How to Increase Your Willpower & Tenacity | Huberman Lab Podcast

Andrew Huberman 0:00 (instrumental music) Welcome to the Huberman Lab Podcast where we discuss science and science-based tools for everyday life. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, we are discussing how to build tenacity and willpower. Previous episodes of the Huberman Lab Podcast have focused on the topic of motivation. And while motivation and willpower are linked thematically and mechanistically, today we are going to discuss tenacity, that is the willingness to persist under pressure and resistance of different kinds, and willpower, which has to do with both the motivation to do things and the motivation to resist certain things. Today, you will learn about the psychology and neuroscience of tenacity and willpower. And I must tell you, this is a fascinating literature. In fact, you will learn about a brain structure that, at least to my knowledge, most neuroscientists are not even aware of. And yet in researching this episode, I absolutely fell in love with this brain structure because of its incredible ability to integrate the very sorts of information from within and from outside of you to harness and build tenacity and willpower. And indeed, today you will learn research-supported tools for how to enhance your level of tenacity and willpower in any circumstance.

Andrew Huberman 1:19 Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero-cost-to-consumer information about science and science-related tools to the general public. In keeping with that theme, I'd like to thank the sponsors of today's podcast. Our first sponsor is Maui Nui Venison. Maui Nui Venison is the most nutrient-dense and delicious red meat available. I've spoken before on this podcast, in solo episodes and with guests, about the need to get approximately one gram of high-quality protein per pound of body weight each day for optimal nutrition. Now, there are many different ways that one can do that, but a key thing is to make sure that you're not doing that by ingesting excessive calories. Maui Nui Venison has the highest density of quality protein per calorie, and it achieves that in delicious things like ground meats, venison steaks, jerky, and bone broth. I particularly like the ground venison. I make those into venison burgers probably five times a week or more. I also like the jerky for its convenience, especially when I'm traveling or I'm especially busy with work and know that I'm getting an extremely nutrient-dense, high-quality source of protein. If you'd like to try Maui Nui Venison, you can go to mauinuivenison.com/huberman and get 20% off your first order. Again, that's mauinuivenison.com/huberman to get 20% off. Today's episode is also brought to us by Helix Sleep. Helix Sleep makes mattresses and pillows that are tailored to your unique sleep needs. Now, sleep is the foundation of mental health, physical health, and performance. When we are sleeping well and enough, mental health, physical health, and performance all stand to be at their best. One of the key things to getting a great night's sleep is to make sure that your mattress is tailored to your unique sleep needs. Helix Sleep has a brief two-minute quiz that if you go to their website, you take that quiz and answer questions such as, do you tend to sleep on your back, your side, or your stomach? Do you tend to run hot or cold in the middle of the night? Maybe you don't know the answers to those questions, and that's fine. At the end of that two-minute quiz, they will match you to a mattress that's ideal for your sleep needs. I sleep on the Dusk, D-U-S-K, mattress, and when I started sleeping on a Dusk mattress about two years ago, my sleep immediately improved. So if you're interested in upgrading your mattress, go to helixsleep.com/huberman, take their two-minute sleep quiz, and they'll match you to a customized mattress for you. And you'll get up to $350 off any mattress order and two free pillows. Again, if interested, go to helixsleep.com/huberman for up to $350 off and two free pillows.

Andrew Huberman 3:49 Okay. Let's talk about tenacity and willpower and how to enhance your level of tenacity and willpower. I will also mention certain cases where having too much tenacity and willpower can be problematic for mental health and physical health. But for most people, I believe that enhancing one's level of tenacity and willpower would be advantageous. Now, you'll be relieved to know that while there are a near infinite number of different circumstances where one would need to draw on tenacity and willpower in order to succeed, there is one major mechanism within the brain, indeed one major mechanism, by which tenacity and willpower are generated, and it arrives through the activation of a particular brain center that is a hub. That is, it lies at the interface of many other neural circuits and has input from all the critical neural circuits that one would need in order to generate tenacity and willpower. Now, we are going to return to that particular neural circuit a little bit later after we talk about the psychology of willpower, because in talking about the psychology of willpower, it will frame up as to why understanding this one particular brain center or hub of inputs and outputs from different neural structures in the brain and body will indeed allow you to get the most out of the tools that have been shown in scientific research to enhance your level of tenacity and willpower. In other words, understanding the psychology of tenacity and willpower, while valuable, if it's coupled with an understanding of the underlying neural mechanism, and notice I use the singular, neural mechanism, not mechanisms, for generating tenacity and willpower, will allow you to use and to tailor the specific protocols for enhancing tenacity and willpower to your unique circumstances. So this is yet another case where certainly life circumstances vary from one person to the next. The need for tenacity and willpower varies tremendously. For instance, some people may need more tenacity and willpower in order to engage in certain behaviors. Others of us might need more tenacity and willpower in order to resist certain types of behaviors. Today, you will learn about the brain center that governs all of that, and then you can frame it within the psychological understanding of tenacity and willpower so that you can get the most out of the protocols that we will discuss. Let's start by talking about what tenacity and willpower clearly are and separating tenacity and willpower from some other psychological constructs that they often get confused with. ... because this will be important in understanding exactly what we are trying to build when we say we want to build tenacity and willpower. So, tenacity and willpower can be distinguished from habit execution. Habit execution is what you do any time you wake up in the morning, maybe you lie there for a bit, maybe you get out of bed immediately, hopefully you get outside and get some sunlight in your eyes, especially on cloudy days, go brush your teeth, use the restroom, engage with others in your home if you live with others, et cetera. All of those sorts of behaviors, while on some days can be a bit more challenging, especially the get out of bed part, maybe you didn't get a great night's sleep the night before, for instance. But all of those sorts of behaviors are behaviors that you have the neural circuits to generate, and that typically, you can generate without a lot of willpower required. Now, willpower, sometimes also referred to as tenacity, grit, or persistence, is a distinctly different phenomenon than habit execution, because willpower and tenacity require that we intervene in our own default neural processes, such as habits or particular patterns of thinking, and essentially govern ourselves to do or not do some particular thing. And that process requires effort. It requires energy. And I think all of us are familiar with that feeling of effort or energy that's required in order to engage in a behavior that we really don't feel like engaging in, or avoiding a behavior or a thought that, by default, we would naturally just engage in. And when I talk about energy in this context, I'm mainly talking about neural energy. Remember that neurons, nerve cells in your brain and body, use chemical and electrical signaling to communicate with one another. That's what allows you and all of us to do all the things that we do, think, feel, move, et cetera. Now, of course, that chemical and electrical communication requires fuel sources that indeed come from things like glucose, ketones, the creatine phosphate system. Multiple fuel systems feed the energetics of the brain. But ultimately, when I talk about energy in today's discussion, I'm talking about the energy required to engage in or to resist in a particular behavior, and that level of energy can be quite high depending on how much resistance we are feeling internally or externally, right? Somebody can be telling us, "You're not going to be able to do this. You can't do it," and you can say, "No, I have a ton of resolve, I have a ton of tenacity, willpower, and I'm gonna push past all the barriers that you are setting up for me on the outside." Oftentimes, all too often, I should say, we experience resistance from the inside, where we are feeling like we don't want to do something, or we really want to do something and we are having trouble either engaging in the thing that we don't want to do or that we know we should do but we just don't feel that level of motivation for, or we are having a hard time resisting the thing that's pulling us toward it. So, in that context, it's important for us not to just distinguish tenacity and willpower from habit execution, but also draw out a continuum with tenacity and willpower at their most extreme on one end of that continuum, and apathy and, yes, depression on the other end of that continuum. And we will return to the topic of depression a little bit later, but I can just cue it up right now by saying that one of the hallmark features of major depression is a lack of positive anticipation about the future that leads to, this is important, there's a verb tense here, that leads to a much lower tendency to engage in the specific types of behavior that would allow one to arrive at a particular new, different, and positive future. So, I'm deliberately putting apathy and depression next to one another at one end of the continuum, and I'm putting grit, persistence, tenacity, and willpower at the other end of the continuum. And a little bit later, it will become very clear to you why I put those particular items on the continuum as opposed to other psychological constructs such as motivation, because it turns out that motivation is what allows you to move up and down that continuum. But motivation itself, as a verb, is distinct from what we call tenacity and willpower, and motivation itself is distinct from what we call apathy and depression. But motivation is the engine or the motor, the verb that allows you to move up and down that continuum, and today you will learn multiple tools that will allow you to move toward the tenacity and willpower end of that continuum by engaging a very specific neural circuit.

Andrew Huberman 10:40 Before we get into the discussion of neural circuits, I'd like to talk about the psychology of willpower, and this is something that really has been considered by psychologists for well over 100 years. William James wrote about this. The ancient Greeks wrote about this. The topic of willpower is certainly not a new one, and yet the formal study of willpower in the laboratory context, that is bringing human subjects into the laboratory and examining what sorts of conditions allow them to engage their willpower and tenacity, what sorts of conditions really sap or drain their willpower and tenacity, and of course parallel experiments done in what we call pre-clinical models, which are animal studies, have revealed to us a lot about the sorts of conditions that allow us to generate willpower and the sorts of conditions that drain our willpower. Now, if we are to throw our arms around that entire literature, there is a big batch of that literature, not the whole batch, but there's a big batch of that literature that believed and still believes that willpower is a limited resource, much like fuel in the body or fuel in a car. Now, the idea of willpower as a limited resource is certainly not a new idea, but again, the formal study of willpower and willpower as a limited resource really dates back a little over 20, 25 years when Roy Baumeister and colleagues started to explore the idea that, of course, had been kicked around for years, that with each additional decision...... that we have to engage across the day, and with each additional bout of willpower that we have to draw on as a resource, that we would drain this reservoir of willpower that we all have within us. Now, Baumeister and colleagues referred to that process as ego depletion. Now, when people hear the word 'ego', some people think Freud, ego, super-ego, id, and so forth. Most people think ego, like somebody having a big personality where they think a lot of themselves. When Baumeister referred to ego depletion, he was defining ego depletion as a concept of one's self and a concept of outside challenges, and the degree of effort required to bridge one's concept of self and those challenges. And so ego depletion is really a operational construct within the field of psychology. So we don't want to get too distracted by that word 'ego'. There's a tendency anytime people hear 'ego', or if they hear 'narcissism', or if they hear 'gaslighting', to immediately assume that they know what that means, when in fact the formal definitions of those quite often differ from the way that they're kicked around on social media or the internet, and even in a lot of popular writing about psychology. Okay? So let's just note that ego depletion is the term that Baumeister used to describe the ability for our willpower to be depleted with each successive attempt to engage willpower and, by extension, our ability to replenish our degree of willpower if we take a break from making decisions and engaging our willpower. But ego depletion itself isn't the focus right now. The focus right now is whether or not indeed willpower is a limited resource, and whether or not with each decision that we make and each effort to either engage in an activity that we would prefer not to, at least in that moment, and with each attempt to resist a behavior, thought, et cetera, that is pulling on us or that we feel that we want to engage in by default, either, you know, eating the cookie, or thinking the thought, or engaging in a particular type of behavior of any kind, and we need to resist that, that it is draining that willpower resource. Now, before I go any further, I know that some of you out there are probably aware that ego depletion and the Baumeister theory of willpower as a limited resource has been very contentious, especially in recent years. And so today what I'm going to do is I'm going to first present the Baumeister and colleagues' work about willpower as a limited resource, and then I'm going to present some of the conflicting evidence that Carol Dweck, my colleague at Stanford School of Medicine, and researchers elsewhere have carried out meta-analyses and entirely new experiments which indeed, in some cases, contradict the findings of Baumeister, but more often than not contradict the conclusions that Baumeister drew about willpower. So if we are to understand the psychology of willpower and tenacity, it's important that we understand the concepts of ego depletion and willpower as a limited resource, even if, after hearing all the evidence, you decide that willpower is not a limited resource. And in fact, I'm quite confident that once you hear about the Baumeister work, and then you hear about the work of Dweck and others, which in some ways counters the conclusions of Baumeister, that you'll have a much firmer and certainly a much more complete understanding about what tenacity and willpower are. And perhaps, and here I'm revealing my own leanings when having examined the totality of the data, that tenacity and willpower in some cases is a limited resource that can be replenished by engaging particular processes within the body, that's right, within the body, but that willpower and tenacity, and most importantly how to engage tenacity and willpower, especially when you have a lot of challenges in front of you, not just one challenge but multiple challenges that need to be carried out throughout the day, over weeks, over months, et cetera, that tenacity and willpower can be drawn upon repeatedly without them being depleted if you are clear on your beliefs about tenacity and willpower. So I realize that what I just brought up was a controversy about something that I haven't even discussed yet, so it might seem like a bit of a swirl of information for which there's really no context. But the reason I bring up the controversy at this stage of our conversation is that the moment that the words 'ego depletion' or 'willpower as a limited resource' falls out of my mouth, I can hear those voices out there saying, "Wait a second. I thought that was all debunked," and I want to make very clear, willpower as a limited resource and ego depletion have not been debunked. It's simply a controversial area of psychological research. And more importantly for today's discussion, we have to understand the theory of willpower as a limited resource if we are to understand the controversy that is the counterargument of what willpower really is that comes from other groups. So I really want to give you both sides of the story so that when we get to the underlying neural mechanisms for tenacity and willpower, and we get to the tools and protocols for increasing your level of tenacity and willpower, and your flexibility of willpower in different contexts, that you'll be able to get the most out of those tools and protocols. Okay, so let's take a look at the evidence that willpower is a limited resource. I think most of us are familiar with what willpower feels like, that is what it feels like to be tenacious. And again, there are two sides to this coin. There's willpower and tenacity of the sort of trying to engage in a behavior when we really don't want to, or when our impulse is not to engage in that behavior. And I say when our impulse is not to engage in that behavior because oftentimes we want to engage in the behavior. We want to study. We want to learn the instrument. We want to perform well. We want to exercise. We want the benefits of all those things. So it's not that we don't want the outcomes or the rewards of those things, and in many cases, it's not that we don't enjoy those activities, but that for whatever reason, we are feeling a lack of motivation. We are drifting down that continuum toward the more apathetic end of things, hopefully not all the way to deep depression and apathy, but we're drifting that way. Or we're not far enough up the continuum, and we're not engaging enough motivation to feel like the desire to do something...... either for its own sake or for the rewards and outcomes of that thing, are sufficient to allow us to just do that thing. Hence, the Nike slogan, "Just Do It." Which is a wonderful slogan, except that in the absence of any understanding about the mechanisms of how we can get ourselves to just do something, oftentimes it falls short. And, to be honest, any time I hear about people saying, "Well, just eliminate the thinking and just do it," that is valuable advice until it doesn't work. Because when it doesn't work, it simply doesn't work, and then you need to rely on other tools and mechanisms, which are the sort that we will talk about today. So, while I have great respect for the "Just Do It" mantra, when it doesn't work, it doesn't offer any alternative solutions to engage tenacity and willpower. And I do not know anyone on this planet, I don't care if you're David Goggins or Courtney Dauwalter, there will be days when telling yourself, "Just do this." Or, "Just don't do that." Is not going to be sufficient for you to engage in the behaviors, or resist the behaviors or thoughts that you need to engage in or resist. That's just reality.

Andrew Huberman 19:14 And we should ask ourselves, "Why is that reality?" And this is a very important point, and in fact really illustrates the first bucket of tools and protocols for increasing tenacity and willpower, and these are the tools and protocols that I would categorize under the rubric of modulators. I've talked before on this podcast about the important distinction between mediators and modulators. Mediators are things, either psychological or biological, et cetera, that are directly in the mechanisms that generate some sort of action or emotion. This could be neurochemicals like dopamine or serotonin and so on. Modulators are things that can modulate, that is can change our probability of doing something or not doing something, but they do so indirectly. And in the context of tools and protocols to increase our level of tenacity and willpower, I would be completely remiss if one of the sets of tools, that is the protocols, for increasing the probability that we can access high levels of tenacity and willpower didn't include at least some of these modulators. So I'm just going to spend about three minutes on these modulators, because what we know for certain is that the regions of the brain that generate tenacity, and again (laughs) there is literally a brain hub for generating willpower and tenacity, gets strong input from the so-called autonomic nervous system. The autonomic nervous system has two major components, they are referred to as the sympathetic nervous system and the parasympathetic nervous system. Keep in mind, because when most people hear the word "sympathetic" they think sympathy, they think emotion, it has nothing to do with that. "Sympa" means together, and the sympathetic arm of the autonomic nervous system, I know that's a mouthful, is responsible for generating states of alertness in our brain and body. Everything from panic to being alert and calm, our tendency to move or our likelihood of moving under pressure. It is also responsible for our ability to resist movement when we need to resist movement, and therefore it's an active process. So the sympathetic nervous system is all the things of action, and when it is involved in generating inaction those are cases where inaction requires energy, okay? I want to be very clear about this. The sympathetic nervous system isn't just about moving our body, although it has a lot to do with that, it is also responsible for our ability to resist movement or thought or emotion when we need to do that, clamp down on ourselves. The parasympathetic aspect of our autonomic nervous system is the one that's sometimes referred to as the rest-and-digest neural circuits and chemicals, and that's true but there's a lot more to the parasympathetic component of the autonomic nervous system. It's also responsible for falling asleep, it's responsible for us feeling relaxed, it is responsible for most of the states of mind and body in which we are quiescent, where we don't feel an impulse to move, or when we have a difficult time getting into action. So the sympathetic and the parasympathetic aspect of the autonomic nervous system are always in a push-pull with one another. Think of them more or less on a teeter-totter, when one end goes up the other end goes down. They're really in competition with one another and it's their balance that reflects how alert or how sleepy we happen to be. Now, the reason I'm giving you this rather geeky, nerd-speak, nomenclature-filled discussion about the autonomic nervous system in the context of willpower is that regardless of whether or not you believe willpower is a limited or an unlimited resource, we know one thing for sure, and that's that willpower and tenacity ride on our current autonomic function. We can translate that to everyday language by saying that when we are well-rested, for instance when we've been getting great sleep of sufficient duration the previous night and the night before that, our level of tenacity and willpower to engage in things that we would not ordinarily engage in by default, and our ability to resist behaviors and thought patterns that would otherwise be our default behaviors and thought patterns, is much higher. Conversely, when we are not getting enough quality sleep on a regular basis, our ability to call on tenacity and willpower is diminished. Now, that series of statements I just made is clearly going to be a duh for most people, but it is very important to understand that when we are sleep-deprived, when we are in physical pain, when we are in emotional pain, and/or when we are distracted, when we are thinking about something else aside from what we are trying to engage tenacity and willpower in order to do or not do, tenacity and willpower will be diminished. Now, all of those things together are just a bigger duh, we all know this. If you've got a splinter in your foot, it's really hard to think about not thinking about something else. If you are extremely hungry or if you had an argument with somebody that you really care about and they said something that was particularly vexing to you and it's looping around in your head, it's going to be very hard to engage in something else that you need to do because you're going to be distracted. Likewise if you're sleep-deprived, likewise if you are a bit sick or rundown, if you're in any kind of physical or emotional pain, your ability to draw on tenacity and willpower will be diminished. So...... it's an absolute truth that your ability to generate tenacity and willpower rides on a reservoir of autonomic function. And to date, we don't really have a way of quantifying the level of autonomic function or dysfunction in a very simple way. It's not like resting heart rate, although resting heart rate is involved. For instance, if you haven't slept well for a few nights or if you're particularly stressed, over-trained, you'll wake up in the morning with a significantly elevated heart rate. However, there is no simple metric like heart rate or blood pressure or even cortisol level that can tell you whether or not your autonomic function is in balance, that is the sympathetic and parasympathetic systems of your autonomic nervous system are in the best possible balance to generate tenacity and willpower. We don't yet have such a metric, although there are companies that are starting to develop devices that hopefully will give us indices of autonomic function or dysfunction. But, it is important that we acknowledge that if you're not taking care of the foundational modulators of tenacity and willpower, none of the subsequent tools and protocols that we will discuss are going to help you that much over time. You might get tenacity and willpower to engage one day when you're very sleep-deprived, but it's going to be very difficult to consistently engage tenacity and willpower. For that reason, if you have any struggles with sleep, that is getting enough quality sleep on a regular basis, please see the zero-cost toolkit for sleep that we've put at hubermanlab.com. Please also see the Perfect Your Sleep, Master Your Sleep episodes, also at hubermanlab.com. And please also see the episode with expert guest, Dr. Matthew Walker, professor of sleep, neuroscience, and psychology at University of California, Berkeley. We just revamped the Huberman Lab website, so if you go to hubermanlab.com and you put something like sleep into the search function, it will take you not just to the toolkit for sleep, but to the exact timestamps that will cue up particular topics and protocols around sleep. So if you were to put "sleep and light," it would take you to those particular protocols. If you were to put "sleep and magnesium threonate," it would take you to those particular protocols, and so on and so forth. 'Kay? I don't want to get too far off-topic here during today's discussion, but if you're not sleeping well and if you're not managing your stress levels well, it's going to be much harder for you to engage tenacity and willpower regardless of the tools you happen to use, and those tools could be everything from behavioral tools to supplements to prescription drugs. You need to get those foundational modulators in check, and there are a lot of zero-cost ways to do that, that are all spelled out very clearly at the resources I just described. Likewise, for stress, if you're experiencing challenges with stress, both short-term, medium-term, or long-term stress, if you think you have elevated cortisol levels, which by the way may not be the case, there are a lot of tools for modulating stress in real time, increasing your stress threshold, et cetera. Simply go to the hubermanlab.com website and put in "stress threshold tools" or "stress real-time tools," and you'll get a bunch of zero-cost tools that will allow you to do that. It's also worth mentioning that when we get to our discussion about the neuroscience of tenacity and willpower that you will understand why autonomic health and autonomic function is so important for our ability to engage tenacity and willpower. I'll just tell you right now, it's because the neural circuits of the autonomic nervous system provide direct and robust input to this hub in the brain, this brain location that governs our ability to allocate our mind and body toward particular activities or to resist particular activities.

Andrew Huberman 28:02 As many of you know, I've been taking AG1 daily since 2012, so I'm delighted that they're sponsoring the podcast. AG1 is a vitamin-mineral probiotic drink that's designed to meet all of your foundational nutrition needs. Now, of course, I try to get enough servings of vitamins and minerals through whole food sources that include vegetables and fruits every day, but oftentimes, I simply can't get enough servings. But with AG1, I'm sure to get enough vitamins and minerals and the probiotics that I need, and it also contains adaptogens to help buffer stress. Simply put, I always feel better when I take AG1. I have more focus and energy, and I sleep better, and it also happens to taste great. For all these reasons, whenever I'm asked, "If you could take just one supplement, what would it be?" I answer "AG1." If you'd like to try AG1, go to drinkag1.com/huberman to claim a special offer. They'll give you five free travel packs plus a year supply of vitamin D3K2. Again, that's drinkag1.com/huberman.

Andrew Huberman 28:59 Okay, so let's think about the Baumeister data on willpower as a limited resource. I'm going to briefly describe one of the first studies that really said to the field, "Willpower is a limited resource." But I want to be clear that there are other studies like it, and they all generally follow the same contour, and that general contour is as follows: Baumeister and colleagues, and now many other laboratories, have done experiments where they bring human subjects into the laboratory, and those human subjects have to do something that requires mental effort or energy, AKA willpower. The classic example of this is you bring people into the laboratory. Some of them might actually be dieting or fasted, although not always, and there are two platters set out for them. One platter contains radishes, just plain radishes. By the way, I hate radishes unless they're pickled radishes. I don't know why that is. So these experiments picked my least favorite vegetable. I love many other vegetables. I disdain the radish. That was just a personal editorial. In any case, the radishes are set out, and next to them are freshly baked cookies, and in the room is the wafting aromas of freshly baked cookies. So I think it's fair to say that most people, because of a hardwired tendency to like sugar and fat, especially when they are combined, would prefer to eat the cookies versus the radishes. I know that there are some mutants out there that are saying, "I like radishes more than cookies," but look, most people like cookies more than radishes. The subjects in these studies are divided into two groups. One group is told, "You have to resist eating the radishes." The other group is told, "You have to resist eating the cookies."And then, the subjects are observed during this time, typically. But this is really not what the experiment is about, per se. This stage of the experiment is really designed to get people to resist a certain kind of behavior. And the assumption, again, this is an assumption 'cause there's no brain recordings here, no one's in an MRI machine looking at what brain areas are activated or not activated. There's no cortisol being measured, at least not in these early experiments. These people are either resisting something that's pretty easy to resist, radishes, or they are being asked to resist something that, for most people, is going to be harder to resist than resisting radishes, which is resisting freshly baked cookies. And that challenge has been made even more difficult by the wafting aromas of freshly baked cookies in the room, and in some cases, has been made even more difficult because these people are dieting. And keep in mind that when you calorie restrict or when you put yourself on a diet of any kind, there is a well-established mechanism in the brain by which the neurons that engage hunger, especially hunger for fat and sugar, and that respond to things like aromas and tastes, are heightened. That is, their activity levels are heightened, which means that things that smell really good, smell really, really good when you're hungry. Things that ordinarily would taste really good, taste really, really, really good when you finally eat them. So the key component of this stage of the experiment is to engage people's willpower. The second part of the experiment has all of the subjects separately engage in another challenging task, and the challenging task that they are asked to engage in is to solve a particular puzzle. And again, different experiments use different puzzles, different experiments use different contexts, but the original experiments that Baumeister and colleagues did had people try and solve a puzzle that could not be solved. So it's very, very difficult. In fact, it's impossible, but the subjects weren't aware of that. And then what was measured was how long subjects persisted in trying to solve this impossible to solve puzzle, depending on whether or not previously they had to resist the radishes, which is pretty easy to resist, or resist the cookies, which is at least harder to resist and for some people would be very, very hard to resist. Now, you can probably already guess what the outcome of this and similar studies was, because it birthed this entire belief camp within the field of psychology that willpower is a limited resource. The outcome was that if people had to resist the cookies, which is harder to do than resisting the radishes, that they would persist for less time when they had to try and solve a puzzle that, unbeknownst to them, could not be solved. Conversely, if people had to resist something that was pretty easy to resist, such as resisting eating radishes, something that for me would be very, very easy to resist, well, when they were subsequently faced with trying to solve a very difficult, indeed impossible to solve puzzle, they persisted much longer. Okay, so put very simply, this study concluded that if you have to resist one thing and it's a hard thing to resist, well, then you have less, air quotes here, "resistance" in you, willpower, to engage in another difficult task subsequently. Whereas if you had an easy challenge just prior or no challenge just prior to being faced with a challenge such as a very difficult puzzle, well, then you had more resource, more willpower to apply to the solving of that puzzle. So the conclusion that Baumeister and colleagues drew from those results was that willpower is a limited resource. But it didn't specify, nor did they specify, exactly what that limited resource is. And this was quite an attractive theory because it jived well with most people's perception of what willpower and tenacity was for them. This idea that yes, there are things that challenge us both to do and to resist, but that we can do that, but when we are asked to do that again and again and again, while we may build up some capacity to engage our willpower and tenacity, and of course, there are those rare individuals that we've heard about and some of us know that seem to have just a kind of bottomless reservoir of willpower and tenacity, most of us have an intuitive understanding of how hard it is to constantly be in friction with life, to constantly have to push ourselves to do things and to resist things. And that while that capacity can expand and grow and we can get better at it, that there does seem to be something, here just subjectively speaking, there does seem to be something about engaging tenacity and willpower that, yeah, it can feel good but it also requires effort, this neural energy that we were

Andrew Huberman 35:36 talking about. So that raised the question of, okay, if willpower is a limited resource, what exactly is that resource at a physiological level? So Baumeister and colleagues subsequently went on to explore what I think is a really interesting and clever idea. Frankly, I can't confess that I would've thought of this, but they did. They said, "Okay, you know, in some cases people are eating the cookie and then they're engaging in this very difficult puzzle." In other cases, they're eating the radish and engaging in this difficult puzzle. And of course other experiments used non-food challenging choices, but they came up with an idea which was the brain, as one of the most metabolically active organs in our entire body, if not the most metabolically active organ in our entire body, requires a lot of fuel. It requires a lot of glucose. Now, of course the brain mainly runs on glucose, but if you're following a ketogenic diet, your brain will mainly run on ketones. But for most people who are omnivores or eating carbohydrates, glucose is the main and preferred fuel source for neurons, for nerve cells in your brain, and body for that matter. Baumeister and colleagues raised the hypothesis that perhaps glucose availability itself is the resource that's limiting willpower. And in a whole set of experiments, they really showed that if people are asked to do a difficult task, to engage their willpower, and this could be done by resisting a particular behavior or by engaging in a particular behavior. I'll just give you an example of engaging in a particular behavior.... that requires willpower or at least focus and mental energy, to contrast it with the resisting radishes versus resisting cookies example that I gave earlier. One common practice within experiments like this is to give people a very long passage of words, so it's a story, and then to give them some sort of rule about how to edit that passage. Maybe they have to cross out every third E, or the Es that arrive in the middle of sentences next to consonants but not v- other vowels, you know, stuff that takes a lot of energy. So these are dos as opposed to resisting behaviors, like we were talking about earlier, resisting the radish, resisting the cookies. Although, in many of these experiments, there's a command to do something, you know, cross out certain letter Es in this passage, but also to resist the reflex to cross out other Es. And of course, all of this is under time pressure and oftentimes, it's being rewarded or scored. This is the way that psychology researchers get people to engage in particular, uh, experiments and behaviors and resist certain things i- in the context of a laboratory environment when those things, frankly, are kind of boring and meaningless. They'll pay you more if you do well with the task. Um, they'll give you money and then subtract the money that you're going to get at the end of the experiment if you make errors and things like that, and they'll do it under time constraint as I mentioned earlier. So there were lots of different conditions for, again, here, air quotes, "draining" people's willpower and tenacity, and certainly draining their mental attention, and then they would have them do another subsequent task. So in many ways, this just mirrors the first cookie radish experiment done by Baumeister and colleagues. But, there was an important intervention put between the first and the second hard task, and that intervention was to give one group a glucose beverage of about 150 calories or so, so they would drink a glucose beverage to increase levels of blood glucose, the preferred fuel source for the brain, versus giving them an artificially flavored drink or just water or something that was, of course, matched for flavor but that did not contain any glucose or calories. Now, this is a clever experimental design if you think about it, because, at least at a first glance, the only thing that really seems to be different is the availability of glucose for the brain. And you can probably guess what the outcome of these studies was. The outcome of these studies was that when subjects are given glucose in between a first hard task that required willpower and a second hard task that required willpower and in some experiments a third hard task that required willpower, that their levels of willpower were maintained consistently from one task to the next, and in some cases, increased from one task to the next if they had more glucose available because they drank this glucose drink. So what's really interesting and frankly really nice about these studies is that they attempted to bridge a psychological construct, like tenacity and willpower, and to test the argument that willpower is an expendable resource and yet it's an expendable resource that is replenishable by linking that to a physiological variable, and the physiological variable they linked it to was glucose availability in the brain. Now, this set the field of psychology and, in fact, the field of pop psychology, that is the discussion about formal findings in the field of formal psychological research, ablaze. People were so excited about this. I mean, this set of findings really pointed to the argument that if you could just keep levels of brain glucose elevated across your day, or at least stable across the day, that you would have more willpower and tenacity, this thing that humans have been seeking more of since the beginning of time. Now all of that seemed fine and good, and in fact, a lot of products and courses were born out of that literature. People were arguing that you should sip on a glucose drink while doing any kind of hard task, that you should sip on glucose drinks between tasks, that you should be thinking about literally fuel that you ingest into your body as fuel for psychological processes within your brain that would allow you to perform better in work, in school, in athletics, in relationships, in all of (laughs) the domains of life. But of course, any time there is a prominence or a real excitement about a particular finding in any field of science but in particular in psychology where it feels so applicable, as did the Baumeister results, you are going to get other groups that are going to try and replicate those findings and that are going to dig into the findings themselves and look at the statistics, look at how well or poorly powered those studies were. We don't want to get into a full discussion about powering studies right now but powering studies has a lot to do with addressing the question of whether or not there were enough subjects in the study to really draw the conclusions that one drew or whether or not the statistics fell out as, yes, there was a significant effect of glucose ingestion on willpower and tenacity, but if there weren't enough subjects, well then there are other variables that could potentially explain those results. So there were a lot of meta-analyses and other studies trying to replicate the work of Baumeister, and that's where things got controversial. Now we can take a step back from all of that controversy. After all, we don't want to spend too much time on the controversy itself. Rather, we want to know what the counter-interpretation of the Baumeister results was, and I want to be very clear. There was no real dispute as to whether or not Baumeister got the results that he and his colleagues claim to have obtained. They did get those results. The question really was about the interpretation. Is willpower a limited resource, and if it is, is the physiological resource itself glucose availability to

Andrew Huberman 42:44 the brain? So in 2013, a colleague of mine at Stanford, Dr. Carol Dweck, in our Department of Psychology did a study in which she examined this idea that willpower is a limited resource and the idea that the resource that's limited is glucose availability for the brain. So Dweck and colleagues did an experiment that in many ways mirrored the overall organization of the experiments done by Baumeister and colleagues. There was a difficult task. In some cases, the difficult task was that crossing out of particular Es within a passage task, followed by another difficult task, and the difficult task that came second was the Stroop task. This is a task I've talked about before on this podcast, although...... some episodes ago, so f- those of you that are not familiar with the Stroop task, the Stroop task is where subjects are presented with words in different colors, and they are instructed to either read the word, so to pay attention to the content of the word, or to the color in which the font of the word is written. This might seem pretty easy to most of you, right? If I put up a, a card that says "apple" on it, and "apple" is written in green, you probably wouldn't have a hard time, if you had been instructed to tell me what color is the word written in, for you to just say green. Okay? But if I were to hold up a card that said "red," but the font is actually in the color green, it's a little bit harder. And if I were to then do that for 100 cards or 300 cards and put you under time pressure, where you're losing money that you're sure to get if you make mistakes, or you will earn money at the end of the experiment if you get answers correctly, well, then you start making more mistakes. That's just the way these experiments work. So they did a variation on the Stroop task that isn't exactly the way I just described it, and the Stroop task, by the way, is one that's used to probe prefrontal cortex function, this area of our brain right behind our foreheads that is responsible for many things, but in part is responsible for context and strategy-setting given a particular set of rules. So if you get onto the bus or get onto the subway versus walk into a black tie dinner, the context and rules are very, very different as to what you would say or not say, how you would behave, how you would dress. Your prefrontal cortex is largely, although not entirely, is largely responsible for a lot of the context-setting and rule-setting from one situation to the next. And if you think about the Stroop task, it's really just a context-dependent strategy task. You either have to pay attention to the meaning of the words or the colors in which those words are written, and the number of mistakes that you'll make depends on how much time pressure you're under, what sorts of neurologic or psychiatric challenges you might be facing or not facing, so on and so forth. But it's a very robust task that's existed in the scientific literature for a long period of time. So the Dweck experiment, and by the way, there were actually three experiments in this paper. I won't go through all of them in detail for sake of time, but I will provide a link to the paper in the show note captions, but the major focus of the study was to have people engage in one hard task and then in another hard task, both of which draw on willpower, testing the idea that willpower is a limited resource, and then providing some of those subjects with a glucose-rich drink or other subjects with a drink that was artificially sweetened, so it had no glucose, no calories, but tasted, yes, they matched them for taste. I know some of you who (laughs) don't like artificial sweeteners are saying, "Those don't taste exactly like, uh, real sugar." But they managed to match these drinks for taste, but in one case the drink would clearly increase blood glucose. In the other case the drink would not raise blood glucose. So the results of this study are really (laughs) spectacular, in my mind, because what this study found was that, yes, indeed, ingesting glucose can improve performance on these multiple challenging willpower-requiring tasks. However, the degree to which the glucose-containing drink could improve performance depended on whether or not you believed that willpower was a limited resource and whether or not you believed that resource was glucose. In other words, if you hear and believe that willpower is a limited resource, well then, indeed, with each subsequent task that you engage in or life event of any kind that you engage in that requires willpower and tenacity, you will have less willpower and tenacity to draw on, whereas if you believe that willpower and tenacity are unlimited, and in fact are divorced from blood glucose as the physiological source of willpower and tenacity, well then you can engage in one challenging task and another challenging task and another challenging task without any diminishment in performance. Now, that of course leaves us all in a very tough position, because how are we to decide what to believe if we know that willpower can be a limited resource or willpower can not be a limited resource? Ah. Well, the results of the Dweck study, and by the way, I should share with you the title of the study. The title of the study, not surprisingly, is Beliefs about Willpower Determine the Impact of Glucose on Self-Control. And this was a study published in the Proceedings of the National Academy of Sciences. Again, I will provide a link to this study in the show note captions. There are three major experiments in this study, as I mentioned before. I just gave you the major conclusion of all of them, sort of woven together, and if it wasn't clear already, the major conclusions are that, yes, ingesting glucose can improve your ability to engage tenacity and willpower, A.K.A. self-control, from one task to the next, provided that you believe (laughs) that glucose is the limiting resource for engaging tenacity and willpower. If you don't believe that, well then, you can engage tenacity and willpower without ingesting glucose, and that's where the artificially flavored drink comes in. I'll leave it to you to kind of unpack what that means experimentally, but it's a very clever experimental design that Dweck and colleagues came up with, because it argues that, yes indeed, it's hard to do a challenging thing right after another challenging thing. But there's no reason to think that you can't do both of those things while engaging the utmost tenacity and willpower if you believe that tenacity and willpower exist within you as a single mechanism that can be harnessed, and that it's not a single mechanism that has a reservoir that runs down as you engage in one hard thing to the next. Now, this is very important, because we are about to transition into our discussion of the physiological, that is the neural underpinnings of tenacity and willpower, which, as it turns out, is one major set of brain circuits. Now, there could be others that are yet to be discovered, but we know that there is one major set of brain circuits, in particular one brain area, believe it or not, that an entire collection of more than two dozen studies really points to as the seat, the origin of what we call tenacity and willpower. But before we transition to that and the tools and protocols that that physiological neural understanding set forth for us to all use and apply, let-I'd be remiss if I didn't mention that Baumeister wasn't about to hear these results from Dweck and colleagues, and just say, "Okay. Willpower is not a limited resource, it's not blood glucose. It's all what you believe about willpower. It's all what you believe about blood glucose." Rather, Baumeister himself went back to the lab and did subsequent experiments that, in some ways, not all, counter the Dweck results. So I'm not trying to confuse anybody, but I wouldn't be doing my job if I didn't give you both sides of the story. Now, the good news is that the tools and protocols that we are going to arrive at work regardless of which psychological camp you happen to be in, the Baumeister camp or the Dweck camp. Now, I don't want to give the impression that these are warring camps, and I also don't want to give the impression that these are the only two camps of thought and experimentation within the field of tenacity and willpower. There are many groups working on these subjects. Indeed, there have been meta-analyses that have confirmed the major theories of Baumeister, and there are meta-analyses that have refuted the major findings of Baumeister. I will provide links in the show note captions to a couple examples of each so that you have those to peruse if you like. But let's discuss for a moment what Baumeister found when they went back and re-researched, I think that's a word, re-researched the idea that willpower is a limited resource and that glucose is that limiting resource. Baumeister and colleagues looked at the Dweck data and said, "Okay, fine. The data look great," except for the fact that in real life and in many previous experiments that they and others had done, it wasn't just two hard challenges back to back, but often two or three or four. And what Baumeister and others found was that when subjects are presented not with just two challenges back to back, but three or more challenges, so back to back to back to back, challenges that have to engage a lot of neural energy, a lot of willpower, tenacity, resistance to do certain things, and effort to engage in certain kinds of behaviors and cognitive processes, that when subjects had glucose available to them in the brain by way of ingesting these glucose drinks, sipping those in between the tasks, sometimes even during the tasks, that their performance, that is their willpower and tenacity to engage in challenges, was maintained across those multiple challenges. And they conceded that one's belief about willpower could indeed dictate whether or not willpower was or was not a limited resource, and whether glucose would or would not enhance one's ability to engage willpower. But, they argued that if one confronts multiple challenging circumstances, as is very naturalistic as we say, it's very typical of everyday real life, then the availability of glucose during and between tasks, the ability for the brain to engage in its external environment and take reads of its internal environment, how we feel inside relative to what's expected of us, was very valuable in allowing people to engage this thing that psychologically we describe as tenacity and willpower.

Andrew Huberman 52:43 I'd like to just take a brief break and thank one of our sponsors, which is LMNT. LMNT is an electrolyte drink that has everything you need and nothing you don't. That means plenty of salt, sodium, magnesium, and potassium, the so-called electrolytes, and no sugar. Now, salt, magnesium, and potassium are critical to the function of all the cells in your body, in particular to the function of your nerve cells, also called neurons. Now, people of course have varying levels of requirements for sodium, so people with hypertension or pre-hypertension probably shouldn't increase their sodium. However, many people are surprised to find that by increasing their sodium intake, they are able to function better cognitively and physically, and that's because a lot of people, especially people who are following low carbohydrate or even moderate carbohydrate and really clean diets, oftentimes they're excreting a lot of water and electrolytes along with it, and simply by increasing their electrolyte intake using LMNT, they just feel better and function better. I typically drink LMNT first thing in the morning when I wake up in order to hydrate my body and make sure I have enough electrolytes, and while I do any kind of physical training, and certainly I drink LMNT in my water when I'm in the sauna and after going in the sauna, because that causes quite a lot of sweating. If you'd like to try LMNT, you can go to Drink LMNT, that's lmnt.com/huberman to claim a free LMNT sample pack with your purchase. Again, that's Drink LMNT, lmnt.com/huberman.

Andrew Huberman 54:01 Let's talk about the physiology of tenacity and willpower, and I assure you that the conversation we are about to have is not going to be just a bunch of nomenclature and mechanistic understanding of the origins of tenacity and willpower. Rather, it argues that tenacity and willpower have a unified source, that is, a specific set of brain areas that, when active, engage that feeling of tenacity and willpower regardless of what we are confronted with, regardless of whether or not we are trying to engage in something that reflexively we wouldn't otherwise want to engage in, and regardless of whether or not we are confronted with something that we have to resist. And to me, that's extremely reassuring, because whether or not you believe that blood glucose is a limiting resource for willpower, whether or not you believe that your beliefs about willpower and blood glucose impact your level of willpower, what we know for sure is that there's a single set of brain circuits, indeed there's a single brain area, that seems to be able to largely, if not entirely, explain this phenomenon that we call tenacity and willpower. And that should be reassuring because what it means is that tenacity and willpower is the reflection of a neural circuit function that is a skill. It's an expression of something that we all have within us. We all have this particular brain area, and, quite excitingly, this is the third point, this brain area is highly subject to plasticity. There are specific things that we can do and there are specific mindsets that we can adopt that allow us to increase the activity of this particular brain area, indeed to increase the size of this particular brain area, so that we can call on tenacity and willpower not just in one circumstance, like school or musical learning-... or athletic endeavors, or relationship endeavors, but rather that we can call on this brain area in the context of any and all circumstances where willpower and tenacity are required. Now, we talk about neuroscience a lot on this podcast, but it's not often that I point to a particular brain area and can confidently say, "This particular brain area has an absolutely integral role in something as kind of high-level psychological as tenacity and willpower." But today, we can do that, and that's because there's a collection of more than two dozen studies that point to one particular brain area, and of course, its connections with other brain areas, because no single brain area operates in isolation. Every brain area is operating in the context of neural circuits, other brain areas that it receives inputs from and gives inputs to, and so on. But this one particular brain area really does seem to underlie what we call tenacity and willpower, and we know that through several lines of evidence. First of all, I'll tell you the name of the brain area, although the name itself isn't going to tell you much unless you're a neuroscientist or anatomist, so I'll give a little bit of background about it. The name of the brain area is the anterior mid-cingulate cortex. The anterior mid-cingulate cortex is part of a larger brain area called the cingulate cortex, and in humans versus animals, it goes by slightly different names, unfortunately. It's just one of the consequences of different researchers in different labs calling the same thing different things. It can be really frustrating, but we'll make it very simple, because today, we will refer to this area as the anterior mid-cingulate cortex, which is a subdivision of a larger brain area simply called the cingulate cortex. The anterior mid-cingulate cortex resides in the frontal lobes, so it's behind your forehead, although that doesn't tell you anything because all of your brain is behind your forehead, if you think about it, and it's about a third of the way back toward the back of your head. And you actually have two of these structures, two anterior mid-cingulate cortices, one on each side of the brain, and they receive a lot of inputs from a lot of different areas. And we'll talk about what those areas are because this is extremely important when thinking about the different psychological and physiological resources that you can draw upon to engage tenacity and willpower. But for the time being, let me just go through the evidence in kind of list format of why we feel so confident that the anterior mid-cingulate cortex is such a vital hub for engaging tenacity and willpower. For each of these points that I'm about to make, there is indeed at least one, if not several, quality peer-reviewed studies in humans. So there's a lot of data from animals, both rodents and primate models, et cetera, that we're not talking about today, but I should mention, all of which supports the human data and vice versa. The data I'm going to describe now come from humans and from a variety of different types of studies. So there are a lot of different ways that one can consider if a brain area is implicated in a given psychological or physiological phenomenon, like motivation, or sadness, or visual perception, and those include, for instance, if a brain area is active during a given phenomenon. So, one way to explore this is to put literally wire electrodes down below the skull, record the electric activity of neurons, and assess whether or not the electrical activity of those neurons changes when a person is, say, viewing faces, or feeling a particular way, like feeling tenacious, or feeling bored, or feeling aggressive, and so on. Another way of assessing a particular brain area's role in a given physiological or psychological phenomenon is in individuals where that particular brain area is injured, you might expect that a particular phenomenon, like willpower, like the ability to perceive faces, is present or absent, whether or not it's exacerbated or whether or not it's diminished. Other ways of assessing whether or not a given brain area is involved in a given phenomenon is whether or not that brain area literally changes size, whether or not it changes in volume over the course of some sort of training. So for instance, if somebody is not able to play a musical instrument, such as myself, and then I or a subject in one of these experiments learns a musical instrument and the volume, the size of that particular brain area is assessed across the learning, or simply before and after that musical learning, and it grows, or perhaps even if it shrinks or changes shape, one might determine that it is somehow, somehow involved in the process of learning a musical instrument. You couldn't unequivocally conclude that, but along with other types of evidence, one could perhaps conclude that. So that's just a partial list of ways to assess brain area function. Other ways include assessing what other areas a given brain area gets input from, so for instance, in the case of the anterior mid-cingulate cortex, we will soon discuss the fact that it gets robust input from the autonomic nervous system, which you already learned about, it gets robust input from reward systems of the brain, such as the dopamine and serotonin-based reward systems of the brain, and it gets robust input from the context and strategy-setting areas of the brain as well, and many other different brain areas. So there's a structural logic as to why the anterior mid-cingulate cortex would be involved in tenacity and willpower. But no single anatomical, or physiological, or lesion-based finding is as compelling as when we consider all of the results about the anterior mid-cingulate cortex together and side by side. So for instance, recordings by neural imaging of the anterior mid-cingulate cortex, in an unbiased way, meaning people are put into a brain scanner and brain activity is examined en masse, all of the brain areas are looked at, and people are presented with either a hard task or an easy task, revealed that the anterior mid-cingulate cortex shows elevated levels of activity in the hard versus the easy task. And again, I want to point out that the researchers were not looking for that result, they simply observed that result.In addition, if people who exhibit high levels of academic performance across many different subjects are put into a brain scanner that evaluates so-called resting state connectivity, so no task, but simply levels of activity in different brain areas that occur spontaneously, so they're just sitting in the scanner looking at a blank screen, the resting or spontaneous levels of activity in the anterior mid-cingulate cortex of high achieving individuals is higher relative to those of lower achieving individuals. In addition, people that have lesions or disruptions of anterior mid-cingulate cortical function show increased apathy and depression and reduced levels of tenacity and motivation across the board, regardless of what domain of life one is asking about, whether or not it's athletic or academic, et cetera. Indeed, successful dieters show elevated spontaneous and what's called evoked levels of activity in the anterior mid-cingulate cortex, so spontaneous, again, just at rest they have higher levels of activity in the anterior mid-cingulate cortex, and for those that are presented with food and they have to resist that food, and they have to resist the smell of that food and the potential taste of that food, the activity of the anterior mid-cingulate cortex goes up even further, especially in those individuals who can resist, that is who can engage willpower to not eat the delicious food item. Conversely, individuals that have failed to exert sufficient willpower to lose their desired weight, and this was for medical reasons related to trying to achieve medical health, as well as people who are obese seem to have diminished levels of activity in the anterior mid-cingulate cortex. In addition, people who are depressed, who express a lot of apathy, and here we're talking about clinically diagnosed major depression, show reduced levels of activity in the anterior mid-cingulate cortex. Humans that express a lot of what's called learned helplessness, that is they've adopted the belief and the actions associated with the belief that no matter what they do, the outcomes are not going to be what they desire, express lower levels of neural activity in the anterior mid-cingulate cortex. So you can see this list goes on and on, but it in fact gets even more interesting. Remember earlier I mentioned that successful dieters have elevated levels of neural activity in the anterior mid-cingulate cortex. Now, that might seem like a good thing, and indeed it can be a good thing, but there's a pathologic condition associated with dieting and one's ability to engage willpower and resist food, and that's in the case of eating disorders such as anorexia nervosa. Now, I've done a Huberman Lab podcast solo episode about anorexia nervosa, and on that podcast I made the point that I'll make again now, which is that anorexia nervosa is the most deadly of all the psychiatric conditions, leading to death in a very large percentage of people that have it. Now fortunately, there are treatments and more are emerging all the time, but it's a very serious psychological and physiological condition that is extremely deadly. Individuals with anorexia nervosa exhibit heightened levels of activity in their anterior mid-cingulate cortex, both at rest and when presented with food. And I don't want to go on a full tangent about anorexia because we covered anorexia on the previous podcast episode about anorexia, which by the way you can find at hubermanlab.com. Simply search anorexia or eating disorders within the search function. But one of the clear symptoms of anorexia nervosa is that the reward pathways of the brain, which we know feed into, that is send direct connections to the anterior mid-cingulate cortex seem to be activated under conditions in which people with anorexia avoid food as opposed to eat food. And then there's a very interesting and positive literature about so-called super agers. So, what we know for sure is that as people age, in particular between the ages of 60 and 90, there's a reduction in the size of many brain areas, but the anterior mid-cingulate cortex in particular, unless certain things are done to offset that, we are going to talk about what those particular things are in just a few minutes. But there's a particular category of humans that's alive now and that live a very long time. These are the people that stand the greatest chance of becoming centenarians, and many of them are centenarians, so-called super agers, but also within the category of super agers are people who are 60 years old or more, because not all of them have reached 80, 90 yet, and have the cognition of 40-year-olds, 30-year-olds, and often even of people in their mid-20s. Now, there are a lot of things that are different about these super agers, super agers in the sense that they are maintaining very youthful levels of cognition. But one of the things that's become very apparent from the neuroimaging data is that super agers maintain a volume, a size of the anterior mid-cingulate cortex that is significantly greater than their age-matched cohorts. So the exciting thing is that there are many, many lines of evidence pointing to the fact that the anterior mid-cingulate cortex at least has something to do with our ability to generate tenacity and willpower, and that it, when active, moves us up that continuum away from apathy and depression toward states of being able to engage in or resist particular types of behaviors.

Andrew Huberman 1:07:15 So what I just described is a bunch of neuroimaging, structural volume data, blood uptake data, lesion studies, and so on and so forth. But we can simplify all of that and in fact address something that perhaps I should have said earlier, which is that when we're talking about tenacity and willpower, we're really talking about one of two things. We are either talking about that sense within us that has us saying, "I will. No matter what you tell me, no matter what you put in front of me, no matter what is rolled my way, I will blank." Now, the other expression of tenacity and willpower is that...... within us, within you, within me. When tenacity and willpower are active, we have that sense within us, that feeling in our body, and that thought pattern, a.k.a. feeling in our brain, that no matter what you say, no matter what you do, no matter what you put in front of me, I won't. So really, willpower is either an expression of "I will" or "I absolutely will" is perhaps a better way to state it, or "I absolutely won't." Now, that might seem like just a simple, subjective reordering of a bunch of physiological data and psychology studies, but it's not. It's actually far more important for us to understand this "I absolutely will" and "I absolutely won't" aspect of willpower, because if indeed there is a single brain area that can govern willpower, and willpower is not one but is at least two things, the sense of "I absolutely will" no matter what you say, do, et cetera, or "I absolutely won't" no matter what you say, do, et cetera, well, then this brain area can't be a simple switch. It can't be willpower on, willpower off. Willpower on, willpower off. It can't be absolute, as we say. It must be graded. It must have levels. So it's more like a slider on a light switch than an on-versus-off light switch. In addition to that, if there is truly one brain area that plays a critical role in generating tenacity and willpower, and tenacity and willpower is something that's required from us in a lot of different contexts where we have to say, "I absolutely will, yes, this. I absolutely won't, no, that. I absolutely will also, yes, this." Et cetera, et cetera. Right? Because life is complex. Even just the simple thing of, say, dieting or trying to get a particular degree or trying to navigate even a simple illness, like, "I'm going to get through this week despite feeling lousy. I'm going to take good care of myself." You know, all of these things in some sense require tenacity and willpower, and the behaviors we need to engage in and avoid engaging in is very dynamic depending not just on who we are and what we're trying to do or not do, but also where we are that day, that moment. Well, that means that the anterior mid-cingulate cortex also needs access to information about context. It needs to understand what's rewarding or non-rewarding in the context of what we're trying to accomplish, not just what feels good in the moment. Now, fortunately, there have been a number of studies exploring not just the activity levels of the anterior mid-cingulate cortex or the size of the anterior mid-cingulate cortex and the various conditions we talked about before, depression, obesity, successful dieters, successful students, successful athletes, et cetera, but a lot of anatomical tracing studies, both from fixed, that is from dead brain tissue, so postmortem brain tissue in humans, but also nowadays, there are certain types of neuroimaging, particular something called diffusion tensor imaging that allows one to examine the flow of information in and out of different brain areas through so-called white matter tracts. Tracts, meaning T-R-A-C-T-S, tracts. So these are the wires that connect neurons are called axons, and those axons are ensheathed with a fatty substance called myelin, and that ensheathment with myelin allows them to transmit information very quickly. You'll see where I'm going with all this in just a moment. And what we know is that the anterior mid-cingulate cortex, again, of which you have one on each side of the brain, about a third of the way back from your forehead to the back of your brain approximately, right above the so-called corpus callosum, this very robust collection of white matter tracts that connects the two sides of the brain. Well, it gets input and sends input to a number of different brain areas, including but not limited to the following: autonomic centers that control, for instance, cardiovascular function, increases or decreases in heart rate, respiration, how fast and how deeply you breathe, or how shallowly and slowly you breathe, immune system, inputs and outputs with the spleen, not directly, but through a couple of different stations with the very organs in your body that can release B-cells and T-cells, and immune molecules that can combat bacterial, viral, and fungal infections, and that can repair physical wounds. And it communicates with the endocrine system, with the systems of the brain and body that release, for instance, estrogen and testosterone, which by the way, are present in both males and females, and on a previous episode of the Huberman Lab Podcast with Robert Sapolsky as my guest, we talked about, for instance, the role of testosterone and many people think, "Oh, testosterone is all about aggression. Testosterone is all about attack. Testosterone is all about mating." That is completely false. While it can be involved in those different processes, what Dr. Sapolsky and I discussed is that one of the major functions of testosterone in the brain is to make effort feel good, and you can see, and we'll talk a little bit more about how that links up very directly with this concept of tenacity and willpower. So the first point is that the anterior mid-cingulate cortex is in direct communication with all of the areas of the brain, and through a couple of other stations, the body that modulate our sense of tenacity and willpower, which we talked about earlier, the need for sleep, the need for pain or lack of pain or emotional comfort or discomfort to modulate our level of tenacity and willpower. The anterior mid-cingulate cortex is also directly linked up with pre-motor centers. These are the centers of the brain that organize particular patterns of behavior and indeed that can suppress particular patterns of behavior. As I tell you that, you're probably filling in the blanks. This is engaging in a behavior or resisting a behavior. The anterior mid-cingulate cortex is also directly wired in with the reward pathways of the brain and can trigger the release of dopamine. It can also respond to the release of dopamine, and that dopamine release could be generated behaviorally, it could be generated-... through some sort of food reward, it could be pharmacologic. There are a number of different ways that the dopamine system can communicate with the anterior mid-cingulate cortex. The point here is that it is in direct communication with the anterior mid-cingulate cortex, and the anterior mid-cingulate cortex is in direct communication with the dopamine system. And what I just gave you is frankly just a partial list of the different areas of the brain that are communicating robustly with the anterior mid-cingulate cortex. It gets information about interoception, our readout of how we feel in our body. It also has robust inputs and outputs with the areas of the brain that are associated with exteroception, our perception of what is out around us. So, all of that provides a logical basis for the neuroimaging data, the lesion data, the volumetric data that we talked about a few minutes ago in the context of depression, anxiety, high performance, anorexia, and so on. But

Andrew Huberman 1:14:55 one of the most important arguments that's ever been made in favor of the anterior mid-cingulate cortex being a major seat for tenacity and willpower comes from Dr. Lisa Feldman Barrett, who is soon to be a guest on the Huberman Lab Podcast. We've actually recorded that episode already, and it should be out very soon. Lisa's laboratory is well-known for pioneering research on emotion and affect. I strongly encourage you to listen to that episode once it comes out. And it was actually Lisa herself that cued me to the importance of the anterior mid-cingulate cortex. And Lisa and colleagues have written several spectacular reviews about the anterior mid-cingulate cortex and its role in tenacity and motivation. I will provide links to a few of those in the show note captions. One that I'm particularly excited about, the one that I've spent now an immense amount of time with, is entitled The Tenacious Brain: How the Anterior Mid-Cingulate Cortex Contributes to Achieving Goals. So, if you have a background in biology, even if you don't, I think you'll find that review to be very interesting, and it further substantiates a lot of the points that I made a few moments ago about the different scenarios and types of individuals that seem to be able to engage their anterior mid-cingulate cortex under different conditions, and to a greater or lesser extent than others. So, hats off to Lisa for cuing me to this incredibly interesting brain structure. I had known that it existed. After all, I teach neuroanatomy to medical students at Stanford, and I taught neuroanatomy for many, many years. But I don't think enough people, and indeed very few professional neuroscientists, could tell you what the anterior mid-cingulate cortex does, but it has this apparently incredible function in generating tenacity and motivation. Along those lines, one of the most incredible and important studies about the anterior mid-cingulate cortex and its capacity to generate feelings of tenacity and willpower comes from one of my colleagues at Stanford, Joe Parvizi, who essentially went into human beings who needed brain surgery for other reasons and stimulated particular brain areas with a very high degree of precision. The title of the paper that I'm referring to was published in 2013 in the journal Neuron, Cell Press journal, excellent journal. And it's entitled The Will to Persevere Induced by Electrical Stimulation of the Human Cingulate Gyrus. Now, you'll notice the title said, "Human cingulate gyrus," not "Anterior mid-cingulate gyrus," but because they had electrodes and a stimulation technique that would allow them to stimulate in very small regions extending as little as five millimeters, but no more, away from the stimulation site, they were able to march their stimulation around different subregions of the cingulate gyrus of humans while those people were awake, and then ask those people, "How do you feel? What are you experiencing in this moment?" In addition to that, they were recording various autonomic parameters from those people, so heart rate, breathing, in addition to brain wave activity. So, what the subjects report when their anterior mid-cingulate cortex was stimulated is that, in their words, something was about to happen. They felt as if there was some sort of pressure upon them from the outside. Not physical pressure, but that something was about to happen. In fact, one of the subjects described the sensation as, "It's as if there's a storm off in the distance, but I know I need to go into the storm, and I know I can make it through the storm." Okay? Another subject described the experience of having their anterior mid-cingulate cortex stimulated as, "Okay, something not necessarily good is going to happen, but I know that I need to marshal resources and resist, and I'm confident that I can push through." Now, because Parvizi and colleagues are excellent scientists, they of course did control experiments where they would tell the person, "Okay, we're stimulating that same brain area that a moment ago you told me created this feeling of some pressure upon you that you have to resist, some sense of fight or urgency to push back." But in reality, during certain control conditions, they were not stimulating those brain areas, and the subjects then reported, "Mm, I don't feel like anything's about to happen. Yeah, I don't feel anything at all." In other words, it was the stimulation of the anterior mid-cingulate cortex, and only the anterior mid-cingulate cortex, that created the sensation within people that there was something to resist, that there was something putting pressure on them. Again, not physical pressure, but psychological pressure, and that they were going to have to marshal resources in order to push back upon. In fact, they reported feeling as if their body was getting ready to do something. One subject said something along the lines of, "I feel like I'm about to do something, I'm about to go someplace or do something to resist this foreboding sense that's now coming over me." So, this is very interesting, and of course is in line with all of the data that we discussed before about neural activity patterns, both spontaneous and evoked, about brain volume changes in the anterior mid-cingulate cortex, so on and so forth. And it really points to the idea that the anterior mid-cingulate cortex is a hub, a hub that receives information from a diversity of brain areas that we talked about a few minutes ago, and that generates a particular sense within us that we are going to be forward center of mass, that we are going to resist something, and that perhaps we are going to move or act in some particular way, or-... as we've been discussing all along, resist action in some particular way, but that it requires that we marshal resources. Which takes us back, of course, to the studies of Baumeister, and indeed of Dweck, where they explored willpower as a limited resource, perhaps, glucose perhaps as that limited resource, beliefs about willpower and glucose probably, with a high degree of certainty, are going to be involved there too. But regardless of that controversy, it's clear that there's an energy required. There's an activation state of engagement or resistance to a particular behavior or thought pattern that we all associate with this phenomenon of tenacity and willpower. And in a kind of miraculous way, you know, as a neuroscientist we're generally taught nowadays that individual brain areas don't really trigger individual functions and perceptions of the brain. There are a few exceptions to that, you know, you have a fusiform face area that really does seem to be involved in the perception of faces, and when lesioned, you can't recognize faces. But outside of just a few limited contexts, it's very rare that one comes across a literature that, across all of the studies involved, point to a single brain structure and its networks as giving rise to something as complex and flexible as tenacity and willpower. But in the case of the anterior mid-cingulate cortex, it really does seem to meet those criteria as the brain hub responsible for tenacity and willpower. Now, a key idea that Dr. Feldman Barrett has contributed to studies of the anterior mid-cingulate cortex as a structure that helps us generate what we call tenacity and willpower to help us achieve different types of goals is this idea of allostasis. Most of you have perhaps heard of homeostasis, which is the idea that all of our cells, all of our organs, indeed our entire body and psychology are always seeking homeostasis, the perfect balance of sleep and activity, of food and burning fuels, of oxygen and carbon dioxide, and so on and so forth. And while homeostasis certainly exists and is a valid phenomenon, there's also a concept that we hear far less about but that is equally important, which is the concept of allostasis. Allostasis is the idea that much of what our brain and body need to do, but especially our brain, is to allocate, right? Allostasis, to allocate resources to particular functions depending on our motivational goals and the challenges upon us. And in every way, what we understand about the structure and function of the anterior mid-cingulate cortex is that it is doing just that. It is deciding how much glucose should a given brain area consume? Perhaps a brain area that's involved in visual perception, because you're involved in a motivational task where, in order to succeed, you need to pay careful visual attention to particular things. Or you're involved in a task where you have to listen to particular things, or perhaps you are involved in a physical foot race where you don't want to allocate a lot of energy towards thinking about your stride or your step unless that's necessary, and you actually want to shut down your brain activity as much as possible except for the brain areas that are required to get you to continue to run. In that sense, the anterior mid-cingulate cortex