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?

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 brain stem 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 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, 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, it truly 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, 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 tends to cheat a little bit, or the other person is extremely rigid about the rules, or maybe it's extremely rigid about the way they organize their pieces on the board, or 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, 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 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 clearly trying to take everybody's money, or somebody who is clearly trying to 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 going to 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 neural plasticity 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, often times 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 basically making their eyelids closer together somewhat, but keeping their eyes together.

In particular for aggression, they'll bring their eyes towards what we call a virgin's eye movement, bring it towards the center that actually narrows the aperture of the visual field.

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 of 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 we're 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 10 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 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, you couldn't pack rocks into the dirt clods.

And you could run across to the other side and you could jump on the other person's mound, you could throw dirt clods in there.

I guess this is stuff that 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, because actually he's grown into a very 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 in bounds, 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 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 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?

It 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.

It actually is what leads to these things like soft eyes and head tilts and puppies making, 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, etcetera.

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 papers and manuscripts, perhaps the best one is a review published in Neuroscience and Biobehavioral Reviews by the very Yak Pangcept, although he has a co-author, which is Steven Sivi, 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, being able to focus is largely reliant on things like adrenaline, epinephrine, but also the presence of dopamine, 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, or 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 10 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, etcetera, 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 learned 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.

If 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, was involved in the Manhattan Project, but was also known for being a lifelong tinkerer, right?

He also was a mischievous tinkerer.

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 picking all the locks at the 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.

Obviously, they weren't released to the general public.

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 a 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, would be to teach you about the utility of play.

And last but certainly not least, thank you for your interest in science.