The Neuroscience Of Memory: Deja Vu, Photographic Memory, Improving Cognition & Why We Remember With Charan Ranganath, PhD

Dr. Charan Ranganath is a prominent neuroscientist, a professor at UC Davis, and the author of the influential book “Why We Remember.” This conversation explores the profound intersection of neuroscience and human experience. Charan reveals that our most resonant memories resemble paintings more than photographs, continuously reshaped by the present moment. We discuss the role of memory in identity, survival, and healing, as well as its implications in our digital age. During our exchange, I gained insight into why my cherished memories might be less reliable than I had previously believed. Charan is an impressive yet approachable voice in memory science. This exploration might make you question your narrative. Enjoy! Show notes + MORE Watch on YouTube Newsletter Sign-Up Today’s Sponsors: Bon Charge: Use code RICHROLL to save 15% OFF 👉 boncharge.com On: High-performance shoes & apparel crafted for comfort and style 👉 on.com/richroll Airbnb: Your home might be worth more than you think. Find out how much 👉 airbnb.com/host Birch: For 20% off ALL mattresses and 2 free eco-rest pillows 👉 BirchLiving.com/richroll AG1: Get a FREE 76$ gift when you sign up 👉 drinkAG1.com/richroll Squarespace: Use the offer code RichRoll to save 10% off your first purchase 👉Squarespace.com/RichRoll Check out all of the amazing discounts from our Sponsors 👉 richroll.com/sponsors Find out more about Voicing Change Media at voicingchange.media and follow us @voicingchange Learn more about your ad choices. Visit podcastchoices.com/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

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• 1:06Speaker 01

  The brain is really being selective about forming episodic memories. And whatever's happening in the brain during the rest of those times is just not meaningful. A lot of what's happening in your brain in this moment is completely unimportant for memory.

• 1:24Rich Roll?

  Dr. Sharan Ranganath is a neuroscientist who has devoted his entire career to understanding the science of memory and unlocking its many mysteries.

• 1:33Speaker 01

  To me, the question is really, why do we remember anything? Why do we have this capability if it's not to document the past in some library form? And the answer is it's about the future.

• 1:44Rich Roll?

  Today, we explore these mysteries. We confront wrong-headed assumptions we make about memory, and discuss the many ways in which memory, for better or worse, profoundly influences not just our identity, but every aspect of being human.

• 2:00Speaker 01

  People don't necessarily have a good idea of what "better memory" means, right? I can give you a million strategies for keys. I can give you a million strategies for names. But the fact is, if you don't use those strategies, I can't help you. What are the main things that we do that unnecessarily impair our memory? There's so many. I think the biggest thing that we do is...

• 2:31Rich Roll?

  Happy to have you here. Obviously, today, we're going to talk about memory. And in immersing myself in your work and your really wonderful book, I think this book is tremendous. So first off, congrats on that.

• 2:44Rich Roll?

  As we were saying before we started recording, the more that I've been reflecting on memory and what it actually is, the more profound it becomes. It's just so central to everything. And yet, as we're going to get into, memory is not indeed this archive of factual events, but is much more, as you say, a painting versus a photograph. It's an interpretation of events that has as much to do with imagination as reality.

• 3:17Speaker 01

  That was perfect.

• 3:17Rich Roll?

  Did I get that right?

• 3:18Speaker 01

  Yeah, I should have you narrate the next audio book. For me, that was brilliant. Yeah. No, that's exactly right. And I think that's one thing that I really wanted to do with the book is give people an appreciation, not just for the science of memory, but for really what an amazing ability it is and how pervasive it is in all our lives. And how to use that capability in a way that is going to be helpful as opposed to using it in ways that could be counterproductive. I like to say that you don't want, you want memory to be your valued co-pilot, but you don't want it in the driver's seat.

• 3:58Rich Roll?

  How did you initially get interested in this field?

• 4:01Speaker 01

  Well, it's a kind of a circumlocutus path, shall we say. But I probably, I went into grad school in clinical psychology. And part of my time was spent doing neuropsychological testing. And in the neuropsychological testing, I would be seeing patients who would be coming in and they would be saying, you know, well, they were referred for many reasons. Sometimes it was an insurance company trying to see if somebody is truly has brain damage. Sometimes it was a person who was concerned that they might have Alzheimer's disease. Sometimes it was family members bringing someone in and saying, hey, this person is Shane. And it could be whether or not the issue was, you know, early Alzheimer's,

• 4:43Speaker 01

  traumatic brain injury, even things like clinical depression. Memory was what brought them in. And so it really struck me just how important memory was because when that domino falls, people were just not functional. And in many cases, you know, we would be asking, can this person live independently? And if they had significant memory problems, the answer would be no. Sure. It just wasn't. So it was extraordinarily important to people's lives. And then in therapy settings, I was seeing patients and you would be talking to people and connecting with people. And I was doing cognitive behavior therapy, which in and of itself is based

• 5:26Speaker 01

  a lot on learning theory and the mechanisms of learning. But on top of it, you'd be doing these standardized protocols for treatment. And sometimes what brought them in, it wasn't the problem that they really wanted to solve. So in other words, I'll just give you an example. My first patient was a guy who came in for a driving phobia. So what you do for treating a driving phobia is you have someone drive the same stretch over and over again, until that fear response basically habituates. It's actually the brain learning to suppress the fear response, which is something we can come back to. Yeah. It's a fascinating point. But he was able to do that, but he wasn't really there

• 6:06Speaker 01

  as far as feeling like happy with this outcome. And we went more and more into it. And he really wanted to share with me these stories that he hadn't shared with anyone. And one of them came out was that he was gay and he came out of the closet and had a big argument with his father, right before that car accident. And so to him, once we worked that through, and once he told me that story, and once I kind of reacted to that story, and we built this narrative together, he felt relieved. He felt like that was a major factor in what caused his driving phobia. Now, as a scientist, I can't say that had anything to do with

• 6:50Speaker 01

  it necessarily, but it meant something to him, you know? And this was just one of many, many stories where people, a lot of what people come into therapy for- Or as they have a shameful memory or a memory that's just traumatic in some way. And so in both sides of this equation, it just really occurred to me, whether it's doing neuropsych testing or therapy, how important memory is to people. And yet, how little we knew about it, because the tests we had were all from the 1930s.

• 7:20Rich Roll?

  Yeah, I mean, that was my next question, which is, what was the current state of scientific affairs? When you decided this was going to be the path that you were going to pursue?

• 7:30Speaker 01

  Well, it was interesting because there is a difference between where things were in the clinic, where basically it's all about measuring things reliably and measuring it in a broad range of people. And a lot of those measures were developed back, you know, around World War II or even earlier than that. The science had progressed farther, but it was still fairly early in the sense that brain imaging was just getting off the ground. And there's this technique called functional magnetic resonance imaging that was just taking off. And it just happened to be while I was in grad school. And so all of a sudden, you could see maps of individuals' brains while they were remembering something. And that was in its infancy. And I just couldn't help myself.

• 8:15Speaker 01

  I mean, that that was really the chance that I was waiting for to take these questions that I had from my work in the clinic and then say, well, maybe if we understood the brain, we could go back and really figure things out in a different way.

• 8:28Rich Roll?

  So the FMRI technology allows the science of understanding memory to progress from the therapeutic, psychological kind of canon of how we think about memory and put it in a lab to actually perform tests that were going to reveal not just what's happening in the brain, but deeper implications and more sophisticated sorts of studies that would, over time, begin to elucidate the very nature of this mysterious thing.

• 9:02Speaker 01

  Yes, I mean, I will say that before FMRI, people were using studies of patients with brain damage, and that was really the first major breakthrough in the human neuroscience of memory was looking at people, like, there's a patient named HM, who's probably the most famous neurological patient of all time, who had dense amnesia after he had damage to a brain area called the hippocampus. And so that's what got a lot of people then studying in the hippocampus in animals and studying humans with hippocampal damage. But I think what FMRI allowed us to do was do, you know, more studies, because it was really hard to find people who had amnesia, but it was pretty easy to stick someone in an MRI scanner

• 9:46Speaker 01

  and ask them to remember things. And it allowed us to get a broader map of the brain and relate it more to the kinds of things that people were doing in psychology labs. There wasn't so much about the clinic, but it also wasn't tied to the brain.

• 10:02Rich Roll?

  As I said at the outset, my sense is that many of our intuitions regarding memory are wrong. So we probably should take a minute and define our terms a little bit. Like, when we talk about memory, how do you define that?

• 10:17Speaker 01

  I would say when people are colloquially talking about memory, they're usually talking about some form of episodic memory. Episodic memory is that ability we have to remember something we did once. So, for instance, it's like, where did I put my keys? That's episodic memory. People aren't asking, where do I usually put my keys, which could be a form of what's called semantic memory, or it could be even a form of what's called procedural memory, which is just your habits and so forth. But episodic memory is this ability we have to travel back in time, and actually to travel forward in time, too, and be able to use singular experiences to project ourselves into the past and re-experience

• 11:02Speaker 01

  it, but also use it to plan and imagine.

• 11:07Rich Roll?

  It is a form, episodic memory being this form of mental time travel.

• 11:12Speaker 01

  Yeah, yeah. And when I first heard it as I wrote in the book, I thought, Handel Tovin, who came up with this term episodic memory, I thought this was crazy. He's talking about this thing called mental time travel. And what I found was that, well, of course, if you, you know, if I listen to a song that I haven't listened to in 20 years, it gives you this palpable feeling of being in the past, right? Or if you go back to your, someplace that you went to and hung out in, like if I went back to the mall that we used to hang out in during lunchtime when I was in high school, I'm sure I would feel like I was back in high school. There's a palpable sense of your brain being rebooted in time. And

• 11:53Speaker 01

  we've since seen this in our lab and in other labs where you can see the brain reset, so to speak, not completely, but move towards a state that it was in, in the past, when people remember and recollect an event.

• 12:09Rich Roll?

  Part of our mistaken assumptions around memory is this expectation that we should remember everything that happens to us. So talk a little bit about the relationship between forgetting and memory, the purpose of memory, and the role that it's truly intended to play to serve us, and how we should perhaps better think about our capacity, our important capacity to forget.

• 12:35Speaker 01

  Yeah, it's something that I was really excited about writing the book because I felt like, early on, when people would talk to me about this, they would say, well, how do I improve my memory? And it really occurred to me that people don't necessarily have a good idea of what better memory means, right? So, first of all, what's normal? Well, we know that from the earliest scientific studies of memory, that the majority of what people experience, that is the details, the arbitrary, random stuff, the majority of that is gone within 24 hours. In fact, actually, a lot of it, like 40% disappears in about two hours. It's just remarkable how fast the stuff disappears.

• 13:16Rich Roll?

  Forty percent.

• 13:17Speaker 01

  Yeah, it's, it's just a huge, steep, steep drop off in the amount of information we have over time. Now, what does that mean? Well, it means that basically,

• 13:30Speaker 01

  If we're having this experience, right? We're having a great conversation. If we're lucky, we will get bits and pieces of this conversation that will allow us that sense of mental time travel, but most of the details will be gone, right? And what's funny is, is that people both kick themselves for not having a good enough memory. But in the moment, people rely scientifically, you can measure this, are highly overconfident that they will remember everything from the experience, right? So they both reflect this belief that we're supposed to remember everything. And scientifically, that's just not true. So then that, that's why I didn't title the book, Why We Forget. There is another book, that's a good book, that's called that.

• 14:14Speaker 01

  But it's like, to me, the question is really, why do we remember anything? Why, why do we have this capability if it's not to document the past in some library form? And the answer is, it's about the future. And the more you study the brain, the more you look at the way the brain, the kinds of information prioritized by the brain, the way the brain deploys information from the past in real time, you realize memory is about the present and it's about the future.

• 14:42Rich Roll?

  The brain being this machine that is always searching for patterns and, and has this functionality around predicting the future. And so, memory operates like a selection device. The brain is having to make decisions about what's important to retain and what can be discarded for evolutionary survival, so that you can, with some fidelity, predict events that will happen in the future, such that when they occur, that memory can be recalled to better prepare the human animal to navigate that without perishing.

• 15:18Speaker 01

  That's right. It's an enormously complicated world, and it's an enormously, you know, dynamic world. Things change, right? And so, what memory allows you to do is rapidly adapt to a changing and uncertain world and generate predictions and plans, but also change those plans and be flexible. When things don't work out as planned. I mean, this is something why I think a lot of conventional AI. I mean, if you think about the carbon footprint of something like ChatGPT, and you compare it to the human brain, which is like the estimates are that our power consumption is something like 12 to 20 watts. The lights here are probably using more than that, right?

• 15:59Rich Roll?

  That is amazing.

• 16:00Speaker 01

  And in certain ways, we're worse than other ways, but we're better at being able to stop on a dime and change our view of the future based on single things that we've experienced.

• 16:12Rich Roll?

  Is there an understanding of how that selection process occurs? Because it's happening unconsciously. So how is the brain making that decision around what's going to get stuck in the hard drive and what's going to get tossed in the trash? Because every day, we were exposed to, I don't know, probably trillions of external stimuli, right? And so this expectation that we're supposed to remember everything is insane.

• 16:37Speaker 01

  Yeah.

• 16:38Rich Roll?

  We have to limit, you know, what we're going to retain. And, and that's something that occurs without conscious intervention. I mean, you talk about, and you talk about this book, you can bring mindfulness to this. And there's things that you can do to enhance your ability to, to, you know, retain certain information. But to the extent that this thing is operating in the background all of the time, what is creating the quality of that mechanism?

• 17:08Speaker 01

  Well, we know that part of the story is the way plasticity works. And what I mean by this is, is that the brain is thinking and computation in the brain is thought to be the outcome of neurons communicating with each other. So these are the individual cells in the brain that are thought to be the basic computational unit. But a memory is not Driven by one neuron, but rather by a whole collection or an assembly of neurons. And so when we experience something, that memory is manifest in a change in the strength of the connections between these neurons, right? So let's just say, for instance, and I'll just use an analogy to social networks, right?

• 17:51Speaker 01

  Let's say you go to a party, you meet someone really interesting, right? So to the extent that you are able to communicate with them later on, you're more connected than you were before, right? Through that one experience. And that's, I don't know, it might not be the best analogy, but it's, that's how the brain works too, is that there's these changes that are actually, if they're lasting, they're actually physical changes in the neurons themselves that allow them to communicate more efficiently. They communicate chemically, but it allows those changes to be more efficient. So how does that happen? Well, a big part of it seems to be these chemicals called neuromodulators. So your listeners probably know about a lot of these already, like dopamine, norepinephrine,

• 18:35Speaker 01

  cortisol, serotonin is a big one. But even, you know, hormones like estrogen can play a part in promoting plasticity. There are all these chemicals in the brain, but if you look at when these chemicals are released kind of phasingly, it is related to events that are biologically important. Reward, novelty, curiosity, attachment, you know, attachment, love, sex, drugs, rock and roll. Yeah. But all of these novelty, surprise, these are all the different kinds of emotional states that we have that are related to biologically important experiences. And so what it tells you right off the bat is the brain is trying to prioritize the stuff

• 19:20Speaker 01

  that is, as you said, important for survival. But of course, we can also pay attention and remember random things from an evolutionary perspective.

• 19:31Rich Roll?

  Yeah, this is like where I question whether we're sort of operating optimally because on the presumption that this, there's a limited amount of hard drive space here, and maybe that's not true, I don't know, I'd be interested in hearing your thoughts on that. Why is it that I can remember lyrics of songs I heard 40 years ago, like I just learned them today and can't remember things that are actually far more relevant in my day-to-day kind of life that I can't, I forgot to do the thing and my wife's mad because she's like, I told you four times to do that and I didn't remember, that kind of thing. Like, it seems like, like, there's some broken spokes in the wheel here.

• 20:15Rich Roll?

  But maybe not, maybe there's a, maybe there's a reason for this.

• 20:19Speaker 01

  Well, you know, so there's, there's actually so much in your question, it's a great question. And so maybe I'll just speak first to this idea of like, what, what is it about these old memories that stick around, like the lyrics to these songs? And there's all sorts of experiences that we have, especially from our formative years, like the teenage years, for instance, and early adulthood, that do stick around more because we often retrieve those memories over and over again. So we're often not aware of how many of these old memories we've forgotten because we're only thinking about the ones that we actually are retrieving and recalling over and over again. But the next part of your question is, why am I forgetting the things that are important now?

• 21:03Speaker 01

  And that's like, there's a lot of reasons for that. But a lot of the everyday forgetting is not necessarily that it's gone, but that the memory wasn't there when you needed it, right? So you might have forgotten an appointment, meaning that you didn't go to the appointment when you were, you didn't recall the appointment when it would have been appropriate to go to this appointment. But that doesn't mean later on, if your wife reminded you, oh, did you go to the appointment? You'll go, oh, yes, that's right. So you have the memory, but you just didn't pull it up at the right time. And that kind of remembering is actually the hardest kind of remembering. It's called prospective memory. And it's super hard because you have to pull up a memory of something that hasn't happened yet, right?

• 21:46Rich Roll?

  Right.

• 21:47Speaker 01

  So you're trying to remember something in the future and set an intention to do that, which is extraordinarily difficult for you to do.

• 21:55Rich Roll?

  Yeah.

• 21:56Speaker 01

  So, but you, we also have a lot of other forgetting, like, what was the name of that guy who was in that thing? I can't remember. And often a lot of those problems have to do with the fact that we have many memories that are overlapping and similar with each other, right? Just as an example, people will always tell me, oh, I'm good with faces, but I'm terrible with names. But what they really mean is I'm terrible remembering which names went with which faces, right? So for instance, the name Rich, I have no, I knew somebody in grad school who was named Rich and we were pretty good friends. And we both wrote for the same punk music magazine.

• 22:36Speaker 01

  And so that name is associated with one person. It's also associated with other persons I know. I know like Richards, many Richards who are really good friends and so forth. So there's, anytime I would try to link your name with your face, there's all these competitors out there, right? And that's the problem is that a lot of our forgetting comes from the competition between memories. It's not like you're just pulling something out of a slot. It's like, there's this ecosystem of memories battling it out. And you're trying to find the one amidst this whole jungle of possible.

• 23:10Rich Roll?

  Yeah, that's super interesting. There is something unique about memory and, and our emotional experience when we can't remember something, that's deeply troubling and confronting because I think we so heavily associate memory with selfhood, right? It is one in, one in the same of who we are. So when we can't remember something, we're very hard on ourselves. We get not only frustrated. It's disturbing, right? And also, that's generally followed with a lot of, you know, kind of self judgment or self flagellation. I mean, if there was something dysfunctional about my kidney, I wouldn't be angry with myself necessarily.

• 23:54Rich Roll?

  You would just go and have it treated. But memory is a whole unique thing. And I think that's what makes it so fascinating because it is so part and parcel of who we are when it's not serving us or serving us sub optimally.

• 24:11Rich Roll?

  It becomes a very emotional thing, I guess is what I'm saying.

• 24:15Speaker 01

  It's, yeah, it's emotional and it's scary. I mean, there's, I mean, you think about like a moment where you get distracted or something and you're in conversation and you come back like 10 seconds later and you're like, what were we talking about? That's, I don't know about you, but that's scary.

• 24:31Rich Roll?

  Yeah, or, you know, I've driven cross country a number of times and, you know, you get lost in thought and, you know, half an hour will go by and then you kind of come to and realize you have no idea where you were.

• 24:44Rich Roll?

  You're like on some weird autopilot because you're, you know, you're lost in rumination. And again, that goes to the selective nature of like what's important. I'm sure, you know, the autopilot was heavily focused on making sure the car doesn't go off the road. But I couldn't tell you a single thing about anything that I saw, smelt, heard.

• 25:05Speaker 01

  Yeah, actually, the same thing happened to me earlier this morning where I missed the exit for my parking for the airport on my way there. So, yeah, I know exactly what you're talking about. And that's where like attention plays such a big role in interfacing with memory. Because essentially, if our attention gets diverted, then our ability to form kind of memories that are distinctive and easy to access becomes obliterated. Or we remember things that are inane at the expense of the things that are important to us, right? And people often ask me, okay, what's, what's, just forget all this. Just tell me how I can find my keys, right?

• 25:43Rich Roll?

  Yeah.

• 25:43Speaker 01

  I can give you a million strategies for keys. I can give you a million strategies for names and faces and so forth. In fact, actually, there's books out there that can do it a lot better than I could. But the fact is, if you don't use those strategies. I can't help you, right? And the problem that we often have is that we lose that intention to do things based on our goals. And that's dependent on a brain area that I love to talk about, which is the prefrontal cortex.

• 26:12Rich Roll?

  Yeah, so talk about that more. What does that mean? We lose, what did you say? Say it again. We lose.

• 26:17Speaker 01

  Lose the ability to guide our behavior based on our intentions and goals. And what I mean by that is, so I did a lot of work in the clinic and also a little bit of work and research, testing people with frontal lobe damage or damage to the prefrontal cortex. And what happens is, is that you talk to them and they seem very knowledgeable. They have all the knowledge in the world, but they don't use that knowledge in their decision making every day. Right? And so it's like, I would do a test and I'm giving them a test, but then if they hear a plane go by, they're just off to the races. Right? But we are, you know, we, meaning people who are more neurotypical, do this to ourselves.

• 27:02Speaker 01

  I mean, we lobotomize ourselves because we're trying to do 10 things at once or thinking about 10 things, even when we're doing whatever it is we're doing. And so as a result, we're more reactive to what's around us and less guided by our intentions. So even though I know, like, if I just take a moment to reflect, I'm going to lose my cellphone because I do this all the time. What can I do to prevent this from happening? Because the, the utmost obvious outcome is that I will misplace my cellphone, my glasses and my keys. But the fact is, is that we don't walk into the house with that intention in mind because I'm checking my phone. I'm literally doing this, right? I'm checking my phone. I'm thinking about what I'm going to be doing in the future.

• 27:47Speaker 01

  I'm thinking about what happened in the past. And so I'm literally not there in that moment. And so if I'm not, then I can't use any of these great strategies.

• 27:56Rich Roll?

  Sure, I mean, the solution is bringing mindful attention to those things that, you know, recur in suboptimal ways, right?

• 28:03Speaker 01

  Yeah.

• 28:04Rich Roll?

  Okay, today I'm gonna practice paying attention when I walk in the door and where I place my keys and like purposely like make a mental note of that. I mean, I'm certain that would cure the deficiency, wouldn't it?

• 28:14Speaker 01

  Yeah, yeah, and building habits, I think, can be very important because habits allow you to do things very quickly and efficiently and automatically. And in fact, you brought up mindfulness. And so my friend, you might have talked to her, Mishi Jah, she wrote a book called, oh god, what is it called? I'm blanking on the name. Peak Mind.

• 28:34Rich Roll?

  Your memory is failing.

• 28:35Speaker 01

  I know.

• 28:37Rich Roll?

  Every researcher. They're sort of reassuring. Okay, I'm glad you had a little blip there for a second. You recovered, though.

• 28:44Speaker 01

  I recovered, yeah. So she writes about the neuroscience of mindfulness. And so I was reading the book and I was thinking about the fact that when I tried to do a mindfulness-based stress reduction class, and by the end I concluded I suck at mindfulness, right? And what I didn't realize at the time was that it's really, you're learning a skill, and that skill is one of observation, to notice when you go off. And so it's actually a success if you realize, I'm losing the ball. Because most of the time, I don't realize that, right? And so that's a habit that people build up to just become more and more aware of when their mind wanders.

• 29:39Rich Roll?

  The awareness, the paying attention to the activity, that's the thing, right? It's the same idea of saying, I'm a terrible meditator, I can't meditate because my mind is going 100 miles an hour. Well, drawing attention to that very fact is the practice of meditation.

• 29:55Speaker 01

  That's right. That's right. And once you start doing that, you can be more capable of doing that at any moment. And then realizing, wait a minute, I better stop because I know I don't want to lose my glasses this time because I'm gonna be in a hurry to get out the door tomorrow morning.

• 30:12Rich Roll?

  Yeah, this idea that that our memories are tethered to some version of reality. I want to talk about malleability and unreliability. You talk in the book about

• 30:29Rich Roll?

  You know, eyewitness testimony and the various levels of reliability with that. That reminded me of Malcolm Gladwell, who's written on that extensively. So where do we stand in terms of like, how much we can reliably depend upon our memories as accurate depictions of what actually transpired?

• 30:52Speaker 01

  Well, one of the interesting facts about memories that it's so connected to meaning. If you try to remember something like if I, if you don't read Chinese and you've never been exposed to it, and I show you a Chinese character, it's really hard to memorize it because you have nothing to attach it to, right? And on the other hand, it's easier to learn about things that connect to things that we already have meaning to. And that's because the brain is essentially designed to recycle information that you've already learned, right? So if you've learned something once, and you can just tack on some new information to it, it's a lot more efficient than trying to form an entirely new memory for something else, right?

• 31:35Speaker 01

  Now, that serves us very well, but it also can lead to some problems where we don't necessarily remember things as well, because we've used meaning, we've generated meaning into our experiences in a way that made us actually miss things that were going on. But also, this happens at the time of remembering too. And that's something I think that's very counterintuitive. So the scientist Frederick Bartlett, who studied memory, he described remembering as an imaginative reconstruction. And what he meant by that is, is that when we remember a past event, we're not replaying the memory, we're imagining how the past could have been and generating this big scenario in our head. And that act of imagination...

• 32:21Speaker 01

  Is often based in truth because it's like, I like to think of it as based on a true story, right? Because you do, memory does give you a bunch of little bits and pieces, some context, some details that allow you to imagine that that event fairly accurately. But it can also stray. It's also incomplete and it's a little bit deceptive that you can vividly remember something and think that you've got everything, when in fact, you have a selective set of bits, and then a lot of imagination that you've used to fill in the blanks in between.

• 32:57Rich Roll?

  Just the fact that imagination is involved at all, you know, should not alarm people, but you know, give you an idea that memory really is this interpretation. Like it is an impressionistic painting, not a photograph, to use your analogy, from which we divine meaning about ourselves that then inform how we, you know, kind of show up in the world. So it's kind of nuts that that would be the case. And I can't help but think how that is, on some level, I guess, there's, you know, there's a good reason for

• 33:39Rich Roll?

  it that is self-preserving. But I have to believe that at the same time, this is steering people in the wrong direction, like, all the time.

• 33:49Speaker 01

  Yeah, I mean, I would say that it's more often than not, giving you a fairly accurate idea of the gist of what happened. Although sometimes we can get the gist completely wrong, usually it serves us very well and allows us to go through life fairly efficiently. But as you pointed out, it does give us this illusion of that we have more information available to us than we really do. And one of the fascinating things that came out of fMRI research is that if you ask people to imagine things that haven't happened yet, or even couldn't happen, that if you look at that brain image of the areas that are

• 34:31Speaker 01

  active, and you look at, do other kinds of machine learning analyses on it, it's not easy to tell the difference between those imagined things and things that you've really experienced. And then, if you scan people's brains while they're watching a movie, or listening to a story in real time, What you find is that those patterns of brain activity are similar to what's happening when people remember the past, or they imagine the future. In all of these cases, we're basically constructing a narrative in our head. So, a lot of people in neuroscience will be like, "Well, if somebody's watching a movie, it's being processed by the visual cortex and then these higher-order areas." When really, what's happening is, is like, I'm watching a horror movie,

• 35:15Speaker 01

  and there's someone walking down a dimly lit hallway. I'm not watching this person at all. I'm thinking about whether or not the chainsaw-wielding maniac around the corner is just gonna jump out at any moment. I'm thinking about the past in terms of, like, why did this person break off from the group? You know she's going to get killed. And so, we're constantly doing these acts of mental time travel in real time to give us a sense of where we are, what the current situation is, what's your intention in this conversation, where are we at? And then, where am I going? What does the future have in store for me? And in a way, that's what you want. You want to have the sense of meaning.

• 36:00Speaker 01

  You don't want to be literal in terms of remembering. You want to be able to infuse meaning into the past and the present to the future. But it also means that we do have a little bit of an illusion that we're getting everything that we see in real time, or that the future is going to unfold exactly as we think it will, or that the past is exactly what we thought it was. And one of the interesting things for memory research is that we reconstruct the past and remember events based on what we know and our perspective in the present. So if I'm in a happy mood, I will remember things that are happy. And if I'm in a bad mood, I'll remember things that are negative.

• 36:42Speaker 01

  But I'll also take the same experiences and accentuate the negative or the positive, depending on how I feel, right? So it's like, if you have a close relationship with a partner or something, you get into an argument. How easy is it to remember all the great times you've had in that relationship? It's not easy, right?

• 36:58Rich Roll?

  Right.

• 36:59Speaker 01

  You're thinking about all the reasons that you have to dislike this person. And then you make up and you can't even remember why you fought in the first place.

• 37:06Rich Roll?

  And when you're watching a movie and that person is walking down the dark hallway, memory has to be activated because the only reason that you know that it's a dark hallway is because you yourself have walked down a dark hallway and you know what that looks like. So on some level, you're pulling that file up to contextualize what you're seeing so that you understand what it is.

• 37:27Speaker 01

  That's right. We have this general idea of different kinds of events that can happen, which is based on a kind of knowledge called schemas. And so a schema would allow me to just get a general prediction of what can happen in most life situations. Like if I say, hey, um, uh, my friend's getting married. You want to be my date or something like that? So we go to the wedding together or whatever. You can predict a huge amount of information before you have a memory for that event before it even happened because you know all of these things that are going to take place. There's going to be a cake. If I tell you it's a Jewish wedding, there's probably going to be somebody stepping on a glass. You can imagine people will be dressed up quite nicely, maybe a throwing of the bouquet.

• 38:12Speaker 01

  All these things you have a memory for before they even happen. And so that's the infrastructure for this memory before it takes place. And then you have little episodic memories that you can call upon and say, well, I know this. I remember meeting this person once who's getting married. And so now you can use that to flesh out your simulation of what's about to happen. And I know the place where we're going to. And so you can remember events from that and say, oh, so it's probably going to be cold. I better bring a jacket and so forth. And so these are all little things that we do in real time to make sense of the present and the future based on memory.

• 38:48Rich Roll?

  Yeah. It's fascinating. And you talk about this in the book also, like, we actually don't know what's going to happen. And you use the example of when you go to the barista, you know, okay, I'm going to make my order. And I could predictably expect that. In a minute or two, this person is gonna hand me a cup of coffee. And sure enough, that's gonna happen. But in truth, we don't know that that's gonna happen. But it's memory that is this engine of prediction and reliability, right? Because we have this experience where this has happened so many times in the past. And we've seen it happen to other people or on television. We can reliably expect that it's going to happen. And that's where memory is really serving its purpose, right?

• 39:33Rich Roll?

  It's serving this function of predicting future events with varying degrees of reliability that allow us to move safely in the world.

• 39:43Speaker 01

  Yeah, a lot of our memory-based decisions are based on statistics from the past, right? Which are the best predictors of the future. So in that sense, it's very sound to use memories to generate predictions. But as you mentioned, we're often overconfident, both in our memories for the past and our projections for the future. And we often confuse the vividness or ease with which something comes to mind as evidence for what's likely to happen. And what I mean by this is, for instance, people in decision-making have talked about how you hear one vivid story, let's say you read a vivid story in the newspaper or something, about somebody who got sick from a vaccine.

• 40:25Speaker 01

  And that memory overrides anything that you might have read about the clinical trials on this vaccine and the number of lives that are saved. And so you might go, well, I'm not gonna get this vaccine based on this one crazy memory that I have, because you're sure you're gonna get some adverse reaction, even if that was like much less dangerous than actually exposing yourself to the virus that's going around.

• 40:49Rich Roll?

  This speaks to the relationship between emotion and memory and the interplay there.

• 40:55Rich Roll?

  Can you talk a little bit more about that?

• 40:58Speaker 01

  It has a huge effect on memory. And I think any listener who can think of memories from their life at random, they're going to be almost always emotionally relevant information that comes to mind. So our emotions are linked to neural circuits that have been shaped through evolution. Right? So we have neural circuitry that gets us motivated to get rewards. For instance, what things that are biologically significant to keep us alive or help us reproduce. And those chemicals promote plasticity, as I was saying. And so they can actually allow a new experience to stick very easily. Likewise, we have neural systems to allow us to escape from threats and predators.

• 41:43Speaker 01

  And that would be like our fight or flight response and so forth. And to learn to avoid threats and predators. And so those responses will lock in a memory as well. Because you don't just want to remember that you escaped from a bear, but you want to remember where the bear was so that you don't go back to that bear later on. So our brains are designed to lock in on these memories for emotional experiences. But emotion also is a context for our memories. So in other words, it's part of this backdrop of the tapestry in which these memories, the events unfold. And it's also the backdrop of our present thinking and cognition. And so when I'm in a particular emotional state, it affects the kinds of memories I can access.

• 42:27Speaker 01

  And it also blinds us to memories that I can't access. And when I'm in an emotional state also, sometimes these emotional states can shut down areas like the prefrontal cortex. For instance, if I'm under high stress, the prefrontal cortex becomes downregulated and I become less intentional and more reactive in my thinking because it's about essentially escaping threats. You don't want to be planning when you're being chased by a bear or something.

• 42:59Rich Roll?

  Yeah, that's the self-preservation piece to it. But there's also dysfunction that can erupt from this. You gave the example of the young man who had the, who was gay and had that traumatic experience in a car. So his emotional.

• 43:20Rich Roll?

  The emotional piece to that memory drove the dysfunction of being unable to drive a car, right? Like, it's maladaptive, I guess, right, in that regard? And I guess similarly, if you look at PTSD and just trauma generally, we suffer some heightened emotional experience. It's so resonant that it gets locked into our memory as a sort of signal to avoid those scenarios in the future. Yes.

• 43:51Speaker 01

  Yeah, yeah, exactly.

• 43:53Rich Roll?

  But then it shows up later in maladaptive ways to prevent us from, you know, living our lives in a healthy way.

• 44:00Speaker 01

  Yeah, I think that PTSD is a good example of this because essentially, people vary enormously in their responses to stressful events. I mean, we actually did a stress study, ran a lot of people in the study relative to the normal amount we would. And our effects were really small, like looking at the effects of stress on memory and the brain responses. But it was because almost all of it was determined by individual differences. People, some people had huge stress responses biologically and some people had very tiny stress responses, right? So not everybody who experiences the same traumatic event, like, let's say, first responders in 9/11,

• 44:43Speaker 01

  most of them would not develop PTSD, but some proportion of them do, right? Now, that's not because it's a weakness or something. It's essentially, you want to have these differences in brain function where some brains are just optimized to really be good at avoiding threats. And the best way to avoid a threat is to have a good memory for the threats that you've experienced, right? Now, the problem in PTSD, there's a lot of theories. One theory which I really like is the idea that essentially... Memories become unmoored from the place and time that they occurred. So the act of remembering in and of itself changes the memory.

• 45:28Speaker 01

  And when you're under chronic stress, it actually affects the hippocampus and the prefrontal cortex in ways that can cause some blurriness in memories to take place, period. So if you have these blurry memories, and then, let's say, you're in a context which is similar to a place that was the site of a traumatic memory. Like, a good example was my PTSD patients that I worked with in the VA hospital. Around the 4th of July, they would hear fireworks and reliably flashback into Vietnam, because that loud music brought back a traumatic memory of the Vietnam War.

• 46:11Speaker 01

  But it wasn't because it was, and it's, like you said, it's maladaptive in some ways to consider this loud noise to be anything associated with being under gunfire in Vietnam. But it's related enough that it was able to pull up that memory. And what happens in PTSD is every time these flashbacks happen in a new place and a new time, now the traumatic memory kind of grows a little bit like a tumor. It becomes attached to more and more contexts. And so as a result, that memory comes up easier and easier. And people end up hyperreactive to things that are very tangentially related to the experience that took place.

• 46:52Rich Roll?

  Two thoughts on that. The first is, there's something about PTSD or traumatic experiences that when recalled, there's a certain heightened vividness to them. Like, the recall is like experiencing the event itself. It's so technicolor. So I'm curious about that. And then, the second piece is this idea, well, actually, I'll put that aside. Like, I don't want to ask you two questions.

• 47:22Speaker 01

  All right, yeah.

• 47:23Rich Roll?

  Focus on that one.

• 47:24Speaker 01

  That will be a good memory test. But yeah, this is, we've done studies and other people have done studies where you ask people about how vivid a memory is. And when there's information that's emotionally arousing, even if it's just like a photo of a car accident or something that you've just had people memorize, people will report having a more vivid experience. Now, interestingly, that vividness is not necessarily tied to the amount of information people can actually recall. So sometimes people will remember all these contextual details from a past event, but they won't say that they remembered it as vividly as something that is emotionally

• 48:06Speaker 01

  charged, even if they, but they didn't have all those details that they, objective details they can pull out. And the reason for that is, is that the emotional response, or I should say, the, the, um, the survival circuitry that's tied to those emotions, like, for instance, if you think of something like fear, um, when I'm remembering something that was scary, I will get a memory that activates that fear response in me. But that circuitry that ties the information, the cues and so forth, then the memory to the actual fear response, is somewhat different than the circuitry that ties the context and all the details together to allow you to remember everything accurately. And so

• 48:50Speaker 01

  what happens is, is that when we experience that visceral feeling, we feel like we are back there, even if you can't remember all those details. And so that's where a lot of the potency of emotional memories come is, comes, it's from that basic response that is driving the physical sense of remembering.

• 49:11Rich Roll?

  Hmm. I did remember the second question, but mainly because I wrote it down right here. And it has to do with the dynamic nature of memory. You basically said that the act of remembering something changes the memory itself. And in the book, you talk about the copy of the copy of the copy and how that reminded you of the punk rock days when you were making flyers and, you know, you get them all, you, you make so many copies of copies that they get all like granular and, you know, and that creates a cool effect. But, um, that's super interesting in the sense that,

• 49:52Speaker 01

  That it's not a static thing, that memory is an always changing kind of shapeshifter. It's a moving target. It's a, um, the more, so there's, there's different debates on the details of how this happens. Some people will say that you just overwrite the old memory when you recall the, the original memory. Um, but I don't think that's really well-supported. There's some evidence suggests sometimes that you form a new memory every time you remember something. So you remember, but you also remember the time that you remembered it. Um, but I think probably the truth is somewhere in between that every time we recall a past event, we're modifying that memory a little bit, or sometimes a lot in certain

• 50:35Speaker 01

  cases. And so what that means is, is that if I'm remembering a story, an event that I've told to many, many people, many, many places, many situations, that memory will now be imbued with all of those stories that I've told in all these places and all these situations. And it can take on a life of its own. And so what that means is, is often the stories that we've told ourselves the most are the ones that maybe become, they can sometimes become strengthened in ways that give you the gist and the common elements quite strongly. And that can be a good thing. But at the same time, we'll often get a lot of the details wrong and make all these flubs and introduce new things that, and embellish

• 51:20Speaker 01

  things that didn't really happen. And sometimes that can have disastrous effects.

• 51:23Rich Roll?

  I've had this experience, uh, because I get asked to give talks a lot and I go on other podcasts as a guest and I'm asked to recount this story, you know, about my life. And I've done it so many times, uh, that it often leaves me thinking like, and I, and I know kind of like how to do it. Like I can go on autopilot and I've really tried to stop myself from that autopilot and to really think more deeply because when you're in that space, it's like, is this even true? Like I'm making a copy of a copy of a copy. And then I think, Maybe it didn't go down like that at all, but I'm reinforcing this memory. And every time I'm remembering it, I'm shifting it a little bit.

• 52:08Rich Roll?

  And the good part of that is like, it connects me to what's important about things that have happened to me and I continue to learn from that, that is helpful. But I often question like the veracity of it after having told it so many times.

• 52:24Speaker 01

  Mm hmm. And I think when we look back at these past events, it's really important for people to understand that the details that we pull up from those memories are different than the story we tell. And the story we tell is where a lot of the shape shifting can happen, especially. Often like there's studies of false memories that have been done. Elizabeth Loftus did beautiful studies on this topic where basically you ask people to remember something that never actually happened, or you give people some wrong information about something that did happen.

• 52:59Rich Roll?

  Like the example with discovering the woman in the pool.

• 53:02Speaker 01

  Yeah.

• 53:03Rich Roll?

  You talk about, yeah.

• 53:04Speaker 01

  Yeah, exactly. Yeah, she'd heard that she had discovered her mother who had died and the dead body was in the pool. And it turned out this uncle who gave her that wrong information had gotten it wrong. But in the time that she'd been exposed to that misinformation, she started running it in her head and kind of got these glimpses of memories for seeing, you know, for finding her mother's body. And it's not that that's a false memory because it's a memory for things that she imagined. And it's a memory that's constructed from other bits of pieces of experiences that she had.

• 53:38Rich Roll?

  Except that it's entirely untrue.

• 53:40Speaker 01

  Except that it's entirely untrue, right? But what's interesting is, is our brains, it's just a mental experience and things that we've imagined versus things that we've lived versus things that we've read about. They're all memories that are experiences in our head. And so my former advisor, Marsha Johnson, was one of the first people to really realize this creates a huge problem, which is telling the difference between imagination, embellishments, and lived experience.

• 54:11Rich Roll?

  Well, it's profound and it's something I don't think that we really ponder deeply enough because it is the ultimate predictor of our lives. As I was thinking about this, I was remembering. Many years ago, like an enlightened Indian master came to our house and he gave a discourse and he was talking about the stories that we tell ourselves about who we are. And the analogy that he used was those stories are like buds on the limbs of a tree and our brains selectively choose memories to become those buds. And the matrix

• 54:54Rich Roll?

  of all of these buds is the construct of your life. So we have all these stories that are based on our memory of experiences, some traumatic, some wonderful and happy, but all together, taken in totality, becomes the story of who we are. And that in turn dictates our sense of not only who we are, but what we're capable of and what we're not capable of, what we can and can't do, the decisions we make, the way we interact with other people. I mean, it is everything all told, right? And when you reflect on the fact that memory is this dynamic thing, that we're making copies of copies all the

• 55:34Rich Roll?

  time, that it's malleable, that it can be influenced by misinformation, it's quite stunning. So I guess the question I want to ask you is, to the point of malleability, how much agency do we have? Like, what if we could recreate the story of who we are by de-selecting those memories or traumatic experiences that are acting as limiters or inhibitors to our fully actualized self? And instead, you know, probe the memory bank and select better ones that would help us, you know, make better decisions and empower us, I guess is what I'm saying.

• 56:13Speaker 01

  Yeah, we have a lot of agency. I mean, just to give people an idea, it's not as if we go around confabulating and generating memories for events that never happened all the time. We're pretty good at it, right? So we do have some agency in controlling and managing the malleability.

• 56:28Rich Roll?

  That is happening, sorry to tell you. It's happening like without conscious involvement for the most part.

• 56:34Speaker 01

  Well, yeah, I mean, I think that probably, I mean, we don't really know how much conscious involvement there is, but definitely when you're remembering something that's hard to remember, you will apply some memory monitoring processes spontaneously, even if you're not thinking about it, you'll be doing it. But let me go back to your real point, the deep point in what you're saying, because I think, I don't want to get all, I don't want to lose the tree for the buds.

• 57:01Rich Roll?

  Yeah, and let me just say, let me, I mean, the first line of your book is, take a moment to think about who you are right now. Like, that encapsulates everything that, you know, we're talking about.

• 57:12Speaker 01

  That's right. And we are so capable of change. And, I mean, even though people will try to market products and say, oh, you're 70 years old, you need some vitamin to be more plastic, or whatever. No, your brain's plastic. As long as you're capable of remembering something that had happened five minutes ago, you have a plastic brain. We know it, right? So you have that plasticity. And the important part of the malleability of memory, to me, is that the world changes, and you get new information, and you want to change the way you look at the past in light of new information that comes in, right? So you find out after all these years that somebody who you, was your business partner,

• 57:56Speaker 01

  had been stealing from you and embezzling from the company, or whatever, right? You want to look back at those same experiences from a different lens. Now, that's a very negative example, but there's also positive examples where growth can come from this. So in the book, I had one incident where I went paddle boarding down this creek, and it was just a series of bad decisions, so many bad decisions. I was with a friend, and the shortest version of the story is, is that I endured a lot of pain, my board was damaged, and I ended up pinned at some point in this really bad current, like, just hanging on to the board for my life, and just terrified. And eventually, I made it back onto my board.

• 58:38Speaker 01

  I did make it out, because basically, failure wasn't an option, and something just kicked in, and I did it. And the funny thing is, I felt terrible after this experience. I mean, it was an objectively terrible experience. And yet, every time I told the story, it became funnier and funnier. It became kind of cool. And it's not cool because it's like, I want to repeat it again. It's not cool because I'm proud of it per se. But it's a, I survived it. I got past it and I can look back with it, with a sense of humor. Because I'm not under, you know, I'm not in a life threatening situation anymore.

• 59:19Speaker 01

  And I think that's a powerful example of how sharing memories with other people can allow us to constructively transform those memories and thereby transform our life stories. Right? So we all have these stories that, that are based, that were related to our sense of who we are, that start from childhood. And some of the research shows, for instance, that the way parents interact with their children can have this really powerful effect on those stories. That is, parents who really encourage children to remember and build these stories about who they are. Turns out that those kids, for whatever reason, have much better outcomes in terms of mental health, in terms of academic success.

• 1:00:03Speaker 01

  Than children where the parents are like, oh, you got that wrong. That's not how it really was. And the ones who are very negating, for instance.

• 1:00:22Speaker 01

  Everything that happens to us is neutral until we apply our perspective. Right? So let's say I got fired from a number of jobs over the course of my life. And I then apply a perspective to those occurrences to create a story around my unemployability. Like, I just, I can't hold a job down. I'm not meant for the workplace. But I'm doing that at the cost of not looking at the 10 other jobs that I had that I didn't get fired from. But for some reason, I over index on those ones that I got fired from and I create a whole story around that. The agency piece comes in.

• 1:01:06Rich Roll?

  With the power to reframe those experiences with humor or some other device to recontextualize them, so that they don't hold that power and they're not creating that story. Because if that's the story you're walking around with, you've got a rain cloud over your head and you're going to produce those outcomes again and again and again in your life to validate and further enforce that story.

• 1:01:30Speaker 01

  That's right. And whenever I talk about trauma, I try to be very sensitive to the fact that a lot of people have these experiences that are just unshakable, or at least they feel unshakable. And so like when I do events, nine out of 10 people will come up to me and say, oh, I thought I had such a bad memory, this was reassuring, or how can you help me improve? But one out of 10 will say, how can you help me forget? I have these terrible experiences that I can't get over. And so I never want to minimize that and just say, well, if you just try it harder, you'll feel better. But it is true that these memories can be transformed. It's difficult with particularly painful experiences and painful memories.

• 1:02:14Speaker 01

  But one of the factors that really helps is sharing memories can transform memories. That is, social interactions can play a huge part in reshaping our memory. Now, that can be bad in the case of misinformation that spreads and so forth, but it can have a very powerful positive role because what we know is that when I'm remembering something, just to communicate it to you, I'm picking up different pieces of it and shaping that into a narrative. But that narrative might be different than if I just keep it in my head on my own. Now, you hear it and you communicate it to me from this completely different perspective based on your knowledge of me and the current situation, your current perspective. And now I get to see things from a new light.

• 1:02:58Speaker 01

  And that kind of deviation between the stories we tell in our head and what other people tell to us gives the opportunity for change and memory updating.

• 1:03:08Rich Roll?

  Yeah, the idea that memory as a shared experience or a group dynamic turns it into this very interior experience into almost a living, breathing organism that exists as much outside yourself as it does within yourself.

• 1:03:27Speaker 01

  Absolutely. I mean, think about families, for instance. Every family has all sorts of stories and often one of the biggest reasons for family disputes is because people remember their shared experiences differently. But there's no doubt that those memories-

• 1:03:42Rich Roll?

  That's the source of many Thanksgiving dinner arguments.

• 1:03:45Speaker 01

  Exactly.

• 1:03:46Rich Roll?

  That's not what happened.

• 1:03:47Speaker 01

  Exactly, yeah. At best, you agree to disagree at some of those points.

• 1:03:51Rich Roll?

  But is the point you're trying to make in the sharing of these stories and how they take on a different tenor when they're reflected back to us, where is the, like, I'm trying to understand the therapeutic piece there?

• 1:04:08Speaker 01

  Well, the therapeutic piece is a lot of memories that are really affecting people in terms of their life narratives and just haunting them in the present, even if they're not like pure PTSD memories, but just things that are just rooted in people's life stories, like exactly like what you were saying. Those memories are often associated with shame. They're things that people don't share, right? And so, once I share this memory and you react with a completely different, in a completely different way than the way that I've experienced it when I remember, now my memory is no longer the memory of just what happened, but my

• 1:04:50Speaker 01

  memory of also having shared this experience with you and gotten, getting your reaction. And there's an actual mismatch between the feedback you're giving me and the memory that I constructed on my own. And so, that mismatch actually gives the brain a chance to update the memory in a way that becomes less toxic and less painful. And so, through those kinds of experiences, people can really change the way they see their past. Because again, there's the data from the past, which are these little bits and pieces that we can verify as things that happen. But then there's the theories that we generate, and those theories can change based on new information and new perspectives.

• 1:05:30Rich Roll?

  Well, when shame is at play and we compartmentalize and hide those memories because of shame, they only fester and metastasize and turn into these tumors. And shame is something that can't survive the light, right? So I've been in recovery for a long time. And this is a fundamental premise of every 12-step group. You get up in front of a group of people and you share these shameful things. And then it becomes, to your point, like this shared memory. But it is this cathartic release of the hold and the power that those memories have over us. Like when we release them in a group setting or to another human

• 1:06:11Rich Roll?

  being, they're not commandeering us in the same way. Like, there's a freedom that comes with that.

• 1:06:18Speaker 01

  Yeah. And my guess would be, and I'll just ask you, because I'm curious about this. So in your experience, when you've been in these groups and you tell a story like that, do you find that the discussion after you're telling the story changes the way that you remember it later on?

• 1:06:34Rich Roll?

  Sure. Because you go in, let's say you've never done anything like that before. And so you're terrified, you're going to tell this secret, you're deeply ashamed or embarrassed about. And you have an expectation that you will be judged, or shunned, or kind of pushed out of the group. And human beings, that's the greatest threat, right? To be ostracized by the group. And when that is instead met with compassion, and laughter, and hugs, that contrary, that sort of counter indicated response becomes incredibly healing. And you realize this thing, that you allowed to have so much power over you, need not have

• 1:07:14Rich Roll?

  that power at all. And in fact, it can actually be helpful to other people who see some version of their own story in your sharing of your story, and then feel empowered to kind of follow in suit and do the same.

• 1:07:31Speaker 01

  Glad to hear the way that you described it because it's so perfectly captures, I think, a memory-based view of how therapy and just sharing memories that are traumatic work. Because I think there's a school of thought that's kind of based on Freudian kinds of views that just the act of having that catharsis makes everything better.

• 1:07:54Rich Roll?

  Yeah.

• 1:07:54Speaker 01

  Revealing the memory in and of itself makes everything better. Now, there's a tiny bit of that, just because you're telling the story, and that transforms the memory a little bit right there. But if you just wallow in that memory and that interpretation, that doesn't help you. It's really this act of getting those responses from other people and the compassion, like you're saying, and reframing and viewing the same experience from a totally different perspective where the transformation can really happen.

• 1:08:22Rich Roll?

  Sure. You know, in the same way that you shared the story about paddleboarding and changing the memory to be one of humor rather than embarrassment or fear, you know, when someone sits up at an AA meeting and they just tell the most outrageous story about the most horrific thing they did that's so thoroughly embarrassing that you just can't even believe it, it's like, but they do it with such like freedom and joie de vivre that you're like, oh my God. And like, you know, it's not uncommon for, you know, everybody to just be howling with laughter because there's something about that vulnerability that breeds connection, you know, and intimacy.

• 1:09:06Rich Roll?

  And in that shared, you know, interaction of a memory, that memory is transmuted or its quality is completely altered.

• 1:09:18Speaker 01

  Yeah, that's another beautiful thing about sharing memories is that we feel More social connection, at least the research shows that we feel social connection with people with whom we have shared memories. And the nice thing is, is that this person who told you this ridiculous story, you didn't experience it, you weren't there. But now that memory for that experience is not just his experience or her experience, it's a collective memory now, that you have a memory for it even though you didn't experience it. And so it's a memory that you share now, is I remember when you told the story about something, right? And that is another powerful aspect of sharing memories, is that it can actually enhance our sense of social connection.

• 1:10:00Speaker 01

  And then that feeds back into our sense of who we are, because our sense of who we are is so tied to the social context.

• 1:10:08Rich Roll?

  If you continue to share memories and those people share that memory with someone else, memories become far more immortal than the human animal itself, right? A memory can persist in the collective consciousness forever. So on some level, it's, it's a, it's a, you know, I mean, it gets into like deeper questions about consciousness, I suppose. But like, when you think of memory in that context, again, I think it just lends itself to developing a deeper appreciation of its power.

• 1:10:44Speaker 01

  Yeah, yeah. And my wife is a historian, actually. And it wasn't until writing the book that I realized, well, we're both studying memory.

• 1:10:52Rich Roll?

  Right.

• 1:10:52Speaker 01

  And so she's studying the-

• 1:10:54Rich Roll?

  That's all history is.

• 1:10:55Speaker 01

  Yeah. Yeah. And in fact, like, one of the cool things about what she's working on is documenting the stories of women who immigrated, who weren't literate, and who had a lot of traumatic experiences in their migration. And these stories would have just disappeared. They would have been forgotten in the collective memory. And that act of documenting it as a historian is now preserving it and allowing that collective memory to become immortalized. And it really just dawned upon me just how important it was for these stories to be told, because just like our individual memories- Are selective and based on perspectives and narratives. So are histories and our collective memories.

• 1:11:40Rich Roll?

  Right, history is written by the victors. The dominant cultural paradigm will dictate how that story gets told. Similarly, a memory shared will be reflected back with that person's own inherent biases and prejudices and predilections. So the human continues to degrade the relationship between memory and reality, I guess, on some level, and it's important to understand that in the context of understanding memory.

• 1:12:16Speaker 01

  Yeah, and I think it's very important for people to, I think it's, people want to go one way or another and say, "Memory is all true," or "It's all false." "History is all true," or "It's all made up," right? And it's like, we don't live in a post-truth world. There's truth, there are things that have actually happened in reality, right? But we're limited in our ability to recall that reality, and we're limited in our ability to even perceive that reality, right? And our stories of the past are going to be selective and perspective-based, but hopefully also rooted in things that actually happened. And so I think it's not that we're doomed to generate histories that are false, or generate individual memories that are false, but it's really important to take that agency

• 1:13:00Speaker 01

  that we've been coming back to over and over again to make sure that we're getting it right. And so whether that's in our individual memories, making sure to be a little bit skeptical, especially when things go along a little bit too well with our beliefs, our pre-existing beliefs, that is where the misinformation can really creep in, because misinformation, we digest it well if it comes in a flavor that we like.

• 1:13:25Rich Roll?

  Yeah. Why is it that when I...

• 1:13:30Rich Roll?

  Have a certain, I smell something that I haven't smelled in a while, and it will conjure an incredibly vivid nostalgic memory from long ago, as if it just happened in the immediate preceding five seconds.

• 1:13:45Speaker 01

  Well, memory, episodic memory, which is these memories for specific experiences we've had, like what you were just talking about. Those are, the hippocampus, I should say, is this brain area that ties up all of these different aspects of that experience that you've had, like where it happened. It's getting information about where things happened. It's getting information about who was there, what you were feeling, what you were thinking about. And it's tying that all up into a little blob that basically reflects what was happening in that unique moment. Now, to recall that memory, what you need is a cue, a reminder, something that's out there that links up specifically with that memory

• 1:14:28Speaker 01

  and not so much with other competing memories, right? So smells are a very powerful thing because we often will smell something that's very uniquely associated with a time and place. But it's not just smells, right? Songs are another very powerful one for people because we often listen to songs during particular times in our life or being in a place that you haven't been to in a long time. All of these cues uniquely allow us to go back in time to that particular zone and remember events that we might not have realized were there. They're just these dormant memories. But these cues, whether it's a smell or a song or being in a place, give us the keys to unlock that memory that was otherwise, we were blinded to.

• 1:15:12Rich Roll?

  There must be experiments or studies on trying to deploy that with precision, like by exposing patients or people to very particular smells or songs that are of that person's childhood as a way of recapturing lost memory in the same way that perhaps hypnosis is oriented around.

• 1:15:38Speaker 01

  Yeah, well, I just can't help myself, but I'll say hypnosis is a little problematic. And the reason it's problematic is because basically you get people in the state of super relaxation, where you're kind of shutting down memory monitoring processes, the stuff that you're shutting down prefrontal cortex, basically, if I'm oversimplify it. And so you're not going to be as skeptical or as critical of your memories. And that's going to be a situation where you are going to be vulnerable to suggestion and vulnerable to imagine things and then confuse them with experiences.

• 1:16:14Rich Roll?

  So that can be, that can be weaponized. There's some fuckery that could happen there.

• 1:16:19Speaker 01

  Oh, absolutely. Yeah, yeah. And that's been shown in lab studies and it's definitely happened in real life where you get people who go in hardcore into hypnosis based therapies like past life regression.

• 1:16:31Rich Roll?

  And they say, I remember, you know, some incident and I remember it vividly, when in fact, that's actually an unreliable memory.

• 1:16:40Speaker 01

  Yeah, like I remember, I remember when I was coming out of my mother's womb and it was really painful. You don't remember that.

• 1:16:48Rich Roll?

  Or I remember in my past life, you don't remember that. What about EMDR?

• 1:16:53Speaker 01

  EMDR is an interesting one. We don't know, at least based on last-

• 1:16:57Rich Roll?

  That's where the lights are on a panel, right? And they're going back and forth.

• 1:17:01Speaker 01

  Yeah, yeah. And the basic idea is in EMDR, it's called eye movement desensitization. I can't remember what the R is for, but it's something, or something. But basically it's for people, it's a treatment for PTSD where they have people remember traumatic events, but they move their eyes around all over the place. And it's not clear why it works, it's effective, and it's not clear, it's controversial as to how effective it is. But one of the theories that's out there is, is that it might induce something called reconsolidation. And what this is, is it's something that's been described in studies of animals where a memory can be updated in a way that fundamentally changes the memory.

• 1:17:46Speaker 01

  And so one set of experiments that's been done in kind of using more minor emotional memories has shown that if you have people, just you reactivate a memory briefly, but then you induce all these distractions to change the, to pull out and remove that emotional response in certain ways. Or disrupted, that that can actually change the memory. And so it relates back to this idea of memory updating. And so that may be where EMDR gets its power from. And I think that's also where a lot of the psychedelic work like MDMA treatment for PTSD may be coming in, is that when you remember an event and you're given these drugs that

• 1:18:26Speaker 01

  induce massive plasticity and change your perspective in a very profound way, you're allowing the brain to really transform and update that memory quite significantly.

• 1:18:38Rich Roll?

  So it changes the relationship that you have with that memory in a healthy way. So it doesn't, it doesn't create that negative heightened emotional response.

• 1:18:48Speaker 01

  That's, that's my pet theory for it. And, but plasticity definitely has something to do with it in the case of psychedelics.

• 1:18:56Rich Roll?

  What are the main things that we do that unnecessarily impair our memory?

• 1:19:02Speaker 01

  There's so many. If we just think about like the basic lifestyle things, I think the biggest thing that we do is we engage in behaviors. Well, I guess this is just repeating your question. We're engaging in behaviors that are governed by, yeah. Let me give you like a few examples. So one is multitasking. I'll be walking down, like I was just literally walking from the airport towards my parking lot and where I was picking up the rental car and I'm texting you and I'm thinking about where I'm gonna, you know, the route that I'm gonna take to come to Agoura Hills and so forth. And so I'm not really there, but I'm trying to do two things at once, right?

• 1:19:44Speaker 01

  And people do this to themselves where they'll have like, you know, watch, smart watch. I noticed you're wearing a smart watch, right? So if you have alerts turned on to that watch, you probably, you might be getting text message alerts every time, you know, I text you or someone else texts you, you're looking at the watch. And that moment of just checking the watch now takes you out of the event that you're in right now. So what happens is you create these little boundaries in your head, we call them event boundaries, where the conversation event is put on pause and you're doing a new event, which is figuring out what's going on in this text message. You have to reconfiguration the way you're thinking towards this new goal of figuring out what's in the text message.

• 1:20:27Speaker 01

  That's going to take you a little time to catch up. It's going to require executive functioning. It's going to, you can actually see a big blip of activity in the prefrontal cortex when people do. So what's happening is, is that I've formed a little fragmented memory for our conversation. I've now gone to this new task. I've used up some executive function just to be able to focus on what's going on with this text message. Then I come back and now I'm like, just to even re-get back to where we were before, I have to engage in some mental time travel just to figure out what was happening right before I checked that text message. That's going to use up more executive function. I'm behind schedule in our conversation. I'm barely catching up.

• 1:21:12Speaker 01

  And so I'm not really thinking meaningfully about what you're saying because I'm still stuck in that past moment. And meanwhile, every time I'm getting distracted and forming these little fragmented memories where I'm still catching up and I'm behind schedule. And so now when I want to remember this experience later on, I don't have a coherent, meaningful memory. I just have a bunch of bits and pieces, right? So that's kind of one example.

• 1:21:34Rich Roll?

  Yeah, the toggle shift of attention switching constantly. And when we think about the fact that we all have these mobile devices and we're running this massive social experiment, what you're saying is actually, the more that we engage with these phones and the notifications and the distractions and the scrolling, we're basically all collectively impairing our, not only our ability to be present and aware of our surroundings, but to actually form and retain memories.

• 1:22:08Speaker 01

  Yeah, it's a massive form of self-sabotage, but it doesn't have to be. So I'll give you another example, which is phone, cameras that we use on our phones, right? So a lot of the research shows that when people have the opportunity to take pictures of things with their cameras, they actually remember it more poorly than if they didn't. Now, think about how many times people go in, I mean, just think of the proliferation of Instagram walls everywhere, right? Or you think about like how people go to concerts and they're just constantly filming everything from their phone. And you have this impression that I'm creating a memory because I'm taking a picture of it. But actually, what happens is it's taking you away from that experience and distracting

• 1:22:52Speaker 01

  you in a way because you're mindlessly taking pictures of things with the idea that I'll access the pictures later on. People don't, right? And if you look at the example of, for instance, the concert that you're at and you're taking a video of the concert, well, you don't want to remember, you're not going to remember the song and every note that was sang in the way it was sung. You're going to remember your experience of being there and what you're feeling and your experience of hearing that music. But if you're experiencing it through the phone, that's a pretty impoverished experience, right? Because you're confusing the memory of what happened versus the actual episodic experience

• 1:23:36Rich Roll?

  of that event. Because you're so focused on documenting it, you're not having the experience. And because you're not having the experience, you're short-circuiting your ability to actually form a resonant memory.

• 1:23:49Speaker 01

  That's exactly right. That's beautifully put.

• 1:23:51Rich Roll?

  That's wild. I'm interested in what might be a converse to that, which is the idea that the younger generation is now a generation in which not only do they have a lot of photographs of their life, literally every day is documented in photographs and video. I don't know about you, but you know, my parents have some photo albums and when I visit them, I can flip through them and you know, there's a couple of pictures at each holiday and maybe some vacation we went on. But they're few and far between, right? And I look at them and they help me remember those experiences, or maybe they're creating

• 1:24:36Rich Roll?

  their own version of a memory where I think I'm remembering it, but I'm actually just remembering the photograph. But now, with respect to, you know, anyone who's, you know, under the age of, I don't know, 25 or 20, it's a whole different thing. So what happens to somebody who's currently 15 years old when they're

• 1:24:57Rich Roll?

  60 years old and they just have, you know, I don't know, hundreds of thousands of photos and they begin the process of going through them. Like when they look at all of these photos, are they going to trigger memory? Like, what is that? Maybe we don't know, but like, to have your entire life documented in that way, my, my instinct is that that would help you to remember so many things that ordinarily we would forget. And I would love to have had that so that I could better remember many childhood experiences that, you know, are long gone from the memory bank.

• 1:25:32Speaker 01

  Well, yeah. So, I mean, this, the question of what does the 70 year old version of, of your teenage son or whatever, what, what they're gonna like?

• 1:25:42Rich Roll?

  By then, AI is gonna be a whole brain world, but you know, who knows? But let's just say, for purposes of this thought experiment, when they're 60 or 70, the world looks like it does right now.

• 1:25:51Speaker 01

  Yeah. I mean, what's interesting is that photos that are taken, on the one hand, they're leaving this trail of documentation, but on the other hand, people don't really go back to them very often. And what happens is if you do go back to them, there are beautiful ways of strengthening the memories. Because if I see a picture and I use it and I take the time to actually reconstruct the whole memory, now that memory will become more implanted. It will become easier to access later on. So the more times you recall it, again, because remembering transforms the memory. So it can strengthen it, right?

• 1:26:28Rich Roll?

  So if you revisited that photo album regularly, and also in the, in the kind of immediate wake of those experiences to constantly reinforce that memory. So when you are 60 or 70, you're not looking at them for the first time. If you're doing that, you're gonna see a stranger's life. You're not gonna remember any of this stuff, right?

• 1:26:47Speaker 01

  That's right. That's exactly right. And that's the thing. I think you, you hit the nail on the head, is that without some actual episodic memory that's very rich and distinctive, you can look at the picture and have all the evidence right in front of you, but it's just like opening up a history book. For events that you never experienced. And you know, I have that. I talk about the experience of like watching videos that I took of some of my daughter's birthday parties and having no memory, even I can hear my voice and I have no memory of these experiences. And then there were some where I wasn't behind the camera where I can remember it very vividly.

• 1:27:28Rich Roll?

  Right. And that speaks to how we can improve and enhance memory. The story of the birthday party was one in which you were sort of, you know, in a traumatized situation, trying to problem solve, you know, on the fly. And because it was a heightened experience and you weren't preoccupied with documenting it, that memory lives more strongly, right?

• 1:27:52Speaker 01

  Yeah. Yeah, yeah, absolutely. That's right. It's, I mean, it had all the ingredients. It was emotional. It was, but I was also my, I was there. I was really having to react. I was present. And, you know, when you're behind the camera, you're just kind of like, okay, what am I taking a picture of? And again, it can be mindful. You can really, I know someone, I have a friend who is like, he has a lot of, he hosts a lot of social events. And when he does, he's there, but he's really thinking about what are these specific moments that I can capture? And he must have a hard drive that's filled with these photos. And I'm sure most of them will just be lost to the ages in the archives or whatever.

• 1:28:34Speaker 01

  But he probably has very rich memories of these experiences because he was looking for them.

• 1:28:42Rich Roll?

  If we're thinking of our memory as a hard drive, can the phone act like a cloud device? Like when the, when the hard drive gets full, we can upload all these memories to the cloud and we can retrieve them as long as we're kind of periodically revisiting them to reaffirm a certain memory. Does that expand the capacity of the overall hard drive? Or are we all just dealing with a certain amount of limitation there?

• 1:29:12Speaker 01

  Yeah, there's no evidence that that people hit a capacity problem in memory. And part of the reason is, is that unlike the hard drive where every, let's just say if you're talking about images, right, so every JPEG file that you have will be stored independently of each other. But in memory, you've got the same set of neurons, basically, more or less, encoding multiple memories through these various configurations of different assemblies of neurons, but they overlap with each other. And we're also constantly recycling materials from old memories to construct new memories. And so as a result, we don't have these capacity problems.

• 1:29:52Speaker 01

  Human memory works very, very differently from a lot of machine learning in that sense. And it does also because we have different kinds of memory systems that interact with each other. But I think that's where the storage issue really comes into play is we're not, first of all, we're not even experiencing everything that that we really, or we're not processing everything that's even in front of us. So we have, I have this illusion that I'm seeing everything. But really, what happens is my eyes dart around a few different places and get high-resolution bits of different parts of the room, and then my brain stitches it together into a sense of what's happening in the moment.

• 1:30:34Speaker 01

  And that's why you can have phenomena like change blindness, where, I mean, literally you have experiments where a person in a gorilla suit might run behind me or something, and you might not even notice it. So that's because you've constructed, you've imagined essentially what's happening in the present, rather than actually seeing everything that's in the present.

• 1:30:54Rich Roll?

  The raw data of what is actually real. You mean to tell me that you're not sitting across from me, fully present and appreciative of the fact that we're on a rock that's spinning around in space?

• 1:31:07Rich Roll?

  With billions of stars surrounding us at all times and a vastness that our human brains can't contemplate, you're not, you're not sort of, you know, aware of that in this moment?

• 1:31:17Speaker 01

  Yeah, this is actually, this is, I mean, I couldn't even pay attention to what you were saying because I was thinking, are you paraphrasing "Do You Realize?" by the Flaming Lips, which is like, very much like, like, "Do you realize we're floating in space?"

• 1:31:30Rich Roll?

  Sure.

• 1:31:30Speaker 01

  I think he said something about it, like, "There's an illusion."

• 1:31:34Rich Roll?

  "Do you realize?"

• 1:31:36Speaker 01

  Such a cool... You could probably do, like, be Wayne Coyne for, like, Halloween.

• 1:31:41Rich Roll?

  I certainly can't sing, though. I'm not gonna do that part. What about the idea, well, this gets into, and we're still on the phones, the relationship between memory and learning and how we learn. Now that we have these supercomputers in our pocket, it's obviated the need to memorize anything. And you talk a lot about how memorization is actually a poor skill for memory retention in the first place, that our ability to form memories and retain them has a lot more to do with struggle and, you know, other kind of techniques about how we approach new material. But given the fact that memorization is now like a relic of a bygone era, I'm curious

• 1:32:26Rich Roll?

  if there's any science or what your thoughts are around our relationship to, to remembering facts. Like, we've now outsourced any kind of mental, you know, energy around memorization, because we can always just Google something and look it up really quickly. So, again, protracting, you know, kind of projecting out into the future, what is this doing to our brains and to memory at large when we're not pushing ourselves to kind of remember things in the way we used to have to, we used to have to remember phone numbers and like, all kinds of things, right? Now that's, I'm sure our brains find other ways to use that capacity, but have you thought

• 1:33:10Rich Roll?

  about that, or is there any research on this?

• 1:33:13Speaker 01

  Yeah, yeah. So, I mean, on one hand... Uh, let me just say a couple of things. So one is that when we're, when you're saying memorization, we should be clear, that's rote memorization, like basically trying to repeat a phone number

• 1:33:27Rich Roll?

  like, you know, remember we went to school, we had to, we had to learn the capitals of all the state, you know, all that kind of stuff.

• 1:33:33Speaker 01

  Yeah, yeah, exactly. And that's, that's characterized by just rote repetition, but without like trying to actively learn. So active learning is like, active memorization would be like, I test myself with flashcards as opposed to just reading the words that I'm trying to memorize in Spanish or something like that. Right? And so there's a big difference there. And I mean, I just have to editorialize that it's shocking that in education, you don't teach study skills to,

• 1:34:02Rich Roll?

  Yeah.

• 1:34:02Speaker 01

  you know, learning skills to children early on and often throughout school. I mean, that's such a big thing is just memorization skills or, I mean, study skills are a huge factor in success in school.

• 1:34:16Rich Roll?

  You know what else is shocking?

• 1:34:17Speaker 01

  What?

• 1:34:18Rich Roll?

  I don't know that I could tell you a single thing that I learned at my very expensive Stanford University education and, and probably only a few things from an equally expensive law school education.

• 1:34:32Speaker 01

  Yeah.

• 1:34:32Rich Roll?

  It's depressing.

• 1:34:34Speaker 01

  Well, you probably, you probably do have more than you remember in the sense that you probably have some knowledge that you picked up here and there, but it is true. Again, you don't remember nearly as much as you think you will, right? And, uh, but getting back to this idea of like the, how you learn, I think probably one of the factors that you're probably linking to is that when I was in high school, you were in high school, when I was in college, you're in college, the whole system is geared around. Pract-- basically, it encourages practices that are actually bad for long-term retention. So what I would do is I would stay up all night right before the test.

• 1:35:16Speaker 01

  I'd even study an hour, you know, literally up till walking in the room. And then I would take the test and I would do well. And then a week later, I'd forgotten everything.

• 1:35:25Rich Roll?

  That's the story of my life.

• 1:35:27Speaker 01

  That's right.

• 1:35:27Rich Roll?

  Yeah.

• 1:35:28Speaker 01

  And that's because like you will do well in the short run if you cram, basically, and you do everything the night before the test and then you just regurgitate that information. But what happens is later on, you're not able to access that memory because it's associated very uniquely to that place in time that you studied it. And once that place in time is in the past, you can't access it anymore. So the act of struggling, though, to recall things actually like, so if you use tests not as a how much do you know from this past experience, but rather you use it as a learning tool, what happens is you expose the weaknesses in that memory.

• 1:36:08Speaker 01

  And the brain can actually repair those problems in the memory to tighten it up and make it more lean and mean so that it's more accessible later on. So that act of struggling to remember something can be an educational experience. Likewise, if you space out your learning, all these, basically, almost any learning method that you use that feels painful, you're going to gain more from it in the long run, that you'll retain more from it.

• 1:36:34Rich Roll?

  What you're suggesting in turn suggests a revamping of education writ large, right? Like, our entire education system is sort of oriented around test-taking and cramming for tests and, you know, trying to absorb as much information as possible so that we can spit it back out and move forward. And this is just a terrible way to not only learn things, but to retain them.

• 1:36:59Speaker 01

  Yeah, and it really comes down to keeping your eyes on what the goal is. So if the goal is for people to get something that they'll carry with them in the future, it should be all about retention. And that retention should be guided, I mean, can be promoted by basic stuff that we know from memory research in terms of study practices that can actually enhance memory. But that involves things like, you know, testing yourself or spacing out your study events so that you're engaged throughout the process rather than just kind of studying for one big test. Curiosity is another factor and self-guided active learning can be a big part of it, too. So I do think revamping is good.

• 1:37:42Speaker 01

  I think part of the revamping is also a change in mindset about what it should be like to be educated. What I mean by this is we really think, okay, somebody got good grades, they're smart. Somebody got bad grades, they're dumb, right? But really, people would be learning, in theory, anyway, people would learn the most if they were getting 70 to 80% on every test they took, meaning that the act of testing would actually enhance their memory the most if they're actually making mistakes quite a bit, quite often. That's when you're learning the most, right? So, and it's obvious to some extent, if you're a skateboarder, or a surfer, or a basketball

• 1:38:26Speaker 01

  player, you don't keep doing the same simple thing over and over because you're good at

• 1:38:30Rich Roll?

  Right. You welcome failure and failure becomes the teacher, right?

• 1:38:35Speaker 01

  Exactly.

• 1:38:35Rich Roll?

  Whereas in education, we're trying to avoid failure. But those experiences are very tactile, surfing, skateboarding, whatever it is, they're experiential. So, and, and, and experience is the way that we learn and retain greater understanding the best, is it not? Like, when we go out into the world and we have to, you were talking about testing yourself. Well, if you're testing some base of knowledge in the context of an experience, it feels like that would be a much more resonant way to kind of lock in, you know, you know, some new knowledge.

• 1:39:12Speaker 01

  It definitely is in the sense of like, especially if you want to be able to deploy that knowledge in a particular situation, right? So obviously, it's like if you're, you want to... Play basketball better. You play basketball and that's the way you want to learn, right? But even like things that are fairly arbitrary, like I'm trying to memorize a new language or something like that. Active learning, giving yourself the opportunity to produce the mistake. In fact, actually, I'll just go even farther. This is something that I mentioned briefly in the book. Some research shows, actually quite a bit of research shows that if you test yourself and give yourself the opportunity to make a mistake before you

• 1:39:51Speaker 01

  even know the correct answer, you will actually learn more than if you just get the answer.

• 1:39:58Rich Roll?

  Wow.

• 1:39:59Speaker 01

  And so we've done studies on this too, and we can show in our computer models of the brain why this happens. It's because essentially when you get the right answer, you then wipe out the parts of the memory that would have activated the wrong answer. And so this act of like getting people to generate answers and getting people to play an active role in their learning, I think is hugely important. It can be important for the experience stuff that we're talking about, but it can also be important for even the, you know, more abstract things that we want to get knowledge about, but aren't necessarily going to be concrete, physical acts in the world, right? I do this now when I'm like, trying to find my way around a new place, I'll use Google

• 1:40:42Speaker 01

  Maps, but I'll try to guess where I'm supposed to go before I look at my phone. And I find it really helps me so that after about two or three of those times around, I learn the map pretty easily.

• 1:40:53Rich Roll?

  That's the other thing. In addition to photos, outsourcing our sense of where we are in the world. I notice this, you know, with my kids who, you know, we were here in Los Angeles. It's large and sprawling, but growing up with GPS all the time, it's shocking that, you know, they often like have no idea where they are.

• 1:41:16Speaker 01

  Yeah.

• 1:41:19Speaker 01

  My daughter is saying way.

• 1:41:20Rich Roll?

  It's like, this is not good. The other, on the, on the subject of things that are impeding our ability to retain information or, or process memories, you talk about stress. When you think of stress, there's acute stress, there's chronic stress. I'm thinking of the stress in higher education, like if you're under duress to, you know, get ready for a test, what that does to long-term memory, but talk a little bit about like the impact of stress.

• 1:41:53Speaker 01

  So, a little bit of stress can actually enhance memory for the stressful experience, right? So if you're under a moderate degree of stress, what can happen is, is that you actually get these chemicals like cortisol, maybe norepinephrine release that can actually promote plasticity.

• 1:42:10Rich Roll?

  Like a heightened attention to what's happening.

• 1:42:13Speaker 01

  It can heighten your attention and arousal, and it can also facilitate that actual sticking of the memories that are formed through the plasticity enhancement. But if you get too stressed, what happens is it really shuts down the prefrontal cortex and you're not processing things in a meaningful way. And so you're getting just little bits and pieces and fragments. But the other part of it is, is that if you're trying to remember something that happened in the past and you're stressed, stress is unequivocally bad for remembering those old events. So that's where you want stress management is super important. You want to get the right amount of stress at the right time.

• 1:42:53Rich Roll?

  It's often a fine line between being in that heightened state where you want to perform well and tipping over into too much stress that actually works at cross purposes. Like I'm thinking about stage fright, like you want, if you're going to go up on stage and deliver a talk, you're in a heightened state and part of that is, is necessary to kind of get amped up and, you know, kind of, you know, excited about what you're about to do. But that's a hair's breadth away from, you know, panic and not being able to remember anything about what you're supposed to say. And it's really hard to modulate that sometimes.

• 1:43:31Speaker 01

  Yeah, yeah. And different people have different magnitudes of stress responses to, which complicates things further. And I don't know how to advise people, get this stress, but not this, you know, not, don't let it go up to that level. But I think in general, one of the things that people need to keep in mind is, is that stress will generally put you in a reactive mode, give you arousal, and it can kind of get you moving. But when you're in a state of high stress, it can sort of, like I said, shut down your more reflective capabilities and the ability to think about things in a meaningful sense, which sometimes is good, because if I'm telling the same story over and over again, sometimes I can

• 1:44:15Speaker 01

  get stressed, and it just becomes easier to fall into habits and just let things go. But it can also create problems. I mean, I think this is kind of tangential, but it's, gets back to your point about modern life and the way things go. When we're stressed, as I said, we kind of go into what feels natural and fluent. And our brains are constantly tweaking, even in the absence of explicit memory, just tweaking themselves to do better based on experience, right? And one place where I've really noticed this is in auto-completion in emails. So once Google started to incorporate AI to autocomplete sentences in Gmail, what

• 1:44:57Speaker 01

  I noticed was, like, there'd be some times where I would just say, no, that's not what I was gonna type and type in. What happened? Sometimes it was exactly what I wanted, and I go, yep, autocomplete it. And sometimes it's not what I wanted, but it's good enough, and I don't want to type this stuff, so I just let it go, right? But what happens is, the more we're exposed to those patterns over and over again, and we actually let it auto-correct our own spontaneous patterns, the more those become the natural

• 1:45:27Speaker 01

  Elements that we will just produce on our own, if that makes any sense. The more fluent those suggestions become. And so what I

• 1:45:36Rich Roll?

  Not because the AI is getting better, but we're we're relenting to the AI and then convincing ourselves that its idea was the same as our idea, when in fact, the repetition of the AI, you know, telling us that, you know, this is what it should say, is leading us to believe that that's us and not it.

• 1:45:56Speaker 01

  Exactly, exactly. It's the tail wagging the dog.

• 1:45:59Rich Roll?

  That's terrifying, you know.

• 1:46:01Speaker 01

  I mean, well, think about like the fact, like just a typewriter or, you know, people who text on their phone. I mean, this is an incredibly complex skill that people learn to communicate because those are the limitations of the device, right?

• 1:46:14Rich Roll?

  Yeah.

• 1:46:15Speaker 01

  And we're constantly shaping ourselves to be, to perform, to basically function effortlessly in whatever context we're in. And if that context is interacting with machines, we will adapt to the way the machines, and that's not necessarily bad, right? But I think it often does turn out to be bad because we just let things go. We're stressed out and we don't have time to think about what we're writing or think about what we're saying or think about what we're doing.

• 1:46:47Rich Roll?

  Well, this is just an example of how it's unfolding, right? Like, instead of adapting the machines to us, we're unknowingly adapting ourselves to the machine.

• 1:46:56Speaker 01

  Yeah, there's a really interesting episode of Radiolab that I was listening to where they talked about the Turing test, where they had, the Turing test, the idea is that essentially if you can't tell the difference between some kind of AI agent versus a human communicating with you, then that agent must have intelligence. And the thing was that they did this with a computer dating situation. And there was one time where like the computer dating tool was so effective. This was long before LLMs became so powerful, like ChatGPT. But essentially, like the machine, people couldn't tell the difference in the machine-generated texts and a person-generated text.

• 1:47:39Speaker 01

  But the conclusion wasn't that the machine was so intelligent, but rather that human communication over text messaging had devolved to such a simplistic point of view. That basically, it's like, people were sort of lowered to the level of the machine.

• 1:47:53Rich Roll?

  Oh my god. Yeah, the Turing, the standard for the Turing test just diminished, basically.

• 1:48:01Speaker 01

  The bar became extremely low.

• 1:48:04Rich Roll?

  How about this one? On the subject of stress, I'm imagining a detective who's trying to solve a crime and calls into, into the precinct a witness or perhaps somebody they're looking at as the perpetrator. And they start asking them questions about what happened and where they were and what their memory of this evening was, whatnot. But that is by definition, in extremely high-stress environment for anybody, right? So the question then becomes, how reliable is anything they say? When you're suggesting that such a high-stress environment

• 1:48:48Rich Roll?

  is going to impair the credibility of a, of a recollection?

• 1:48:52Speaker 01

  If it's the first time someone's recalling something, and somebody recalls and they're like, this is exactly as it happened, they're often correct, they're usually correct. So it's like, if you'd never been asked about this crime, and then you show up and I just show you, here's a bunch of mugshots, and you're like, that's definitely the person, they're usually going to be correct. Even if they're stressed out, it'll often be correct if it just, they have that aha moment of remembering. Where things go awry is if they're not sure. And then you're asking them the same question over and over again, and they're under stress. And now what happens is that they're shutting down their memory monitoring

• 1:49:33Speaker 01

  and they're confusing the actual memory of what happened versus the pictures that I've just showed you or the information that the questioner is supplying in their question, like leading information that could be in the question. And that's the point where memories really start to stray from reality. So. People are pretty good at remembering what happened. And more importantly, they're pretty good at saying, eh, this, I don't, I don't know if this happened or not. But where things go awry is going to be in cases where people are now asked to remember things a second time or a third time. Or they're under stress and they're getting a lot of suggestions and being encouraged

• 1:50:17Speaker 01

  to think, what could have happened here? That's where things really go off.

• 1:50:21Rich Roll?

  Or leading questions.

• 1:50:22Speaker 01

  Yeah.

• 1:50:23Rich Roll?

  Yeah, exactly. Yeah. Is it different qualitatively? Like, for example, you know, identifying a face in a mugshot. Is that qualitatively different from, say, walk me through all your movements on this evening, you know, like minute to minute, you know, to account for your whereabouts? Is that a different exercise? Or does that?

• 1:50:45Speaker 01

  It is a different exercise, yeah. It's funny, no one's asked me that before, but it's a very different exercise because one, I mean, technically, the terms we would use is the face would be recognition memory and the step by step is what we would call free recall. And the difference between them is the face is the cue that is right there in front of you, this photograph. And so that's a cue that can trigger memory retrieval in your head just because it's right in front of you.

• 1:51:09Rich Roll?

  Right, but there's only really three responses to that, which is yes, no, or maybe.

• 1:51:13Speaker 01

  That's right, yeah. I mean, or you can say, I'm sure, I'm kind of sure.

• 1:51:18Rich Roll?

  Right, a spectrum of certainty.

• 1:51:20Speaker 01

  Yeah, exactly. But on the other hand, when you're regenerating, you know, I want you to walk me through step by step what happened, all you have is some kind of a vague sense of the gist of that event, like some kind of context information. Well, I was in this place. And then you use that context to trigger a little bit more retrieval. And then you use that little bit that you pull up to pull up more information and you start to build the story from there. So in one case, you're using the person's face, basically, as a cue to retrieve that context information. In the other case, you're actually reconstructing the context itself and then generating the story from there. So the step by step thing is much harder.

• 1:52:05Speaker 01

  Again, if people can go, "Yeah, I vividly remember blah, blah, blah," they'll be getting some of the story correct. But sometimes what can happen is they vividly remember being there. And then some of the other embellishments that they have, they'll treat that with the same amount of confidence, even though it's not necessarily remembered so accurately. So if you're remembering, "Ah, so it was like this really emotionally arousing event. I was so scared." You'll have this feeling of vividly remembering it, and you will remember that something happened. But now you might be more likely to be saying, "Oh, yeah, and this person was wearing green shoes," or something like that. Maybe they didn't, but you'd be as sure of that than as you would be of the fact

• 1:52:50Speaker 01

  that the person held a knife to your throat sometimes. That's where things can get a little bit off.

• 1:52:54Rich Roll?

  Now, let me throw another variable at you. That person who's recalling that vivid memory or walking through step by step their whereabouts, let's presume one of two things. Either that person got a full eight hours of sleep the night before, or they didn't sleep at all. Or they got, I don't know, an hour or two of sleep. How does that then impact the reliability of that account?

• 1:53:22Speaker 01

  Well, what it's going to do is, especially if you're talking about the reconstructing of the past event, it's going to make it worse. And how it's worse might depend on particular... There's a lot of times you talk to a scientist, they'll say, "It depends."

• 1:53:38Rich Roll?

  Yeah, yeah.

• 1:53:38Speaker 01

  But basically...

• 1:53:39Rich Roll?

  Well, that's when you know you're talking to a real scientist, when they don't turn to the camera and say, "Let me tell you exactly how it is."

• 1:53:45Speaker 01

  It's just like this.

• 1:53:46Rich Roll?

  They're constantly talking about how it depends.

• 1:53:49Speaker 01

  Yeah, yeah. But I mean, more or less what happens is when I'm sleep deprived, again, it really shuts down the prefrontal cortex. So now I'm sleep deprived and I'm under stress, which is basically what most new parents are experiencing every day, right? So now it becomes harder to pull up that old context because you're stuck in what's in front of you, and you can't engage a strategy or engage in kind of the reasoning processes that you need to step by step walk through that past event. Now, the officer suggests something. So like, "Oh, maybe, you know, do you remember, was the perp wearing a green sweater?"

• 1:54:28Speaker 01

  Well, now I'm stressed out. I'm kind of tired. I'm not really engaging these more critical processes to keep my memory accurate. And so I'm like, yeah, yeah, I think so. In fact, come to think of it, the more I think about it, the more sure I am that the person was wearing a green sweater. And so now people start to get confused between what was suggested to them and what actually happened.

• 1:54:51Rich Roll?

  Right. But it's unclear whether that has to do with memory or suggestibility, like a heightened suggestibility due to fatigue.

• 1:55:03Speaker 01

  Yes, but those two can become intertwined.

• 1:55:05Rich Roll?

  But I guess they inform each other, right?

• 1:55:07Speaker 01

  Yeah. So, once it's suggested, then it can become a memory that takes on a life of its own. It can become incorporated. In the absence of that kind of misinformation, what often happens is people just don't remember. They're like, ah, it's really blurry. I don't know. I'm tired. I'm under stress. I can't remember. Now, what's dangerous is they try to remember it. They're being asked all these questions. And then later on, you bring them back again, and they're more relaxed. Ah, yeah, I remember what happened. But they're already contaminated now because they've been asked once, and that attempt to remember it previously can create all this information that then gets mixed up. And especially, it's true with mugshot. So if I see a mugshot, and I'm like, I'm not sure, maybe this was

• 1:55:52Speaker 01

  the person. Later on, I get confused between the memory for what happened versus my attempt to remember what happened and seeing the mugshot, right? So, and this is even worse. We can take it even one step further when people are trying to do face identifications, and it's a total stranger, and it's somebody of a different race. Because what happens then is that people don't have the, it's really partly an expertise effect, that they really don't have the ability to discriminate as well between, discriminate, I mean, literally see the differences between members of other races, right? Just like a, somebody who doesn't know anything about cars, they might look at three different cars and be like, they

• 1:56:37Speaker 01

  all look the same to me, even though they might be different makes and models, right? So, in fact, some research shows that when people, this was done on Caucasian people, but when they were literally looking at faces of, you know, white and black faces, let's say, they were

• 1:56:58Speaker 01

  They were worse at being able to remember the identity of people of other races. Like, in other words, Caucasian people were worse at remembering faces of people of color. But they were faster and better at identifying that the person was black. So in other words, they're literally seeing the race, but not seeing the individual characteristics of a person. And so like the race biases in face recognition, meaning worse recognition of faces of other races, is quite bad. It's actually true, you see this in machine learning too, because automated face recognition systems are trained on these databases that mostly are white, mostly male people.

• 1:57:43Rich Roll?

  That's super interesting. But the indisputable point is that sleep is important to memory.

• 1:57:54Speaker 01

  Oh, yeah.

• 1:57:54Rich Roll?

  Right? We all know the experience of struggling to remember things or, you know, putting our sentences together when we haven't slept well. And the drastic difference when we've had an incredible night of sleep and everything just comes super easy and our recall is, feels precise and our ability to put language to our thoughts, all those sorts of things seem to come together.

• 1:58:18Speaker 01

  Yeah, yeah, that's right. And we know that, well, there's good evidence suggests that memories for recent experiences are reactivated spontaneously in the brain during sleep. And there's a lot that we don't know about sleep, but just the fact that you get these reactivation experiences gives the brain the opportunity to put everything into a larger perspective. So for instance, if I see you one week from now, I might have a memory for that experience and I have a memory for this experience. But by reactivating and free associating between these different memories during sleep, I can get a better schema for who rich is from all of these disparate experiences that

• 1:59:01Speaker 01

  I've had in different times, places, and situations. And some research suggests that in fact, after sleep, what happens isn't just that you remember the information better than you did before sleep, but it's that you're able to use that information more.

• 1:59:18Speaker 01

  You're able to deploy that information when you need it in a particular way. So for instance, if I'm trying to memorize words in a new language, I can actually put them in sentences spontaneously better after sleep.

• 1:59:30Rich Roll?

  Right.

• 1:59:31Speaker 01

  There's other work, it's more controversial, suggesting that you can problem solve from little bits and pieces of information you've learned. You can put that together to solve a problem better after sleep. I think that's controversial partly because some of the methods used in these studies are a bit esoteric. But, but I think that there's no doubt that sleep has some kinds of effects on memory. What's interesting though is some of those effects can even be gotten from down states in general. So a friend of mine, Sarah Mednick, wrote a beautiful book called The Power of the Downstate. And she talks about rest and naps. She did great work on naps, showing that a half hour nap can produce a lot of the same benefits that you get from sleep over the course of a night.

• 2:00:16Speaker 01

  And we've and others have shown that memories can even be reactivated while people are just zoning out and resting. And what's really interesting is just listening to a talk a couple of weeks ago, where people were talking about how after you listen to a story or you see a movie, these thoughts spontaneously bubble up when people are just resting and free associating even. So giving ourselves these non-goal oriented down states can be really good for memory, not only for just remembering things that have just happened, but actually being able to assemble those little bits of experience into some wisdom.

• 2:00:56Rich Roll?

  Right, all this synthesis is occurring. Is that distinct or related to that thing that happens when you're trying to remember this thing and it's right on the tip of your tongue? Let's say you, you, you, you see an actor in a movie and you're like, what is that guy's name? I know it. I know that face. I've seen this person. Why can't I think of who that like, dang man, like I know this.

• 2:01:19Speaker 01

  Yeah.

• 2:01:20Rich Roll?

  But the more you, you drive yourself, you drive your attention toward it, the more elusive it becomes. And it's not until you let go, you distract yourself, you walk away from it, you forget about it, that it suddenly just pops into your head.

• 2:01:35Speaker 01

  Yeah, yeah, there's a whole field of this called the tip of the tongue effect. And what it seems to come, one of the reasons, there's a number of reasons, as you often get in psychology for these things, but one of the big ones is we often, even if it's not a threshold, will often be searching and reactivate the wrong answer. And remember, I was saying memories compete with each other. So if I activate the wrong answer, even if I know it's wrong, now that set of neurons is highly active and more likely to be reactivated. And it's inhibiting competitors, competing memories that could be activated. And so what happens is you need to somehow be able to suppress the wrong answer so that you can activate the right answer.

• 2:02:17Speaker 01

  But what can often happen is you're so sucked in to that wrong answer that it's really hard to get out of it. In fact, they actually, in computational models, they call it an attractor state, meaning that it's like these memories can attract so much activation that they suck up all the air away from all the other memories that could be activated. Now, when you give it some time and you go into a new context, now what happens is you've sort of wiped the slate clean. And now that memory isn't competing so much, and now you can find the right information that you're looking for much easier. Yeah, so the worst thing you can do for yourself is to kick yourself and be like, "I'm losing my mind, I'm going senile." That's only going to stress you out, it's only going to shut down your prefrontal cortex,

• 2:03:01Speaker 01

  which is, the research shows is, that activates when people successfully overcome that tip of the tongue state. But it's really hard to do that. And the more you stress out about it, the worse it's going to be. So take it easy on yourself. If you can't remember the name, it's fine.

• 2:03:18Rich Roll?

  What is going on with déjà vu?

• 2:03:21Speaker 01

  Déjà vu is another, really, it's one of those topics that I really got into when I was writing the book. And it's fascinating because it actually has a long history in neurology. Early in the history of neurology, Hülens-Jackson, who's this famous neurologist, found that some epilepsy patients would have a strong, almost overwhelming sense of déjà vu, meaning feeling like they've experienced whatever's happening, like they have a... Strong sense that they've experienced it before, even though they know they haven't. And that would happen right before a seizure, almost like predictably, it's called. And they called that an aura that would happen sometime.

• 2:04:03Speaker 01

  And later on, some epilepsy surgeons like Wilder Penfield found that if he stimulated a part of the temporal lobes of the brain, where epilepsy often happens, people would get this sense of déjà vu and it would happen very spontaneously. And so our research and research from other labs has shown that that sense of déjà vu may be related to the brain circuitry for generating a sense of familiarity. So, right off the bat, you can get a sense that some things are familiar and some things aren't, even if you don't have to search your memory for it, right? So, like I use in the book, an example of rambutan, which is a fruit that many people in America have not had.

• 2:04:47Speaker 01

  And right away, people could say rambutan is less familiar than apple, even though they're both fruits. But one, I mean, even before you think about it, just the act of processing it, it's so much more effortful for this thing that you don't hear very much, that you can make that inference that it's familiar. And what happens is we've found, and other people have found, that when you process even a single word like that, you can see a little bit of plasticity in this area of the brain, in the temporal lobe, called the perirhinal cortex. And that area seems to be very important for generating that palpable sense of familiarity, like I've experienced this before. And so, what may be happening, and it's still not clear, is that when you have a sense

• 2:05:30Speaker 01

  of déjà vu, you know, and you're not having a seizure or something like that, what's really happening is, there's something out there that's cueing memories in a way that's activating weakly some memories for things that you already have. But there's enough mismatch out there that you're not going to recollect that old memory. And so, as a result, you're having this sense of familiarity that's based on your normal brain's ability to generate a sense of familiarity, but it's becoming exaggerated. Because it's a close enough match that it's strongly activating one particular memory, but it also deviates in some very important ways. So your brain's not going to generate

• 2:06:11Speaker 01

  that recollection response that allows you to fully mentally time travel. Does that make sense?

• 2:06:17Rich Roll?

  Yeah, no, I get it. I mean, to kind of really ground it down, what I'm gathering from what you shared is, for example, let's say you're going on a camping trip with your family and you enter into some cabin in the woods and you're like, I've been to this, I've been here before. And what you're saying is, your brain is, is looking for all, it's sort of taking survey of all these experiences that it has stored over the course of your life. And it's pulling out like, well, you went to, you know, when you were nine, you went to a cabin. And when you were 14, there was something that kind of looked like a cab. It's pulling all of these things, and it's creating a lattice work or a frame or a lens. And, and the purpose of that is to

• 2:07:01Rich Roll?

  help you interpret your environment and create a prediction about what you can expect when you enter it so that you can be safe, right? But those past memories are only tangentially related to what you're experiencing. So you're not pulling up those memories per se. It's just creating almost a somatic experience of, of, of recollection without it being exactly tethered to a specific memory.

• 2:07:31Speaker 01

  Yeah, it's giving you like the sense of a memory being there without an actual memory. It's, it's very bizarre. You feel like there's something there. I mean, in some sense, it's very similar to what we were talking about with the tip of the tongue state, right? Where it's like, in that case, you have this knowledge of what is supposed to be there, but you can't find it. You have no evidence of it. And in the case of déjà vu, it's like you have no evidence of a memory or sometimes counter evidence. Like you know, I've never been in this place before, but there's something uncannily similar between this place and some other place that I've been. And in fact, my, I'm collaborating right now with Nigel Peterson. And and clear and and develop this beautiful virtual reality thing where she can reliably

• 2:08:15Speaker 01

  get people to experience deja vu by putting them into virtual environments that if you just looked at the locations of the objects and layout of the rooms, they're exactly the same. But one looks like a video arcade and one looks like a museum. And if I see these movies, or you know, if I walk through these virtual environments, I feel like they're very different. I don't have any memory from one or the other. But often what happens is people have the sense of deja vu because it's such a close match to their mental map for this other place.

• 2:08:48Rich Roll?

  Well, that's because it's a glitch in the matrix.

• 2:08:50Speaker 01

  It's a glitch in the matrix.

• 2:08:52Rich Roll?

  Right. I was hoping you were gonna say, this is what you're studying. You're gonna prove that we're actually in a simulated reality.

• 2:08:59Speaker 01

  Well, I mean, we are really simulating. That's what's happening in our brains right now. Just to understand you, I'm simulating what it is I think you're thinking about.

• 2:09:07Rich Roll?

  Yeah, that is true. Right. Now we're gonna, now we're getting into like pothead questions. Which I do have a couple of, but before that, maybe this is kind of like a semi pothead question, but what is going on with someone who has photographic, a photographic memory? Do they truly have a photographic memory? And what does that mean?

• 2:09:30Speaker 01

  Well, so first of all, yeah, so if you think of a photographic memory in a very literal sense, that it's like, I literally can have every pixel of what's in front of me right now. No one has been shown to have a photographic memory. You know, my phone has a photographic memory, I don't. But there are some people who have an extraordinarily detailed memory for some narrow range of things, right? So you can find this in so-called memory savants, for instance, they'll have this extraordinary capabilities to remember, let's say, like, you know, we're playing a game of cards, they'll remember every card that was dealt or something throughout the game. Or like people who will remember like

• 2:10:14Speaker 01

  every, like I saw a documentary on these twins who could remember every episode.

• 2:10:20Speaker 01

  Of the, I think it was the $10,000 pyramid, this game show with Dick Clark. And they could remember every one of those in extraordinary detail. Or there's this guy named Steven Wiltshire, who could go up in a helicopter, fly once over a city and draw like an extraordinarily photorealistic map of the city.

• 2:10:38Rich Roll?

  I've seen that, yeah.

• 2:10:38Speaker 01

  But it's not perfect. There are always gaps and there are always errors, but it's extraordinarily good.

• 2:10:44Rich Roll?

  Or the people, you can just throw a date at them and they can tell you like what happened, what they were doing on that day. It doesn't matter how far back.

• 2:10:52Speaker 01

  Yeah, yeah. They call that hypothemia or highly superior autobiographical memory. And there's some people like that. Mary Lou Henner is a famous actress who has that capability. But again, they're still in very narrow domains. So it turns out that basically people with highly superior autobiographical memory have a very detailed and accurate memory for experiences in their own lives that have to do with them. But if you give them arbitrary information, like here's a bunch of words I want you to memorize, they don't perform any differently than anyone else. There's, so what seems to happen is people have these capabilities for extraordinary memory

• 2:11:36Speaker 01

  in very narrow domains. And even though we think of that as being like exceptionally, and it's some kind of weird talent, I would argue we all have this in ways that we don't even think about. So I use in the book an example, the example of LeBron James. So LeBron James, if you go on YouTube, has this beautiful memory of games that he's played in, and in particular, games where they lost. And so you can see videos of him recounting from memory, a play by play, you know, blow by blow account of what's happened in a series of plays and videos side by side with his account that follow it. Like it's almost like as if he's watching the movie of it in his head.

• 2:12:19Speaker 01

  But the thing is, he has so much, first of all, he's paying attention, right? He's, and he's got so much expertise in basketball that he can see everything playing out in real time and reduce it to the bare essentials of what's important. He can use his extensive library of knowledge of all the previous basketball games that he's had to basically match up. A huge, complicated situation that's unfolding in real time and apply it to one template that he's seen before. And so as a result, he's got a memory for some of these plays before they've even happened because he can match it up to things that have happened

• 2:13:00Speaker 01

  in the past. But that also allows him to rapidly form detailed memories of what's happening in real time. You can look at chess experts, they'll have these extraordinary memories for entire matches, even things that they've seen other people play. A grandmaster can reproduce an entire sequence of moves, which a normal, I mean, a non-grandmaster would look and be like, where were these pieces even at this time? They wouldn't be able to do it.

• 2:13:25Rich Roll?

  But those two examples are rooted in decades of experience as opposed to some kind of genetic mutation or weird outlier context in the case of someone like Mary Lou Henner.

• 2:13:39Speaker 01

  Well, we don't know what it is that, I mean, I will say-

• 2:13:44Rich Roll?

  There's no locus in the, like, there's no, there's no DNA sequence for this or certain area of the brain that's overdeveloped?

• 2:13:52Speaker 01

  We don't know. I mean, I will say, one of the things I love to talk about is how much we don't know, because I think, I don't think, I don't think civilians quite hear from scientists enough about the uncertainty of science and the gaps in our knowledge. And one of the many things that we don't know is how individuals differ. Like, like, you might say, well, I have a great memory, and I might say I have a terrible memory. As scientists, we could not agree on this. We don't have the data to really support. Now, it may be that I could give you some tests and you would consistently perform better than me, but that's not really a deep sense of like how memory really differs across people. So we don't know. We're just starting to learn. I get emails from people a lot

• 2:14:37Speaker 01

  saying, I can't visualize things in my head. And so when I remember, it's not like a visual unfolding, it's not, it's the opposite of photographic memory. And so therefore, you won't understand memory until you study people like me. And, you know, I understand that because we don't- You know, I'm not describing their experience in my book. Most of what I write in the book applies perfectly well to them. But we don't know what makes them differ from the people who can see everything right in memory in detail. And we don't know what part of the brain is there's some in evidence to indicate that some of these obsessive characteristics that come in and autistic spectrum and,

• 2:15:18Speaker 01

  you know, maybe OCD like characteristics might be related to the Mary Lou Henner kind of thing. But it's kind of anecdotal right now. We don't really know for sure. What it is and how it relates to.

• 2:15:33Rich Roll?

  Right, like the kind of Rain Man idea.

• 2:15:36Speaker 01

  Yeah, there does seem to be some kind of a hyper focus of attention and interest that seems to be tied to it, right? So like, people who have highly superior autobiographical memory tend to be people who are like very, you know, obsessed with dates and record keeping and so forth. And they're very attentive to, they often engage in journaling, which will of course help your memory. But that kind of interest really and focus will give you more of that hyper detailed memory.

• 2:16:07Rich Roll?

  What is the question that's lodged in your brain like a sliver that you have to find the answer to? In other words, like, what is the study of your dreams that would help kind of resolve the questions, the remaining questions that you have about how memory operates?

• 2:16:27Speaker 01

  Oh, this is a good question. It's one that I'll probably next week I'll probably go, oh, this is what I should have told Rich. I could tell you.

• 2:16:34Rich Roll?

  You could call in. We'll record it and supplement it. If you don't have an answer right now, that's okay.

• 2:16:40Speaker 01

  No, no, no, no, but I could think of a few. I think for me. We are several steps away from understanding what happens in the real world as people remember. And a big part of this is that we tend to study brain areas in isolation from each other. And we study kind of memory for this micro level information. But what we know is the brain areas are interacting with each other and people interact with each other and they interact with the environment. And that gives us a very unique kind of memory that we don't really understand as well as I would like. So, one of the things that I would really like, one of the things that we're doing right now is to

• 2:17:24Speaker 01

  make everything more complicated, to use virtual reality where we can develop controlled experiments. For instance, where people are, we know the environment that people are in. But we can get people actively interacting with the world, being able to navigate through places that they've never been to. But we know and we can manipulate them in experiments or things where we can get people out in the real world, doing real interactions, or even things that are simpler like seeing movies and so forth. And building computer models to try to say, how do these different brain areas interact and change flexibly over time? And track, not memory, because I think part of the problem is our science is still,

• 2:18:07Speaker 01

  it's easier to think of memory in a very static way, even though we know it's a moving target. And we know it's dynamic and involves these dynamics between brain regions. It involves these dynamics between people, and that's the part we don't understand. And when people say something like, oh, ChatGPT, it's got intelligence, it's thinking and remembering just like a person. It's like, no, people move around and physically interact in the real world. People have random experiences, right? You have, you say that you don't remember anything from college, but you had one person who was on the floor of your dorm, who profoundly influenced you in some way. And that, your episodic memories of those little experiences

• 2:18:52Speaker 01

  allow you to produce creative works in ways that somebody else could never do, you know? And so, finding those kinds of threads between our lived experiences in the real world. And memory and imagination, that's where I think of, that would be my ideal question to answer.

• 2:19:10Rich Roll?

  Yeah, that's cool. What is your, your wildest, like, hot take on memory that you can't prove as a scientist, but your gut, your instinct is telling you is true? That might, you know, ah, ruffle feathers or blow some minds?

• 2:19:31Speaker 01

  Oh, yeah, yeah, no, my hot take, actually, I've got one that I'm really, I'm gonna give a talk on this in a couple of weeks, and I'm sure it will make people very mad. A lot of our research is based on the idea that the brain is always trying to form memories. We might not always succeed, but we're always trying. And so we've got, I give you a bunch of words, and the idea is, is that your brain, if it were working perfectly, you'd memorize every one of these words after hearing it, right? And likewise, studies rats, you can record from the hippocampus and find neurons that will fire, you know, some neuron might fire when an animal's in a particular place, and another neuron will fire when an animal's in a different place. And people go, oh, well, that's like, the animal's formed a mental map of its environment.

• 2:20:14Speaker 01

  And what I think is, based on some of our research and some really compelling research from other labs that's coming out, is in fact, the brain is really being selective about forming episodic memories at unique points in time that are important. And just whatever's happening in the brain during the rest of those times, it's just housekeeping. It's not really doing anything important, and that a lot of the brain activity that people record is not meaningful. A lot of what's happening in your brain in this moment is completely unimportant for memory.

• 2:20:50Rich Roll?

  Yeah, that will, that's gonna upset some people, I think.

• 2:20:53Speaker 01

  That's my hot take.

• 2:20:54Rich Roll?

  Yeah. All right, last thing, and this is sort of a pothead question, which is, we've all seen examples of the young child prodigy with almost no training, who can sit down and, you know, play a perfect Mozart concerto at the piano. And it's hard to Look at these individuals and not think, is there like, what is the role of memory in something like that? And is this a recollection from a past life or some kind of multi-dimensional version of reality?

• 2:21:35Speaker 01

  I mean, I definitely don't think about the multi-dimensional.

• 2:21:37Rich Roll?

  You don't think about the multiverse or past lives?

• 2:21:39Speaker 01

  Yeah, I don't think about that. But what I do think is-

• 2:21:43Rich Roll?

  I mean, come on, like, these kid, like, it's, it's like, there's no way, it's hard to imagine they could have learned all of that with such facility.

• 2:21:51Speaker 01

  Yeah. Yeah. I mean, well, it's like the Steven Wilcher thing, right? How does he just go up on a helicopter and see like, an entire like, city? And then like, be able to draw it from memory? Not only just remember it, but actually draw it in this photorealistic way. And we don't have answers for these things. I mean, but I think it's, this comes down to a very, very basic thing in biology, which is, we study the averages. We do not study the individual differences. You know, I've been on a lot of things where people are like, tell me how I can improve my memory. Tell me how I can do this. And the fact of the matter is, is that we don't know the thing that, the diet that makes you mentally

• 2:22:34Speaker 01

  opt, I mean, there's the whole culture, as you know, in this wellness world of optimization and trying to be like, reach my peak cognition, or whatever that is. And the fact is, it's like, I know if I drink, if I don't have coffee in the morning, I'm a dead man. But if I give my daughter a cup of coffee, she'll not be functional, you know? And that's like a very basic thing that is a difference in our brains that we don't get. We don't understand it. And so, I guess I would say that when I would look at something like that, it would just impress upon me both some humility, and some fascination about the complexity of the human brain, and just how much we still need to know about what makes us different from each other.

• 2:23:18Rich Roll?

  Well, there's lots of work ahead for you, my friend.

• 2:23:21Speaker 01

  Exactly.

• 2:23:21Rich Roll?

  Yeah, you're not gonna, I don't think you're gonna answer all these questions in your lifetime, but I appreciate the commitment to it. And I think the book is really profound, as is your work. As I said at the outset, there's just no ceiling on the profundity of memory and how it operates in our lives as a dictate of how we experience life and the outcomes. And I think the more that we can be mindful of that and apply ourselves to maybe reframing some of the memories that don't serve us and recontextualizing the story that we tell ourselves about who we are and the fact that, as you expressly said, like, we do have

• 2:24:04Rich Roll?

  agency over that, is in and of itself like, just, you know, a phenomenal, like, wisdom nugget that I hope everybody can hear. And if you want to learn more, please pick up the book, Why We Remember, at all your favorite bookstores, and thank you for coming here today.

• 2:24:20Speaker 01

  Thanks for an amazing conversation.

• 2:24:22Rich Roll?

  I appreciate it. If people want to learn more about you, what's the best place for them to do that?

• 2:24:28Speaker 01

  Well, you can go to my website, which is charanranganath.com. And I can, hopefully you can have it printed on your site.

• 2:24:36Rich Roll?

  No, we'll link all that stuff up in the show notes.

• 2:24:39Speaker 01

  I have an Instagram, too, The Memory Doc. It's a little bit easier for people to find, and that's where I put up kind of random tidbits about memory, as well as information about events and interviews and things like that.

• 2:24:50Rich Roll?

  Just don't, don't drive up to UC Davis and knock on his, knock on his office door.

• 2:24:56Speaker 01

  Well, I do try to respond to as many emails as I can. I've been getting a lot of, I mean, it's been one of the amazing things, is people have been touched by the book or curious about things based on the book, and that's what I wrote it for, so I'm super excited about it.

• 2:25:09Rich Roll?

  Yeah, it's cool that you're having that experience. It's well deserved. The book is really phenomenal. So, thank you. It's a, it's a, it's an act of service. It's a gift for all of us.

• 2:25:18Speaker 01

  Well, thank you. It was a gift to be able to write it and get it out to people.

• 2:25:21Rich Roll?

  Cool. Well, thank you, appreciate it, and come back sometime, and when you have a breakthrough, tell me what's going on.

• 2:25:27Speaker 01

  Awesome. Thank you. I will.

• 2:25:29Rich Roll?

  Cheers.

• 2:25:29Speaker 01

  Peace.

• 2:25:41Rich Roll?

  That's it for today. Thank you for listening. I truly hope you enjoyed the conversation. To learn more about today's guest, including links and resources related to everything discussed today, visit the episode page at richroll.com where you can find the entire podcast archive, my books, Finding Ultra, Voicing Change, and The Plant Power Way, as well as the Plant Power Meal Planner at meals.richroll.com. If you'd like to support the podcast, the easiest and most impactful thing you can do is to subscribe to the show on Apple Podcasts, on Spotify, and on YouTube, and leave a review and/or comment. This show just wouldn't be

• 2:26:22Rich Roll?

  possible without the help of our amazing sponsors who keep this podcast running wild and free. To check out all their amazing offers, head to richroll.com/sponsors. And sharing the show or your favorite episode with friends or on social media is, of course, awesome and very helpful. And finally, for podcast updates, special offers on books, the meal planner, and other subjects, please subscribe to our newsletter, which you can find on the footer of any page at richroll.com. Today's show was produced and engineered by Jason Camiolo. The video edition of the podcast was created by Blake Curtis with assistance by our creative director, Dan Drake. Portraits by Davy Greenberg. Graphic and social media

• 2:27:04Rich Roll?

  assets courtesy of Daniel Solis. And thank you Georgia Whaley for copywriting and website management. And of course, our theme music was created by Tyler Pyatt, Trapper Pyatt, and Harry Mathis. Appreciate the love, love the support. See you back here soon. Peace. Plants.