How to Improve Memory & Focus Using Science Protocols | Dr. Charan Ranganath

1. 0:00 – 2:06

   Dr. Charan Ranganath

   1. AHAndrew Huberman0:00

      (uptempo music) Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. My guest today is Dr. Charan Ranganath. Dr. Charan Ranganath is a professor of psychology and neuroscience at the University of California Davis. He is one of the world's leading researchers in the topic of human memory. And memory, of course, is an essential component to our entire lives. Memory isn't just important for remembering things that we learn, it's also vitally important for setting the context of our entire life. Meaning, only by understanding where we come from, who we were, and who we are currently can we frame what we want to do in the next moments, the next day, the next years, and indeed, for the rest of our life. This is why, for instance, that people who have deficits in memory, either due to brain damage or due to age-related cognitive decline or diseases like Alzheimer's dementia, suffer so much. Not just in terms of not being able to remember things for sake of daily tasks, but also for sake of placing themselves in the larger context of their life. Recognizing family members isn't just about being able to relate to those family members on a day-to-day basis, it's also about understanding the full context of all one's memories with those people and what meaning a given interaction brings to any of life's experiences. So today you're going to learn how memory works. You're going to learn about things like deja vu. You're going to learn ways to offset age-related cognitive decline, what the research really says about that, and ways to prevent things like Alzheimer's dementia. We also talk about ADHD, or attention deficit hyperactivity disorder, and Dr. Ranganath shares his own experience with ADHD, how it relates to memory, and the tools that he has used in order to combat his own ADHD. Doctor Ranganath has an exquisite ability to describe research studies in clear terms and to combine that with his own narrative and life experience in a way that really frames for you practical tools that you can apply in your daily

2. 2:06 – 6:48

   Sponsors: David, Levels & Waking Up

   1. AHAndrew Huberman2:06

      life. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero cost to consumer information about science and science-related tools to the general public. In keeping with that theme, I'd like to thank the sponsors of today's podcast. Our first sponsor is David. David makes a protein bar unlike any other. It has 28 grams of protein, only 150 calories, and zero grams of sugar. That's right, 28 grams of protein, and 75% of its calories come from protein. This is 50% higher than the next closest protein bar. These bars from David also taste incredible. My favorite bar is the cake-flavored one, but then again, I also like the chocolate-flavored one and I like the berry-flavored one. Basically, I like all the flavors. They're all incredibly delicious. Now, for me personally, I try to get most of my calories from whole foods. However, when I'm in a rush or I'm away from home or I'm just looking for a quick afternoon snack, I often find that I'm looking for a high-quality protein source, and with David, I'm able to get 28 grams of high-quality protein with the calories of a snack, which makes it very easy to hit my protein goals of one gram of protein per pound of body weight, and it allows me to do so without taking on an excess of calories. Again, I focus on getting most of my food from whole food sources throughout the day, but I typically eat a David bar in the late afternoon when I get hungry between lunch and dinner. Sometimes also mid-morning if I get hungry then, and sometimes I'll use it as a meal replacement, although not a complete meal replacement. It can get me to the next meal. So if I need to eat in a couple of hours but I'm really hungry, I'll eat a David bar. As I mentioned before, they are incredibly delicious. In fact, they're surprisingly delicious. Even the consistency is great. It's more like a cookie consistency, kind of a chewy cookie consistency, which is unlike other bars, which I tend to kind of saturate on. I was never a big fan of bars until I discovered David bars. If you give them a try, you'll know what I mean. So if you'd like to try David, you can go to davidprotein.com/huberman. Again, the link is davidprotein.com/huberman. Today's episode is also brought to us by Levels. Levels is a program that lets you see how different foods affect your health by giving you real-time feedback on your diet using a continuous glucose monitor. Now, one of the most important factors in both your short and long-term health, and your energy levels each day, is your body's ability to manage blood glucose. To maintain energy and focus throughout the day, you want to keep your blood glucose levels steady without big spikes or crashes. Now, I first started using Levels about three years ago as a way to understand how different foods impacted my blood glucose levels, and it's proven incredibly informative for determining what food choices I make, when best to time my food intake around things like workouts, both cardiovascular training versus resistance training, and when and what to eat close to sleep or not so close to sleep, when I wake up in the morning, if I'm fasting or breaking a fast, et cetera. Indeed, using Levels has helped me shape my entire schedule so I have more energy, more cognitive focus, my workouts are better, my sleep is better. Everything got better when I understood how different things, especially food, were impacting my blood glucose levels. So if you're interested in learning more about Levels and trying a CGM yourself, you can go to levels.link/huberman. Right now, Levels is also offering an additional two free months of membership. Again, that's levels.link, L-I-N-K, /huberman to try their new sensor and two free months of membership. Today's episode is also brought to us by Waking Up. Waking Up is a meditation app that offers hundreds of guided meditation programs, mindfulness trainings, yoga nidra sessions, and more. I started practicing meditation when I was about 15 years old, and it made a profound impact on my life. And by now, there are thousands of quality peer-reviewed studies that emphasize how useful mindfulness meditation can be for improving our focus, managing stress and anxiety, improving our mood, and much more. In recent years, I started using the Waking Up app for my meditations, because I find it to be a terrific resource for allowing me to really be consistent with my meditation practice.Many people start a meditation practice and experience some benefits, but many people also have challenges keeping up with that practice. What I and so many other people love about the Waking Up app is that it has a lot of different meditations to choose from, and those meditations are of different durations. So it makes it very easy to keep up with your meditation practice, both from the perspective of novelty, you never get tired of those meditations, there's always something new to explore and to learn about yourself and about the effectiveness of meditation, and you can always fit meditation into your schedule even if you only have two or three minutes per day in which to meditate. If you'd like to try the Waking Up app, please go to wakingup.com/huberman where you can access a free 30-day trial. Again, that's wakingup.com/huberman to access a free 30-day trial. And now for my discussion with Dr. Charan Ranganath.

3. 6:48 – 13:23

   Memory: Past, Present & Future; Sleep

   1. AHAndrew Huberman6:48

      Dr. Charan Ranganath, welcome.

   2. CRCharan Ranganath6:51

      Thank you.

   3. AHAndrew Huberman6:52

      Speaking of memory, we go way back.

   4. CRCharan Ranganath6:54

      We do. We do.

   5. AHAndrew Huberman6:56

      I was a graduate student when you were first hired as an assistant professor, which for those that aren't familiar with the academic nomenclature and trajectories, assistant professors are professors that have not yet received tenure, but now of course you're a full professor and you are a world expert in memory, something that I think occupies the minds of, uh, all of us, even if we're not trying. Um, so that's actually the segue to my first question, which is, as we move through our day, how much of our cognition, our perception is focused on things that are happening in the present as opposed to being driven by prior memories? Um, you know, uh, study's ever been done that evaluate how often our brain, you know, switches to thoughts about the past? Of course, we learn about things that are in our present. I know this is a cup because I was taught that-

   6. CRCharan Ranganath7:52

      Mm-hmm.

   7. AHAndrew Huberman7:53

      ... um, at some point. But what I'm referring to is how much of our thinking on a day-to-day basis is literally in the past?

   8. CRCharan Ranganath8:01

      Well, it's interesting that... I mean, it's first of all, it's a great question to start off with, and it's interesting because I actually don't think memory is about the past. I think memory is about the present and the future. It's about taking selectively what you need from the past to make sense of the present and to project to the future. Hey, I know you're a vision guy, right? And so if you look at people's just eye movements, right? The first time I came into this room, I'm sure, I wasn't aware of it, but I'm sure my eyes were going all over the place. Now, if I came back to visit, you say, if you're like, "Oh, that was an awesome interview," or whatever, right? Um, hopefully, but maybe not. But let's say I do, right?

   9. AHAndrew Huberman8:40

      Chances are.

   10. CRCharan Ranganath8:41

       Yeah. So I go and my eyes will probably go right to the Rick Rubin photo, then I'll go right to, you know, something el- or to the espresso machine. And so my memory allows me to make predictions about where things are, and it's almost pre-conscious so that it's happening without our awareness and it's like confirmatory. We're grabbing the important stuff and making sure everything's where it's supposed to be. And you can see this play out in phenomena also like change blindness, and it's a little bit of a different phenomena, but basically in change blindness there's a famous example where they show a video of people playing basketball and they're passing the ball back and forth, and then this guy in a gorilla costume just walks behind them, and about, I think it's 40% of the people who watch this video don't see the gorilla. And the reason is, is that you're generating these serious expectations about what's in front of you, and so you're not literally seeing what's in front of you. You are creating an internal model, a simulation really of what the outside world is. And memory, whether it's semantic memory, which we'll talk about, I'm sure, uh, your knowledge about the world like the cup thing, if it's episodic memory, which is your memory of what happened, let's say just a minute ago, it's all coming into play in terms of your sense of where you are, right? If I just ask you what day is it, you will use episodic memory for that. Tomorrow morning, I'm gonna wake up in a hotel room. If I don't have episodic memory, I will freak out because I'll be like, "Where am I? Did I get kidnapped? Why am I here?" And that's really the experience of people with memory disorders. I mean, they have to be in really familiar environments because it's frightening otherwise, right? So even... I wouldn't necessarily say that we are never seeing the present. Of course, we are, right? But our understanding of the present is so informed by the past that it allows us both to focus on what's important, what's non-redundant with what we already know, and it also allows us to detect surprises and find out the things that are unexpected and grab the most informative stuff as well.

   11. AHAndrew Huberman10:55

       Yesterday I took a brief nap in the afternoon. I do this practice of non-sleep deep rest-

   12. CRCharan Ranganath10:59

       Oh, yeah, yeah.

   13. AHAndrew Huberman11:00

       ... um, in the afternoon.

   14. CRCharan Ranganath11:01

       I'm gonna have you teach this to me sometime, maybe.

   15. AHAndrew Huberman11:03

       Um, yeah, it's, it's very restorative-

   16. CRCharan Ranganath11:05

       Mm-hmm.

   17. AHAndrew Huberman11:05

       ... for mental and physical energy I find. Um, but I fell asleep, uh, toward the end of it. And when I woke up, I was in a dark room. Um, but I didn't know where I was for about, felt like 10, 15 seconds. Somewhat scary-

   18. CRCharan Ranganath11:21

       Mm-hmm.

   19. AHAndrew Huberman11:21

       ... but I, I'd forgotten that I was in my solo studio. I had tur- turned the room lights down. Um, what is it when we have these lapses in memory as we emerge from sleep or sometimes, um, if one has been severely jet lagged, um, you can experience this, uh, disorientation of, of place. Do we know what that is?

   20. CRCharan Ranganath11:42

       Well, a lot of your sense of where you are comes from episodic memory. Now, there's a school of thought that says that episodic memory, which is your ability to remember past events, is, comes from your ability to understand where you are. And we have, we have some interesting data from sea lions, actually, that speaks to this issue.

   21. AHAndrew Huberman12:00

       Sea lions?

   22. CRCharan Ranganath12:01

       Sea lions, yeah.

   23. AHAndrew Huberman12:01

       Okay. We'll get back to that.

   24. CRCharan Ranganath12:02

       We'll get back to-

   25. AHAndrew Huberman12:03

       Okay.

   26. CRCharan Ranganath12:03

       ... the sea lions. But, um, I would argue that to remember, like, where you are when you first get up, you have to engage in an act of episodic memory retrieval. That is, you have to figure out, "Well, how did I get here?"

   27. AHAndrew Huberman12:15

       Mm-hmm.

   28. CRCharan Ranganath12:16

       And that takes a moment, orienting yourself takes a moment.

   29. AHAndrew Huberman12:19

       Mm-hmm.

   30. CRCharan Ranganath12:20

       And that, because it's, it's a little bit of a controlled memory search, right? It's not something that's in front of you that reminds you of where you are initially, and you're also in this little bit of a fog when you wake up. Um, I don't know enough about sleep to say, but I would suspect that people probably are in some kind of a stage one-ish or just high alpha-
4. 13:23 – 18:50

   Self, Memory & Age, Neuroplasticity

   1. AHAndrew Huberman13:23

      Uh, I'm curious also why it is that most all of us have a stable representation of who we are.

   2. CRCharan Ranganath13:29

      Mm-hmm.

   3. AHAndrew Huberman13:30

      So, my understanding is that even people with very severe memory deficits don't wake up in the morning and wonder, you know, "Who am I?" Or, "Who is this person in this body?" That somehow, um, we remember that we have a self, that we are separate from other selves. That that kind of knowledge, uh, might be innate.

   4. CRCharan Ranganath13:50

      Mm-hmm.

   5. AHAndrew Huberman13:50

      We might be born with it. Um, and that the representation of self and memory is very stable. Is that true?

   6. CRCharan Ranganath13:57

      Well, here's what I'll say there. It's a really interesting and complex question. Everything's, you always talk to a scientist, you get that it's complicated. But, um, I'll give you as simple of a thing as I can, which is, so if you look at patients with amnesia, so they have a memory disorder where they can't form new memories, they have a sense of who they are, as you mentioned, right? They, it's not like they don't know who they are. And I mean, like, they know their names, they know their biographies and so forth. But what happens is, at the time, let's say if you had gone swimming and you nearly drowned, you had a hypoxia incident or a cardiac arrest or, um, you know, you had, like, a traumatic brain injury, severe memory deficit, right? Your sense of self doesn't update. It gets kind of stuck.

   7. AHAndrew Huberman14:44

      Mm-hmm.

   8. CRCharan Ranganath14:45

      And so there is kind of a sense of looking and not expecting yourself to be as old as you used to be-

   9. AHAndrew Huberman14:52

      (laughs)

   10. CRCharan Ranganath14:52

       ... uh, uh, as you are, because, like, you're thi- you're stuck in your sense of who you were. And I do think, I talked, my good friend, Rick Robbins at, at Davis is a personality psychologist, and he studies the development of personality. And it does develop. You know, it kind of stabilizes in these adolescent years, and that's actually also interestingly related to memory.

   11. AHAndrew Huberman15:12

       Mm-hmm.

   12. CRCharan Ranganath15:13

       But it does change. People do change in really interesting ways. So one thing is that people grow more optimistic on average as they get older. Um, and-

   13. AHAndrew Huberman15:22

       Is that right?

   14. CRCharan Ranganath15:23

       Yeah, yeah, that's true. So Laura Carstensen, your colleague at Stanford, actually has done some really cool work on that topic.

   15. AHAndrew Huberman15:29

       They become more, uh, optimistic, and yet I would argue that we become more, quote unquote, "set in our ways," because neuroplasticity, the ability to re- reshape our neur- neural circuits diminishes with age.

   16. CRCharan Ranganath15:41

       Well, you know, so I think that's overdone a little bit. I think you're right. You know, you definitely see less dopamine activity, for instance, as people get older and, um, uh, but what I'll say is that people have gobs, if you have a healthy aging person, they have gobs of neuroplasticity. But often what happens is, is yeah, you get stuck in your ways, and that could be related to a few things. One is that you get changes in the prefrontal cortex, and that leads you to be less cognitively flexible. Um, it can be also because people just build up so much prior knowledge about the world that it just becomes kind of ingrained that this is the way it is, and it's harder to be surprised. I mean, you kind of see this with old scientists, right? They go like, "Nothing's new." Everything, everything's been discovered in 1960, and nothing new has happened since then, and-

   17. AHAndrew Huberman16:32

       And by the way, for folks listening who are considering a career in science, nothing could be further-

   18. CRCharan Ranganath16:36

       From the truth.

   19. AHAndrew Huberman16:37

       ... from the truth. In fact, prior to recording, uh, you told me a saying that I've never heard before.

   20. CRCharan Ranganath16:42

       (laughs)

   21. AHAndrew Huberman16:43

       I don't know if it's cynical or optimistic, but if I recall the, the quote, uh, that Dr. Ranganath passed along, which does not come from him, it descends from somebody else, not to be named.

   22. CRCharan Ranganath16:53

       (laughs)

   23. AHAndrew Huberman16:53

       Is that, quote, "Science progresses one funeral at a time." Very, very, actually, uh, very interesting statement.

   24. CRCharan Ranganath17:02

       (laughs)

   25. AHAndrew Huberman17:02

       It could, it could be examined from a number of directions.

   26. CRCharan Ranganath17:04

       (laughs) It's dark.

   27. AHAndrew Huberman17:05

       But I agree. I agree. I mean, there's some wonderful, let's call them aged scientists-

   28. CRCharan Ranganath17:09

       Mm-hmm.

   29. AHAndrew Huberman17:09

       ... with tremendous knowledge and excitement. I mean, uh, one only has to listen to, like, the Nobel Prize winner Richard Axel talk about his love of olfaction and perception, and you can sense his delight.

   30. CRCharan Ranganath17:20

       Mm-hmm.
5. 18:50 – 26:55

   Tool: Curiosity & Dopamine

   1. CRCharan Ranganath18:50

      So here's just an example, and this is... I know I'm gonna be free associating all over the place.

   2. AHAndrew Huberman18:55

      Please.

   3. CRCharan Ranganath18:55

      We can get into that, but it's like one of the coolest studies that we ever did, um, and I totally credit my postdoc, Matthias Gruber, for this. He came into my lab. Uh, he was originally German, came in from University College London, and he told me he wanted to study curiosity and its effect on memory. I'm like, "This is just..." I am being totally closed-minded, and I said, "This is just a dumb topic." You know, it's... Everybody knows if you're curious about something, you'll remember it better just 'cause you're interested, right? So he said, "No, no, no, this is really interesting." And so he did this experiment, and I got on board with it. I, you know, we really kind of collectively... It was just this beautiful thing where I was exposed to something new, and I got excited about it. And so the idea was we would give people these trivia questions, and so it's kind of like a pub quiz, right? You sit in a pub quiz. Sometimes you get a question, and it's like, "I don't know the answer." Sometimes you get it, and you go, "I know it." Sometimes you go, "I don't know. God, I really need to know the answer to this," and you get this itch, right? Or sometimes your listeners, I mean, they're probably very curious people, and that's why they listen to this, and maybe some of them go to your show notes afterwards 'cause they want to learn more, right? So we actually scan people's brains using functional MRI, and so we scan them when they get questions, and sometimes they had said, "I'm really curious to find out the answer to these question." Sometimes they weren't curious, and then we make them wait about eight seconds and then... or 10 seconds I think it was, something like that, and then we show them the answer. So they're kind of in suspense, kind of like you're watching like Breaking Bad or something back in the day, people had commercials, and so you're like, "Oh, no, I gotta find out what's gonna happen to Walt," right? So you're in suspense. You need to know the answer to this, or you don't care. Uh, sometimes you just don't care. You're just sitting around. So we show a little face, and we say, "Hey, how likely is it you think this person knows the answer to the question?" That was a totally dumb thing to do because they don't know this person. They're just looking at a face. They're just making some arbitrary decision. But I'll get to why we did that because that was, I think, the coolest part of the experiment. But let's first get back to the, the trivia question. So we found that when we looked at brain activity when we give people the question, right afterwards there is a burst of activity throughout the so-called reward circuit of the brain. There's a s- seri- it's not really a reward circuit, as we've discussed offline. It's really these areas of the brain that process the neurotransmitter dopamine. And unlike many other neuromodulators that just go all over the place, dopamine is much more restricted in its effect. And so in the midbrain near the ventral tegmental area... Sorry, I'm geeking out on this.

   4. AHAndrew Huberman21:33

      No, we've talked about that in this podcast. There's a particular... Uh, I think the key statement that you made that people should hold onto as we progress through this is that dopamine is not dumped everywhere. It's not sprinklered all over the brain. It's released in, uh, fairly restricted sites in order to drive particular processes.

   5. CRCharan Ranganath21:50

      That's right. Yeah, yeah, perfect.

   6. AHAndrew Huberman21:50

      I think that's sufficient for now.

   7. CRCharan Ranganath21:51

      Yeah, yeah. And so when we look at functional MRI, we can't measure dopamine, but what we see is activity in the dopaminergic midbrain area, meaning the area of the brain around the midbrain. And you see it in the nucleus accumbens or what's called the ventral striatum, which is another area that's super high dopamine reward processing area. The more curious people are, like on a one to six scale, the more activity you see. It's just like this beautiful relationship, right? And it's not driven by the answer. Now, there's a reason we probably didn't get it for the answer, but it's driven by the question. So it's not like they're like, "Oh, I learned something new." It's like, "I want to get this knowledge." And so that's part one of the story. Part two of the story is we show that face right after the question, and if people are curious to find the answer to the question, they get a bump in memory for the faces relative to if they're not curious. Now, the faces have nothing to do with the trivia question, but it's being in that curious state that drives this dopaminergic activity in the midbrain. So there's a whole lot, a lot of other studies, findings from that study, but basically, I think if... God, I gotta... You know how sometimes you do a lot of studies, and I've published like 180 studies. (laughs) So it's like, I'm trying to remember the exact word. I think it was like functional connectivity between the hippocampus and the midbrain during the face was predicting better memory for these faces in general, something like that.

   8. AHAndrew Huberman23:26

      Mm-hmm. We can put a link to the paper, of course-

   9. CRCharan Ranganath23:28

      Yeah.

   10. AHAndrew Huberman23:28

       ... in the show note capture.

   11. CRCharan Ranganath23:28

       Good.

   12. AHAndrew Huberman23:28

       So let me make sure I understand that the, um... When people are prompted with a question-

   13. CRCharan Ranganath23:33

       Yeah.

   14. AHAndrew Huberman23:33

       ... that drives the release of dopamine.

   15. CRCharan Ranganath23:35

       Yeah.

   16. AHAndrew Huberman23:35

       The amount of dopamine is proportional to how curious they are to get the answer to that particular question, and then the dopamine itself, if elevated because they are very curious, can increase the probability that they will remember the answer.It creates a milieu, an environment-

   17. CRCharan Ranganath23:55

       Mm-hmm.

   18. AHAndrew Huberman23:55

       ... for better memory. But that can confuse us and make us think that dopamine improves our memory, but it's that curiosity increases dopamine, which increases the capacity to store information that comes subsequent to curiosity.

   19. CRCharan Ranganath24:08

       Beautiful synopsis, but I'll do two cheerful amendments. (laughs) So, one is, um, technically we're not measuring dopamine, so I have to be very clear about that. This is bold signal, meaning it's, you know, m- metabolic activity. But it's following all the usual suspects of where you'd expect it to be. Um, the second thing is I do think that dopamine is playing a part, and I mean, it definitely facilitates plasticity. So, I do think it helps in learning the answer, for sure. And there's a whole theory called synaptic tagging, which basically says that if you just release a bunch of dopamine and then you have these potentiated synapses, that you can drive plasticity in those synapses even if it's not happening at the same time.

   20. AHAndrew Huberman24:50

       Mm-hmm.

   21. CRCharan Ranganath24:51

       But what's really cool is the face has nothing to do with the trivia question. The theory that we have is when you get that bump in dopamine activity, you're motivated, you're energized to get the answer, and you're driven towards a state of plasticity, and now I've given you something that has nothing to do with this question (fingers snap) and boom, you got it, you know? And-

   22. AHAndrew Huberman25:14

       So, when people ask me, and they ask me a lot-

   23. CRCharan Ranganath25:17

       Yes.

   24. AHAndrew Huberman25:17

       ... how best to elevate their brain dopamine, one reasonable answer based on this study is curiosity, to engage curiosity. Do you know the quote by Dorothy Parker? "The cure for boredom is curiosity."

   25. CRCharan Ranganath25:33

       (laughs)

   26. AHAndrew Huberman25:34

       "There is no cure for curiosity." Um, I believe is, it was Dorothy Parker. Um-

   27. CRCharan Ranganath25:39

       I love that.

   28. AHAndrew Huberman25:39

       ... if it wasn't, I'm sure we'll find out quickly in the, uh, uh, in the comments on YouTube.

   29. CRCharan Ranganath25:44

       Older people show the effect just as much as younger people do.

   30. AHAndrew Huberman25:47

       Mm-hmm.
6. 26:55 – 33:09

   Dopamine, Forward Movement

   1. CRCharan Ranganath26:55

   2. AHAndrew Huberman26:55

      Recently, we had, uh, one of the world's experts on romantic relationships, uh, on this podcast, um, Esther Perel to be specific, and we talked a li- about a lot of things related to romantic relationships, but she said that one of the most, um, sustaining factors for romantic relationships over long periods of time is a sense of curiosity, both about the other person-

   3. CRCharan Ranganath27:18

      Mm-hmm.

   4. AHAndrew Huberman27:18

      ... but also about one's self and how one changes in the context of the relationship, and also curiosity about where the relationship could eventually go-

   5. CRCharan Ranganath27:26

      Yeah.

   6. AHAndrew Huberman27:26

      ... were one to continue to invest in it.

   7. CRCharan Ranganath27:28

      Mm-hmm.

   8. AHAndrew Huberman27:28

      So, this word of curiosity seems to be a resounding theme. Um, I'm struck by, although it makes total sense, that curiosity would drive dopamine release in these, uh, pathways, that novelty would drive dopamine release in these pathways, and that also in the physical realm, dopamine is so important for physical movement.

   9. CRCharan Ranganath27:48

      Yes.

   10. AHAndrew Huberman27:48

       I don't think this is a, a coincidence, right?

   11. CRCharan Ranganath27:50

       No.

   12. AHAndrew Huberman27:50

       Some- somehow evolution organized this neuromodulator, dopamine, to be involved, the way I think about it is in both a physical movement.

   13. CRCharan Ranganath27:58

       Mm-hmm.

   14. AHAndrew Huberman27:58

       It's required for it, in fact, as well as cognitive movement. What we're really talking about is, is cognitive forward movement, if there is such a thing. Is th- is there a, a... uh, we're both neuroscientists-

   15. CRCharan Ranganath28:09

       Yeah, yeah.

   16. AHAndrew Huberman28:10

       ... but you're the memory researcher.

   17. CRCharan Ranganath28:11

       Mm-hmm.

   18. AHAndrew Huberman28:11

       Is there, is there sort of a, a word or a framework for thinking about cognitive movement forward? Meaning, um, as opposed to just recycling past ideas-

   19. CRCharan Ranganath28:20

       Mm-hmm.

   20. AHAndrew Huberman28:20

       ... and memories, the notion of taking memories and actually putting them, as you said earlier, into the present to anticipate the future, actually forward mental movement?

   21. CRCharan Ranganath28:31

       Huh, that's a really interesting question. Well, first of all, I wanna be careful and not to say dopamine does this, because it's gonna, you're all, it's a trap, right? (laughs) It's like-

   22. AHAndrew Huberman28:40

       Well, to be clear-

   23. CRCharan Ranganath28:41

       But, but, but again-

   24. AHAndrew Huberman28:41

       ... you observed-

   25. CRCharan Ranganath28:42

       Yeah, but I don't know-

   26. AHAndrew Huberman28:42

       ... heightened activity in a-

   27. CRCharan Ranganath28:43

       Yeah, yeah, yeah.

   28. AHAndrew Huberman28:44

       ... in a, in a dopaminergic circuit.

   29. CRCharan Ranganath28:45

       Yeah, yeah, yeah.

   30. AHAndrew Huberman28:46

       So, the idea that it would not involve dopamine is a, is a bit of a stretch. But you didn't directly show that it was dopamine.
7. 33:09 – 34:22

   Sponsor: AG1

   1. CRCharan Ranganath33:09

   2. AHAndrew Huberman33:09

      I'd like to take a quick break and acknowledge our sponsor, AG1. By now, many of you have heard me say that if I could take just one supplement, that supplement would be AG1. The reason for that is AG1 is the highest quality and most complete of the foundational nutritional supplements available. What that means is that it contains not just vitamins and minerals, but also probiotics, prebiotics, and adaptogens to cover any gaps you may have in your diet and provide support for a demanding life. For me, even if I eat mostly whole foods and minimally processed foods, which I do for most of my food intake, it's very difficult for me to get enough fruits and vegetables, vitamins and minerals, micronutrients, and adaptogens from food alone. For that reason, I've been taking AG1 daily since 2012, and often twice a day, once in the morning or mid-morning, and again in the afternoon or evening. When I do that, it clearly bolsters my energy, my immune system, and my gut microbiome. These are all critical to brain function, mood, physical performance, and much more. If you'd like to try AG1, you can go to drinkag1.com/huberman to claim their special offer. Right now they're giving away five free travel packs plus a year supply of vitamin D3 K2. Again, that's drinkag1.com/huberman to claim that special offer.

8. 34:22 – 40:31

   Dopamine, Learning; Curiosity & Appraisal

   1. AHAndrew Huberman34:22

      One thing that we talked about just briefly earlier was this non-sleep deep rest protocol.

   2. CRCharan Ranganath34:27

      Mm-hmm.

   3. AHAndrew Huberman34:27

      Um, that in, uh, um, yoga tradition is called Yoga Nidra or Yoga Sleep, because you lie down-

   4. CRCharan Ranganath34:33

      Mm-hmm.

   5. AHAndrew Huberman34:33

      ... it's self-directed relaxation, long exhale breathing to slow your heart rate, et cetera, et cetera. I called it no-, uh, NSDR not to appropriate it, but because the language of Yoga Nidra is a little bit of a separator for people.

   6. CRCharan Ranganath34:44

      Mm-hmm.

   7. AHAndrew Huberman34:44

      It sounds a little bit esoteric, right? And non-sleep deep rest tells you what it is, right?

   8. CRCharan Ranganath34:48

      Mm-hmm.

   9. AHAndrew Huberman34:49

      Um, there's a study, uh, out of the University of Copenhagen. I can provide a link to it in the show note captions, and I'd love your thoughts on it, that show that people who do this practice, this is a PET, um, imaging study-

   10. CRCharan Ranganath34:59

       Mm-hmm.

   11. AHAndrew Huberman34:59

       ... so positron emission tomography for those that don't know, and they see, uh, significant increases in, uh, striatal dopamine, uh, in the condition of people that do this self-directed relaxation as opposed to a more traditional meditation.

   12. CRCharan Ranganath35:12

       Hmm.

   13. AHAndrew Huberman35:13

       And this is why I say that NSDR is useful for restoring mental and physical vigor, which translates to this idea that dopamine prepares us for, or is a reservoir for potential movement-

   14. CRCharan Ranganath35:24

       Mm-hmm.

   15. AHAndrew Huberman35:24

       ... typically toward rewards. And I love that we're talking about some of the other facets of dopamine, because all too often people b- think about it as pleasure or motivation, and certainly it's involved in motivation. Um, and, uh, I'm very happy, um, to learn that, uh, it's also involved in learning. I think that's a-

   16. CRCharan Ranganath35:41

       Oh, seriously.

   17. AHAndrew Huberman35:41

       ... that's a n-, that's a, that's a novel perspective on dopamine. And we hear so much about dopamine. Do you think that when dopamine is released as a consequence of curiosity in a way that primes the memory system...... that, um, we become, uh, entrenched in particular behaviors or, um, routes of, uh, pursuing curiosity, um, to the exclusion of others? What I'm thinking about here is a kid. Um, we've seen these data, um, kids with ADHD, um, actually have terrific ability to focus if it's something that they're really excited about-

   18. CRCharan Ranganath36:13

       Mm-hmm.

   19. AHAndrew Huberman36:13

       ... really curious about.

   20. CRCharan Ranganath36:14

       Yeah.

   21. AHAndrew Huberman36:14

       So you give a kid with ADHD who loves video games a video game, and they're like a laser.

   22. CRCharan Ranganath36:18

       Yeah.

   23. AHAndrew Huberman36:18

       So it's not that they lack the capacity-

   24. CRCharan Ranganath36:20

       Yep.

   25. AHAndrew Huberman36:20

       ... to focus. It's that they have a harder time dropping into focus.

   26. CRCharan Ranganath36:24

       Yep.

   27. AHAndrew Huberman36:24

       But it seems that because of the learning asso- um, dimension to dopamine, that the circuits could potentially, quote unquote, "learn" that it's video games that provides that feeling of focus to the exclusion of other things. Meaning, how does one keep a diversification of, of, um, inputs to the dopamine system so that we're continually driving dopamine through lots of different things, as opposed to just social media or just video games, or just, pick your favorite-

   28. CRCharan Ranganath36:53

       Yeah, yeah.

   29. AHAndrew Huberman36:53

       ... thing. Um, because a, a f- becoming a functional human being, uh, involves the requirement to focus on many things, not just the things we were curious about.

   30. CRCharan Ranganath37:01

       Yeah. Yeah, yeah. Um, I mean, to me, I talk about this a little bit in the book, but, um, to me, and, and if you look at the literature too, you can see this. A big part of being curious is the appraisal process, so to speak. And what I mean by that is saying something happens, right? Let's say something in your environment happens. If you're gonna ... You have a decision to make. Is this interesting? (laughs) Is this important? Is this scary? And I think the thing is, is that you need to be open to that possibility that it's interesting. So, like, so f- let me just give you, like, a, an example that I, um, that I often give. Let's say you're walking in a neighborhood. You're traveling like you do for many of your, uh, events, and you walk into a new neighborhood you haven't been to. It's nighttime, kinda poorly lit, and you hear a loud noise, right? You could be like, "Well, that's a gunshot. I better hide, or I better run." Or you could be like, "Oh, maybe there's a club nearby, and there's, like, a cool band playing. I should go check this out." That appraisal is really critical for how you respond. And, uh, so it's not just a matter of curiosity happens. It's a process of cultivation, and it's a process of appraisal. And so, I mean, this is, I think ... You know, I'm not a wellness guru or anything, but it's like, I think this is one of the cool things about mindfulness training, is it forces you to take the mundane and be curious about it.
9. 40:31 – 43:34

   Memory, Hippocampus

   1. AHAndrew Huberman40:31

      maybe now would be a good time for us to discuss a little bit about the, the circuitry involved in memory-

   2. CRCharan Ranganath40:35

      Okay.

   3. AHAndrew Huberman40:35

      ... so that we have that as a template-

   4. CRCharan Ranganath40:37

      Mm-hmm.

   5. AHAndrew Huberman40:38

      ... to, to, uh, to, um, digest some other themes in memory. Um, most people are probably familiar with the so-called hippocampus.

   6. CRCharan Ranganath40:44

      Mm-hmm.

   7. AHAndrew Huberman40:45

      Um, which is, uh, s- it means seahorse.

   8. CRCharan Ranganath40:48

      Mm-hmm.

   9. AHAndrew Huberman40:49

      It looks a little bit like a seahorse-

   10. CRCharan Ranganath40:50

       Mm-hmm.

   11. AHAndrew Huberman40:50

       ... although the anatomists had a little bit of an imagination there-

   12. CRCharan Ranganath40:52

       (laughs)

   13. AHAndrew Huberman40:52

       ... in my opinion. But, um, hippocampus, um, let's add to it prefrontal cortex, which you've already-

   14. CRCharan Ranganath40:59

       Mm-hmm.

   15. AHAndrew Huberman40:59

       ... uh, mentioned. And, um, and then these neuromodulatory systems. So if we were going to, uh, assign a, a one-sentence definition, functional definition to each of those areas, um, what would you say the hippocampus does?

   16. CRCharan Ranganath41:12

       Mm-hmm. Well, first of all-

   17. AHAndrew Huberman41:13

       If you need more than one sentence, uh-

   18. CRCharan Ranganath41:14

       ... I have a whole lot of other neocortical areas we could talk about.

   19. AHAndrew Huberman41:15

       Please, and let's add those in. But I think-

   20. CRCharan Ranganath41:16

       Yeah, yeah.

   21. AHAndrew Huberman41:17

       ... if you can start with three, I think then-

   22. CRCharan Ranganath41:18

       Mm-hmm.

   23. AHAndrew Huberman41:18

       ... folks, uh, can digest it.

   24. CRCharan Ranganath41:20

       Yeah. So the hippocampus is controversial. I mean, it's the most studied area of the brain, arguably, except for maybe V1. Um, uh-

   25. AHAndrew Huberman41:27

       Visual cortex, V1.

   26. CRCharan Ranganath41:28

       Yeah.

   27. AHAndrew Huberman41:28

       Yeah, yeah.

   28. CRCharan Ranganath41:28

       Yeah. Um, and, uh, but I believe, and my colleagues do ... I wrote a big paper with Howard Eichen- the late Howard Eichenbaum and Andy Alinas on this, who, um, you know, from Davis. And, uh, we believe that it's about linking various experiences to a context. And what I mean by that is you've got information about smell, high-level vision, high-level semantic knowledge information, right? And-... the hippocampus's wiring is really set up to not understand what's going on. So, the late David Morrow was a pioneer in computational neuroscience-

   29. AHAndrew Huberman42:03

       Mm-hmm.

   30. CRCharan Ranganath42:04

       ... proposed that what the hippocampus is about is s- what he called simple memory. It's basically saying, "I know Andy Huberman." Sorry, is it okay if I call you-
10. 43:34 – 50:07

    Prefrontal Cortex & Memory, Aging

    1. CRCharan Ranganath43:34

       And where the prefrontal cortex comes in, and it's, it's a huge area, it's about one-third of the primate brain. So, it's just massive. Uh, there are a lot of people who go, "Well, there's no real... There's a bunch of different areas, they all do different things." And I subscribe to the view that that is very true, and at the same time, there's a global function of the prefrontal cortex, which is what's called cognitive control. It's this ability to say, "I'm going to regulate my movements, and I'm gonna regulate my perceptions and my thoughts based on what's important to me in terms of this higher order goal," right? So, um, when I've tested, for instance, patients with prefrontal lesions, I'm sure Mark Esposito talked to you about this, it's like the hallmark of them... You know, they used to say, "Well, the prefrontal cortex, it's important for working memory," and you could record from neurons in the prefrontal cortex or look at fMRI signal, um, and if a person or a animal is holding something in their mind, like a phone number, neurons or BOLD signal in MRI will be highly elevated. Their activity will be elevated, um, throughout this period of time where they're holding it in mind. But it turns out if you just ask somebody with a major prefrontal lesion, "Here's a bunch of numbers, five, two, seven, eight," you know, I ask you to tell them back to me in right order, they can do it just fine. But now I start to distract them, I move my hands around, there's a plane going on, you know, flying outside the window, I mean, I had that literally happen once, now they start to bomb it because their attention is not controlled by their goal. It's controlled by the environment around them.

    2. AHAndrew Huberman45:16

       Mm-hmm.

    3. CRCharan Ranganath45:17

       And so this is where things get really interesting. So, I once tested a, a patient, and I had heard about this, but until you see it, it, like, doesn't register. It really blew my mind. So, there's a, a test called the Wisconsin Card Sorting Test, and we don't have to get into all the details of it, but basically, it's this test where people learn some rule about where to put a card on a table, right? And they don't get told the rule, they just learn it. And patients learn this w- with prefrontal damage, learn it just fine, right?

    4. AHAndrew Huberman45:47

       Is it that they get a, a error signal or a correct signal if they're doing it in the right direction? Over time, they just kind of... The brain figures it out?

    5. CRCharan Ranganath45:54

       Yeah, yeah.

    6. AHAndrew Huberman45:54

       Yeah.

    7. CRCharan Ranganath45:54

       So, maybe I'll give a little bit more background, but I don't wanna go in the weeds on it.

    8. AHAndrew Huberman45:57

       No, that's okay. I'm- I- my-

    9. CRCharan Ranganath45:59

       Yeah.

    10. AHAndrew Huberman45:59

        If I'm correct, if I'm wrong, I forget the Wisconsin Card Sorting Test-

    11. CRCharan Ranganath46:01

        Yeah.

    12. AHAndrew Huberman46:02

        ... details. But, you know, like, they, they're told to just start sorting the cards and that the, the, um, the alg- the correct algorithm will reveal itself-

    13. CRCharan Ranganath46:08

        Mm-hmm.

    14. AHAndrew Huberman46:09

        ... by a series of error and, um, correct signals. And so maybe I'm taking all the red cards and putting them in one pile, black cards and putting them in another.

    15. CRCharan Ranganath46:16

        Yeah.

    16. AHAndrew Huberman46:16

        I'm getting error signals, so then maybe I go odds, evens.

    17. CRCharan Ranganath46:18

        Yeah.

    18. AHAndrew Huberman46:18

        Maybe I divide by suit if it, depending on what kind of cards they are.

    19. CRCharan Ranganath46:21

        Mm-hmm. Yeah.

    20. AHAndrew Huberman46:22

        Maybe I organize by even, odd alteration. And sooner or later, the brain figures it out.

    21. CRCharan Ranganath46:27

        Yeah, exactly.

    22. AHAndrew Huberman46:28

        Yeah, yeah.

    23. CRCharan Ranganath46:28

        Exactly. And you don't need a prefrontal cortex to do that.

    24. AHAndrew Huberman46:31

        Really?

    25. CRCharan Ranganath46:32

        Which is surprising, but you don't. You can do it.

    26. AHAndrew Huberman46:34

        Hmm.

    27. CRCharan Ranganath46:34

        And-

    28. AHAndrew Huberman46:34

        So, there's context-dependent action and learning without the prefrontal cortex?

    29. CRCharan Ranganath46:41

        Yes, but let's, let's unpack this context then-

    30. AHAndrew Huberman46:44

        Mm-hmm.
11. 50:07 – 58:53

    Aging, Prefrontal Cortex & Memory; Depression, Rumination

    1. AHAndrew Huberman50:07

       it speaks to, um, almost two, um, parallel processing streams for memory, if I'm not mistaken. Um, or maybe, uh, so what's going on there? Is it that, um, one form of memory involves the suppression of information and that circuit is actually, uh, quite active in these older people and young people.

    2. CRCharan Ranganath50:27

       Mm-hmm.

    3. AHAndrew Huberman50:27

       Whereas curiosity for, um-

    4. CRCharan Ranganath50:30

       Oh, that's interesting.

    5. AHAndrew Huberman50:30

       ... and the ability to remember and integrate new information is somehow diminished in older people. Earlier we, um, we were talking about how that's not the case. That curios- if curiosity is intact-

    6. CRCharan Ranganath50:41

       Mm-hmm.

    7. AHAndrew Huberman50:41

       ... memory is intact and growing.

    8. CRCharan Ranganath50:43

       Yeah. Yeah. Well, o- okay. I should say the benefit of curiosity on memory is intact in older people. I, I got that wrong.

    9. AHAndrew Huberman50:51

       Mm-hmm.

    10. CRCharan Ranganath50:51

        I don't know, Mathias could tell me if I just (laughs) email him if, at a break or something. But, uh, I don't know if curiosity itself is as high in older adults.

    11. AHAndrew Huberman51:02

        I would guess-

    12. CRCharan Ranganath51:02

        Just self-reported or...

    13. AHAndrew Huberman51:04

        I would guess no, but this is why I asked about movement earlier.

    14. CRCharan Ranganath51:07

        Mm-hmm. Yeah.

    15. AHAndrew Huberman51:07

        It's also, curiosity is also linked to your ability to access novel scenarios.

    16. CRCharan Ranganath51:12

        Mm-hmm.

    17. AHAndrew Huberman51:12

        Of course online you can just thumb scroll or click-

    18. CRCharan Ranganath51:16

        Yeah.

    19. AHAndrew Huberman51:16

        ... and access all sorts of novelty. Um, is there any, there must be data as to whether or not people in their 70s, 80s, and 90s are, um, scrolling social media, uh, to the same extent that, um, younger people are?

    20. CRCharan Ranganath51:32

        I don't know, but I can say two things to this. One is, is that definitely there's a lot of work on media multitasking and-

    21. AHAndrew Huberman51:39

        Mm-hmm.

    22. CRCharan Ranganath51:40

        ... the short answer is bad for memory period. (laughs)

    23. AHAndrew Huberman51:42

        Okay. So, so scrolling-

    24. CRCharan Ranganath51:43

        Um, uh, but, and then older people-

    25. AHAndrew Huberman51:44

        ... so scrolling is bad for memory.

    26. CRCharan Ranganath51:45

        Well, media multitasking is bad for memory.

    27. AHAndrew Huberman51:49

        Hmm.

    28. CRCharan Ranganath51:49

        Scrolling, we, the tech thing is a super fascinating area in general. It's really how we interact with the tech that's bad.

    29. AHAndrew Huberman51:56

        Mm-hmm.

    30. CRCharan Ranganath51:57

        But if you're an older adult, your frontal function is not going to be as good. You will be more distractable, you'll be more likely to go off course. And so that scrolling is gonna be more potent because as you pointed out, the algorithms are all designed to suck up our attention. So psychologist Herb Simon came up with this beautiful term called the attention economy, right?
12. 58:53 – 1:00:40

    Sponsor: Function

    1. CRCharan Ranganath58:53

    2. AHAndrew Huberman58:53

       I'd like to take a quick break and thank one of our sponsors, Function. I recently became a Function member after searching for the most comprehensive approach to lab testing. While I've long been a fan of blood testing, I really wanted to find a more in-depth program for analyzing blood, urine, and saliva to get a full picture of my heart health, my hormone status, my immune system regulation, my metabolic function, my vitamin and mineral status, and other critical areas of my overall health and vitality. Function not only provides testing of over 100 biomarkers key to physical and mental health, but it also analyzes these results and provides insights from top doctors on your results. For example, in one of my first tests with Function, I learned that I had too high levels of mercury in my blood. This was totally surprising to me. I had no idea prior to taking the test. Function not only helped me detect this, but offered medical doctor informed insights on how to best reduce those mercury levels, which included limiting my tuna consumption, because I had been eating a lot of tuna, while also making an effort to eat more leafy greens and supplementing with NAC, N-acetylcysteine, both of which can support glutathione production and detoxification and worked to reduce my mercury levels. Comprehensive lab testing like this is so important for health, and while I've been doing it for years, I've always found it to be overly complicated and expensive. I've been so impressed by Function, both at the level of ease of use, that is getting the tests done, as well as how comprehensive and how actionable the tests are, that I recently joined their advisory board, and I'm thrilled that they're sponsoring the podcast. If you'd like to try Function, go to functionhealth.com/huberman. Function currently has a wait list of over 250,000 people, but they're offering early access to Huberman Lab listeners. Again, that's functionhealth.com/huberman to get early access to Function.You

13. 1:00:40 – 1:09:39

    Tool: Lifestyle Factors, Minimizing Age-Related Cognitive Decline

    1. AHAndrew Huberman1:00:41

       probably think a fair amount about age-related cognitive decline and Alzheimer's.

    2. CRCharan Ranganath1:00:46

       Mm-hmm.

    3. AHAndrew Huberman1:00:46

       And, and I'm just curious, um, at a personal level, uh, w- what are the sorts of things that you do to try and offset cognitive decline? Uh, you seem to be a very vivacious and curious person. Um, I've known you a long time, and I don't know whether or not you were caffeinated every time we met, but-

    4. CRCharan Ranganath1:01:03

       (laughs)

    5. AHAndrew Huberman1:01:03

       ... you have a lot of energy. You're a very curious person. Um, you just wrote a book, um, we'll talk more about, and you're going on podcasts.

    6. CRCharan Ranganath1:01:10

       (laughs)

    7. AHAndrew Huberman1:01:10

       You're doing a lot of things besides running a, you know, w- world-class research laboratory, so clearly a lot of curiosity. Um, what did the data say about ways to maintain or enhance one's memory capacity, with the understanding that curiosity is probably involved, as we talked about earlier, but at a, at, at a really basic level? Um, I mean, a number of things leap to mind, but I'm just curious what your, um... if you had to pick, like, three to five things that are clearly substantiated in the data as supporting the maintenance or enhancement of memory as we get older, what are those?

    8. CRCharan Ranganath1:01:44

       I mean, as a memory researcher, I almost find, uh, myself, like, ashamed when I talk (laughs) about these things because, as you know, so many of the most important factors are ones that are related to just health. So for instance, uh, you mentioned sleep. That's a big one. Um, we can... actually, there's a beautiful study that speaks to this that was done, 29,000 subjects in China, and they followed them up for 10 years. Now, at the beginning of... so they divided people into three groups. They said, "Okay, here's..." well, what they said is, "There's six lifestyle factors that we're gonna investigate." One was, I think, uh, um, engagement in cognitive activities. I think one was social engagement. One was, uh, um, physical exercise, uh, not smoking, I think no alcohol. But they identified these lifestyle factors that were basically just kind of good lifestyle factors, right? So they get people who have four to six of these lifestyle factors going versus, uh, zero to one of these lifestyle factors. We'll just take the extreme. When they start, they're all the same. 10 years later, the people with four to six lifestyle factors going for them are performing almost twice as high on memory tests as the people with zero to one lifestyle factors.

    9. AHAndrew Huberman1:03:01

       Wow, so these are people exercising, paying attention to their sleep, um, social engagement.

    10. CRCharan Ranganath1:03:05

        Mm-hmm.

    11. AHAndrew Huberman1:03:06

        What are some of the other...

    12. CRCharan Ranganath1:03:07

        Oh, I believe-

    13. AHAndrew Huberman1:03:08

        I'm guessing low inflammatory diet.

    14. CRCharan Ranganath1:03:10

        Yeah, yeah, definitely not smoking.

    15. AHAndrew Huberman1:03:12

        Okay.

    16. CRCharan Ranganath1:03:12

        And, uh, and smoking and alcohol, um, I think were big ones. Um-

    17. AHAndrew Huberman1:03:17

        The smoking one is interesting because we know smoking can cause cancer-

    18. CRCharan Ranganath1:03:20

        Mm-hmm.

    19. AHAndrew Huberman1:03:20

        ... and cardiovascular risk is, is real there, although there are some data, as I understand, that nicotine itself, not smoking, vaping, dipping, or snuffing, but that nicotine-

    20. CRCharan Ranganath1:03:32

        Hmm.

    21. AHAndrew Huberman1:03:32

        ... can be pro-cognition and maybe even pro-memory. Um, and nowadays-

    22. CRCharan Ranganath1:03:38

        Mm-hmm.

    23. AHAndrew Huberman1:03:38

        ... people are using nicotine more and more. I'm not a big proponent of this because-

    24. CRCharan Ranganath1:03:41

        Mm-hmm.

    25. AHAndrew Huberman1:03:41

        ... of the blood pressure increase and the typical routes of administration are dangerous.

    26. CRCharan Ranganath1:03:45

        Mm-hmm.

    27. AHAndrew Huberman1:03:45

        But, um, nicotine, I've been told, is protective for Parkinson's and Alzheimer's. Is that true?

    28. CRCharan Ranganath1:03:52

        Well, um, let me... oh, by the way, I just have to say, I forgot healthy diet. Healthy diet was (laughs) a big one too.

    29. AHAndrew Huberman1:03:59

        Right, well-

    30. CRCharan Ranganath1:03:59

        Yeah, yeah.
14. 1:09:39 – 1:17:26

    Exercise, Brain Function; ADHD

    1. AHAndrew Huberman1:09:39

       my understanding, I've been looking at this in detail lately but I'd love your thoughts, is that while everybody, we now believe men, women, et cetera should both, uh, should do both cardiovascular exercise-

    2. CRCharan Ranganath1:09:50

       Mm-hmm.

    3. AHAndrew Huberman1:09:50

       ... so to speak, elevate heart rate for 12 to 60 minutes kind of thing, depending on the intensity, as well as resistance training-

    4. CRCharan Ranganath1:09:56

       Mm-hmm.

    5. AHAndrew Huberman1:09:56

       ... to maintain neuromuscular function, offset sarcopenia, et cetera, to me, the really impressive effects of exercise on learning capacity and the brain in terms of brain health-

    6. CRCharan Ranganath1:10:07

       Mm-hmm.

    7. AHAndrew Huberman1:10:07

       ... seem to come from cardiovascular exercise.

    8. CRCharan Ranganath1:10:10

       Mm-hmm.

    9. AHAndrew Huberman1:10:10

       A- and that could just be because that's what's been emphasized in the studies-

    10. CRCharan Ranganath1:10:14

        Yeah.

    11. AHAndrew Huberman1:10:14

        ... but even when one looks at some and compares the best human studies-

    12. CRCharan Ranganath1:10:18

        Mm-hmm.

    13. AHAndrew Huberman1:10:19

        ... um, it really does seem like getting blood flow up to the brain-

    14. CRCharan Ranganath1:10:21

        Yeah.

    15. AHAndrew Huberman1:10:21

        ... yeah, getting a, a nice, um, release of neuromodulators into the brain facilitates learning-

    16. CRCharan Ranganath1:10:27

        Mm-hmm.

    17. AHAndrew Huberman1:10:28

        ... and then, of course, people have to do something with that learning.

    18. CRCharan Ranganath1:10:30

        Mm-hmm.

    19. AHAndrew Huberman1:10:30

        Right? So, um, do you make an effort to exercise for the specific purpose of maintaining or enhancing brain function?

    20. CRCharan Ranganath1:10:37

        Yes. Yeah. Actually, so I, like, when I finished my book, I limped to the finish line. I had all sorts of crazy stuff happen. I won't depress the readers with all the crazy stuff that I've had. (laughs)

    21. AHAndrew Huberman1:10:47

        Mm-hmm. I'm sure people will be curious what w-

    22. CRCharan Ranganath1:10:49

        Listening.

    23. AHAndrew Huberman1:10:49

        ... what does it take to finish a book and how much d- you mean, what, it took a toll on your body?

    24. CRCharan Ranganath1:10:53

        It took probably, I mean, I don't know, I probably lost some, like, biological years in that. (laughs) But it was really, like, I mean, it was great. I mean, it was really an emotional rollercoaster though, but then I had a bunch of, you know, I'm trying to do science, write this book basically in my spare time, which doesn't really exist as you know (laughs) how it goes.

    25. AHAndrew Huberman1:11:13

        Sure.

    26. CRCharan Ranganath1:11:13

        And then, I had life happen. You know, my mom was in the hospital. My cat died on my birthday.

    27. AHAndrew Huberman1:11:18

        Sure.

    28. CRCharan Ranganath1:11:18

        I mean, it was just like... Yeah. See, I didn't want to depress people with all this stuff.

    29. AHAndrew Huberman1:11:21

        Yeah. I mean, it's real li- real life.

    30. CRCharan Ranganath1:11:22

        But I mean, it was like-

Episode duration: 2:39:08