Using Play to Rewire & Improve Your Brain | Huberman Lab Essentials

Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science-based tools for mental health, physical health, and performance. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, we are going to talk about the biology, psychology, and utility of play. Much of our childhood development centers around play, whether or not it's organized play or spontaneous play. But as adults, we also need to play, and today I'm going to talk about what I like to refer to as the power of play. Let's talk about play. What is the utility of play? You know, why do we play when we're younger? Why do we tend to play less as we get older? And what in the world is play for? As we're going to learn later in the podcast, play is generated through the connectivity of many brain areas, but one of the key brain areas is an area called PAG, periaqueductal gray. The periaqueductal gray is a brainstem area, so it's pretty far back as the brain kind of transitions into the spinal cord, and it's rich with neurons that make endogenous opioids. So these are not the kinds of opioids that are causing the opioid crisis. These are neurons that you and I all have that release endogenous, meaning self-made or biologically made opioids. They go by names like enkephalin and things of that sort. Play evokes small amounts of opioid release into the system, and that turns out to be a very important chemical state because there's something about having an abundance of these endogenous opioids released into the brain that allows other areas of the brain, like the prefrontal cortex, the area of the front that's responsible for what we call executive function. Executive function is the ability to make predictions, to assess contingencies, like, if I do this, then that happens. If I do that, then that happens. Well, prefrontal cortex is often seen as a kind of rigid executive of the whole brain. That's one way to view it, but probably a better way to view it is that the prefrontal cortex works in concert with these other more primitive circuitries. And when the periaqueductal gray releases these endogenous opioids during play, the prefrontal cortex doesn't get stupid. It actually gets smarter. It develops the ability to take on different roles and explore different contingencies, and we're going to talk about role play later in different contexts. And what we will find is that so much of play is really about exploring things in a way that feels safe enough to explore. As we move forward in the discussion, what I'd love for everyone to do is to stop thinking about play as just a child activity, not just a sport-related activity, but really as an exploration in contingencies. Again, it's an exploration of, if I do A, what happens? If I do B, what happens? If someone else takes on behavior or, um, attitude C, what am I going to do? And play is really where we can expand our catalog of potential outcomes, and it can be enormously enriching. And indeed, as we'll talk about, the tinkerers of the world, the true creatives, the people that build incredible technologies and art, and also that just have incredibly rich emotional and intellectual and social lives, all have a strong element of play. Many of us, including myself, probably haven't played that much as adults. But as children, most all of us engage in a lot of play. And in looking at the way that very young children, and especially toddlers, play, we can learn a lot because it reveals the fundamental rules by which the toddler brain interacts with the world. Now, there are hundreds of different types of play and hundreds of different types of contingency testing, but the key theme here is that play allows children, and adults for that matter, to explore different outcomes in a kind of low-stakes environment. So the key theme here is that play is contingency testing under conditions where the stakes are sufficiently low that individuals should feel comfortable assuming different roles, even roles that they're not entirely comfortable with in their outside life. And that all relates, again, to the release of these endogenous opioids in this brain center, periaqueductal gray, and the way that it allows the prefrontal cortex in a very direct way, I mean, truly, it allows it in a biological way, to expand the number of operations that it can run and start thinking about, "Oh, well, okay, normally, I'm kind of a loner, and I like to read and work and, and, you know, hang out alone, maybe even play alone, but, you know, okay, I'll play a board game or a game of tennis where I have a partner, and we're going to play as partners against two other people. Okay, that's a little uncomfortable, uh, but I'll do it." And in doing that, you discover certain ways in which you are proficient and certain ways in which you are less proficient. You discover that the other person actually, uh, tends to cheat a little bit, or the other person is extremely rigid about the rules, or maybe is extremely rigid about the way they organize their pieces on the board, or they're crossing the line into your side of the tennis court. There are all sorts of things that we learn in these rather low-stakes scenarios. That's the key theme here. So before I continue, I just want to point to a tool that anyone can use, but in particular, the less playful of the group, and I would put myself into this category. What I'm about to tell you is that anyone and everyone can benefit from engaging in a bit more of this playful mindset. It's really about allowing yourself to expand the number of outcomes that you're willing to entertain and to think about how you relate to those different outcomes. So what this means is putting yourself into scenarios where you might not be the top performer, right? Playing a game that you're not really that good at. I had this experience recently. Uh, friends that like to play cards, they like to do some low-stakes gambling, and-... I generally don't buy into the game. I generally don't play, mostly because they end up winning and taking whatever it is [chuckles] that I have. But in the mode of assuming a more playful spirit, the idea would be, well, if the stakes are low enough, then to play simply for the sake of playing, because there's something to learn there about the other people in the group and about oneself, and how one reacts to things like someone who's, um, clearly trying to take everybody's money, or somebody who is, [lip smack] uh, clearly trying to, um, cheat, or somebody who's clearly very, very rigid about every last detail, including how the cards are dealt and shuffled, right? There is learning in this exploration, and so you can immediately see how just a small increase in your willingness to put yourself into conditions where you don't understand all the rules, perhaps, or you're not super proficient at something, but you enter it because it is low stakes and because there is information to learn about yourself and others, could start to open up these prefrontal cortex circuits. And when I say open up, I don't mean that literally there's an opening in your skull. What I mean is that your prefrontal cortex can work in very rigid ways, meaning if A, then B. If I go down this street, turn left, and go that way to work, it is fast. If I go down the other street, it's slow. If there's a traffic jam there, I'm gonna go there. But it's starting to explore different possibilities, and there are very, very few opportunities in life to explore contingencies in this low-stakes way, such that it engages neuroplasticity of the prefrontal cortex. So play is powerful at making your prefrontal cortex more plastic, more able to change in response to experience, but not just during the period of play, but in all scenarios. Because you get one prefrontal cortex, you don't get a prefrontal cortex just for play. You get a prefrontal cortex that engages in everything. Another really interesting and important aspect of play is so-called play postures. These are seen in animals, and these are seen in humans. And for those of you that are watching this podcast on YouTube, I'll do my best to adopt them here. For those of you that are listening, you'll just have to imagine them in your mind's eye. Perhaps the most familiar one is seen in dogs and in wolves, where they will lower their head to the ground, and they'll put their paws out in front of them, and they will make eye contact with another typically dog or wolf, to so-called call the play. Now, when they do this posture, it's obvious that they're lowering themselves. They're not in an aggressive stance because they're lowering their head, and this is universally known among canines as play posture. Turns out that humans do this as well, although in a different form. I'm sure there are some that go into the, the down dog play posture, but more typically, when humans want to play, they will do a subtle or not so subtle head tilt. The head tilt with eyes open is considered the universal head and facial expression posture of play in humans. So when two people see one another, if they are aggressive towards one another, they will assume certain facial expressions and postures. But if they're feeling playful towards one another, oftentimes they'll tip their head to the side just a little bit, and they'll open their eyes. They might even raise their eyebrows briefly. Another hardwired feature of so-called play postures is what's called soft eyes. When animals are aggressive or when they're sad, they tend to reduce the size of their eye openings by, um, basically making their eyelids closer together, somewhat, by keeping their eyes together. In particular, for aggression, they'll bring their eyes towards what we call a vergence eye movement, bring it towards the center. That actually narrows the, the aperture of the visual field. [lip smack] When people or animals want to engage in play, they tend to open their eyelids somewhat, and they tend to purse their lips just a little bit. They'll open their eyes a little bit, and they'll often do the head tilt as well, sometimes with a little bit of a smile. The other thing that we see during play are what are called partial postures. Partial postures are a kind of play enactment of postures that would otherwise be threatening. So a partial posture that we see during play in animals and humans that relates to aggressive play, so things like wrestling or things like rough-and-tumble play, which is very common in animals and kids, and some adults, is that because there's going to be physical interaction, in animals, what will happen is they will march toward one another, often very slowly, but rather than having their hair up, which we call piloerection, which is when the hair goes up. Animals do this to make themselves look bigger. Think about the, the cat that's trying to look bigger, or an animal that's being aggressive, trying to look bigger in the presence of a, of a, um, a foe, a different animal that they're either going to try and kill or fight in some way, even if it's to defend themselves. Partial postures occur when animals will approach one another, but they'll keep their fur down. Humans will do this, too. They will approach during play, but unless it's highly competitive play, like a football game or a boxing match, they will actually shrink their body size somewhat. The failures to do this are also very informative in how we develop in social groups, and this also can inform why some people really play well with others, and other people don't, and some people seem to get along well with groups and can handle other people, and some people are very rigid. In fact, I have an anecdote about this. When I was a kid, we used to play this game. It's not a game I suggest, but we used to do what were called dirt clod wars. So a friend of mine, his parents were generally not home in the afternoon, so we must have been somewhere around ten or 11 years old, and we would set up these two big dirt mounds. We would shovel them to big dirt mounds on two sides of the yard, and then we would just take cl-- dirt clods, and we'd throw them at one another and just have dirt clod wars. But there were rules, and the rules were, for instance, um, you couldn't pack rocks into the dirt clods. Um, and you could run across to the other side, and you could jump on the other person's mound, and you could throw dirt clods in there. I guess this is stuff that [chuckles] we, we thought was entertaining. But-... If someone got hit in the head, generally, there was an unspoken rule that you kind of stop and see whether or not they were damaged or not before you'd continue. You couldn't continue pelting them. And, of course, people broke this rule. In fact, I remember one kid, I'm not going to name him, um, because actually he's grown into a very, uh, very [chuckles] actually prominent and functional adult. But he got hit once in the head, and then I think someone had thrown a dirt clod shortly thereafter, and all of a sudden, he just went into a rage, picking up rocks and sticks and attacking another kid. And so clearly, that was a case in which the rules of the game were now being violated. But the idea is that there's an agreed-upon set of rules about how high the stakes are and what we're all going to do. And this is separate from sport, where there are clearly defined rules about what's out of bounds, what's inbounds, what sorts of behaviors will get you a yellow card or a red card, for instance, on the soccer field. All animals, including humans, are doing this low stakes contingency testing, and all animals, including humans, you will find, start to up the stakes. And inevitably, in group play, one member of the group will kind of break rules. So we could all look at our adult counterparts, and indeed, we should probably look at ourselves and ask, you know, did we learn proper play contingency when we were younger? Do we tend to take things too seriously? Do we tend to overreact aggressively when other people are clearly engaging in, you know, playful, um, jabbing or sarcasm or things of that sort? So each of you will have a different experience of this, but the point is that play serves many functions. It's not just about the self, it's also about interactions between multiple people. It's about rule testing and low stakes contingency. Rule breaking also serves an important role, as is with the example of the dirt clod war. And last but not least, there are different forms of play that help us establish who we will become as adults. One of the more powerful of these is role play, when children and sometimes adults will take on different roles that are distinct from their natural world roles in order to, for instance, establish hierarchies. So someone's going to be the leader and someone's going to be the follower. Someone will, uh, work alone, other people will work in a group. These kinds of role-playing are, again, ways in which the prefrontal cortex has to expand the number of operations. In neuroscience, we call these algorithms that it has to run in order to make predictions. You have to take in a lot of information about your environment all the time and make predictions. But if you are suddenly cast into a new role, well, then you definitely have to make even more predictions from a different standpoint. So these are very powerful for teaching the brain how to function. And so what I'm hoping is coming through is that play is not just about having fun. Play is about testing, it's about experimenting, and it's about expanding your brain's capacity. And that's true early in development, and it's true throughout the lifespan. So at this point in the discussion, I want to take a step back, look at the biology and neurochemistry of play just a little bit, and in doing that, really define what is effective play. If the goal of play is to explore different contingencies in low stakes environments and to expand the function of our prefrontal cortex so that we can see new possibilities and new ways of being, become more flexible, more creative, more effective outside of the games of play or the arenas of play, I should say, well, then we should be asking: How do I know if I'm playing? How do I know if I'm playing correctly? Turns out there's an answer to that. Earlier, I referred to this brain area, the periaqueductal gray, that releases opioids, endogenous opioids, into our brain and body, and tends to relax us a bit. Uh, it actually is what leads to these things like soft eyes, and head tilts, and puppies making, uh, you know, puppy postures, and things of that sort, and how that opens up the number of different functions or algorithms that the prefrontal cortex can run. But there's another piece of the puzzle, which is for something to genuinely be play and playful, and for it to have this effect of expanding our brain and engaging neuroplasticity, of really changing our brain so that we can see and engage in more possible behaviors and thoughts, et cetera, we also have to have low amounts of adrenaline, so-called epinephrine, in our brain and body. Now, the background science for this is quite extensive, but for those of you that are interested in, uh, papers and manuscripts, uh, perhaps the best one is a review published in Neuroscience and Biobehavioral Reviews by the very Jaak Panksepp, although he has a co-author, which is Steven Sivy, S-I-V-I-Y. And the title of this paper is In Search of the Neurobiological Substrates for Social Playfulness in Mammalian Brains. And it's a quite extensive review, but it basically boils down to some key findings whereby any sorts of drugs or behaviors or scenarios that increase levels of adrenaline too much will tend to inhibit play. And drugs and scenarios, and I'm not suggesting recreational drugs here, but these were experiments that were done in the laboratory setting, that increase the endogenous opioid output, will tend to increase playfulness. And so really the state of mind that one needs to adopt when playing is, first of all, you have to engage in the play, whatever it happens to be, with some degree of focus and seriousness. And focus and seriousness in the neurobiological context generally means epinephrine. Um, being able to focus is largely reliant on things like adrenaline, epinephrine, but also the presence of dopamine, uh, which is a molecule that generates motivation and focus in concert with epinephrine, but also that these endogenous opioids be liberated. And it's really the low stakes feature of play that allows those endogenous opioids to be liberated. What do I mean by that? Well, if you are very, very concerned about the outcome, like you've put a lot of money on the table in a given game, um-... or, uh, you're a football player in the Super Bowl, or you're playing a game for which, you know, defeating the other person or your team winning is absolutely crucial to you, well, then that's not really going to engage the play circuitry. On the contrary, if you're engaging in those same behaviors or any other behavior in a way that you're simply there to explore, but you don't have high levels of adrenaline in your system, you're not stressed about the potential outcome, well, then that constitutes play. Now, that's somewhat obvious on the one hand, that you take seriously what you take seriously, and you can be more playful about things that you don't take so seriously. But what is absolutely not obvious is that the state of playfulness is actually what allows you to perform best, because the state of playfulness offers you the opportunity to engage in novel types of behaviors and interactions that you would not otherwise be able to access if you are so focused on the outcome. And for all of us who are thinking about tools and things that we can extract from science to enrich our lives, I would say, for those of you that are already playing on a regular basis in one form or another, terrific. Start to expand other forms of play, in particular, forms of play that involve new groups of individuals. This is the way that your brain learns and evolves and changes and gets better. And I raise this because another one of the top ten questions I get is: How can I keep my brain young? How can I continue to learn? How can I get better in school, in sport, in life, in relationships, et cetera, emotionally, cognitively? Yes, there are brain games and apps that can support neuroplasticity, but if you really want to engage neuroplasticity at any age, what you need to do is return to the same sorts of practices and tools that your nervous system naturally used throughout development, and that evolved over hundreds of thousands of years to trigger this thing that we call neuroplasticity. Play at every stage of life is the way in which we learn the rules for that stage of life. And play is the way in which we were able to test how we might function in the real-world context. So play is powerful, and we could even say that play is the most powerful portal to plasticity. The reason for that is that, yes, this high opioid, low epinephrine or adrenaline state is what opens up play, but then inside of the arena of play, when the prefrontal cortex is running all these different possibilities in this low-stakes way, but with some degree of focus, there are a number of other chemicals that are deployed. Things like brain-derived neurotrophic factor and other growth factors that actually trigger the rewiring of brain circuits that allow for it to expand, and indeed, that's what is neuroplasticity. Thus far, I've tried to convince you through a combination of data and anecdote and explanation, that adopting a stance of playfulness and indeed engaging in play on a somewhat regular basis, could be beneficial to you, regardless of circumstances or goals. There's even some evidence, that's at this point, largely anecdotal, but there's some data starting to emerge, that adults that maintain a playful stance, that engage in things, again, that are low stakes, contingency exploring, important enough that people focus and that people pay attention to what they're doing, but that they are not, you know, filled with adrenaline, you know, freaked out about the outcome being A or B. They're not super, super competitive, maybe just a little bit competitive or not competitive at all. That allows for more ongoing plasticity. And one of the people that comes to mind in thinking about this is, of course, the physicist, and I should say, the great physicist, Richard Feynman, Nobel Prize winner, professor at Caltech, um, was involved in the Manhattan Project, but was also known for being a lifelong tinkerer, right? He also was a mischievous tinkerer. Uh, if you read any of the books about Feynman or by Feynman, Surely You're Joking, Mr. Feynman! or What Do You Care What Other People Think? These are wonderful short stories, mostly about Feynman doing things like, uh, picking all the locks at the Lamo- Los Alamos Laboratory and putting all the top-secret documents out on the floor of the office, so that when people came in in the morning, they were all out there. Um, obviously, they weren't released to the general public. Um, he didn't want to threaten national security. Playing pranks like that. In some of his writings, he pointed to the fact that that playful spirit was something that he worked very hard to continue to cultivate in himself because it was the way in which he could see the world differently and to indeed make great discoveries in the field of physics, but also to kind of evolve his relationship to life more generally. And so he comes to mind as, as a prominent example of somebody who, who did this. And if I could achieve anything with this episode, besides teaching you something about the biology of play, it would be to teach you about the utility of play. Uh, again, I'm-- don't consider myself a particularly playful person by nature, but I've tried over the years to adopt this stance of exploring things that are, um, you know, very focused on contingencies of different kinds, but keep the stakes low enough that I can have some fun doing them, and I like to think that it's benefited me somewhat. Now, I'd like to drill a little bit further into this thing that we call neuroplasticity. Now, there are particular forms of play that lend themselves best to neuroplasticity, and those particular forms of play, again, are not designed to necessarily just engage the plasticity that allows you to perform that behavior, but rather to expand the number of possibilities for your brain to change in general throughout life. And the two major forms of those for which there's good peer-reviewed research, is to engage in novel forms of movement, including different speeds of movement. So let's say, for instance, you're somebody who runs. Running doesn't lend itself to a lot of novel forms of movement, lateral movement, so, so for you nerds out there, movement in the sagittal plane, [chuckles] um, or angled movements. But it does appear that things like dance or sports, where you end up-... generating a lot of dynamic movements where there's jumping, where there's movement at different angles, where there's ducking, where there's leaping, that basically involve a lot of dynamic movement and aren't just strictly linear. Those seem to open the portals for plasticity, and that's because they mimic a lot of the brain circuitry that is associated with play. And the reason for that is the way in which those dynamic movements and movements of different speeds engage the vestibular system, the balance system. The vestibular system is in the inner ear, relates to the cerebellum, which translates to mini-brain. You got a little mini-brain in the back of your brain. It brings together visual information in a very direct way. I talked a lot about this in the episode on how to learn faster, so if you want to go in depth on how vestibular and different types of motor movements can open plasticity, I talk a little bit more, or I should say a lot more there. But suffice to say that engaging in play that has a lot of dynamic movement or movements of different speeds, things like dance, things like sports, like soccer, where you're moving in different dimensions, that tends to be very conducive to what we would call play-related circuitry, provided you don't take it too seriously. You don't get those high levels of epinephrine. Now, for those of you that are also interested in non-physical or non-athletic forms of play that can really expand plasticity, there's some very interesting research about the game of chess. There's a really nice paper that was published in the International Journal of Research in Education and Science in twenty seventeen, and the title of this paper is, "Is Chess Just a Game or Is It a Mirror That Reflects a Child's Inner World?" That's a very, uh, a very intense title for a biologist like me. Um, but this paper is so interesting because what it really points to is the fact that in a single game, chess, you have, at least as I understand, two players, and those two players are moving pieces on the chessboard for which each piece can do different things, right? Can move in different ways under different scenarios, but there are different rules for different pieces, and so each player actually has to assume multiple identities during the same game, and each of those identities has different rules and ways of interacting. So in a way, we can think of chess as one game, but actually, chess is a kind of a substrate for exploring multiple roles for different characters. And this is quite a bit different than, for instance, video games, where somebody has their favorite video game player, or they have an avatar, and they're always in the same role. So for those of you that are interested in leveraging play for neuroplasticity and expanding your mind, if you will, I highly recommend picking an activity that will allow you to adopt different roles within that activity, where it's not rigidly linear. This is actually a way in which I start to depart from this modern and important but somewhat narrow idea that exercise is the only route to plasticity. Play is about dynamically exploring different kinds of movements, dynamically exploring different kinds of thoughts, dynamically exploring different kinds of roles that one could adopt, and that is the way that the brain learns new things. In researching this episode, one of the most interesting areas I discovered was this notion of personal play identity. There are four components to personal play identity: how you play, your personality, socioculture, and environment. So that's the third one. That's together, socioculture, environment, and economics and technology. Now, that sounds somewhat complex, but basically what it says is that we bring together certain aspects of ourselves and how we react to different play scenarios when we're younger, and we bring that forward into the world in all contexts as adults. To illustrate this, I'm going to ask you a question. When you were a child, let's say ten years old, would you have considered yourself competitive? Would you have considered yourself somebody who's cooperative and realize, of course, that those are not mutually exclusive? Would you consider yourself somebody that preferred to play alone or preferred to play with one or two close friends? Or were you somebody that really enjoyed playing in large groups? Here's a key one: Were you somebody that enjoyed playing the leader in one moment and was equally okay with being a follower at a later moment? Were you okay with having your role switched midway through a game? Would you get upset or be delighted or not care at all about having to switch teams during the middle of a game because your team was winning, right? To even things out. You can imagine how that would, um, play out internally. You would immediately register that you must be a valuable player because you're being moved off the winning team toward the losing team, but then again, you're now being forced to join the losing team. How did you feel about that? The point is that if we look back to our early adolescence, somewhere between ten and fourteen years old, a peak time for social development, a peak time for play of various kinds, a peak time for motor development, a peak time of psychosocial development, where we learn where we fit into hierarchies as we relate to members of the same sex, of the opposite sex, et cetera, we can start to get a portal into how and why we show up to various activities in work and relationship, et cetera, as adults. One of my favorite things about developmental biology and developmental psychology is that it is grounded in the fact that we don't just have a childhood and an adulthood. There isn't just our child self and our adult self. And even though there are transitions around the mechanisms that underlie neuroplasticity at approximately age twenty-five, it is simply the case that development is our entire lifespan, that our lifespan is one long developmental arc. How long depends on our genetics, our lifestyle, accidents, injury, and disease, of course, but it is one long developmental arc. And so it shouldn't surprise us at all that how we learn to play as a ten-year-old or twelve-year-old would impact how we play and interact with people as a teenager and a young adult, and on and on and on. And that play is the place in which we explore and which we learn. Play is the substrate by which our nervous system changes us from this hyper-connected batch of neurons, where everything is connected to everything, more or less, to a brain and nervous system whereby certain circuits work with immense proficiency and others are less accessible to us. Play is really about not even worrying if you're going to get good at it or really proficient at it. It's really a- about exploring contingencies with truly low stakes. That's what will allow you to access these neurochemical combinations of elevated endogenous opioids, low epinephrine, et cetera, that will open up neuroplasticity. We have brain circuits from back to front and within our body that are there for play, and they don't disappear. They do not get pruned away as we go from development to adulthood. So if ever you needed a neurobiological explanation for why play is important throughout the lifespan, it's that. It's that biology does not waste resources. It's extremely efficient. And were the circuits for play not to be important in adulthood, they would have been pruned away. But I guarantee you, they are there in your brain and nervous system now, they will be there tomorrow, and they will be there going forward. So my suggestion is that you use them. Thank you once again for joining me for this discussion about the incredible biology and psychology and power of this thing that we call play. And last but certainly not least, thank you for your interest in science. [upbeat music]