413 ‒ The neuroscience of emotion: challenging conventional theories of emotion and much more

1. 0:00 – 0:11

   Intro

   1. PAPeter Attia0:00

      [upbeat music] Hey, everyone. Welcome to the Drive podcast. I'm your host, Peter Attia. [upbeat music]

2. 0:11 – 13:00

   How unexpected results in graduate school changed Lisa’s understanding of emotion

   1. PAPeter Attia0:11

      Lisa, it's so great to see you, and I know how busy you are, so I'm, uh, incredibly appreciative of you making the time to sit down with me today.

   2. LBDr. Lisa Feldman Barrett0:19

      I'm delighted to be here, so thank you for the invitation.

   3. PAPeter Attia0:23

      So as we just discovered a few minutes ago, um, we both have this thing in common, having grown up in the same city.

   4. LBDr. Lisa Feldman Barrett0:29

      Mm-hmm.

   5. PAPeter Attia0:30

      Um, but it sounds like, uh, we've both lived in our current home longer than our previous home.

   6. LBDr. Lisa Feldman Barrett0:35

      Indeed. [chuckles] Indeed.

   7. PAPeter Attia0:38

      Um, I wanna kind of understand when the first time you appreciated the idea of emotions as a, as a topic for study.

   8. LBDr. Lisa Feldman Barrett0:50

      Well, when I was in graduate school, I-- So I, I, uh, went to graduate school to-- I decided not to go to medical school and like all my other friends, and I decided to go to graduate school to be a clinical psychologist. And so obviously, right away, you're starting to learn about emotion and how they work and what they are and so on. And so I thought I had a pretty good idea. Um, and I was, um, doing research for my PhD, um, actually on a topic that was something other than emotion, but I had to measure emotion. Um, and I did it in a pretty standard way, which is to ask people how they feel. Um, and, um, what I realized was that, um, I wasn't able to replicate the experiment. So usually in graduate school, what you do is you take a published a, a, a, a research study that's been published in a peer-reviewed journal. You try to replicate it just so that you can show that you know how to do an experiment. And then you go on, and you do your own stuff. So I was preparing for my own line of work, and I tried to replicate this experiment, and I realized pretty, pretty early on into it that the findings were not replicating. So I'll spare you all the gruesome details, but, uh, over a three-year period, I tried to replicate eight different-- eight different times, I, I tried to replicate experiments, probably a total of three or four experiments multiple times, and wasn't able to do it. And, um, my first response to that was, "Well, obviously, I'm not cut out to be, um, a scientist. Good thing I'll train to be a therapist." Um, and then I took a closer look at my data, and I realized that while I was not replicating the published work, I was replicating myself over and over and over again, which to me was an indication that something w- interesting was happening. And, um, and luckily, I was working with research advisors who were willing to be persuaded by, um, my observations.

   9. PAPeter Attia3:06

      So I just can't resist pulling on this thread, though, in that I wanna hear some of the details of this, 'cause I-- this was clearly such a pivotal moment in your career that, uh, it would be helpful, I think, for, for me and I think the listeners to understand the nature of these experiments, what was published, and why you couldn't reproduce it, and perhaps more importantly, what it is that you kept reproducing that was distinct from the published findings.

   10. LBDr. Lisa Feldman Barrett3:28

       Sure. So usually, when you ask people how they feel, you give them a set of adjectives or m- sometimes it's a set of statements, but some usually set of adjectives, um, um, which are labels for emotion categories, angry, sad, happy, whatever. And you ask people, you know, "How frequently have you felt this in the last week?" or, "How intensely do you feel this now?" Um, and in particular, I was really interested in anxiety and depression, um, and so I was also using clinical scales. Um, in this case, I was using, uh, a number of clinical scales, but including the Beck Depression Inventory and the Beck Anxiety Inventory, where you're asking-- you're giving people statements about, um, symptoms, um, and like, "I feel sad," "I feel tired," "I have no appetite." And you're asking people to rate the extent to which those symptoms describe, um, their experience. And in the, the studies I was trying to replicate were, um, basically, this was a-- these were a set of experiments about the self, about your self-concept, um, where if you compare your beliefs about who you are right now in relation to, say, who you ideally would like to be or who you think you ought to be, maybe because your parents told you this or s- there's some, you know, standard that you think you have to meet, that if you fail-- if you compare your experience of yourself as you are to, um, who you ideally would like to be, you would feel depressed. And if you, um, were failing to live up to the shoulds, the oughts, then you would feel anxious. This, of course, requires that people can distinguish between anxiety and depression as feeling states, where I wasn't really dealing with clinical samples at this point. Um, but, uh, one thing that I found was that, um, I wasn't able to replicate this effect because when people reported feeling anxious, they also reported feeling sad or depressed. And when they reported feeling, um, happy, they reported an absence of anxiety, and they would report feeling calm. So they were basically reporting, "I feel like shit," or, "I feel okay," even though the instruments I was using gave them the opportunity to be much more granular, much more specific And now, here what I was doing was what most scientists do, which is to test a group of people and then look at the averages, right, of, of the group and make inferences about it, about, you know, what you think is true based on what you observe, um, at the group level. Um, and the way that I phrased the question at that time was very much dictated by what I had learned up till that point, which is that, you know, anger, sadness, fear, depression, anxiety, you name it, emotions are biological categories that are distinct and that people were having trouble [lips smack] identifying what emotion they were experiencing. And so my first way of phrasing the question was, well, I wonder what features of emotion they're ignoring that d- you know, is causing them to fail to recognize the emotional state they're in. And very quickly, uh, once I actually started, um, I did more than just dip my toe into the emotion literature and read other people's summaries. I actually started digging into the papers myself. I realized actually that the phrasing of that question was in error, which meant something really interesting was going on, um, that an entire field seemed to be missing.

   11. PAPeter Attia7:41

       So Lisa, I wanna just recap something there to make sure I'm understanding it correctly. Um, what you just said actually answers a question I was about to ask, so I'll ask it only to make sure I understood. It seems to me that part of the difference was in the way you posed the question. Is that, is that a fair statement?

   12. LBDr. Lisa Feldman Barrett7:58

       At first, I posed the question the way that I had been taught to pose the question, which is this assumption that there's an assumption, right, that this assumption is still very much with us in certain circles that, you know, human infants are born with circuits embedded in some ancient part of their brain for angs- for sadness, for fear, for anger, for, you know, uh, there are a handful of categories. And that if you could find objective ways, meaning not self-report, so and we, we can come back to what this means, objective, because I think this is actually a big, um, this is a big issue I think.

   13. PAPeter Attia8:38

       It's a huge question. Yeah.

   14. LBDr. Lisa Feldman Barrett8:40

       It's a huge question. But the assumption was that objective meant not the experience of the subject. [chuckles]

   15. PAPeter Attia8:45

       Yeah. Yeah.

   16. LBDr. Lisa Feldman Barrett8:46

       That you could measure something else about the subject, maybe their blood pressure or their heart rate, or you could look inside their brain, or you could look at how their face moves or whatever.

   17. PAPeter Attia8:54

       Yeah.

   18. LBDr. Lisa Feldman Barrett8:54

       But that you could, in some way, determine, because these are biologically distinct categories with separate psychological features, that you should be able to, um, diagnose what emotional state a person is in, and if they don't report that state, then that speaks to the fallibility of-- it suggests that self-reports are very fallible, um, because, you know, there are these objective states. So the assumption is they're, they're these objective states. They're biologically distinct. That is, that the boundaries between these categories are in nature, right? They've been discovered by humans, not placed there by humans. And that there's some-- all instances of fear or anger or sadness, any category, but let's just take fear. All instances of fear should have some set of features that, um, make it fear and make a response fear and not something else like anger or sadness. Um, that is that, that, that all instances of that category should have an essence. So of course, I wasn't phrasing the question with that degree of specificity, but basically, I was like, well, we know that these are universal inborn states, so if people aren't identifying them distinctly, there's something wrong with the identification process. And that's where I started. And in the process of trying to look for an objective measure to diagnose someone's emotional state, I realized there are no, uh, actually objective measures, and that scientists have been debating this for 150 years, and I think at that point it would be more like 100 years since I've been at this for a while. And in science, it's often the case that when a debate, um, persists for a very long time, and even before, you know, even really I would say even before the scientific revolution, there were philosophers who were debating this. [chuckles] Um, when a question has been debated for a really long time, it often means the question's wrong.

   19. PAPeter Attia11:04

       Hmm.

   20. LBDr. Lisa Feldman Barrett11:04

       And that something else is going on. And because I hadn't been educated, schooled in theories of emotion and in the research, I came to it with like a blank slate, you know. I-- And I also came to it with clinical training, and this turns out to be, I think, maybe important, um, uh, to the story because one of the things you learn to do when you're a therapist is identify when people are lying to themselves in your presence.

   21. PAPeter Attia11:38

       Hmm.

   22. LBDr. Lisa Feldman Barrett11:39

       That is, when they're telling themselves a story that just doesn't quite add up. And what I found was a massive story, [chuckles] a massive case of a story not quite adding up. That there was a, I think at the time I would have said the dominant view, but I think at this point I might say a dogma, [chuckles] a bel- a set of beliefs about emotion that were in the research literature So what I discovered was that, you know, if you read the introduction sections of a paper and the discussion sections, they say one thing, but when I looked at the evidence in the results section, to me it said something entirely different. And this set me on the path to, um, where I am really today. I've changed my dissertation topic. I took an extra year to finish my dissertation because I completely changed my entire trajectory and did not become a therapist for very long. I'm-- was so en-enraptured really by the research process and the discovery that I just focused, um, exclusively on that.

   23. PAPeter Attia12:58

       So how did the previous

3. 13:00 – 28:06

   Why variation is the norm for emotion, and the danger in tracking averages instead of characterizing variation

   1. PAPeter Attia13:00

      scientists explain variance in response?

   2. LBDr. Lisa Feldman Barrett13:04

      Well, they, they do a couple of things, um, m-with variance. So, um, I mean, think about, think about-

   3. PAPeter Attia13:14

      Like you alluded to it earlier. You said basically-

   4. LBDr. Lisa Feldman Barrett13:16

      Yeah

   5. PAPeter Attia13:16

      ... they just took an average

   6. LBDr. Lisa Feldman Barrett13:17

      Think about yourself.

   7. PAPeter Attia13:18

      Yeah.

   8. LBDr. Lisa Feldman Barrett13:18

      When you're angry, when you're angry, what do you do when you're angry? Do you make a scowl when you're angry?

   9. PAPeter Attia13:23

      Sometimes.

   10. LBDr. Lisa Feldman Barrett13:24

       I mean, yeah, right, exactly. Actually, research meta-analyses, you know, statistical summaries of many, many studies of thousands and thousands of people show that in Western cultures, people, adults in urban settings scowl about thirty-five percent of the time when they're angry. That's more than chance.

   11. PAPeter Attia13:44

       Mm-hmm.

   12. LBDr. Lisa Feldman Barrett13:44

       So gets you a publication in a good journal, right? But that means sixty-five percent of the time people are doing something else with their face, and half the time when people scowl, they're not angry.

   13. PAPeter Attia13:54

       [chuckles]

   14. LBDr. Lisa Feldman Barrett13:54

       So if you used scowling as an objective measure of anger-

   15. PAPeter Attia13:58

       Yeah, it's got a horrible predictive value.

   16. LBDr. Lisa Feldman Barrett14:00

       Yeah, and I might just add, that's a lot of what AI, uh, emotion AI is doing right now, but, you know, that may be another topic. But, you know, you'd miss, you'd, you'd miss sixty-five percent of the cases, and half the time you'd be wrong.

   17. PAPeter Attia14:13

       You'd overcall it, yeah.

   18. LBDr. Lisa Feldman Barrett14:14

       Yeah. Actually, I, what I would say is, yeah, that's right. Yeah. You'd, you'd have both false positives and false negatives. And every category works that way of emotion, and it doesn't matter what measure you're using. It doesn't matter, you know, does the amygdala show an increase in activity during fear? Yeah. More than chance? Yeah, about thirty, thirty percent of the time it does, but it often doesn't, and it, you see amygdala activation m-in many, many, many, uh, instances of emotion that are not fear and also, uh, across a slew of other phenomena. So, so the, the way that people deal with variance, right? What do you do when you're angry? Well, sometimes you scowl, but probably sometimes you frown, and sometimes you might even smile or laugh. Sometimes you might remain silent, you know, and plot the demise of your enemy. [chuckles] You know, what, does your blood pressure go up, go down, stay the same? Yeah. It all depends on what you're about to do next, which depends on the situation that you're in. So emotions, when it comes to emotions, variation is the norm. People do a lot of different things in the same category. They feel-- Anger can sometimes feel pleasant. It's not always unpleasant.

   19. PAPeter Attia15:35

       Hmm.

   20. LBDr. Lisa Feldman Barrett15:35

       Anger sometimes distances people from one another, but other times it brings people together. And then there are cultural, massive cultural differences that we haven't even-- This is just, like, within one person o-over situations, right? So I think part of what scientists do, it-- The way to think about it, I would say, is that sci- The world is complex. Reality is super complex, and scientists simplify in order to study things, and this is normal. And one of the things that they s- they, they simplify is variance. They're, they try to often control variance as opposed to measure it. So one thing you can do in an experiment is try to capture as much variance as possible and try to model that variance, try to figure out its structure and, um, and how to predict it. Another thing you can do is you can try to limit variability, and that's what experiments typically in emotion up to that point had tried to do. So they would limit the number of categories being studied. They would limit the number of instances being studied. So the sampling of people, the sampling of, um, the stimuli, the triggers to, to pr-provoke emotion would be, uh, limited. Um, the modeling specific- the specifications of the statistical modeling would be designed in such a way as to remove variance or to, or to get rid of variance as error variance. Um, and when you start to look a little more closely, um, at the evidence, you can uncover that variance, and you can even design studies to cultivate that variance, actually, to, to try to observe it. Um, and in the end, that's, you know, that's what I turn to were, were methods like that.

   21. PAPeter Attia17:32

       So Lisa, I'm hearing two things that are related in question, but they seem distinct to me, and I wanna make sure that I'm understanding this because it seems to be the foundation of what was the widely held view at the time you were doing these experiments. The two things are, we should be able to objectively measure an emotion. And again, w- uh, I think that's a very straightforward proposition, um, based on people's understandings of what's objective versus what's subjective. We should be able to not-- We should be able to know your emotion without you telling us. Is that a fair way to say that?

   22. LBDr. Lisa Feldman Barrett18:07

       Yeah. What I would-- Yes, it is, but I just wanna point out that Always objectivity is with, in relation to the subject, meaning you should be able to measure something in a subject that the subject doesn't tell you.

   23. PAPeter Attia18:19

       Mm-hmm.

   24. LBDr. Lisa Feldman Barrett18:20

       But I think it's important to also realize that measurements are never objective because scientists... A scientist's... There's this, the synonym for a scientist's observation is the scientist's experience. I mean, sure, you know, you can quantify numbers, you can quantize it-

   25. PAPeter Attia18:40

       Well, that's why we have to, that's why we do blinding. That's why we want double-blinded studies whenever appropriate.

   26. LBDr. Lisa Feldman Barrett18:46

       Yeah, but you know what? You can have double-blinded studies, but if you think that a double-blinded study actually removes your theoretical view from your study, you're deluding yourself because all experiments are theory-laden. They're theory-laden in the way they're designed, their theory... That's not a bad thing. It just means if you recognize it's, that you can't, you can never have an experiment that s- that samples, um, in a theory neutral way. You can never have an experiment that runs statistical analyses in a theory neutral way. This is a mistake. It's a mistake that scientists often make. Um, once you realize that you yourself have a point of view, and even though you try really hard, you can double blind things, you can... You know, there are a lot of things you can do to try to control the influence of your own point of view. You can't remove it. And as a consequence of that, you can take other steps, additional steps to try to control it, um, that maybe aren't necessarily the norm, you know?

   27. PAPeter Attia19:51

       Can you give me an example? So let's take something, um, uh, uh, let's take the following experiment. I have a hypothesis that I give you, if I give you this pill, it will lower your cholesterol. So I'm gonna take 100 people, and without knowing which ones are which, half of them are going to get the pill that I think will lower their cholesterol, half of them will get a placebo pill. They'll take the pill for three months, and before and after they start, we will measure their blood level of this cholesterol. So what steps, what would, what steps would one have to take to remove as much bias as possible from that, besides the blinding, et cetera?

   28. LBDr. Lisa Feldman Barrett20:28

       What color is the placebo? How big is the pill? What are the other factors that are involved? You know, are your subjects... What are you controlling? Are you controlling what they s- how much they sleep? Are you controlling what they eat? Do, are you controlling, um-

   29. PAPeter Attia20:45

       But does randomization take care of that if I have a large enough sample?

   30. LBDr. Lisa Feldman Barrett20:48

       It doesn't take care... No. So here's the thing.
4. 28:06 – 38:04

   Lisa’s experience with Hashimoto’s disease and the value of modeling individual variation

   1. LBDr. Lisa Feldman Barrett28:06

      uh, I was diagnosed, as many people are, um, with Hashimoto’s disease, and I went to see an endocrinolo- so that's like, you know, where your immune system is destroying your thyroid. And I went to an endocrinologist who was a great endocrinologist. He was super, super knowledgeable. And he said... I said, "So what's the treatment?" And he said, "Well, we just wait for your immune system to destroy your thyroid." I mean, he wasn't being flippant about it, but, you know, he said-

   2. PAPeter Attia28:28

      Yep

   3. LBDr. Lisa Feldman Barrett28:28

      ... "We'll wait till your thyroid is destroyed, and then you start taking synthetic hormones." And I thought, "Yeah, no. I don't think so." [laughs] And so I did something that I often do when I'm dealing with my own physicians. Uh, I went to PubMed, and I just started to read about thyroid diseases. And a gr- admittedly, I'm not an expert, but, you know, I have some ability to read papers. And I found a series of studies which showed really clearly that if you give low doses of levothyroxine, which is a syn- synthetic-

   4. PAPeter Attia29:00

      Synthetic, yeah

   5. LBDr. Lisa Feldman Barrett29:00

      ... thyroid, you can arrest the progress. These aren't clinical trials. They're not large, and they don't, it doesn't work for everybody. So I took, I went back to him, and I went, "Look at these studies." And he said, as you would expect, as I expected, "Yeah, but there are no clinical trials." And so then I explained the thing about averages. [laughs] And then I said, "Yeah, but it seems like it works for some people, and maybe I'm one of those people, so let's do a little experiment." And he was game because, you know, I mean, it's not terribly dangerous to take a low... I mean, there are some things you have to work out, watch out for.

   6. PAPeter Attia29:36

      Yeah.

   7. LBDr. Lisa Feldman Barrett29:37

      Um, um, but we did it together because, you know, he lis- I mean, he was very... We were, we had an open dialogue. And sure enough, not only did it arrest the disease, it actually reversed some of the damage.

   8. PAPeter Attia29:51

      And, and sorry, just to make sure I understand, does that mean that your antibodies went from positive to negative?

   9. LBDr. Lisa Feldman Barrett29:56

      It means... No. It means that, like, nodules disappeared from my thyroid-

   10. PAPeter Attia30:02

       Hmm

   11. LBDr. Lisa Feldman Barrett30:02

       ... and, you know. So what it means is that the damage was-

   12. PAPeter Attia30:05

       But-

   13. LBDr. Lisa Feldman Barrett30:05

       The, the, the antibodies went down. The damage was actually, uh, first arrested and then eventually started to reduce a little bit. And now, um, you know, I'm kind of like a borderline case. I was not a borderline case to begin with. It should have progressed, but it didn't. And I'm not saying it's magic. What I'm saying is that- Um, this is not something that everybody who has thyroid disease should do. It's not gonna work for everybody. Studies already show that. But it will work for some people, and it worked for me. And, uh, uh, this is one example in many, many cases where when you set aside the averages-

   14. PAPeter Attia30:47

       Yeah

   15. LBDr. Lisa Feldman Barrett30:47

       ... what the averages tell you, and you look for variation, and you look for meaning. I mean, it could have happened that it did nothing, but that's not what happened in this case. That doesn't necessarily mean that, um, like I said, that this will work for everybody, and it won't. And it might not work for me forever either. But the thing is, though, now I'm on a low dose of levothyroxine, and I'll be on that low dose for the rest of my life, but that's better, I think, to still have a thyroid and be on this low dose than to be on a much larger dose and not have one for the rest of my life. Uh, I guess I just would... To me, this is just an example. Doesn't prove anything, but, but there are many, many, many, many published studies which do make the point that averages hide meaningful variance, and this is the case, this is absolutely the case when it comes to the science of emotion. Averages or statistical summaries hide v- meaningful variance that is important in everyday life. So if you construct your experiment in a way, in a lab, in a way to get rid of variance, you are creating a fiction that will not predict anything in the real world.

   16. PAPeter Attia32:05

       Yeah, I couldn't agree with you more.

   17. LBDr. Lisa Feldman Barrett32:06

       Let alone replicate.

   18. PAPeter Attia32:07

       Yeah.

   19. LBDr. Lisa Feldman Barrett32:07

       Let alone replicate, you know? Because-

   20. PAPeter Attia32:08

       No, no, I, I mean, I, I agree with everything you're saying, Lisa. I probably, on a personal level, frame it a little bit differently, and I'll, I'll, I'll frame it back to you, but I, I completely agree. Um, I, I have sort of a way that I talk about this in the context of my world, right? So I talk about this thing called Medicine 3.0, and I contrast it with Medicine 2.0, and I say one of the limitations of Medicine 2.0 is it homogenizes data, which is just basically saying what you're saying, right? We... The, the, the, the, the bedrock of Medicine 2.0 is the randomized control trial, where we take a very heterogeneous group of individuals, we apply a clean, homogeneous treatment, and then we homogenize what comes out, and that becomes the recommendation. And on average, that is an excellent way to practice medicine.

   21. LBDr. Lisa Feldman Barrett32:56

       Well, I would say on average, it's a better way to practice medicine than the other ways, for sure.

   22. PAPeter Attia33:01

       Yes, yes. But, and then where I think we would agree is the challenge with that is the variability gets lost. There's nuance that get lost. So I'll give you one example from, from my world. There's a drug called Zetia or ezetimibe. It is a cholesterol-lowering drug, and it has a very specific mechanism of action. It works by blocking, uh, the, one of the r- uh, transporters on the cells of the gut and the liver that reabsorb cholesterol. [lip smack] Now, when you look at the clinical trials of Zetia given as monotherapy, it is rather underwhelming. And we could, uh, without getting into the nuances of it, there was a huge debate as to whether anyone should ever receive Zetia in monotherapy. Um, and it was viewed as not an evidence-based approach because it didn't have the hard outcome trial that said, "If you give Zetia in monotherapy, you will save lives." But once you understand the mechanism of how ezetimibe works, and you understand that we can measure a person's cholesterol absorption using other biomarkers, we could selectively target people who are very high cholesterol absorbers, and those are the people that would do very well in monotherapy. And lo and behold, we do this now. This is what I would call precision medicine or evidence-informed medicine, right? And I think there's still a lot of pushback to that approach. And I would argue that what you've pointed out is another example of that, which is to say, on average, giving Zetia as monotherapy probably doesn't save lives. But if you could target the people who are super responders-

   23. LBDr. Lisa Feldman Barrett34:35

       Yeah, for sure.

   24. PAPeter Attia34:36

       Yeah.

   25. LBDr. Lisa Feldman Barrett34:36

       For sure. For sure. So let me just be really clear. I'm not saying we should throw out clinical trials.

   26. PAPeter Attia34:41

       No, no, I didn't, and I'm, and I want to make sure that the listeners hearing-

   27. LBDr. Lisa Feldman Barrett34:43

       Yeah. Yeah

   28. PAPeter Attia34:43

       ... uh, you and I are on the same page.

   29. LBDr. Lisa Feldman Barrett34:45

       Yeah. Yeah.

   30. PAPeter Attia34:45

       I think what you're saying is very important, and to me, this is exactly where AI could make an improvement in how we interpret clinical trials because we wouldn't have to hide, we wouldn't have to try to compress variability. We could actually explore it more fully.
5. 38:04 – 47:44

   How Lisa’s research challenges common views about emotions, and why there is no biomarker for emotions

   1. LBDr. Lisa Feldman Barrett38:04

      to do it.

   2. PAPeter Attia38:05

      Okay. I wanna go back to one other thing that you said at the outset that I, I think is important for us to ground ourselves in, which is part of what maybe we would call this foundational belief you came into. So one of them we've just talked about, which is, um, the objective measurement of emotion. But then there's something else you talked about, which is a belief that emotions are universal, that emotions are hardwired into our nervous system. And it, and it sounds like you were saying, "No, I ca- I don't think that's the case." These two observations, that emotions are not hardwired into our nervous system and that we don't have an objective way to measure them with a biomarker, those are not-- Those don't require each other to be correct.

   3. LBDr. Lisa Feldman Barrett38:53

      Oh, no. And-

   4. PAPeter Attia38:53

      Those are independent observations, right?

   5. LBDr. Lisa Feldman Barrett38:55

      No, exactly. And also, I mean, I, I think it took me, oh, geez, probably a good 20 years-

   6. PAPeter Attia39:07

      Hmm

   7. LBDr. Lisa Feldman Barrett39:07

      ... before I was willing to say that there was no biomarker. I mean, you know, because I, I had to learn a bunch of literature. I had to retrain basically three times in order to, [chuckles] um, be able to make that claim, you know? I, I think o-one of the things that I became very clear in my own mind about was that I wasn't gonna be able to rely on the summaries of other scientists. I wanted to be able to collect the data and observe myself, and I also wanted to be able to dig into their studies and understand for myself. So basically, I was taking a very empirical stance towards published studies. N-When graduate students sometimes ask me, "Well, how do you-- what do you do when you read a, when you read a paper?" I say, "Well, I read the few sentences that in the introduction that outline the hypothesis. I read the methods and the results, and I throw the rest away. I don't read the introduction. I don't read the discussion. I don't care. I wanna make my own judgment about what I think that shows. And then I will go back and, you know, maybe read or maybe ask colleagues who I, you know, trust." Um, because I'm very aware of how theory-laden publications can be. And so it's not something-- it's not like I ran a couple of studies in graduate school and came to this conclusion. I ran some studies in graduate school and discovered I had to learn how to measure facial movements objectively. And then when that didn't pan out, I had to learn physiology so I could measure physiological patterns to see if there were objective biomarkers. And then when that didn't pan out, I had to retrain in neuroscience to be able to do brain imaging, um, to check that, right? I mean, so I'm not-- These are not conclusions. Same thing about universality. We didn't-- I didn't just read a bunch of papers and test a bunch of college students. Our lab went to Namibia-

   8. PAPeter Attia41:19

      Mm

   9. LBDr. Lisa Feldman Barrett41:19

      ... and we tested the Himba, you know, who live in, um, northwestern Namibia. Um, we went to Tanzania and tested the Hadza hunter-gatherers. We went to rural China. We went... You know, so of course, we used other people's experiments too. We used their data. We used their studies to draw conclusions. But we didn't only do that. We also went and did our own studies, um, um, using-- where we used multiple methods. And it's very, very clear what you find. Um, the findings are really, really clear, and they're clear across domains. It doesn't matter what you measure. Variation is the norm. There's structure in that variation. It's meaningful. It's not that we can-- It's not that it's random. It's not that we can't say anything important about emotion. And also, I didn't come up with my own views on what emotions were or, or how they work right away. I really spent really many years trying just to [chuckles] figure out the simple, um, answer to the question of are there biomarkers and is-- and, you know, are-- is there univer- are there-- is there universality? Like, and what is it that, you know, infants actually can do or can't do? Um- And then I started to think about, well, we have a real paradox here, right? I experience emotion, and I'm pretty certain about what I experience, and I'm sure you do too. And you and I could be, um, you know, at a coffee shop having a conversation, and I would f- ex- I would feel like I was reading your emotions, and you would feel the same.

   10. PAPeter Attia43:03

       Hmm.

   11. LBDr. Lisa Feldman Barrett43:03

       So how is it that this is, that this is the case, and then there are no biomarkers? [laughs] Like, this just felt y- like a really big puzzle.

   12. PAPeter Attia43:10

       I- if it makes you feel any better, Lisa, in, in, in the world where I spend m- all of my time, we don't have a biomarker for aging.

   13. LBDr. Lisa Feldman Barrett43:20

       Right. [laughs]

   14. PAPeter Attia43:20

       Now think about that for a moment. Is there anyone-

   15. LBDr. Lisa Feldman Barrett43:23

       Right

   16. PAPeter Attia43:23

       ... listening to us that disputes that we age? No, of course not.

   17. LBDr. Lisa Feldman Barrett43:27

       No. Right.

   18. PAPeter Attia43:27

       We, we are aging. Do we all have-

   19. LBDr. Lisa Feldman Barrett43:29

       Right

   20. PAPeter Attia43:29

       ... a gestalt of how somebody is aging? Sure. I can look at a person who tells me that they're 60, and I say, "Gosh, they don't look a day over 45." Okay, they're probably aging slower, at least in some dimensions. Of course, I can't see what's happening inside their body. Um, and yes, on average, we can measure things that are changing as a person ages. Their bone density goes down, their muscle mass goes down, they become a little bit more insulin resistant, et cetera. But to actually suggest that at the individual level I could measure anything in you, Lisa, and then do an intervention and then measure it again in a year and definitively conclude I have slowed your rate of aging, absolutely not. Now, there, there are a lot of people that tell you they can do that. It is-

   21. LBDr. Lisa Feldman Barrett44:12

       Sure

   22. PAPeter Attia44:13

       ... absolute nonsense. A- I mean, this is challeng- I mean, this is brutal. It's a, it's a brutal reality.

   23. LBDr. Lisa Feldman Barrett44:19

       Well, it, I don't th- I don't think it's a brutal reality. I think it's a reality, and I think that, that reductionist science isn't the method to get at that brutal reality.

   24. PAPeter Attia44:33

       So, so does that mean you've given up on the biomarker? Do you believe that in 10 years we will have, um, biomarkers for emotions?

   25. LBDr. Lisa Feldman Barrett44:43

       No. I don't think it works like that.

   26. PAPeter Attia44:45

       Okay.

   27. LBDr. Lisa Feldman Barrett44:46

       What I will say is if I measure you-

   28. PAPeter Attia44:48

       Mm-hmm

   29. LBDr. Lisa Feldman Barrett44:48

       ... personally, Peter, uh, many, many, many times over many, many, many situations, and I used a personalized AI for you, I could probably learn to reasonably predict the vocabulary of angers and sadnesses and fears and so on that you experience. That's what I think is plausible.

   30. PAPeter Attia45:16

       You can't use that in a, in an experiment you do with 100 college students, right? That wouldn't help you as much.
6. 47:44 – 52:29

   The difficulty of defining emotions and the brain’s role in regulating the body

   1. PAPeter Attia47:44

      what can we say about an emotion? If you were now trying to explain to somebody what emotions are, we've, we've said two things that we know on the negative. We know that they can't be measured objectively, and we know that they are not necessarily hardwired into each of us as identical states. Fear is not universal.

   2. LBDr. Lisa Feldman Barrett48:05

      Well, let me ask this question. Yeah.

   3. PAPeter Attia48:07

      Yeah.

   4. LBDr. Lisa Feldman Barrett48:07

      Let me ask this question, Peter. What is hardwired into the brain? What is hardwired?

   5. PAPeter Attia48:12

      Yeah, it's a great... I mean, I think certain reflexes are clearly hardwired, right? So for example, if I shine a bright light into your eye, I think it is hardwired that your pupil will constrict, right?

   6. LBDr. Lisa Feldman Barrett48:24

      It will, but how much will it constrict? And, you know, even reflexes which are hardwired are, are not har- they don't always look, they don't m-

   7. PAPeter Attia48:31

      The degree to which. Sure. Yep.

   8. LBDr. Lisa Feldman Barrett48:33

      Yeah. No. Well, but that matters, I think.

   9. PAPeter Attia48:36

      Yes.

   10. LBDr. Lisa Feldman Barrett48:36

       So what I would say is that there's very little in... It's just like genetics, right? I mean, there, sure, there are some cases where a single gene predicts a single characteristic [laughs] a- you know, with a single allele, right?

   11. PAPeter Attia48:51

       Yep.

   12. LBDr. Lisa Feldman Barrett48:51

       Uh, I mean, but those are really rare. Most ... ge- most of genetics doesn't work like that. And I'm certainly not the first person to point out that, you know, NIH spent a tremendous amount of money, um, trying to map the human genome on the assumption that that, you know-

   13. PAPeter Attia49:13

       Yep

   14. LBDr. Lisa Feldman Barrett49:14

       ... would actually, if we just g- knew the genes, we'd, we'd be set. A lot of the devil is in the details of how, of the mechanisms, right? Because of this complex causation, um, that happens, and I would say the same is true, um, in the case of emotion, and pretty much the case of anything a brain does. So the, first of all, I would not-- When someone asks me, "How do you define emotion?" I say, "I don't." [chuckles] You can't. How do I def- I could, it, the way I would define it would be generic. It would be like, well, any mental event basically could, um, you know... The, your brain's most important job is regulating your body, coordinating and regulating your body in the most efficient way. That's why brains evolved. They evolved for, they evolved at the same time as, um, invertebrates. I'm only speaking about vertebrates. I don't know anything about invertebrates. But invertebrates, they evolve around the same time as you get visceral organs and, and you know, a head, and s- distant senses and eyes and, and ears and so on.

   15. PAPeter Attia50:19

       Let's probe that a little bit more. So, so this, th- I think you, you said something in passing that, that is a pretty big idea, right? You've said that the, the purpose of the brain is to support the body. Can you double-click on that a bit more?

   16. LBDr. Lisa Feldman Barrett50:33

       Yeah. So I wouldn't, I'm, I'm trying not to be ter- I mean, I was a little sloppy and a little teleological about it, so I, I would prefer to back up and say, like, the brain's most important job, I'm not saying it's, it's, that's its sole purpose.

   17. PAPeter Attia50:44

       Okay.

   18. LBDr. Lisa Feldman Barrett50:44

       But I think, um, that, um, its most important job is regulating and coordinating the systems of the body, and everything, I think everything it does, psychologically speaking, it's doing in the service of that. And that means that metabolism, writ large, is important to things like feeling and thinking and remembering and, and so on and so forth. So that's a key assumption in our lab that we use when we're designing experiments now. Um, and w- so what I would say is the brain is always receiving signals from the sensory surfaces of its body. Your brain isn't running a model of the world. It's running a model of your body and the sensory surfaces of your body, and of course, some of those sensory surfaces take in signals from the world, some of the signals from the world, but it only knows the world through the body. There's no other way to know a world than through your own body. So your brain is running a model, basically, of signals from the sensory surfaces. It's attempting to predict those signals and give them meaning because those signals that it's receiving are the outcomes of some set of changes that the brain doesn't have access to. It only has access to the outcomes, the signals themselves, and that's an inverse problem. It means the brain has to infer what caused that loud bang, what caused that flash of light, what caused that tug, what caused that change in glucose. It has to make inferences about that, and sometimes those inferences are emotions, and sometimes they're not.

   19. PAPeter Attia52:28

       Okay, I'm gonna-

7. 52:29 – 59:07

   Consciousness, interoception, and the limits of subjective experience

   1. LBDr. Lisa Feldman Barrett52:29

      That's what it is

   2. PAPeter Attia52:29

      ... ask a question that I, I never, uh, yeah, I, I, this is a question I personally struggle with, which is: How do we define consciousness, and how does consciousness overlap with emotion?

   3. LBDr. Lisa Feldman Barrett52:42

      So, yeah.

   4. PAPeter Attia52:43

      I s- I could see the look in your face. I intuited your emotion when I asked that question-

   5. LBDr. Lisa Feldman Barrett52:48

      [chuckles]

   6. PAPeter Attia52:48

      ... and the valence is negative. Why?

   7. LBDr. Lisa Feldman Barrett52:50

      [chuckles] Well, what I would say is that, why is it? Because I think, um, I think that there are a lot of questions that you could answer about emotion without having to take on the big question of consciousness. But, um, but I would say, um, the following, I guess, that, um, I don't know if it's that we're asking the wrong questions or asking questions in the wrong way, but, um, a lot of people have a lot to say about the nature of consciousness, none of which actually explains, [chuckles] um, how it is that we are sentient and how it is that we have c-content, that there's content, that we get content out of, out of electrical and chemical changes. And, um, I just prefer not to speculate. It doesn't mean that I'm not interested. It doesn't mean that I, I'm not curious. I'm, I'm very interested and curious, but I also am not a fan of talking out of my ass, you know? Like, I just, um, I think that we don't know enough maybe yet to ask the right questions or whatever, so we should continue to explore and debate and whatever, but you know, like, people publish books, and they make claims about consciousness. So here's what I have to say. Emotions, um, are there aspects of emotion that you're not conscious of? For sure. [chuckles] That has to be the case. You're not conscious of most of what goes on inside your own body, thank God.

   8. PAPeter Attia54:36

      Mm-hmm.

   9. LBDr. Lisa Feldman Barrett54:37

      'Cause if you were, you'd never pay attention to anything outside ever again. Just think about the last time you ever had, like, gastric distress. [chuckles] I mean, you just can't, you know, you can't focus. It's, there's so much going on in there, right? And we don't have access to most of it. Most of the details are compressed out of the signals before they reach the brain. What the brain is receiving about metabolic and interoceptive signals from the body is more like a gist. It's not getting specific details about everything. It might compute details, like it might infer those details, but like there's no visceral, there's no visceral map of the body in the brain that anybody has found. Some people claim they find it, but when you look closely, they don't. It's not like a retinotopic map, right? So your, your brain has V1, primary visual cortex, has a map of the retina. There's array to array mapping, meaning you have an array-

   10. PAPeter Attia55:40

       Yep

   11. LBDr. Lisa Feldman Barrett55:40

       ... of cells in your retina, you have an array in your brain, they map. The mapping changes all the time, right? So, uh, what a, like we would say the, um, the, um, receptive field of a V1 neuron, a pr- a neuron in primary visual cortex changes actually with the context of, with the neural context of the brain. But it's always the m- it's always a map, right? But there is no map of the body like that in your brain, just like there is no map of your olfactory sys- There's, you know, you have olfactory receptors in your nose. There's no map. There's no spatial map in your brain. That information is compressed out of the signal before it ever reaches your brain. There's temporal information, but not, um, not spatial information. In the body, the, the brain has like... It can tell... There's some spatial information, like is, is a signal coming from the thora- upper thorax? Is it coming from the gut? You know, lower... It's not even gut so much as like lower part of your abdomen, upper part. There's like a little bit more detail here. But it's nothing like a retina or a cochlea where you have array to array mapping. This turns out to be super important. Um, um, you know, we- in science, people talk about exteroceptive versus interoceptive, like signals that come from the world versus signals that come from the body. That turns out not to be so important, I think. I think what's more important is, is it a proximal sense or a distance sense?

   12. PAPeter Attia57:10

       Hmm.

   13. LBDr. Lisa Feldman Barrett57:10

       Meaning the, the distance senses, the best examples are vision and audition. They're processed... The c- the signal processing, the compression of those signals is very different in the brain than, say, olfaction, which is a proximal sense, or gustatory or anything interoceptive. Gustatory is usually considered, um, interoceptive. Um, taste is not, but gustatory, you know, signals from the gut are interoceptive. So, and then there are a bunch of signals that kind of don't fit the exteroceptive, in- the internal-external distinction. Like proprioception, is that internal or external? It's kind of both, right? So if you just look at the signal processing, the signal processing properties, then other distinctions become important. And I would say it's the same thing about cognition and emotion or thinking and feeling. There aren't a lot of distinctions that you can find in the brain or anywhere else to distinguish what is a thought and what is a feeling. But there, if, but if you look at the signal processing, you know, architecture and dynamics, other distinctions become important for explaining how a thought arises or how a feeling arises. None of those explain how you get from, you know, um, a very, very high dimensional set of chemical and electrical signals to a very low dimensional, um, you know, um, mental feature like, um, pleasantness or unpleasantness. Like nobody has that. Um, and if they're claiming to, which some people claim they do, then they're lying either to you or to themselves, probably to themselves in your presence.

8. 59:07 – 1:13:05

   Defining emotion: fear and anger

   1. PAPeter Attia59:07

      So let's try to disentangle without defining an emotion some of the broad differences between, say, the positive and negatively valenced emotions. So again, we'll go back to this idea that there's a belief that, God, some of these are really primal. Like I'm gonna anthropomorphize this as well, right? So fear is so essential, right? Without fear, we could not have evolved as a species. We couldn't have figured out a way to avoid predators or things like that. Um, so let's just start with fear. What is it that, that you could say today we know about that emotion?

   2. LBDr. Lisa Feldman Barrett59:45

      I'm just gonna let the point go about we couldn't have evolved without fear. [chuckles] Like it's a primal emotion.

   3. PAPeter Attia59:51

      And, and by the way, feel free to attack that point by, by the way. I just, I'm just-

   4. LBDr. Lisa Feldman Barrett59:54

      No, I don't even want to attack that point. It's just I, I don't think that's gonna take us down a productive avenue. But w- here's what I'll say about fear. There are no pleasant or unpleasant emotions. You think fear isn't pleasant? People pay money to go on a rollercoaster. They pay money to go to a horror movie. I used to run a haunted house in my basement for charity for 13 years-

   5. PAPeter Attia1:00:13

      [laughs]

   6. LBDr. Lisa Feldman Barrett1:00:13

      ... an auspicious number, where we scared the shit out of people.

   7. PAPeter Attia1:00:17

      [laughs]

   8. LBDr. Lisa Feldman Barrett1:00:18

      We donated all the money, but we scared... We basically... I used to tell people, "I scare little children for ch- for..." I sc- you know, I, I have their parents pay me, and I scare little children for money, and then I donate it all to the Boston Food Bank, which is what we did for years and years and years. And we had three levels of scary, you know? Um, so people could choose and, and, um, and all of my graduate students helped us-

   9. PAPeter Attia1:00:41

      But is that, is that a uniquely, is that a uniquely human feature? Is there any evidence that in, that anything else in the animal kingdom will voluntarily put themselves in a situation that produces fear?

   10. LBDr. Lisa Feldman Barrett1:00:52

       Yeah. Absolutely. I mean, there are an- there is a wh- there is a whole literature on how animals play, and, um-

   11. PAPeter Attia1:00:59

       Hmm

   12. LBDr. Lisa Feldman Barrett1:00:59

       ... and they're often playing in ways that would, you know, that could be considered ... practice. Like it, it's a way-

   13. PAPeter Attia1:01:08

       Interesting

   14. LBDr. Lisa Feldman Barrett1:01:09

       ... of foraging for information and for, like, innovation basically. Um, whether they are feeling fear, I can't comment on that, but what I would say is that you don't have access to whether an animal, what an animal feels. You've, you're... If you experience, if you look at an animal and you say that animal is fearful, that's your experience of what those signals mean out of that animal, and that doesn't necessarily mean that it tells you anything about what's actually going on inside that animal from a feeling perspective. However, I think you can say, like if you watch an animal work hard to avoid certain stimuli, um, that will pr- cause it damage, right? Or if you, if an animal is willing to, like, expose its... So you, there are these studies, you know, where they'll, like, damage an animal in some way, and then the animal will actually work hard and even expose itself to the possibility of a predator in order to get an opioid. That's a pretty good indication, I think, that the animal is feeling something like pain. Maybe not the way we feel pain, but it's definitely feeling something unpleasant because it's willing to incur a cost, a significant cost in order to, um, um, to get a drug that will reduce presumably its awareness of the... Well, maybe awareness isn't the... But you know, it's feeling in relation to some kind of tissue damage. Um, that's very different than what, like, a fly will do, you know, where it does, you know, you damage the leg of a fly or a wing of a fly and it will still continue to behave in exactly the same way. Um, then, you know, you, you know, you can sort of make inferences that way, which I, I... So I'm not talking about pleasure and pain. I'm talking about the specific, the specific categories and distinctions that we make about humans that come from human experience. You have to be super careful when you impose those on other creatures to which, for which we have no access to what they experience. And not, so I'm not advocating to assume that they experience nothing. I'm saying that you just have to be careful, and there are lots of reasons for being careful, both for them and for us. But what I would say about fear is that, you know, what do you think the, the, um, the o- what do you, what is the, um, what is the, what would you think is the prototypic response in fear? Um, to freeze or to run away. Um, well, you know, there's-

   15. PAPeter Attia1:03:55

       I, I, I think it varies. And, and by the way, can-

   16. LBDr. Lisa Feldman Barrett1:03:57

       Well, sure it does, but I mean the theory is in the literature, if you ask most people, fight or flight-

   17. PAPeter Attia1:04:03

       Yeah

   18. LBDr. Lisa Feldman Barrett1:04:03

       ... you know? They're like, "Flight. Flight." They'll freeze. An animal will freeze, you will freeze, or you will, um, flee. But there's a, um, you know, a culture where what people do when they feel afraid is they go to sleep. That seems weird to us, but you can look in the animal kingdom and you can find out that in invertebrates in the water, animals, when there's a predator, will play dead. They will slow their heart rate so sharks can't find them. They will not move. They're not freezing. They're reducing their, um, kind of, um, detectable output so that the predator can't find them. So I, I think, um, I guess what I would say is when it comes to fear, what we could say is that variation is the norm, and that, that what you feel in fear, what you do in fear depends on the situation that you're in and, um, what you're gonna do next. Because your brain doesn't react to things. It predicts, and those predictions always begin, always begin as motor predictions, as visceromotor predictions, predictions of what to do with the viscera to support skeletomotor predictions, whether it's to move your limbs or just to move your eyes in your head or to not move at all. All predictions begin as motor predictions, and copies of those motor predictions become the sensory, the, um, the expected sensory consequences of those movements. So your brain is preemptively... So what is an emotion? It's a, a set of predictions that tells a story about what a set of sensory signals mean to you in that situation. But that's not a specific answer to emotion versus cognition versus perception because that definition encompasses all of those. I could say, well, emotion is when there's some really big change in, um... It's, it's what I just said plus there has to be some really big change in, um, you know, your level of energy or arousal, um, has to go up or down a lot from where you are right now in order for you to experience something as an emotion, and that would hold, that, that aspect would also hold for many, many people around the world, but not everybody, because in some cultures, emotions and cognitions are not separate. In some cultures, emotions and bodily states are not separate. They are considered to be a single set of categories.

   19. PAPeter Attia1:07:11

       Can you double-click on that a little bit so I understand what you mean? Um- the bodily state and the emotion for anger would be the same for every person?

   20. LBDr. Lisa Feldman Barrett1:07:20

       No, no, no. What I'm saying is that in some cultures... So in our culture, we make a very firm distinction between is this an emotion or is it a physical state? [chuckles] Like, is it, you know, do you have a stomach ache or, or are you angry?

   21. PAPeter Attia1:07:36

       Right. But s- when I'm angry, I can feel something in the pit of my stomach. So what is the difference there?

   22. LBDr. Lisa Feldman Barrett1:07:42

       Sure, but you wouldn't... Look, I mean, there's, look, there's neurology, there's internal medicine, and there's psychiatry. And what's the origin of those, of those disciplines? The origin of those disciplines is where they think the cause is of the problem. And there's, there are diagnostic categories that, that you use when you can't figure out medically what's wrong with someone, but, you know, they're having some, what, you know, difficulty in, with mental features or what we would call psychological features, right? And, um, the assumption is that it's all in their head, meaning it's not in their body, right? I mean, I'm not making this up. This is, this is how things were for a very long time. Um, and what I'm telling... So, um, so, um, [lips smack] you-- it's very-- Sure, it's the case that, um, like when you're anxious, you, you might have, um, you know, um, [lips smack] you know, your heart might race or, um, or you might have gastric distress or whatever. But if you think gastric distress is the problem, you'll go to an internist, and if you think that your mood is the problem, you'll go to a psychiatrist, when in fact they are related. So I'm not talking about what I think is the case or what you think is the case. I'm talking about what a lot of people, including a lot of physicians, think is the case. Um, you know, physicians, I've had physicians talk to me about how depression causes heart disease and heart disease causes depression. Or another possibility is that they're both rooted in some meta- set of metabolic problems, and one is not causing the other in the way that A causes B, like a mechanistic cause. It's that they have a common cause that makes both of them more likely. That's a very different way of seeing things. And so what I'm saying is that there are some cultures who wouldn't say... Like in our legal system, we have thoughts. We are, you can be culpable because of what you feel, or you can be, have culpable because of what you do. And you, there are different punishments for that. But there are some cultures where thinking and feeling are the same. They are features of the same state. So you wouldn't call something a... You wouldn't distinguish between a thought and a feeling because they're both... It's like you have thought feelings. There's just, it's not one or the other. They're, they're both, um, you know, it's like blue and green together make turquoise. You wouldn't say it's blue or it's green. You would say it's turquoise. It's both. Um, they're not distinct states. Similarly, there are cultures where there are somatic descriptions for emotion. Like that, that i- uh, that is the, that is the nature of emotion in those cultures. So we need to have a theory of how a brain and a body together in a world full of other brains and bodies, uh, create a mind, [chuckles] and that has to work for everybody on Earth. It c- it's not just to explain Western categories. And that may mean that emotions and, and thoughts and, and perceptions are things we have to explain, but they are not themselves explanatory categories. They're not categories that explain anything.

   23. PAPeter Attia1:11:22

       Are you saying then that the, that the universal theory that is culturally agnostic is that the goal of the brain is to... Well, there's two things I've heard. One is the, a main priority of the brain is to support the body physiologically, metabolically, et cetera. And two, the brain is a predicting machine, and emotions are arising out of predictions of physical sensations or the consequences thereof. Is that directionally what you're saying?

   24. LBDr. Lisa Feldman Barrett1:11:56

       Yeah. I mean, I would never claim that it's, um, it's univer- culturally neutral because I, you know, can't claim that. I'm, I live in a cu- I was pickled in a culture just like you, and there are other... But, you know, I think, um, I think that it's a reasonable, um, it's a reasonable hypothesis.

   25. PAPeter Attia1:12:16

       But if it's biological, it should... I mean, it, it doesn't matter what culture you live in. There are certain biological things that are true across the board.

   26. LBDr. Lisa Feldman Barrett1:12:25

       I'm being a little humble here, Peter. Biology in Western science, it, I'm not, I'm not immune to... I don't, I don't think that... [chuckles] I'm just being, I don't think it's, I don't think it's relevant to say... I don't, I wouldn't claim... I'm trying to think of how to say this without being too negative. Um, I'm very aware of the fact that some of the beliefs that I hold as a scientist, um, come from the fact that I was raised in a Western culture, and I use Western concepts and methods of science, and not everybody, you know, adheres to that. But I would say

9. 1:13:05 – 1:31:36

   The brain as a predictive system rather than a reactive one

   1. LBDr. Lisa Feldman Barrett1:13:05

      that I can defend that statement by looking at anatomy, by looking at physiology, by looking at brain evolution, evolutionary biology. I can defend it by looking at, um, developmental neurobiology. I can defend it by looking at engi- signal processing and engineering. I think that Um, when multiple fields come to the same conclusion using completely different sources of evidence, and they don't talk to each other all that much, then you know that you're probably onto something. The idea that the brain predicts and doesn't react is, is actually a concept that is in other cultures, and it's been in our culture for many, many, many years, like, like centuries.

   2. PAPeter Attia1:13:56

      But this is very counterintuitive, so I really wanna spend some time on this because I've always felt that my brain is just a reaction machine, right? Like I'm riding a, I'm riding a bull, and that sometimes that bull is just walking along and everything is fine, and sometimes it's bucking like crazy, and my vertebrae are getting crunched.

   3. LBDr. Lisa Feldman Barrett1:14:17

      Yeah.

   4. PAPeter Attia1:14:17

      So let's maybe t- in any way you like, let's go through the different lines of evidence a- as you've laid them out from different sort of empirical disciplines to how we can say that the brain is, is not reacting.

   5. LBDr. Lisa Feldman Barrett1:14:29

      Sure. Sure. I mean, uh, just before I do, though, I just wanna say two things. One is, so for you it's a bull, and for John Hite, I think it was an elephant, and for Plato, it was two horses and a charioteer. You know, like th- that idea that is, that, you know, that we have an inner beast that we have to tame and kinda control is wrong. It feels that way. It feels that way to me, but it's not defensible. It's not a great metaphor because it doesn't really reflect, doesn't really reflect the evolution and anatomy of the brain, for one thing. Um, so that's my fir- that's called the triune brain, and it's just, you know, it's really, really popular, but the evidence against that has been in molecular genetics for at least 50 years, if not more. So that's just, we just have to take that off the ta- I just finished doing a video actually with a videographer, just kind of do like, um, to explain, um, why this is not the case and show for the first time, you know, a depiction of what, um, of how, um, a common kind of manufacturing plan for a, a vertebrate brain, um, could produce all different kinds of brains in vertebrates. Really, it's just mammals, but you could make inferences to vertebrates, I think, in general. The data is just about mammals. But, but you can get a mouse-looking brain and a human-looking brain out of the same, um, exactly the same manufacturing plan in an embryo. Um, that's not my work. That's work by Barbara Finley and her colleagues. Um, so that's the first thing I wanna say, and I can't even remember what the second one is. [laughs]

   6. PAPeter Attia1:16:12

      Well, t-t, so l- but tell me why my feeling of-

   7. LBDr. Lisa Feldman Barrett1:16:17

      Oh, your feeling. That was it

   8. PAPeter Attia1:16:18

      ... of this, of riding the bull is, is the wrong-

   9. LBDr. Lisa Feldman Barrett1:16:19

      Well, that's a question. That's a super interesting question. Yeah, that was my second. Thank you, you. That was good. Thanks for that assist.

   10. PAPeter Attia1:16:25

       [chuckles]

   11. LBDr. Lisa Feldman Barrett1:16:25

       Yeah, my second point is that, um, your feeling isn't evidence of anything, and neither is mine.

   12. PAPeter Attia1:16:32

       Agree. Could, yeah, could- couldn't agree more.

   13. LBDr. Lisa Feldman Barrett1:16:33

       Yeah.

   14. PAPeter Attia1:16:33

       Yeah.

   15. LBDr. Lisa Feldman Barrett1:16:34

       So, so I think brains are amazing, right? Because they're like masters of deception. They create experience kind of seamlessly. That experience reflects nothing about how it, they work, but yet, you know, we're, they, they're very tempted to use it that way. [laughs] I was like, so I think that why is it that we experience things that way? That is a great question. That is a great question for science. Somebody should study that because it isn't really good evidence, but it is a phenomenon that is worth studying. Like where does our... So some people study like where does a memory come from and where does the certainty about memory come from? 'Cause they're not re- they're not the same. They're not the same source. Um, and I would say the same thing, um, about this. Um, so why do we take our experience, um, to be evidence of how things work? I don't know why. It's an interesting question. But it is naive realism. It's naive realism in the sense that your experience doesn't reveal to you how many things work, and all science, all scientific progress is a slow march away from naive realism. And the same has to be true for neuroscience and the brain. Same has to be true for neuroscience and the brain.

   16. PAPeter Attia1:18:05

       Let's go deeper into this idea that the brain is not a reacting machine. What is the, what is the, what, what are the threads of evidence?

   17. LBDr. Lisa Feldman Barrett1:18:13

       Well, I think first of all, um, if you look at how a brain is structured, okay. Um, so let's just go back to, um, primary visual cortex. I think this is a really good example. Um, uh, and I should say, I just published a paper that summarizes a lot of this evidence in one place that was, I published with Earl Miller from MIT in Nature Reviews Neuroscience, and most of this is not my own work. This is, you know, me summarizing with Earl other people's work and also some of his electrophysiological work.

   18. PAPeter Attia1:18:51

       We'll, we'll link to that paper in the show notes.

   19. LBDr. Lisa Feldman Barrett1:18:53

       Yeah. But so let's just take V1. I think this is, this is really interesting. So if you look at the synapses, so what, so primary visual cortex is called primary visual cortex because, um, fibers from the retina pass. Basically, they, they run along the optic nerve. They pass. Some of them will, um, t-terminate in a, a subcortical area called the superior colliculus, but most of them proceed to the thalamus and then to V1, to primary visual cortex. The assumption is that those signals are what drive the neural activity in V1, drive those neurons to, to activate, to, to have action potentials, to, to produce electrochemical changes. Except that 95% of the synapses in V1 neurons come from other places in the brain and not from the thalamus. Other places like other cortical areas and not from the thalamus. So most of the n- signals are not bottom up from the retina to the brain. They are from the brain to other parts of the brain. They're top-down. That's one, um, interesting piece of evidence.

   20. PAPeter Attia1:20:23

       So just to make sure I understand it, the visual cortex is getting most of its input not from the optic nerve, but from other areas of the brain that presumably are not receiving light.

   21. LBDr. Lisa Feldman Barrett1:20:39

       Mm-hmm.

   22. PAPeter Attia1:20:41

       Where are those areas, and what type of data are being transmitted?

   23. LBDr. Lisa Feldman Barrett1:20:45

       Okay, so here's one-- This is, like, one... Here's one example. So I'll just say, you know, like, trigger warning, if anyone is unhappy or upset by, um, discussions or descriptions of studies that harm animals, you know, they might not wanna listen to this 'cause it's kind of a brutal experiment. Um, but there was an experiment done where they took mice. I think it was mice. It could've been rats, but I think it was mice, rodents, and they put them, they had them run on a wheel, and they recorded from, uh, all over the brain. They, they sunk electrodes into the, the rodent's brain, and they recorded the neural activity, the electrical activity in the neurons in many places, including in V1, okay? Then they ablated the n- the, um, the retinas of those animals. They destroyed the retinas of those animals. So no light now is getting into the brain. V1 neurons quieten down for 24 hours, and then they ramp back up to a normal level of activity.

   24. PAPeter Attia1:22:00

       Sorry, let me make sure. So, so, but the animals are now blind.

   25. LBDr. Lisa Feldman Barrett1:22:03

       Yeah, they are, but V1 is, is the recordings are back to a normal level. And what is driving those neurons?

   26. PAPeter Attia1:22:14

       And what is the output? Like, what-

   27. LBDr. Lisa Feldman Barrett1:22:17

       Well, those, the, the animals can still move around. I mean, they can smell things. They can-

   28. PAPeter Attia1:22:21

       Sure

   29. LBDr. Lisa Feldman Barrett1:22:21

       ... still move around.

   30. PAPeter Attia1:22:22

       Yeah, because you just-
10. 1:31:36 – 1:45:11

    Baseball as an example of the brain’s predictive nature

    1. PAPeter Attia1:31:37

       I'm still struggling to wrap my head around this, and I now realize why you, you said that sometimes you're still struggling to understand your own work. Um- Let's go from some- not, not to minimize the red light experiment, um, but let's now take that to an emotion.

    2. LBDr. Lisa Feldman Barrett1:31:57

       Okay, before we do that, why don't we take it to baseball or hockey or something like that? Like every sport, every sport would not exist if brains were not predictive. Like there's this really great example that's been worked out for professional baseball. I wish I had a hockey example in my pocket, Peter, but I don't. It's the, unfortunately it's baseball.

    3. PAPeter Attia1:32:17

       That's okay.

    4. LBDr. Lisa Feldman Barrett1:32:17

       But-

    5. PAPeter Attia1:32:18

       We love, we love, we love us some baseball over here.

    6. LBDr. Lisa Feldman Barrett1:32:21

       Okay. So you know that-

    7. PAPeter Attia1:32:22

       Hitting a baseball presumably.

    8. LBDr. Lisa Feldman Barrett1:32:23

       Hitting a baseball, yeah. So if you look at a Major League diam- the size of a Major League diamond, and you look at the speed with which a Major League pitcher usually pitches at like 90, 95 miles an hour, there is absolutely no way that if a batter waited to see the ball, he would ever be able to hit it. There's just literally not enough time. What's happening is that based on who that pitcher is, where they are, what the temperature is, what the wind is, how much he ate earlier that day, how much sleep he got, based on all of these things, based on a huge ensemble of signals, his brain is making a prediction about where that ball's gonna be in a moment from now, and that is where he swings. He's not doing it consciously. Where do predictions come from? They come from mem- predictions are just memories. You don't e- you don't experience yourself remembering anything, but basically your brain is re-implementing signal patterns from the past for the purposes of doing something in the present. That's what a prediction signal is. So every experience you have, every action you take is a combination of your remembered past and your sensory present. The sensory present is there to confirm the remembered past or to change it, and we have a special word in science for changing the remembered past. We call it learning. That's what learning is.

    9. PAPeter Attia1:33:59

       What accounts for the differences between individuals? Why are some people better at prediction? So, um, let's use baseball as an example 'cause it's a very f- uh, it's a very concrete example. So what made, um, w-what makes Shohei Ohtani or Aaron Judge better at hitting home runs? Like presumably they're not aware of it, but, but is it that they saw more reps? Is it that their eyes are better at picking up the cue sooner as the, as they see the hand of the pitcher? Like, um, what, what do you think?

    10. LBDr. Lisa Feldman Barrett1:34:35

        So I, I don't think anyone knows the answer to that question, but, um, certainly it has something to do with experience. It probably doesn't only have thing... Oh, it's probably not only-

    11. PAPeter Attia1:34:46

        Sure

    12. LBDr. Lisa Feldman Barrett1:34:46

        ... um, experience, but certainly lots and lots and lots and lots of practice and repetition, for sure. That's how every skill is built. Like think about exercising. So this is another example that I find really interesting. Like if you wanted to get faster at running a mile, you would run that mile over and over and over again. You would, you would train to, to do the same thing, and you would do it over again as many times a-as you needed to to get to the speed that you physically could manifest, basically. That means you're becoming more efficient, more metabolically efficient with practice. That's what athletes do. But what if you're doing... What if you're exercising not to, um, what if you're exercising to burn calories, or what if you're exercising to remain healthy? Then you do something like interval training, where somebody's calling out to you every 30 seconds. You don't know what they're gonna say. It's changing things up every 30 seconds. That's much more metabolically demanding way of exercising because your brain can't predict what's coming next, so you're always adjusting, adjusting, adjusting. Adjusting, learning, um, processing prediction errors is more metabolically expensive on all things considered than, than, um, when you, um, your motor actions arise from your predictions. So every skill is built by practice. You can't become skillful at something without practice, but that doesn't really account for why some people need more practice than others. Like I, no matter how much practice I ever had, I will never play baseball [chuckles] like a professional, you know, athlete would play baseball. Um, so I think, again, I would say the value, Peter, of, um, of a th- of a new theory is not that it explains everything. It's that it, it, it asks questions that were nev- never been asked before, and it sets aside some questions as... You know, sometimes progress is asking better questions. It's not answering old questions. So I don't know the answer to your question, but, um, what I will say is that practice w- you- repetitive feed- you have to have practice, and you have to have concrete repetitive feedback. Practice alone without, without, um, concrete repetitive feedback is not usually, um, useful for building a skill, and this is also true about emotion. You know, if you want to become more granular in how you experience the world or how you experience other people, you can learn to do that just like you would build any other skill, but it requires feedback, and that feedback is very hard to get in an unambiguous way. Who gives you unambiguous feedback? Maybe your spouse, maybe your mother-

    13. PAPeter Attia1:37:48

        [chuckles]

    14. LBDr. Lisa Feldman Barrett1:37:48

        ... maybe not. You know, maybe your therapist if they're good. And you pay them enough. You know, it's the... It's not like, you know, uh, building other skills where there's concrete, unambiguous feedback to be had. But it is, it is a skill. It's a skill like any other skill that can be built. And that's, I think, the thing that why people find this theory really valuable. They find it valuable because it gives them agency where they didn't think they had any, and it gives them hope.

    15. PAPeter Attia1:38:25

        So, so how do we transition to that? So there, there, there are... If you look at certain, certain areas of cognitive behavioral therapy, for example, we'll talk about the relationship between thought and emotion and action. Um, and I think those are attempts to also give, give agency, right?

    16. LBDr. Lisa Feldman Barrett1:38:43

        I, I think so. Let me just say that the, the treatment strategies work, but they don't work for the reasons that cognitive behavioral therapists say they work because it, they couldn't-

    17. PAPeter Attia1:38:53

        Yeah

    18. LBDr. Lisa Feldman Barrett1:38:53

        ... they couldn't possibly work for that reason. But that's-

    19. PAPeter Attia1:38:55

        So that's, that's kind of where I want... Let's go there, 'cause that's kind of what-

    20. LBDr. Lisa Feldman Barrett1:38:58

        Yeah

    21. PAPeter Attia1:38:58

        ... I was trying to understand is how does this explain an observation of CBT or DBT's effectiveness?

    22. LBDr. Lisa Feldman Barrett1:39:06

        Well, I think first of all, I mean, have you ever tried to not think a thought? [scoffs]

    23. PAPeter Attia1:39:10

        Well, it's impossible. We know that. [chuckles]

    24. LBDr. Lisa Feldman Barrett1:39:12

        Yeah, it's really hard. [chuckles]

    25. PAPeter Attia1:39:13

        Yeah, yeah.

    26. LBDr. Lisa Feldman Barrett1:39:14

        However, if you change your actions or you-

    27. PAPeter Attia1:39:17

        Yes

    28. LBDr. Lisa Feldman Barrett1:39:18

        ... change your circumstance, like you get up, go for a walk, or you don't even have to physically move, you can just virtually, like, move, meaning, like-

    29. PAPeter Attia1:39:26

        Yeah

    30. LBDr. Lisa Feldman Barrett1:39:26

        ... change your attention.
11. 1:45:11 – 1:51:30

    How the human brain differs from that of other animals

    1. PAPeter Attia1:45:11

       So, so now let's, let's think about that through the lens of other animals, other mammals even. Um, w- would you agree with the statement that we as humans have the most developed brains relative to others?

    2. LBDr. Lisa Feldman Barrett1:45:26

       No.

    3. PAPeter Attia1:45:27

       No.

    4. LBDr. Lisa Feldman Barrett1:45:28

       No. No. So I mean, our brains are not more developed, um, our brains are differently developed. You know, our brains are, we have exactly the size, um, of a, you know, our cerebral cortex are not, like, larger than what you would expect for a primate of our size, right? Like we, I mean, our, I mean, primates have a larger, larger proportion of cerebral, larger proportion of the brain is the cerebral cortex than o- for other, for some other mammals. Um, but that's a, that's an innovation that comes with primates. It's not, like, human specific. And there are other animals that have much larger cerebral cortexes than we do, like an elephant, right? Or a, a whale.

    5. PAPeter Attia1:46:13

       So what, what is unique, um, neurobiologically about humans relative to others?

    6. LBDr. Lisa Feldman Barrett1:46:18

       Yeah. So I think one thing that's unique is, um, it's probably not the only thing, but one thing that's unique is our capacity for abstraction, and that you can see the evidence for, or, or what the, maybe not evidence, but the, like, anatomical substrate for that you can see. So if you were to take the cerebral cortex off the rest of the brain and lay it out flat like a napkin, what you would see is that there is, there are, there is an architectural gradient there. And the, the architectural gradient is mostly in the upper layers, and it, it kind of looks like this. That, like, when you're at V1, so you, you have, like, at the out, at the outer part, you have V1, A1, so primary visual cortex, primary auditory cortex, um, primary somatosensory cortex, sort of. And, um, there the neurons are very small, and they have fewer connections to each other. Very s- There, so there are, um, a lot of neurons, but they're very tiny. I'm talking about pyramidal neurons mostly, and they're, they're not very well connected. So they're, they're processing small details. And at the other end of the, um, gradient, w- you know, in the midline, um, w- in the areas that are closest to the subcortex, which we would call limbic, they are, um, there are fewer neurons, but they're honking big, and they have a ton of connections. So the thickness of the cortex is the same, but the constitution of the architecture is different. You go from a lot of little cells to fewer to fewer to fewer to fewest. Okay? There's also a temporal, um, gradient, but we would call that dimensionality reduction or compression. So the signals are being compressed, or you could say they're being decompressed. So what is unique about a human brain, um, or not unique, but what is special about a human brain is that our ability to compress is greater. We have a lot more... That gradient is sharper in a human than it is in any other animal, even our closest relatives, um, like a chimp or, or a, or a gorilla. Why does that matter? Because what it lets us do is it lets us see similarity in differences. It lets us treat, you know, a cup and, um, uh, and, um-

    7. PAPeter Attia1:48:56

       A ladle

    8. LBDr. Lisa Feldman Barrett1:48:57

       ... you know, a pail and a-

    9. PAPeter Attia1:48:59

       Yeah

    10. LBDr. Lisa Feldman Barrett1:48:59

        ... and a, and your hand as, um, something to drink out of. It lets us see, um, a kitty cat and a tiger and a cool guy all as cats.

    11. PAPeter Attia1:49:12

        [chuckles]

    12. LBDr. Lisa Feldman Barrett1:49:13

        It lets us... Right? So, uh, what a chimp or what a, what a chimp can do is a chimp can probably understand that, um, cli- uh, a monkey climbing a tree and a snake climbing a tree is both climbing. They're both to climb. And it might even understand, like, a human climbing s- like literally climbing up the stairs is the same as climbing, whereas I think probably a macaque can't do that. They probably, you know, climbing a stair, climbing the stairs and climbing a tree would be seen as different actions. But I'm guessing. I don't actually know. I'm just sort of inferring. But what it definitely can't do is understand a metaphorical social ladder, whereas a human can understand that. So a human can find functional differences in things that look different, smell different, sound different. This is something that humans can do. Um, now, on the other hand, here's something humans can't do that a chimp can do really well. If you... Do you ever have problems trying to find your keys?

    13. PAPeter Attia1:50:23

        [chuckles] Sure.

    14. LBDr. Lisa Feldman Barrett1:50:25

        A chimp would never lose its keys. Like chimps forage for infor- they forage for food, so their ability, their what we would call episodic detail, their ability to remember detail far outstrips a human's ability to remember the details. So, you know, we would get lost, uh, in the forest, whereas a chimp would not get lost. They would know exactly where they were by fine-grain details that we would probably ignore, which is also a consequence of our great capacity to abstract. And what comes out of this great capacity to abstract?

    15. PAPeter Attia1:51:02

        Invention.

    16. LBDr. Lisa Feldman Barrett1:51:03

        Civilization comes out of it.

    17. PAPeter Attia1:51:03

        Yeah. [laughs]

    18. LBDr. Lisa Feldman Barrett1:51:03

        Civilization comes out of it. I mean, like, uh, basically, uh, uh, there are many, many, many things that exist because humans collectively, we impose functions on things that they don't have by their physical nature. But if we impose them collectively and they dictate our actions, then they do have those functions, like money.

    19. PAPeter Attia1:51:28

        I wanna go back to this idea

12. 1:51:30 – 1:59:00

    The impact of stress on metabolism, and the role of the brain in maintaining allostasis

    1. PAPeter Attia1:51:30

       of chronic stress, right? Because at the end of the day, what I think matters is our, our experience, our subjective experience. W- If-- I mean, we've already touched on the idea that I think we both believe, which is the state of one's mind can impact one's health or vice versa, right? We don't-- We-- I, I shouldn't infer the causality like that, but let's just say that there is a relationship between the state of mind and the state of health. And by the way, even if there wasn't, why would we want to suffer, right? Why would we want to suffer in our, as David Foster Wallace calls it, the tiny little skull-sized kingdoms on our shoulders, right? Like, why, why... We, we don't wanna suffer.

    2. LBDr. Lisa Feldman Barrett1:52:15

       But I think there are a couple of things that, that I would-- a couple of caveats that I would make. First of all, there's a difference between discomfort and suffering.

    3. PAPeter Attia1:52:23

       Mm-hmm.

    4. LBDr. Lisa Feldman Barrett1:52:24

       I can think of lots of reasons why I would in- I would deliberately engage in discomfort.

    5. PAPeter Attia1:52:28

       Yeah, exercise.

    6. LBDr. Lisa Feldman Barrett1:52:29

       Every goddamn morning.

    7. PAPeter Attia1:52:29

       Sure, of course.

    8. LBDr. Lisa Feldman Barrett1:52:30

       Yeah, exactly.

    9. PAPeter Attia1:52:30

       Yeah.

    10. LBDr. Lisa Feldman Barrett1:52:30

        Exactly, exactly. Or, you know, I don't know, learning to play piano or learning-- doing a PhD or whatever. There are lots of reasons to feel discomfort.

    11. PAPeter Attia1:52:38

        You're get, getting your, getting your kid out of bed in the morning when they don't want to. [chuckles]

    12. LBDr. Lisa Feldman Barrett1:52:41

        For sure. Suffering, though, I think is a different mat-matter. Suffering is, is... There's something additional to suffering that over and above discomfort. And in fact, in chronic pain, the goal is often to reduce suffering, even in-- to dissolve it into just mere discomfort. So that's the first point that I wanna make. The second point that I wanna make is that, um, that you can talk about stress. So what-- I mean, you can talk about stress from a metabolic standpoint, or you could talk about stress from, um, from a, from a subjective standpoint. And, and I think it's important to-

    13. PAPeter Attia1:53:24

        But the, but the metabolic standpoint's difficult, Lisa. So for example, like I can-- If I, if I had 10 people lined up and I measured free cortisol levels in all of them and epinephrine and norepinephrine-

    14. LBDr. Lisa Feldman Barrett1:53:36

        I'm not talk-

    15. PAPeter Attia1:53:36

        Yeah, yeah. But I-

    16. LBDr. Lisa Feldman Barrett1:53:36

        Yeah

    17. PAPeter Attia1:53:36

        ... I just wanna make the point for the listener as well. If I measure all the catecholamines and all the adrenocorticoids, the stress hormones, it tells me nothing about what they're experiencing.

    18. LBDr. Lisa Feldman Barrett1:53:46

        Okay. So cortisol is not a stress hormone. Cortisol, as you know, is a glucocorticoid. It's involved in glucose metabolism. That should be a clue. Like if you-- When you, when you wake up in the morning and you go to drag your ass out of bed, you're-- you have a cortisol surge.

    19. PAPeter Attia1:54:04

        Yeah.

    20. LBDr. Lisa Feldman Barrett1:54:04

        Why? Because you're about to do something that costs-

    21. PAPeter Attia1:54:07

        Mm-hmm

    22. LBDr. Lisa Feldman Barrett1:54:07

        ... energy. So that sh-- to me, that was a clue. Like when I realized, you know, somehow... I mean, I took intro physiology in college. I completely wasn't thinking about it until 2010 when I was at a meeting at NCI, National Cancer Institute, and they were talking about, um, glucocorticoid, um, metabolism, and I was like, "Holy shit. Depression. Depression. Major depression has-- people have cortisol dysregulation." It's not a stress hormone. It's just a hormone th-that is involved in regulating glucose metabolism. That means that stress probably has something to do with glucose metabolism. So when I thought about it more and over the years, this is what we've come to. Really, a moment of stress, metabolically speaking, is just whenever your brain is predicting there's gonna be a big metabolic outlay. Allostasis, your brain is anticipating the needs of the body and preparing to meet those needs before it arises.

    23. PAPeter Attia1:55:10

        By the way, Lisa, you've used the term before, and I know what it means, but I want you to contrast homeostasis and allostasis because we talk on this podcast a lot about homeostasis-

    24. LBDr. Lisa Feldman Barrett1:55:20

        Yeah

    25. PAPeter Attia1:55:20

        ... which is the reaction to, but maybe-

    26. LBDr. Lisa Feldman Barrett1:55:23

        Yeah. So, uh-

    27. PAPeter Attia1:55:23

        ... you can put that in context.

    28. LBDr. Lisa Feldman Barrett1:55:24

        Yeah. Yep, sure, sure. So homeostasis is reactive. Allostasis is predictive. Homeostasis is about returning to a set point or a range of set points. Allostasis is not about, um, returning to any set point. It's about efficiency. It's about metabolic efficiency. So I can be-- Well, someone could be in allostasis when they're running a mile and when they're asleep. I mean, I wouldn't be in allostasis [chuckles] when I'm running a mile, but somebody could be. But they would never-- nobody would ever be able to maintain allostasis when they're running a marathon. That's just too much of a disruption. So allostasis is predictive. Homeostasis is reactive. Allostasis is, um, about maintaining balance or, um, efficiency, metabolically speaking. It's not about trying to reduce cost by getting back to a set point. Different systems can work by homeostasis, but they are all coordinated by the brain's allostatic efforts. And there are, you know, global metabolic signals that the brain receives. Um, GDF15, um, there's some indication cortisol actually may function this way. There are a number of kind of general, um, [lips smack] signals that the brain-

    29. PAPeter Attia1:56:50

        I think even lactate probably classifies as one.

    30. LBDr. Lisa Feldman Barrett1:56:52

        Yep, yep, yep, it's possible. So, um, so I'm talking about allostasis because I'm talking about prediction. So when the brain is predicting an allostatic disruption, it's anticipating the needs of the body and preparing to meet those needs. That actually is the definition of allostasis, um, according to Peter Sterling, um, um, that we use in our lab. That is stress. I mean, that's stress. That's when you see a cortisol surge. That's when you see other chemicals and so on. We don't always feel subjectively distressed when, when there is a moment of stress.
13. 1:59:00 – 2:04:41

    Childhood adversity, social regulation of the nervous system, and the effect of chronic stress

    1. PAPeter Attia1:59:00

       let's take another example of, um, a child that is being abused. Um, so there's two things that I can at least imagine that are creating distress. The first is the unpredictability that she said. "I don't know which day Dad's gonna come home drunk, and I don't know what he's gonna do, when he's gonna hit me or when he's gonna hit Mom." And then there's a second feeling that I think is related, but I'd like you to comment on, which is the helplessness of the situation, which is, "I don't have agency in this situation to do anything when Dad comes home drunk." So that's, there's, there's uncertainty, and then even when something's happening, I don't have agency. And to me, I can't imagine a greater, um, set of circumstances to produce distress in anyone, I, even though I use a very pointed example with a child.

    2. LBDr. Lisa Feldman Barrett1:59:49

       Yeah. I would say, though, that there's an additional thing there that, um, there's an additional... So there's uncertainty, but there's also-- and there's lack of agency, but there's also, um... You know, we're social animals, so we don't manage our nervous systems on our own. We, we are the caretakers of each other's nervous systems under best circumstances, right? The best thing for your nervous system, Peter, is another human, and the worst thing for your nervous system is also another human. And so one of the things that we do for our children when things work well, um, is we, we maintain allostasis for them. They can't do it. Their brains actually aren't equipped to do it. They have to kinda learn. They don't know. I mean, a baby is born, it can't even nurse. You have to teach a baby how to nurse. Baby, a baby can't even control its limbs. I mean, babies, the, the wiring is there, but it's not fully developed. Partly what we do when we feed them and clothe, the keep-- regulate their temperature and cuddle them and do all these things, is we're actually regulating their, their nervous system. We're regulating their metabolism. And slowly, slowly, slowly, they learn to take this on themselves, but not completely. We regulate each other all the time. So we can basically create for each other savings and, like, to use that meta, body budgeting metaphor, like your brain's running a budget for your body. It's not budgeting water. I mean, it's not budgeting money. It's budgeting salt and glucose and whatever. You know, this is a metaphor that I've used before. It's a metaphor, so it's not an explanation. It's just a metaphor, but it's a good metaphor for this purpose. Um, we can create savings in e- for each other. We, we regulate each other. We literally regulate each other. You know? There was, um, [lips smack] you know, you have your hand up here like this, and so, you know, if you and I were in a coffee shop, I might do this, and then, you know, you might scratch your head, and then I might, like, push my hair back. People coordinate their actions. They coordinate their breathing. They coordinate their movements. And you coordinate your breathing, you will, you know, more likely coordinate your heart rates. This is something people do when they trust each other, when they like each other. Um, we can also disrupt each other, right? So one of the things that's happening for a little kid who's in an abusive situation is that, um, they're not getting the benefit of that kind of savings that most of us who, um, are in safe environments, you know, benefit from without even thinking about it

    3. PAPeter Attia2:02:44

       But what, how does that translate to the, to the metabolic deficit, right? So in that situation-

    4. LBDr. Lisa Feldman Barrett2:02:49

       Well, it doesn't, it doesn't... It just means everything is costing more. Everything is costing more. Like literally, if you're with a friend and you have like a, a backpack full of rocks on your back like in an experiment, you're with someone that you like and that you trust, you burn fewer calories when you schlep that thing up a hill than if you're by yourself or you're with a stranger. So what this means is j- it just means that like things are more expensive. That means that that kid's gonna just metabolically be less resilient. Plus, if you add to that the fact that they're gonna be more vigilant, and there's actual harm being done to them, it's like a perfect storm of, um, metabolic burden that doesn't show up necessarily then. It shows up in adolescence or in adulthood, and it doesn't just show up as mood disturbance or whatever, behavioral problems. It shows up as like di- likely increased likelihood of a metabolic illness, diabetes, heart disease. I mean, ACE, you know, ACE scores is like-

    5. PAPeter Attia2:03:49

       Yeah, yeah

    6. LBDr. Lisa Feldman Barrett2:03:49

       ... you know, like the adversity in childhood predicts, not perfectly, but-

    7. PAPeter Attia2:03:55

       Bad, bad, bad health outcomes

    8. LBDr. Lisa Feldman Barrett2:03:56

       ... bad health outcomes. So it's like a slow drip on a pipe. One drip is not gonna do anything, you know. 100 drips, not gonna necessarily do anything. But eventually, if it goes on for long enough, that drip will bore a hole in a steel pipe. And-- or, you know, monkeys jumping on a bed or whatever, [chuckles] you know, like, like eventually the bed will break. Maybe not the first time, maybe not with the 10th monkey, maybe not with the 20th monkey, but eventually it will break. And so I think that's the way to think about it, that it's a slow, slow process. So s- chronic stress might make you feel like shit, but it's not actually gonna harm your health immediately,

14. 2:04:41 – 2:12:55

    Understanding chronic stress: why some people respond differently, and its impact on metabolism

    1. LBDr. Lisa Feldman Barrett2:04:41

       but it will inevitably harm your health eventually.

    2. PAPeter Attia2:04:45

       How do we turn that into a prescription? So let's, let's just now talk about a situation where uncertainty and helplessness take a different form. It's no longer something as dangerous as an abusive parent. It's uncertainty about a job. It's uncertainty about a relationship. It's uncertainty about the world we live in. AI. You, you pick. You, you know, there, there-- we could all come up with many things to be uncertain about and to also have some degree of helplessness about that certainly would never rise to the level of trauma or traumatic insult. And yet two entirely different people can be faced with the same set of external circumstances and have a totally different manifestation of this notion of chronic stress. So one, I'd like to understand a little bit why that's the case, and, and perhaps more importantly, what can the person who is having a more negative response to that do in order to shift the balance and take that metabolic cost off their shoulders?

    3. LBDr. Lisa Feldman Barrett2:05:48

       Well, the first thing I would say is that I don't think we have to imagine what it's like to live in uncertainty.

    4. PAPeter Attia2:05:53

       [chuckles]

    5. LBDr. Lisa Feldman Barrett2:05:54

       I think, I think, um, modern life is designed to bankrupt a bo- a human body budget, and we're not equally all affected by these things, but we're all affected in one way or the other. Um, and even people who think that they are immune are not immune, right? So in the popular press, you see people talking about, you know, fight and flight circuits and how they're overworked, and that's why everyone's so stressed. There are no fight or flight circuits in your brain. You don't have fight or flight circuits in your brain. Your periaqueductal gray doesn't contain fight or flight circuits. It contains circuits for regulating your autonomic nervous system, and it regulates your autonomic nervous system throughout your entire life. And of course, during moments of threat, they're-- it's very active. But, uh, we have done these experiments where we have people do a, a memory test where they have to remember one thing, [chuckles] and that modulates the periaqueductal gray, these so-called fight and flight circuits too. You know, it's like e- the task is easier than remembering a phone number. There's no stress involved, um, in the conventional, um, distress sense, but yet you see these circuits being active. So, so I would say there's tremendous amounts of uncertainty, um, combined with, you know, the fact that we-- our niche is much bigger. Like the things that concern us, that affect, uh, our metabolism is much bigger than it used to be because of the news and because of the internet and so on and so forth. So we've got expanded niches, like an expanded potential burden, expanded, um, [lips smack] um, uncertainty, so a lot of expanded cost. Um, and so people are more vulnerable to, um, to metabolic illnesses of all sort. And my prediction would be, you know, peop- I, I hate making predictions, but I will predict this because I won't be alive to see the result. But I think in 100 years, if we still exist as a species, somebody's gonna look back at this time and just see it as a massive public health crisis, right? Where we're basically all bankrupting our body budgets at the same time as we don't sleep enough and we eat pseudo-foods, you know, and like, you know, anything that's not on the, um, periphery of a supermarket, [chuckles] you know. And we're do- doing all these things, each of which is, um, sometimes a nudge and sometimes a massive shove in a particular direction. So that I feel very comfortable making that prediction. Your question about like, well, why are some people more ... susceptible. Like, you know, I mean trauma

    6. PAPeter Attia2:08:43

       Why, why, yeah, why do, why do some have more equanimity?

    7. LBDr. Lisa Feldman Barrett2:08:44

       Yeah, so adversity, adversity is the potential for something negative to, you know. But there are people who experience adversity and who are not stressed, and they're, like subjectively, and there are people who experience stress, they're experiencing things as adverse that like the mythical average person wouldn't. All I can say there is it has something to do with prediction and memory. I think that seems pretty clear. Um, and also remember that, you know, your, your... I don't have to tell you this, I mean, you know this, that while there is no muscle memory really, I mean, in the sense that your muscles don't have a memory, your brain has a memory, um, [lip smack] you know, nervous systems do adjust themselves to the environment that, that they're in. I mean, your brain wires itself to its world. That world includes the body. From your brain's perspective, your body is part of its world. It's like a really important part. It's not just what's out there, it's also anything that it doesn't have direct access to. And that... A brain wires itself to the body. So if there's chronic stress or if there's adversity, and the brain's regulation of the body changes how the body is, the body then sends signals back to the brain that the brain then has to adjust to, right? So what I'm trying to say is that you, Peter, have a brain that is wired to see out of your eyes that are literally in the positions they are. If we magically took your brain and stuck it in somebody else's skull, you wouldn't be able to see the... Right? If somebody, something happens to somebody's ear, right, they, they can't hear for a while. They have to like adjust. I mean, think of it like, uh, when you get your teeth fixed and then your tongue is like constantly probing at the... You know, it's because it's trying to forage. It's learning. And it will wire itself eventually to whatever is new and different. If you have an illness in the-- Like say you have literal tissue damage in the body, and [lip smack] that's a met- that's a metabolic burden right there, just the healing, right? That means the brain doesn't have necessarily the resources that it needs, so that when those signals disappear, the brain is still predicting that it's gonna receive them because it's not updating, it's not learning, because learning is expensive. That's chronic pain. That's pain that is not... Pain is real, but the tissue damage is gone. But you don't feel pain in your body, you feel pain in your brain. You feel everything in your brain. You see in your brain. You hear in your brain. All of your sensations are in your brain. You know, you pinch yourself, you don't feel it here, you feel it here. [lip smack] So I think that one thing, one source of individual difference is, um, you have an adaptable nervous system, you have an adaptable body, you have an adaptable immune system. That means it learns. And we- each of us come to these external circumstances with different learning histories. [lip smack] That means we're wired. I mean, we are wired by our experiences. Not... I mean, there, it, I mean, it's not, I'm not saying that we're blank slates or anything like that, but people come to a situation prepared to experience it in a particular way. Everything you experience, everything you do is a combination of the remembered past and the sensory present. If you don't have a remembered past and your brain can't cobble together bits and pieces of the past to make a prediction, you will be experientially blind in the moment. You just won't... Y- it's just be noise to you.

15. 2:12:55 – 2:16:25

    dHow practicing new predictions can change thoughts and feelings

    1. PAPeter Attia2:12:55

       But how do we change that? So let's... Everything you're saying makes sense, and i- if I'm in a situation where I, I am just manifesting... I'm, I'm just making up this example. I just, I get so anxious under a certain circumstance that you wouldn't get upset about because you bring a different history, a different memory, a different pattern, a different recognition to that system. But I, I, I bring this very negative experience, and I have good reason to because of whatever happened in the past. But now I want to change that. I don't want that to be my experience anymore. What can I do?

    2. LBDr. Lisa Feldman Barrett2:13:34

       Yep. So one th- one thing that you could try to do, which won't be very effective, is you could try to reach back into your past and change your past. Because who are you right now? You're a combination of your remembered past and your sensory present. So one way to change your current experience is to change your past. Well, good luck with that. That's a little bit what some, some-

    3. PAPeter Attia2:13:55

       Sorry, but, but so Lisa, change my past or change my interpretation of my past? Those are two different things, obviously.

    4. LBDr. Lisa Feldman Barrett2:14:01

       Well, they actually aren't different. Exactly... When you remember your past, it is a current experience. Memory isn't different from a perception, okay? Like when you're remembering something, it is a current experience that you are having of something that happened in the past. But it's not identical, and it's actually-

    5. PAPeter Attia2:14:23

       Yeah, I, I-

    6. LBDr. Lisa Feldman Barrett2:14:24

       ... it's a-

    7. PAPeter Attia2:14:24

       ... I sort of, maybe I didn't say this correctly. What I mean is you could change your interpretation of it, couldn't you?

    8. LBDr. Lisa Feldman Barrett2:14:29

       Yes, you can. But the more effective thing... Well, anyways, that's where I was going.

    9. PAPeter Attia2:14:34

       Okay. Okay.

    10. LBDr. Lisa Feldman Barrett2:14:34

        But I, where I was going with this was to say you could try to change the meaning of what happened to you in the past, which some psychotherapies attempt to do, and with more or less success. But one thing that you could do is you could change, you could change something now and practice that change so that you could predict differently in the future. It's like driving. You invest energy in the moment to learn something new, and you practice and practice and practice, and then what be- starts off being deliberate ends up being automatic. Every skill works that way. Driving works that way. So for example, when you are feeling overwhelmed and, um, you have to force yourself to, um, go be, go play soccer with your kid or whatever, you could practice that skill in advance, um, before the heat of the moment, so that in the heat of the moment, your brain is predicting differently.

    11. PAPeter Attia2:15:41

        Hmm.

    12. LBDr. Lisa Feldman Barrett2:15:41

        So let me just put it this way. I don't know what you did in Canada when you lived there. One thing I used to do was the first snowfall, first... It's not really snowfall. It was, like, the first ice that appeared. I would get into my car, and I would deli- I'd go to a, um, like a, a side street or, or a parking lot, and I'd deliberately put myself into a tailspin so that I could remember how to get out of it. I didn't want the first memory to be the time when I really needed it. I wanted to practice. Um, sometimes you can take advantage of moments where you can practice actually making meaning differently.

16. 2:16:25 – 2:25:10

    Lisa’s practice of finding awe in everyday experiences and the greater sense of agency it brings

    1. LBDr. Lisa Feldman Barrett2:16:25

       So, um, here's an example I often use. Um, I have a colleague who studies positive emotion and, like, the benefits of positive emotion, and I'm inherently skeptical person, so I thought, "Well, I'm gonna try it myself." So I thought, "All right. I'm gonna experience awe every day. I'm gonna, like, give myself a little exercise." And so I started with something easy. Like, I would drive along-- I lived in Boston at the time. I'd drive along the pike, Massachusetts Turnpike. There was, like, a billboard of a cute little baby orangutan with its mother. Adorable, adorable little baby. So I would look at the baby as we were passing by it, and I would think about the baby, and I would have a moment of awe, you know? And then I moved on to things like, you know, the sound of the waves, you know, beautiful flowers, the crickets at night, you know, really loud crickets at night. And then eventually, that became easy, so then I started to try, like, um, well, how about a weed? Or how about a weed popping out of a cracked sidewalk? [chuckles] A weed, a dandelion poking its ugly little head out of a cracked sidewalk can be a moment of awe if you understand it as nature's, um, power to be unconstrained by human attempts to control it. Now, it's very easy for me to experience a moment of awe when I most need a break, like when my nervous system most needs a break. For example, w- um, you know, I'm about to take an important meeting.

    2. PAPeter Attia2:18:13

       You're stuck in traffic.

    3. LBDr. Lisa Feldman Barrett2:18:14

       I'm stuck in traffic. I'm about to take an important meeting at, on Zoom, and my computer fails. [chuckles] Um, you know, or, um, you know, a meeting where I really can't lose my temper, you know, where I really have to be cool. Um, or, um, you know, a, a time when, you know, I'm sleep deprived and, uh, my, you know, little kid is doing something to drive me batshit crazy. Um, you know, these are all moments where if I can just get a little distance for two seconds, I can take a breath, metaphorically speaking, and then I can come back into the fray. The thing is-

    4. PAPeter Attia2:18:53

       And, and what are you doing? Are you picturing the dandelion? Are you going back to just raw-

    5. LBDr. Lisa Feldman Barrett2:18:57

       No, I'm finding a moment. Like, for example, if our internet failed right now, and, um, I would, as I often do, I would be like, "Well, it's miraculous that we can even talk to each o-" I don't know where you are, Peter. I'm imagining you're on the West Coast. I'm on the East Coast. That means... No, you're not. Okay. Well, wherever you are. The point being that we could be thousands of miles away from each other and, but we're talking to each other like we were in the same room. So yeah, when it fails, it's frustrating, but the fact that we even get to do it is, like, amazing and awe-inspiring. So no, I find something in the moment to be in awe about.

    6. PAPeter Attia2:19:35

       Mm-hmm.

    7. LBDr. Lisa Feldman Barrett2:19:35

       You know?

    8. PAPeter Attia2:19:36

       And how long did that take?

    9. LBDr. Lisa Feldman Barrett2:19:39

       Well-

    10. PAPeter Attia2:19:39

        The practice

    11. LBDr. Lisa Feldman Barrett2:19:40

        ... I'm giving-

    12. PAPeter Attia2:19:40

        The-

    13. LBDr. Lisa Feldman Barrett2:19:40

        The practice-

    14. PAPeter Attia2:19:40

        No, no. This is a very important example, and I really like it. How many weeks or months did it take to rewire?

    15. LBDr. Lisa Feldman Barrett2:19:47

        It took a couple of months.

    16. PAPeter Attia2:19:49

        Okay.

    17. LBDr. Lisa Feldman Barrett2:19:49

        It took a couple of months of daily practice. The thing I would say about having more control and more agency is that, first of all, it doesn't look the way you expect it to look. You expect, you know, you expect to be able to just in the moment do it. You can't. You... It requires practice. Like I was just telling somebody yesterday, you know, like, who wants to just stand up and give a lecture. I'm like, "Yeah, I can stand up and give a lecture after I've practiced it 30 times." Like, it looks like I'm talking off the cuff, and I am in that moment, but it's all automated. I've practiced it already a ton of times. It... You know, so you can take advantage of that. The control is, looks different than you expect. It's harder to get than you expect, and not everybody has the same opportunities as everybody else. So some people have more options for controlling and for changing things. But even a monk who is being tortured can do it. That means that we all, all of us, even in the most dire moments, we all have a little, a smidge more control th- over our ex- how we experience ourselves in the world than we think we do. And in some moments, that really... That all, all you really need is that little smidge, you know? In some moments, it's, that's good enough. And in other moments, when you have a little bit more energy, you know, you can practice lots of different... You practice basically making meaning differently. You practice... So for example, um, I, every morning, I get up and I have to walk by my office to get to the gym. [chuckles] And the temptation is so always there. I'll just look for a minute. I'll just look for a minute. I know, I know I won't just look for a minute. I, the minute I start looking at my email, I'm gonna be there for an hour, right? But every morning, I am practicing not doing the thing that I feel compelled to do in order to do the thing that I know later I will be glad that I did. That is, you know, in the, in the moment it's trivial, but the practice in being able to do it, um, you know-

    18. PAPeter Attia2:22:18

        And you think everyone is capable of that?

    19. LBDr. Lisa Feldman Barrett2:22:20

        I think everyone is capable of that. I think everyone is capable of something like that.

    20. PAPeter Attia2:22:26

        So what... I, I'm not disagreeing with you. I, I, I'm not agreeing or disagreeing with you, uh, but I want to know what you would say to the person who's listening to us who doesn't... 'Cause you and I, I think, are both cut from that same cloth, Lisa. Um, I've always chalked it up to, um... [lips smack] Well, I... Yeah, let's just say this. So someone's listening to us and they're saying, "I don't have that gene, Lisa. I, I don't have the willpower. What you're describing sounds like willpower to me." And how would you correct them in their thinking?

    21. LBDr. Lisa Feldman Barrett2:22:58

        Well, here's what I would say. First of all, no, willpower is... This is designed to, um... This is just based on s- on empirical evidence, like, how do you build a skill? It, it has nothing to do with willpower. Willpower is putting a bowl of potato chips in front of yourself and trying not to eat it. [chuckles] What I'm talking about is getting rid of the... Like, you construct your niche so that you don't have to deal with the bowl of potato chips. Um, you know, you, you can-- If you wanna change how you feel in the moment, you can either change your remembered past, you can change your, um, sensory present, um, or you can move in some way, which usually involves changing your sensory present. But, like, that's pretty much it. So you h- um, but what I guess... W- I, in the end I'm a scientist, and what I would say is the following: I have emails from, like... I have received more, in excess of, like, 10,000 emails from people who have read both of my books and have found ways... N- neither of those books gives people advice on how to use sci- these scientific findings in their own life, but they do. These people write to me w- with stories about their own lives and how they've used it and how helpful, how it gave them a sense of agency and a sense of hope. I've had people write to me from, um, from a battlefield, like, on a battlefield, like, in the middle of a war. I've had people who've written to me, like, all walks of life, all kinds of people. And I will also say that, um, I... We used... I mean, how I came to any of this, right, how I came to any of this, I mean, I study emotion, and I have a lot to say about emotion and the brain and so on and so forth, but all of the work on metabolism and meaning-making and all of that came later.

    22. PAPeter Attia2:25:08

        Have any of the people

17. 2:25:10 – 2:33:30

    The impact of grief on nervous system regulation and the metabolic "body budget," as well as practices that reduce sadness

    1. PAPeter Attia2:25:10

       who have written to you, um, used any of w- what you've, you've, you've written about through the lens of grief? So you talked about your personal experience where you have a much better capacity to manage your emotions in distressful situations, and part of it is making sense of it, finding awe in, hey, like, I know the internet went down-

    2. LBDr. Lisa Feldman Barrett2:25:33

       Yeah

    3. PAPeter Attia2:25:33

       ... but the fact that we have internet's amazing. But now when, when someone loses their child, loses their spouse, I mean, it's a, it's, it's, it's grief to the highest extent. Is, is there... Tell m- tell me how you, you think about, um, impro- reducing suffering in that state.

    4. LBDr. Lisa Feldman Barrett2:25:50

       Yeah. So I think that, you know... I think that when I'm talking about the brain's meaning-making capacities, I'm not talking about grand things like finding the meaning of life or explaining why someone dies or things like that of a, you know, of a, of a teleological nature. I'm talking about things like, what does a set of sensory signals mean? So the thing about grief, the thing about losing someone that you love, i- is that you are losing a, a source of body budgeting impact. Like, we regulate each other's nervous systems. My daughter when sh- when she was a baby was regulating my nervous system as much as I was regulating hers. Maybe more. [chuckles] And when you lose someone you love, it can feel like you've lost a part of yourself, and you have. You've lost body budgeting support. You've lost somebody- That you are physically connected to in some way. That's what love and safety is. If you feel safe with someone or you make someone feel safe, you create an environment for them to feel safe, you are physically linked to that person in a way that is not necessarily metaphorical really, in that they had an impact on your metabolism and you have an impact on theirs. I have a friend, I can text her. She lives in Belgium. I can text her three little words. She doesn't have to see my face. She doesn't have to hear my voice. What I text her will affect her heart rate, it will affect her breathing rate, it will affect her mood, right? I mean, powerful. Words and actions in relation to other people are powerful. So you, when you lose someone, you've lost that, and you feel it. Now, that doesn't explain why they died. It doesn't make it seem any more fair that they died, but it does help you understand what those sensations mean and that they eventually will, [lips smack] um, in like, I would say the evidence is something like 70% of people who don't experience complicated grief, you know, they will go away.

    5. PAPeter Attia2:28:14

       In, in what period of time?

    6. LBDr. Lisa Feldman Barrett2:28:16

       Well, I think, I'm thinking of George Bonanno's work now, and you're, now you're ca- I mean, I haven't looked at this work for a long time, but I think it's like a couple of months and then complicated grief like loss of a child or something can go on for, for longer. But eventually, within a year or two, I think the evidence is that people, if it ta- even if it takes that long. It's not that they're not sad, it's that they're not suffering, right? So it'll still feel like shit at occasionally, uh, over time, but, um, or maybe every day, but you won't suffer. Um, it'll be discomfort.

    7. PAPeter Attia2:28:58

       And are there things that an individual can do to shorten that period of time between suffering and sadness?

    8. LBDr. Lisa Feldman Barrett2:29:04

       Yeah, y- well, the evidence suggests that you can remember times that, um, were, were happy. So the people who recover faster from, um, the loss of a loved one, um, are people who, um, remember the positive, meaningful time together. Um, that's what the evidence shows. And it's interesting because if you think about there are cultural, like, traditions that get you to do that, like sitting shiva, um, in a, in a Jewish, um, when you're mourning someone Jewish or awake or, you know, that you're remembering things often with other people that, um, that bring the person, make the person closer to you and bring them more alive. Like, so here, you know, so here's example. This is sort of an, a negative example, but I think it's an interesting example. So my daughter, um, uh, doesn't remember herself when she was two. Of course, like who does, right? I remember her when she was two, and my husband remembers her when she was two, and we had, we have a shared memory of her when she was two. She doesn't remember. So that means I had a relationship with someone who's not here anymore. And sometimes, Peter, I miss... I mean, I love my kid to, I love her to bits, but I sometimes miss that exuberant little two-year-old. Like, I really do.

    9. PAPeter Attia2:30:41

       I wanna pause there for a second 'cause this is so funny that you bring this up, Lisa. Two nights ago at dinner, we sat at the table, me and my wife and our three kids, so, uh, nine, 12, and 18, and we all went around the table explaining our first memory in life.

    10. LBDr. Lisa Feldman Barrett2:30:57

        Mm-hmm.

    11. PAPeter Attia2:30:57

        So what is the first thing each of us remembered? And it, for all of us, it took place at around three years old. Now, of course, it's much more... I'm less interested in what me and my wife experienced-

    12. LBDr. Lisa Feldman Barrett2:31:08

        Sure

    13. PAPeter Attia2:31:08

        ... but I loved hearing what the kids experienced 'cause I f- to your point, like I was there.

    14. LBDr. Lisa Feldman Barrett2:31:14

        Right.

    15. PAPeter Attia2:31:14

        I was witnessing it.

    16. LBDr. Lisa Feldman Barrett2:31:15

        Right.

    17. PAPeter Attia2:31:15

        And there's amazing things they can't remember, like the fact that-

    18. LBDr. Lisa Feldman Barrett2:31:18

        Right

    19. PAPeter Attia2:31:18

        ... my daughter doesn't remember the first two houses she lived in. No recollection at all.

    20. LBDr. Lisa Feldman Barrett2:31:23

        Right.

    21. PAPeter Attia2:31:23

        Um, but what you said is so profound and I never thought about it that way, which is, um, my kids get so annoyed with me 'cause I can't stop telling them about how much I adore them. And I'm like, "When you were little, you were the cutest, sweetest, most edible thing on the planet." And they're like, "Dad, shut up." But-

    22. LBDr. Lisa Feldman Barrett2:31:44

        Yeah

    23. PAPeter Attia2:31:44

        ... what they're, what I'm missing, I think, is that was a, they, they don't remember that. They don't know what I'm talking about.

    24. LBDr. Lisa Feldman Barrett2:31:50

        They don't remember that. But your wife remembers.

    25. PAPeter Attia2:31:53

        Yeah.

    26. LBDr. Lisa Feldman Barrett2:31:53

        And so what I'm saying is that, you know-

    27. PAPeter Attia2:31:54

        And we text each other pictures and videos all day long.

    28. LBDr. Lisa Feldman Barrett2:31:56

        Right. No, we do that too.

    29. PAPeter Attia2:31:58

        Yeah.

    30. LBDr. Lisa Feldman Barrett2:31:58

        Yeah, we do that too. And my husband was so great, you know, when, when our daughter was small. [chuckles] He would always like write down these like perfect little gems of things that she would say, like just like out and about.
18. 2:33:30 – 2:36:37

    The connection between memories and predictions, and Peter’s closing thoughts

    1. LBDr. Lisa Feldman Barrett2:33:30

       I really miss that. And-

    2. PAPeter Attia2:33:31

       So, so tell me, though, what is that feeling is predicting what? How do we bring this full circle to the model?

    3. LBDr. Lisa Feldman Barrett2:33:37

       Well, it's a memory. Everything is, every... The thing, this is why thinking and feeling and perceiving are not that different from each other, because they all are rooted in predictions which are memories. Predictions are memories. Predictions are your brain reinstating patterns from the past for the purposes of the present. Like when you wr- when I'm reading a memoir, I'm not literally reading what's happened to someone. I'm reading how they experienced in that moment what happened to... Their experiences in that moment of whatever happened to them in the past. When you have a memory, you're not literally remembering what happened. You're remembering, your memory is creating an experience in the moment, which is informed by some set of signals from the past. And this is also, I think, a very powerful, powerful insight that you can use, that you can use. Memories are not like files in a file drawer. They are not veridical. You are always reconstructing them. When you remember something, whether you, whether you have an experience of remembering or not, you are reconstructing something. You're constructing a set of signals that has, bears some resemblance to the past or bits and pieces of the different pasts that your brain put together. That's how it works. And sometimes wh- sometimes when something comes to mind, like I have an intrusive thought or whatever, I'll be like, "Nope, not that past." Like I literally will say that out loud to myself sometimes. Like, "Nope, not that past."

    4. PAPeter Attia2:35:16

       It's interesting you, you went into psychology thinking you were gonna be a clinical ps- clinical psychologist. Through this series of experiments you're unable to replicate, you completely find a new direction in your career, and yet your, um, your, the work you've done probably has a potential for greater impact in the field of clinical psychology than you could have ever imagined or produced had you become a clinical psychologist.

    5. LBDr. Lisa Feldman Barrett2:35:44

       I'll take that.

    6. PAPeter Attia2:35:45

       Lisa, you've given me a lot to think about, and I'm gonna be... I would be lying if I said I understand everything we talked about today. I think this will be one of the podcasts I have to re-listen to. I don't do that often, actually. Um, but I, I can, I, I think there's going to be a few bike rides I go on. Just for the folks wondering, no, I'm not gonna be riding outside listening to a podcast.

    7. LBDr. Lisa Feldman Barrett2:36:10

       [laughs]

    8. PAPeter Attia2:36:10

       I'll be on a trainer, um, where I'll be, I'll be going over this again, and I, I'll probably come back to you with some other questions over email. So, um-

    9. LBDr. Lisa Feldman Barrett2:36:18

       That'd be great

    10. PAPeter Attia2:36:18

        ... I, I really appreciate your, your time and your, your insight today as a fellow Canuck.

    11. LBDr. Lisa Feldman Barrett2:36:25

        Well, thanks for having me on your podcast. [upbeat music]

Episode duration: 2:36:37