagleman. I'm a neuroscientist and an author at Stanford
Speaker 1: and in these episodes we sail deeply into our three
Speaker 1: pound universe to understand why and how our lives look
Speaker 1: the way they do. Today's episode is about emotions. Now,
Speaker 1: to set this up, let's think about emotion versus cognition.
Speaker 1: In the past half century, neuroscience has been buzzing with
Speaker 1: discoveries about cognition, like how we perceive information, how we
Speaker 1: decide that sort of thing, and this has all been
Speaker 1: enhanced by all the recent advances in artificial intelligence. So
Speaker 1: cognition is all about acquiring and using knowledge, recognizing patterns,
Speaker 1: storing and retrieving informations, creating mental representations, but real neural
Speaker 1: networks the ones living inside organisms. They operate in a
Speaker 1: very different context. Organisms are driven by needs and motives
Speaker 1: and pain and emotions. Without these driving all the cognitive
Speaker 1: processes like learning and representing and taking action.
Speaker 2: These would lack purpose or direction.
Speaker 1: In other words, if nothing matters to an organism, there's
Speaker 1: no reason for it to learn or do anything. This
Speaker 1: is why understanding the brain requires us to include emotion,
Speaker 1: not just cognition, and this consideration has given rise to
Speaker 1: a field that we call affective neuroscience, in other words,
Speaker 1: the neuroscience of emotions as a complement to the field
Speaker 1: of cognitive neuroscience.
Speaker 2: So what is.
Speaker 1: Different about these two fields, Well, at least traditionally, neuroscience
Speaker 1: thinks about cognition as representational and involving symbols and computation
Speaker 1: and degrees of accuracy in how well it reflects the world.
Speaker 1: But emotions they don't fit that model. Take something like fear,
Speaker 1: it's not exactly about rep presentation or symbols that it
Speaker 1: doesn't have accuracy, but instead it varies in intensity. If
Speaker 1: emotions are like forces that rise and fall, or they mix,
Speaker 1: or they remain pure, then cognition is maybe more like
Speaker 1: an encyclopedia, something structured and informational. Now These metaphors are imperfect,
Speaker 1: but I'm just using these to tee up the divide
Speaker 1: between cognition and emotion in conventional thinking. Now, why has
Speaker 1: cognition received all the attention in the laboratory.
Speaker 2: Well, it's because we.
Speaker 1: Can build models or artificial neural networks to tackle cognitive
Speaker 1: tasks like chess and go and math problems. It's a
Speaker 1: lot harder to set up clear experiments with emotions, and
Speaker 1: so these have traditionally received a lot less attention in
Speaker 1: the research world. But the thing to note is that
Speaker 1: emotions are much more ancient and at least here to
Speaker 1: span the animal kingdom, while chess games do not, so
Speaker 1: emotions may be more fundamental in brain wiring. So how
Speaker 1: do emotions get studied? Let's start with Charles Darwin. In
Speaker 1: his book The Expression of the Emotion in Man and Animals.
Speaker 2: Which he published in eighteen seventy.
Speaker 1: Two, Darwin proposed that emotions are biological phenomenon. They're deeply
Speaker 1: rooted in our evolutionary history. So he argued that our
Speaker 1: facial expressions of joy or sadness, or anger or fear
Speaker 1: they evolved to communicate essential information to ourselves and others.
Speaker 1: So for example, it makes sense, he argued, for a
Speaker 1: person who is angry to stand tall and loom large
Speaker 1: and glare and tense their muscles.
Speaker 2: These actions prepare them for physical.
Speaker 1: Action, and these actions can also just serve as a
Speaker 1: visual threat of action. So Darwin proposed that he motions
Speaker 1: are survival tools passed down through the generations, like well
Speaker 1: oiled machinery.
Speaker 2: Although its a.
Speaker 1: Side note, he did mention that this appropriateness hypothesis can't
Speaker 1: be the whole story, since a lot of things didn't
Speaker 1: seem to fit, like a person who is sad moping
Speaker 1: around and recreating conversations in his head and feeling drained.
Speaker 1: But we'll come back to this. So the general thing
Speaker 1: that Darwin emphasized is that certain emotions prepare our body
Speaker 1: to do the next thing, and he suggested this was
Speaker 1: universal across the animal kingdom. He said, look, expressions are
Speaker 1: essentially the same across mammalian species, and things can even
Speaker 1: look a little similar between mammals and reptiles and birds,
Speaker 1: like when the animal is afraid or angry or showing
Speaker 1: parental love. So Darwin said, the core emotional operations relevant
Speaker 1: to behavior are evolutionarily highly conserved, so fast forward to
Speaker 1: the twentieth century, and this research gained momentum with researchers
Speaker 1: like Paul Ekman. Ekman went around the world and he
Speaker 1: concluded that he could identify six basic emotions. There was happiness, sadness, anger, fear, disgust,
Speaker 1: and surprise. And these six emotions, he argued, are universal
Speaker 1: whether you are in New York or New Guinea. A
Speaker 1: smile means joy, and if you have a furrowed brow,
Speaker 1: that means worry and so on. And this model of
Speaker 1: basic emotions that are universal, we see this framework everywhere
Speaker 1: around us. You've probably seen the Pixar movie Inside Out,
Speaker 1: which brought emotions to life. You had the characters of
Speaker 1: joy and sadness and anger and fear and disgust, and
Speaker 1: each one was personified as a little being running the
Speaker 1: control panel of a young girl's mind. And it was
Speaker 1: a great movie and it captured the publicma because it
Speaker 1: felt sort of true. Right, these emotions seem like individual
Speaker 1: entities living inside us. They're always there, They're waiting to
Speaker 1: surface and take charge of the control panel. But what
Speaker 1: if I told you that everything you just heard about
Speaker 1: Darwin and Eckman and Inside Out is not really the
Speaker 1: full story about emotions. What if emotions aren't actually universal?
Speaker 1: What if they're not hardwired programs that move us like
Speaker 1: a marionette, but instead something we create and interpret. So
Speaker 1: the story of the neuroscience of emotions really started taking
Speaker 1: a turn with the work of one neuroscientist, Lisa Feldman Barrett.
Speaker 1: She's a professor of psychology at Northeastern University and she
Speaker 1: wrote a book called How Emotions Are Made. Over the years,
Speaker 1: Barrett's work has really challenged everything we thought we knew
Speaker 1: about emotions. In her view, emotions aren't universal biological reflexes.
Speaker 1: They are constructed experiences, shaped by our brains, by our past,
Speaker 1: and by our culture. So I called up Lisa to
Speaker 1: join us here today, and as we're about to see
Speaker 1: her research flips the script. It suggests that your brain
Speaker 1: doesn't feel emotions as much as it predicts them. So
Speaker 1: that wave of joy or that stab of anger, it's
Speaker 1: not a reaction, it's your brain interpreting the signals of
Speaker 1: your body in the context of your situation and your
Speaker 1: life experience. So Lisa, first I want to ask you
Speaker 1: what the classical view is of emotions, and then we're
Speaker 1: going to transition into how you see it and what
Speaker 1: your research has revealed.
Speaker 2: So let's start with the classical view.
Speaker 1: What is any student can learn in their psychology or
Speaker 1: neuroscience textbook about emotions.
Speaker 3: Right, So you open up an intro textbook, or you
Speaker 3: could even open up a Harvard Business Review or often
Speaker 3: even read the newspaper, and what you see is a
Speaker 3: view that humans are born with six somewhere between six
Speaker 3: and some I don't know, twelve fifteen circuits, one for
Speaker 3: each type of emotion, Anger said, fear discussed. You know,
Speaker 3: the different scientists disagree on how many there are, but
Speaker 3: the ideas that you have these inborn emotions, something happens
Speaker 3: in the world triggers one of them, and you make
Speaker 3: a universal facial expression to express the state. Your body
Speaker 3: changes to express the physical state that is characteristic of
Speaker 3: that emotion, and you are likely to perform a specific behavior. So,
Speaker 3: for example, if your fear circuit is triggered, you'll make
Speaker 3: a wide eyed, gasping face, which is supposed to be
Speaker 3: universe soul. Everybody around the world is supposed to make
Speaker 3: that face when they're afraid, and recognize that as an
Speaker 3: expression of fear. Your heart rate is supposed to race,
Speaker 3: and you're supposed to be likely to flee or freeze
Speaker 3: or make some kind of characteristic movement.
Speaker 4: So that's a bit of a caricature, but not that much.
Speaker 3: That's that is actually the view that a lot of
Speaker 3: people still hold.
Speaker 1: Actually, And when you started graduate school, I assume you
Speaker 1: felt that was the right model as well. That's what
Speaker 1: you were taught, and so you started doing some research
Speaker 1: and what happened there?
Speaker 3: Yeah, So I wasn't even doing research on emotion, David.
Speaker 3: I started graduate school doing research on something else. But
Speaker 3: I had to measure emotion, and I was measuring emotion
Speaker 3: the way a lot of psychologists do, which is to
Speaker 3: ask people, how are you feeling? And what I did
Speaker 3: was I, instead of, you know, analyzing what people say,
Speaker 3: I looked at the statistical structure of what they said.
Speaker 3: So instead of just averaging the ratings and saying, oh,
Speaker 3: this person is, you know, reporting sadness or fear, I
Speaker 3: looked at the whole pattern of their reports. And I
Speaker 3: found people on average don't distinguish between feelings of sadness
Speaker 3: and fear and discuss. They basically group like all the
Speaker 3: negative emotion words together to report I feel terrible and
Speaker 3: all the positive words to I feel great, So I
Speaker 3: feel good, I feel bad, I feel comfortable, I feel uncomfortable.
Speaker 4: That's generally, on average, what it looked like.
Speaker 3: And I thought, well, everybody knows there are universal expressions
Speaker 3: for emotion, and everybody knows that there are these physical patterns,
Speaker 3: you know, for different emotion categories, and eventually, you know,
Speaker 3: everyone knows there are different circuits in the brain. So
Speaker 3: I should be able to objectively measure somebody's emotional state
Speaker 3: and then I can compare that to their reports. Because
Speaker 3: it turned out but when I looked a little closer,
Speaker 3: I could see that actually, on average, it looks like
Speaker 3: people aren't distinguishing, but some people distinguish pretty well, and
Speaker 3: other people, you know, use anger said and fearful to
Speaker 3: mean are synonyms. So I thought, well, I can just
Speaker 3: figure out like who's reporting accurately and who isn't. And
Speaker 3: I thought, you know, not being an expert in emotion
Speaker 3: and also having the exuberance and unrealistic expectations of a
Speaker 3: graduate student, I thought, oh, this will just take me
Speaker 3: a couple of months, Like, I'll figure it out and
Speaker 3: then I'll be able to objectively, you know, measure emotion
Speaker 3: I'll move on and it'll be great.
Speaker 4: And that is not what happened.
Speaker 2: So what did you find.
Speaker 3: I've went to the literature because like probably you and
Speaker 3: almost everybody I know, we were all taught that each
Speaker 3: emotion category that is anger, is a category of instances.
Speaker 3: So we were taught that there are certain categories that
Speaker 3: are universal and should have objective markers. So I started
Speaker 3: with the face because everyone knows that Charles Darwin. I
Speaker 3: mean when I say everyone, I mean you know, scientists
Speaker 3: know Charles Darwin wrote a book called The Expression of
Speaker 3: the Emotions in Man and Animals, and he claimed that
Speaker 3: there were these universal expressions. And so I went to
Speaker 3: the literature and I started to read, and what I
Speaker 3: discovered was that if you just read the introduction of
Speaker 3: papers and you read the discussion section of the papers,
Speaker 3: there are lots of claims about universal expressions.
Speaker 4: But if you actually look at.
Speaker 3: The results and you read you sort of dig into
Speaker 3: the results, you don't see anything which looks like universal expressions.
Speaker 3: Actually what you see is real variations. I'll give an
Speaker 3: example of a recent meta analysis. So this is a
Speaker 3: statistical summary of you know, hundreds of studies. Right, people
Speaker 3: on average scowl when they're angry. Scowling is the supposed
Speaker 3: universal expression of anger. People scowl when they're angry about
Speaker 3: thirty five percent of the time, so that's more than chance,
Speaker 3: and therefore it will get you a good publication if
Speaker 3: you report that finding. But that means sixty five percent
Speaker 3: of the time people are doing something else that is
Speaker 3: meaningful with their face when they're angry, and other research
Speaker 3: suggests that about half the time when people scowl, they're
Speaker 3: not angry. They're feeling something else, and oftentimes it's not
Speaker 3: an emotion.
Speaker 4: And if you combine that with.
Speaker 3: Evidence from people who live in remote cultures who have
Speaker 3: less access to Western values and norms for emotion, what
Speaker 3: you see is that there's nothing that looks like universality
Speaker 3: for anger or for any category that's ever been studied.
Speaker 3: So scowling and anger is certainly one set of facial
Speaker 3: movements that people make in the West when they're angry,
Speaker 3: but it doesn't come anywhere close to having the reliability
Speaker 3: or specificity that we would need to see for a
Speaker 3: universal expression. And I'll just say that in my lab,
Speaker 3: we were very fortunate to be able to visit Tanzania
Speaker 3: and work with members of the Hudsa hunter gatherer culture.
Speaker 3: And we basically took six emotion categories that don't exist
Speaker 3: in English. They don't exist in Hadzane either. They have
Speaker 3: never been claimed to be universal, and then we just
Speaker 3: made up expressions for them, like literally, we sat around
Speaker 3: a table just made up expressions for them. We pretested
Speaker 3: them with American subjects. To make sure that American subjects
Speaker 3: thought these were reasonable expressions of these emotions, we had
Speaker 3: to tell them what the emotion was, you know, like
Speaker 3: there were one emotion category it was gigle, which is
Speaker 3: the desire to squeeze a baby's cheeks, you know, like
Speaker 3: when you see a really cute baby and you just like,
Speaker 3: So there was and then we plopped it into the
Speaker 3: method that everybody uses when they do these cross cultural studies,
Speaker 3: and the method produced evidence that five of the six
Speaker 3: of these categories were universal. So what I'm saying here
Speaker 3: is that there's a method that scientists are using that
Speaker 3: basically is teaching people what the right answers are. But
Speaker 3: the basic answer here is that for every claim of
Speaker 3: a universal marker or signature for emotion, if you just
Speaker 3: look closely and you start to poke a little bit
Speaker 3: at the research. You know, it's like a house of cards,
Speaker 3: it sort of falls apart, and instead what you see
Speaker 3: is that variation is the norm, meaning you, David, probably
Speaker 3: do many things when you're anger. You probably sometimes feel unpleasant,
Speaker 3: and sometimes you probably might even feel pleasant. You know,
Speaker 3: your body probably does many things in anger. It's not random.
Speaker 3: It's structured by the situation, and that leads us to
Speaker 3: ask a whole set of different questions about emotion.
Speaker 1: So when we think about an emotion like anger, it's
Speaker 1: not that there's one thing going on. It's not as
Speaker 1: though I have an anger circuit. So instead, there are
Speaker 1: lots of ways that I might express that based on
Speaker 1: the context that I'm in. Can you give an example
Speaker 1: of that? Sure?
Speaker 4: Have you ever laughed in anger?
Speaker 1: I don't remember if I've ever laughed at anger. It's
Speaker 1: possibly what would be a situation where someone might do that.
Speaker 4: I think.
Speaker 3: People laugh in anger when they're insulted in some way,
Speaker 3: and they cry in anger. I've certainly cried in anger.
Speaker 3: People sit stoically in plot the demise of their enemy.
Speaker 3: In anger, they make no expression whatsoever. I mean, you know,
Speaker 3: I'm sure you've been in a faculty meeting where you've
Speaker 3: done that. I certainly have had my moments. I think
Speaker 3: if you look to the literature, what you see is
Speaker 3: that people do all kinds of things in anger. Heart
Speaker 3: rate can go up, it can go down, blood pressure
Speaker 3: can go up, it can go down, it can stay
Speaker 3: the same. There's not a single pattern. And when it
Speaker 3: comes to the brain, there is no single circuit for
Speaker 3: anger or sadness or fear. It's not even like there
Speaker 3: are multiple circuits. What you see in the brain is
Speaker 3: that there are ingredients or components that work together. So
Speaker 3: anger is a whole brain state. It's not a single circuit.
Speaker 3: In fact, any research that claims to have identified a
Speaker 3: distinct circuit for an emotion is usually equating an emotion
Speaker 3: with a specific action. So when you read research that
Speaker 3: talks about the fear circuit, they mean the circuit in
Speaker 3: animals when the animal freezes. Really careful research shows, for example,
Speaker 3: if you place a rat in a testing box and
Speaker 3: you expose the rat to us tone and then a
Speaker 3: foot shock, eventually the rat will come to freeze when
Speaker 3: it hears the tone. This is what scientists refer to
Speaker 3: as learned fear, so they're equating a freezing behavior to fear,
Speaker 3: and then they look for the circuit for that freezing behavior,
Speaker 3: and then they call it the circuit for fear. The
Speaker 3: really interesting thing is that recent research, for example, will
Speaker 3: train a rat in the way that we just discussed,
Speaker 3: mark the neurons that increase their firing, and then reactivate
Speaker 3: those neurons opt genetically with light, and then they look
Speaker 3: throughout the entire brain, Well, what else is being so
Speaker 3: not just looking at the you know, the circuit, like
Speaker 3: let's say the little subcortical circuit that they might be
Speaker 3: interested in, but they look at through the whole brain
Speaker 3: and what you see is that there's actually a whole
Speaker 3: brain ensemble of neurons which are increasing their firing. Two
Speaker 3: interesting things to me in this body of work. Oftentimes
Speaker 3: scientists think the fear circuit is in neurons in this
Speaker 3: little area called the amygdala, which is deep inside the
Speaker 3: temper lobe of a vertebrate brain. If you reactivate the
Speaker 3: neurons in the amygdala and you bring up this whole
Speaker 3: brain wide ensemble of neurons, but you interfere with the
Speaker 3: firing of the other neurons, including in the cerebral cortex,
Speaker 3: you don't get freezing behavior. So it's the whole ensemble
Speaker 3: that's producing that behavior, not just the neurons in the
Speaker 3: But even more so, what's interesting is that if you
Speaker 3: put the animal in a different box, one that doesn't
Speaker 3: look very much like the box in which it learned
Speaker 3: to freeze, those neurons that you've activated are part of
Speaker 3: a different ensemble, and no freezing behavior happens. So you've
Speaker 3: got this situation where the neurons in question are clearly
Speaker 3: doing something, but whatever they're doing, they're working in a
Speaker 3: larger group, So their psychological meaning is related or relational
Speaker 3: or dependent on that group. And it's very context sensitive,
Speaker 3: and it's just explaining freezing behavior. It's not explaining all
Speaker 3: the other things that animals do in fear. This is
Speaker 3: just one thing they do in a particular kind of context.
Speaker 1: So when you look in a movie like Inside Out
Speaker 1: and you've got these different emotions and they hit a
Speaker 1: button and cause some behavior, what your research has shown
Speaker 1: for a few decades now is that it doesn't seem
Speaker 1: to be the right explanation for emotion. Why do you
Speaker 1: think that view is so popular? And more importantly, what
Speaker 1: is your theory about constructed emotions?
Speaker 2: Explain that to us.
Speaker 3: Yeah, well, first, can I just say about Inside Out.
Speaker 3: I have to say I've seen both movies and I
Speaker 3: love them. I think they're totally fun. They have really
Speaker 3: really clever metaphors that I love, and I think in
Speaker 3: the second movie, I particularly loved on Wei.
Speaker 4: I just love that character.
Speaker 3: But what I'll say is that I also really like
Speaker 3: Roadrunner and Wiley Coyote cartoons, but I don't think that
Speaker 3: I can learn physics from it. So the idea that
Speaker 3: you could learn neuroscience, the neuroscience of emotion from a cartoon,
Speaker 3: and particularly from Pixar that can put emotions into cockroaches
Speaker 3: and cars, and you know, they're so clever, right. I
Speaker 3: think there's nothing wrong with what Pixar did. It's it,
Speaker 3: but the marketing is is pretty problematic.
Speaker 4: And I also want to point out that you just
Speaker 4: watch any single one.
Speaker 3: Of those characters, anger or embarrassment, any of them, and they.
Speaker 4: Show a rate.
Speaker 3: They have a range of emotions, they display a range
Speaker 3: of expressions. If they only ever did their one thing,
Speaker 3: it would be a really boring movie.
Speaker 1: Yeah, so tell us about your theory of constructed emotion
Speaker 1: and what the right way is to think.
Speaker 3: About this, Well, I don't know if it's the right way,
Speaker 3: but it's certainly a different way, and I think a
Speaker 3: way that's more justified by the available evidence. And so
Speaker 3: I'll say that for a long time I didn't have
Speaker 3: a theory. I just was trying to learn. You know,
Speaker 3: we're faced with a paradox, really, and that is that
Speaker 3: there's no single biological marker or pattern of biological markers
Speaker 3: that like, no biomarkers for any category of emotion. Yet
Speaker 3: when I I'm angry, I feel angry, and I don't
Speaker 3: feel sad or happy or you know, I have an
Speaker 3: immediate reaction and I don't think about why I'm having
Speaker 3: it or which one I'm having.
Speaker 4: And pretty much.
Speaker 3: People, you know, that's their experience. They feel like emotions
Speaker 3: happen to them. It feels like something's being triggered. So
Speaker 3: you've got the subjective experiences of certainty.
Speaker 4: And then on the other hand.
Speaker 3: You've got this biological question of like, well, they're no
Speaker 3: markers anywhere. Plus what you have is tremendous variation across cultures,
Speaker 3: just even in the categories that exist. So not all
Speaker 3: the categories that we think of as basic in English
Speaker 3: actually exist in other languages, and there are many other
Speaker 3: categories that are basic for other languages that don't exist
Speaker 3: in our language. So how do you account for all
Speaker 3: of this in one theory? This this was a puzzle
Speaker 3: to me for a really long time. So what I
Speaker 3: did is I started to study brain evolution. So how
Speaker 3: did brains evolve and how are they structured? And how
Speaker 3: do they work? So instead of doing what most scientists
Speaker 3: do is they say, okay, well, I'm I'm really interested
Speaker 3: in anger, fear, sadness, so I'm going to go looking
Speaker 3: for the physical basis of those emotions in the brain
Speaker 3: or in the body. I started with the brain and
Speaker 3: body and said, okay, well, to the best of our knowledge,
Speaker 3: how did a brain like ours evolve, How does it work,
Speaker 3: how is it structured, what's its anatomy? And then how
Speaker 3: is it, you know, communicating with the body. And then,
Speaker 3: given that we have that kind of biology, how could
Speaker 3: it be creating the instances or the events that we
Speaker 3: experience as emotion. And I came up with a really
Speaker 3: different set of hypotheses that required a really different way
Speaker 3: of doing science. And it's a little more complicated. Then
Speaker 3: you've got a circuit in your brain that you were
Speaker 3: born with the triggers and then produces a you know,
Speaker 3: an emotion, prototypical motion, and the theory goes something like this,
Speaker 3: Your brain's most important job is regulating your body. It's
Speaker 3: not to think or feel or see even it's to
Speaker 3: regulate the systems of your body in a metabolically efficient way.
Speaker 3: That's actually the basis of everything your brain does, and
Speaker 3: anything you see or feel, or hear or think is
Speaker 3: in the service of that regulation.
Speaker 4: So that's the first piece. Your brain is part of
Speaker 4: this regulation.
Speaker 3: It's always receiving signals from the body and signals from
Speaker 3: the world. So every experience you have, every action you take,
Speaker 3: is some combination of what's inside your brain and what's
Speaker 3: outside your brain coming to the sensory surfaces of your body.
Speaker 3: So your brain's always regulating your body. Your body is
Speaker 3: always sending sensory signals back to your brain to report
Speaker 3: on the sensory constantquences of those movements inside your body,
Speaker 3: your heart beating, your lungs expanding, whatever. But also you're
Speaker 3: always receiving sensory signals from the surfaces, sensory surfaces that
Speaker 3: we think of as exte receptive signals The interesting thing
Speaker 3: is that these signals from the brain's perspective are ambiguous
Speaker 3: because the brain is trapped in a dark, silent box
Speaker 3: called your skull, and these signals are the outcomes of
Speaker 3: some set of changes in the body and in the
Speaker 3: world that the brain has no access to. Right So,
Speaker 3: like a loud bang could be a door slamming, a
Speaker 3: car backfiring, or a gunshot, what your brain will do
Speaker 3: to keep itself alive and well is very different in
Speaker 3: those circumstances. So how does it know? And the answer
Speaker 3: is it has to guess. This is what what philosophers
Speaker 3: call an inverse problem. And you know where you receive
Speaker 3: the outcome, but you don't know the cause. You have
Speaker 3: to guess at the cause. And what does the brain
Speaker 3: used to guess? It uses past experience. It's remembering, and
Speaker 3: you don't experience yourself remembering. But basically your brain is
Speaker 3: remembering a bunch of instances from the past that are
Speaker 3: similar to the present. A bunch of things which are
Speaker 3: similar is called a category.
Speaker 4: So your brain's.
Speaker 3: Basically using the past to construct categories in the moment
Speaker 3: that will allow it to prepare action. The interesting thing
Speaker 3: is that research suggests the brain is functioning predictively, which
Speaker 3: means the guest starts before the sensory signals arrive. So
Speaker 3: if we were to stop time right now, your brain
Speaker 3: is modeling that what it believes to be the sensory
Speaker 3: state of your body and the sensory conditions of the world,
Speaker 3: and based on that it's remembering. It's reinstating a bunch
Speaker 3: of partial representations a category that's similar to the present
Speaker 3: as a way of preparing the regulation of the body,
Speaker 3: anticipating the needs of the body, and preparing to meet
Speaker 3: those needs before they arise, so that movements can occur
Speaker 3: like eye movements or muscle movements, and the consequences of
Speaker 3: those movements are the predicted sensory inputs that are arriving
Speaker 3: from the sensory surfaces, and so the brain is comparing
Speaker 3: those and the result is your experience. So what's interesting
Speaker 3: about this perspective is a couple of things. One is
Speaker 3: that it's not like you see something and then react
Speaker 3: to it and then move Perception is a consequence of
Speaker 3: movement preparation, not the other way around. The brain is
Speaker 3: functioning predictively, even though it creates experiences of the world
Speaker 3: as if it's reacting to the world. So it's there's
Speaker 3: a real puzzle here, which is why would a brain
Speaker 3: function predictively but create experiences of reactions. Nobody knows the
Speaker 3: answer to that question. And the way that emotions are
Speaker 3: constructed are the way that every psychological feature is constructed.
Speaker 3: There's no specific set of mechanisms to emotion that would
Speaker 3: be different from cognition or perception or attention or what
Speaker 3: have you.
Speaker 4: Do.
Speaker 1: You think of emotion as being sort of a wider
Speaker 1: angle lens on a situation. So when I think about cognition,
Speaker 1: it feels like, Okay, what's the next chess move I'm
Speaker 1: going to make, and I'm really focused on something. Emotion
Speaker 1: sometimes feels to me like, you know, give me the
Speaker 1: wider view of what's happening here. Is this a good situation?
Speaker 1: This is a bad situation.
Speaker 3: I think that things like cognition and emotion and attention
Speaker 3: and perception are features of a brain state. I think
Speaker 3: if there are features that happen to be very salient,
Speaker 3: then we call the event a thought or a memory,
Speaker 3: or an emotion or a perception. But I think about
Speaker 3: the brain holistically as a dynamical system, a system of
Speaker 3: neurons and other bits and bobs that moves from state
Speaker 3: to state to state, and or you could say traverses
Speaker 3: of state space, you know, like it always is in
Speaker 3: a state and the nature of the state changes. So
Speaker 3: I think about emotions as you know, for example, your
Speaker 3: brain is always regulating your body, or you'd be dead.
Speaker 3: So it's always regulating the body. Body is always sending
Speaker 3: signals back to the brain. It's very infrequently that you
Speaker 3: will experience those signals as your heart pounding or your
Speaker 3: lungs expanding. You never feel, you know, your liver excreting
Speaker 3: chemicals or hormones, like, you just don't experience those things.
Speaker 3: The brain's tracking it, but it's not making that information
Speaker 3: available to itself. Instead, what we feel is affect We
Speaker 3: feel pleasant, we feel unpleasant, we feel calm, we feel
Speaker 3: worked up. Those are really simple feelings there that are
Speaker 3: with us all all the time, in every waking moment
Speaker 3: of life. So they're really properties of consciousness. When they
Speaker 3: get really intense, those are the moments that we experience
Speaker 3: them as emotions, but they're always there, even in moments
Speaker 3: of cognition or perception for example. I also want to
Speaker 3: say that there are many cultures in the world that
Speaker 3: don't distinguish cognition from emotion, Like, that's not how people
Speaker 3: in certain cultures experience themselves in the world. They don't
Speaker 3: make that distinction. That's a very Western distinction. And I
Speaker 3: think we have to have a theory of brain function
Speaker 3: that accommodates everybody's experience, not just certain people's experience. Because
Speaker 3: we happen to be the ones with the money and
Speaker 3: who are in control of the journals.
Speaker 2: You know, that's interesting. I mean, what's your experience.
Speaker 1: I feel like when I'm concentrating on something very specific,
Speaker 1: like the chest move, that feels different to me than
Speaker 1: if I'm just feeling generally happy or sad or something.
Speaker 3: It does, but so does in one instance of happiness
Speaker 3: can feel entirely different than another feeling of happiness. So
Speaker 3: my point the question we would ask, is there something
Speaker 3: similar to the brain state for lots of different instances
Speaker 3: of happiness. So we took all the instances where you
Speaker 3: were deciding on a chess move, would those brain states
Speaker 3: look more similar to each other than if we looked
Speaker 3: at all the brain states you had for chess moves
Speaker 3: and happiness. And the answer is not so far. There's
Speaker 3: just structured variation. So when you're happy, that's not the
Speaker 3: same state for you all the time. You know, people
Speaker 3: do lots of things when they are happy. They express
Speaker 3: in different ways. They have their menta mental features of
Speaker 3: their experience can change, their physical state can be different.
Speaker 3: It's not random. It's structured by the situation that they're in,
Speaker 3: including the physical condition of their body and their metabolic state.
Speaker 3: And there's nothing objectively more similar about those instances of
Speaker 3: happiness than is objectively different between happiness and instances of
Speaker 3: planning a chess move. And the interesting question there is
Speaker 3: why it feels that way to us. It's a question
Speaker 3: of consciousness, it's not a question of objective brain function.
Speaker 2: What is your take on that answer?
Speaker 1: Why it feels different, Why we have a distinction, let's say,
Speaker 1: in the West, between let's say, cognition on one end
Speaker 1: of the spectrum and emotion on another end of the spectrum.
Speaker 3: I don't know exactly why we have categories for cognition
Speaker 3: and emotion that are so entrenched, but I will say
Speaker 3: that they derived not out of a theory of brain function,
Speaker 3: but of a theory of morality. In ancient Greece, so
Speaker 3: that's how old they are. That you have an inner
Speaker 3: beast of emotions and instincts, and that inter beece has
Speaker 3: to be kept in check by cognition, by rationality. And
Speaker 3: if you keep that inner beast in check, you know
Speaker 3: you're a moral person and you're a healthy person. And
Speaker 3: if you don't, then you're either immoral, or you're immature,
Speaker 3: or you're mentally ill. This idea of that your mind
Speaker 3: is a battleground between cognition and emotion is a very
Speaker 3: old idea. You can see it in Plato's writings, and
Speaker 3: it's embedded in the law, it's embedded in economics. It's
Speaker 3: just a pervasive idea that has no evidence to support
Speaker 3: it in brain evolution or brain function.
Speaker 2: I have a question, though, I'm not sure.
Speaker 1: I think that's the distinction that I feel about, you know,
Speaker 1: keeping the beast in check. It's more like, if I'm
Speaker 1: planning my next let's say, chess move, then I'm thinking
Speaker 1: about steps.
Speaker 2: I can do it in a very clear, rational way.
Speaker 1: But if I'm at a party and I'm thinking, Wow,
Speaker 1: I'm having a great time at this party, or oh,
Speaker 1: I don't really like this party so much, or something
Speaker 1: I just you know, I have some feeling about it.
Speaker 1: I might not be able to specify the details of why,
Speaker 1: but nonetheless I'm you know, I'm a wash in some feeling,
Speaker 1: some emotion about this. And that's the distinction that I
Speaker 1: intuitively feel. I'm curious if you if you see that
Speaker 1: as a as a meaningful spectrum.
Speaker 3: So I would say it's a meaningful question about consciousness.
Speaker 3: It's not a meaningful question about brain structure or brain
Speaker 3: function in the sense that intuition, our intuitions, our experiences
Speaker 3: of the world in general are very bad explanatory guides
Speaker 3: for how the world works. And this is also true
Speaker 3: when the brain, when brains are trying to explain themselves, right,
Speaker 3: So I would say, yeah, I mean, there are probably
Speaker 3: times when you're planning a chess move that you're really frustrated,
Speaker 3: and there are probably times when you're really happy that
Speaker 3: you're thinking about strategically, how can I meet that person
Speaker 3: or how can I get away from this person? Or
Speaker 3: so I think that this is a question of which
Speaker 3: mental features are in the focus of attention and which
Speaker 3: ones are in the background. Like right now, for example,
Speaker 3: if you are sitting, are you sitting.
Speaker 2: Or stating I'm sitting.
Speaker 3: Okay, So right now, for example, you're probably not concentrating
Speaker 3: on the press of the chair against the back of
Speaker 3: your thighs until now that I just said it, you
Speaker 3: probably are thinking about that for a minute, right. So
Speaker 3: there are features of experience that are available to you
Speaker 3: that are not in the forefront of your experience, but
Speaker 3: you can move them in and out pretty easily. And
Speaker 3: that's really how I think about it. So, for example,
Speaker 3: the next time that you find yourself being really really hungry,
Speaker 3: take a moment and focus your attent on your stomach.
Speaker 3: Are you hungry or are you tired? Because if you're
Speaker 3: tired and you need some energy, your first reaction will
Speaker 3: be to eat, because you have a history of learning
Speaker 3: that energy comes from, Like the feeling of having more
Speaker 3: energy happens after you eat. But a lot of the
Speaker 3: time when we're tired, we should be drinking water, not eating,
Speaker 3: because dehydration is fatigue.
Speaker 1: You know.
Speaker 3: Research shows, for example, that when you drink a whole
Speaker 3: glass of water. Drink a glass of water, your thirst
Speaker 3: is immediately quenched, but actually it takes twenty minutes for
Speaker 3: the water to make its way into your bloodstream. To
Speaker 3: change the osmolarity of your blood to get to the
Speaker 3: brain to tell the brain that now you are hydrated.
Speaker 3: So the brain is constructing experience. It's predicting what the
Speaker 3: sensory consequences of actions will be, and you start to
Speaker 3: experience the consequences well before the actual input arrives to
Speaker 3: the brain to confirm those So I wouldn't go looking
Speaker 3: for distinctions between cognition and emotion because people have looked
Speaker 3: for those distinctions for years and years and years, and
Speaker 3: the one thing that we've learned from all of that
Speaker 3: research is that it's the wrong question to be asking. Instead,
Speaker 3: it's a question about experience and the way the brain
Speaker 3: is constructing experience lived experience, and that's where we should
Speaker 3: be asking those neuroscience based questions.
Speaker 1: I think, could the concept of constructed emotions tell us
Speaker 1: something about AI and the future of machines being able
Speaker 1: to simulate or understand our.
Speaker 3: Everything from evolutionary biology and neuroscience tells us that the
Speaker 3: core of brain function is rooted in the regulation of
Speaker 3: the body. There are metabolic constraints and selection pressures that
Speaker 3: give us the kind of mind we have, and that
Speaker 3: means that there's this sort of imperative that is largely hidden,
Speaker 3: but that scaffolds everything we see and feel and think.
Speaker 4: AI doesn't have that. I'm not saying an AI has
Speaker 4: to have a body.
Speaker 3: I'm saying it has to have a set of really
Speaker 3: complicated systems that it has to regulate, because that's actually
Speaker 3: at the basis of our human minds, actually of any
Speaker 3: mind of any living creature. I'm not reducing everything to
Speaker 3: metabolism or bodily regulation, but it's a hugely important piece
Speaker 3: that we all overlook because we are not aware of it.
Speaker 3: Right now, You and I and every listener has a
Speaker 3: whole drama going on inside each of us that we
Speaker 3: are I mean, I hope we're largely unaware of because
Speaker 3: whenever we become slightly aware of that drama, we're usually
Speaker 3: really uncomfortable and we can't pay attention to anything outside
Speaker 3: in the world. So I think that that's a huge
Speaker 3: piece of what it means to have a human mind.
Speaker 3: Evolutionarily and structurally and functionally, at the core of your brain,
Speaker 3: it's predictive regulation of the body. So exactly the same
Speaker 3: brain regions, exactly the same neurons in certain cases that
Speaker 3: are regulating the body are also implicated in attention or memory,
Speaker 3: or emotion or vision. Right, So the hippocampus. People think
Speaker 3: of this structure as being for memory or for spatial navigation,
Speaker 3: but it has more endocrine receptors than any other part
Speaker 3: of the brain.
Speaker 4: Except the hypothalamus.
Speaker 3: It is clearly a hub for the predictive regulation of
Speaker 3: the body, but that's not how people think of it
Speaker 3: because they're more concerned with understanding the other functions which
Speaker 3: result from that regulation, like memory or spatial navigation.
Speaker 2: How does your theory.
Speaker 1: Of emotion change the way that we think about mental
Speaker 1: health treatments like depression or anxiety.
Speaker 3: The way the brain regulates metabolism is that it's running
Speaker 3: a budget for the body, and I would say depression
Speaker 3: is a bankrupt body budget. The brain believes that there's
Speaker 3: a metabolic problem somewhere in the body, and so it's
Speaker 3: reducing energy output. And the way the brain reduces energy
Speaker 3: output is by reducing movement, reducing sensitivity to the outside world,
Speaker 3: and inducing feelings of fatigue so that you won't move
Speaker 3: very much. So you get context insensitivity, which is a
Speaker 3: major symptom of depression. You also get fatigue and motor retardation,
Speaker 3: so people don't move as much, They move more slowly,
Speaker 3: so the brain is attempting to reduce energy output. And
Speaker 3: the clincher for me is that a couple of things.
Speaker 3: One is that there's a test biological tests for depression
Speaker 3: that involves looking at cortisol levels, which is a chemical
Speaker 3: that people call a stress hormone. Cortisol is a is
Speaker 3: a glu It regulates glucose metabolism, So if you have
Speaker 3: problems with glucose metabolism, then you will very likely have
Speaker 3: depressed mood. And serotonin actually evolved as a metabolic regulator.
Speaker 3: Serotonin uptake reaptake inhibitors are not happiest drugs. They're drugs
Speaker 3: that influence metabolism, and whatever affective consequences they have are
Speaker 3: because they are regulating metabolism.
Speaker 1: So, Lisa, tell us some practical takeaways from your research
Speaker 1: that listeners can think about when they're thinking about how
Speaker 1: to manage their own emotions.
Speaker 3: The first thing I would be doing is asking yourself, like,
Speaker 3: when you feel like crap. Feeling like crap doesn't mean
Speaker 3: that something's wrong. It could mean that you're just doing
Speaker 3: something really hard, or that you didn't get a good
Speaker 3: night's sleep, or that you're dehydrated in some way, so
Speaker 3: it doesn't necessarily mean something is wrong with your life
Speaker 3: or something is wrong with you. In our culture, we
Speaker 3: believe that thoughts cause feelings, but actually, if you look
Speaker 3: at the predictive functioning of the brain, it suggests that
Speaker 3: the signals which give rise to feelings also.
Speaker 4: Give right to thoughts.
Speaker 3: So if you feel like shit, you're probably going to
Speaker 3: feel it's going to feel to you like you're a
Speaker 3: horrible person and that the world is terrible, or you
Speaker 3: need to divorce your spouse or your kids are you know,
Speaker 3: misbehaving or whatever. We have a tendency to see the
Speaker 3: world through affect colored glasses because of how we're wired.
Speaker 3: So the first thing that I do when I feel
Speaker 3: like the world is ending, you know, because lots of
Speaker 3: bad things are happening, The first thing I ask myself
Speaker 3: is did I get enough sleep last night? Have I
Speaker 3: had enough water to drink? Is it better for me
Speaker 3: to have a bath and go to bed and get
Speaker 3: up tomorrow and things will look different even in the
Speaker 3: worst of circumstances. That's always a good strategy.
Speaker 1: That was Lisa Feldman Barrett, professor at Northeastern University and
Speaker 1: one of the world's experts on emotion, and I'll just
Speaker 1: mentioned she's one of the top one percent of the
Speaker 1: most cited psychologists in the world.
Speaker 2: So to summarize what we.
Speaker 1: Saw today, for decades there was a research avalanche suggesting
Speaker 1: that emotions are the same across all people. And we
Speaker 1: had Darwin's universal expressions of emotions, and we had Paul
Speaker 1: Ekman's suggestion that there were a handful of basic emotions,
Speaker 1: and we had pixars inside out. There seemed to be
Speaker 1: a clear map of the emotional landscape that was coming
Speaker 1: into focus. But as we saw, Barrett and her lab
Speaker 1: came to very different conclusions. She became skeptical that there
Speaker 1: was universality of emotional expression, like what she mentioned about
Speaker 1: the assumption that people scowl when they're angry. But it
Speaker 1: turns out when you study this carefully, sixty five percent
Speaker 1: of the time people do something else when they're angry.
Speaker 2: They don't scowl.
Speaker 1: And also when you do see a scowl, it's only
Speaker 1: a fifty percent chance that this has to do with
Speaker 1: anger versus something else. So Barrett argues that emotions are
Speaker 1: not universal reflexes. They are instead constructed. They're shaped by
Speaker 1: the brain's predictive power, and our cultural context and our
Speaker 1: individual experiences. In other words, her framework highlights the role
Speaker 1: of the brain's internal model in interpreting sensations from the
Speaker 1: body what's called introception, and signing meaning to those sensations,
Speaker 1: creating what we label as emotions. It's a paradigm shift
Speaker 1: that invites us to reconsider not only what emotions are,
Speaker 1: but what they mean. If emotions are constructed, then they're
Speaker 1: not simply happening to us, they're happening with us. So
Speaker 1: take a minute to think about some moments in your
Speaker 1: life when you felt something deeply love or rage, or
Speaker 1: despair or hope. Barrett's framework suggests that in those moments,
Speaker 1: your brain was hard at work pulling together past experiences
Speaker 1: in bodily sensations and environmental clues to create the emotion
Speaker 1: that you felt. It wasn't a reflex, it was a narrative.
Speaker 1: And if emotions are readouts from the body, then maybe
Speaker 1: we can get just slightly more agency over them. Not
Speaker 1: in the sense of controlling our feelings, they're too complex
Speaker 1: for that, but in shaping how we interpret and respond
Speaker 1: to them.
Speaker 2: Take something like.
Speaker 1: Anger in the classical view anger is a red hot reaction.
Speaker 1: It's the little guy with fire coming out of his head.
Speaker 1: It's beyond our control. But if anger is constructed, maybe
Speaker 1: we can probe it a bit. What is my body
Speaker 1: telling me? Why does the situation feel threatening? How can
Speaker 1: I reframe this moment? Because emotions appear to be not
Speaker 1: something we simply have, but something we make, not pre
Speaker 1: programmed reactions, but dynamic constructions, shaped by our past and
Speaker 1: our brains predictions of the future. Understanding this can change
Speaker 1: potentially how we see ourselves and others. Are moments of
Speaker 1: joy and fear, and love and anger. They're not fixed,
Speaker 1: but they're flexible. They're a reflection of the stories that
Speaker 1: our brains create, and perhaps in knowing this, we can
Speaker 1: maybe learned to shape those stories a little better, not
Speaker 1: as readers, but as authors. Go to Eagleman dot com
Speaker 1: slash podcast for more information and to find further reading.
Speaker 1: Send me an email at podcast at eagleman dot com
Speaker 1: with questions or discussion, and check out and subscribe to
Speaker 1: Inner Cosmos on YouTube for videos of each episode and
Speaker 1: to leave comments.
Speaker 2: Until next time.
Speaker 1: I'm David Eagleman, and this is Inner Cosmos.