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OUTLINE:
0:00 - Introduction
2:29 - Fear
10:41 - Virtual reality
14:25 - Claustrophobia
16:13 - Skydiving
17:48 - Overcoming fears
22:48 - Optimal performance
26:02 - Deep work
41:27 - Psychedelics
45:13 - Deep work
58:53 - Everything in the brain is an abstraction
1:06:11 - Human vision system
1:17:47 - Neuralink
1:45:17 - Science of consciousness
2:00:05 - David Goggins
2:17:09 - Science communication
2:24:41 - Man's Search for Meaning

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The following is a conversation with Andrew Huberman, a neuroscientist at Stanford, working to understand how the brain works, how it can change through experience, and how to repair brain circuits damaged by injury or disease.

He has a great Instagram account at Huberman Lab, where he teaches the world about the brain and the human mind.

Also, he's a friend and an inspiration in that he shows that you can be humble, giving, and still succeed in the science world.

Quick mention of each sponsor, followed by some thoughts related to the episode.

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As a side note, let me say that I heard from a lot of people about the previous conversation I had with Yaron Brook about objectivism.

Some people loved it, some people hated it.

I misspoken some parts, was more critical on occasion than I meant to be, didn't push on certain points that I should have, was undereducated or completely unaware about some major things that happened in the past or major ideas out there.

I bring all that up to say that if we are to have difficult conversations, We have to give each other space to make mistakes, to learn, to grow.

Taking 1 or 2 statements from a 3 hour podcast and suggesting that they encapsulate who I am, I was, or ever will be, is a standard that we can't hold each other to.

I don't think anyone could live up to that kind of standard.

The conversation with Yaron is mild relative to some conversations that I will likely have in the coming year.

Please continue to challenge me, but please try to do so with love and with patience.

Whether I'm successful at that or not, we shall see.

If you enjoy this thing, subscribe on YouTube, review it with 5 Stars on Apple Podcasts, follow on Spotify, support on Patreon, or connect with me on Twitter at Lex Friedman.

And now, here's my conversation with Andrew Huberman.

You've mentioned that in your lab at Stanford, you induce stress by putting people into a virtual reality and having them go through 1 of a set of experiences.

I think you mentioned this on Rogan or with Whitney, that scare them.

So just on a practical, psychological level and maybe on a philosophical level, what are people afraid of?

What are these fear experiences that you find to be effective?

Yeah, so it depends on the person, obviously.

And we should probably define fear, right?

Cause you can, without going too far down the rabbit hole of defining these things, you know, you can't really have fear without stress, but you could have stress without fear.

And you can't really have trauma without fear and stress, but you could have fear and stress without trauma.

So, you know, we can start playing the word game and that it actually is 1 of the motivations for even having a laboratory that studies these things is that we really need better physiological, neuroscientific and operational definitions of what these things are.

I mean, the field of understanding emotions and states, which is mainly what I'm interested in, is very complicated.

But we can do away with a lot of complicated debate and say in our laboratory, what we're looking for to assign it a value of fear is a big inflection in autonomic arousal.

So increases in heart rate, increases in breathing, perspiration, pupil dilation, all the Hallmark signature features of the stress response.

And in some cases we have the benefit of getting neurosurgery patients where we've got electrodes in their amygdala and their insula and the orbital frontal cortex down beneath the skull.

So these are chronically implanted electrodes.

We're getting multi-unit signals and we can start seeing some central features of meaning within the brain.

And what's interesting is that as trivial as it might seem in listening to it, almost everybody responds to heights and falling from a high virtual place with a very strong stress, if not fear response.

And that's because the visual vestibular apparati, right?

The optic flow and how it links to the, you know, balanced semicircular canals of the inner ears, all this technical stuff, but really all of that pulls all your physiology, the feeling that your stomach is dropping, the feeling that you're suddenly you're sweating, even though you're not afraid of falling off this virtual platform, but you feel as if you're falling, excuse me, because of the optic flow, that 1 is universal.

So we've got a dive with great white sharks experience where you actually exit the cage.

We went out and did this in the real world and brought back 360 video that's built out pretty.

So when we decided to set up this platform, a lot of the motivation was that a lot of the studies of these things in laboratories, I don't want to call them lame because I want to be respectful of the people that did this stuff before, but they'd study fear by showing subjects a picture of a bloody arm or a snake or something like that.

And it just, unless you have a snake phobia, it just wasn't creating a real enough experience.

So we need to do something where people aren't going to get injured, but where we can tap into the physiology and that thing of presence of people momentarily, not the whole time, but momentarily for getting there in a laboratory.

And if people want to challenge me on this, I like to point to that movie, Free Solo, which was wild because it's incredible movie, but I think a lot of its popularity can be explained by a puzzle, which is you knew he was going to live when you walked in the theater or you watched it at home.

You knew before that he survived, and yet it was still scary that people somehow were able to put themselves into that experience or into Alex's experience enough that they were concerned or worried or afraid at some level.

If we get people who have generalized anxiety, these are people who wake up and move through life at a generally higher state of autonomic arousal and anxiety, then we can tip them a little bit more easily with things that don't necessarily get everyone afraid.

Things like claustrophobia, public speaking, that's gonna vary from person to person.

And then if you're afraid of sharks, like my sister for instance is afraid of sharks, she won't even come to my laboratory because there's a thing about sharks in it.

That's how terrified some people are of these specific stimuli.

It's, you know, when we have you step off a platform, virtual platform, and it's a flat floor in my lab, but we, you're up there- Well, you actually allow them the possibility in

the virtual world to actually take the leap of faith.

Yeah, maybe I should describe a little bit of the experiment.

So without giving away too much, in case someone wants to be a subject in 1 of these experiments, we have them playing a cognitive game.

It's a simple lights out kind of game where you're pointing a cursor and turning out lights on a grid, but it gets increasingly complex and it speeds up on them.

And, you know, there's a failure point for everybody where they just can't make the motor commands fast enough.

And then we surprise people essentially by placing them virtually all of a sudden, they're on a narrow platform between 2 buildings.

And then we encourage them or we cue them with talking to them through a microphone to continue across that platform to continue the game.

And, you know, some people, they just won't, they actually will hold, get down on the ground and hold onto a virtual beam that doesn't even exist on a flat floor.

And so what this really tells us is the power of the brain to enter these virtual states as if they were real.

And we really think that anchoring the visual and the vestibular, the balance components of the nervous system are what bring people into that presence so quickly.

There's also the potential, and we haven't done this yet, to bring in 360 sound.

So the reason we did 360 video is that when we started all this back in

a lot of the VR was pretty lame, frankly, it was CGI.

But with 360 video, we knew that we could get people into this presence where they think they're in a real experience more quickly.

And our friend, Michael Muller, who I was introduced to because of the project, I reached out to some friends.

Michael Muller is a very famous portrait photographer in Hollywood, but he dives with great white sharks and he leaves the cage.

And so we worked with him to build a 360 video apparatus that we could swim underwater with, went out to Guadalupe Island, Mexico, and actually got the experience.

It was, there were some interesting moments out there of danger, but it came back with that video and built that for the sharks.

And then we realized we need to do this for everything.

We need to do it for public speaking, for claustrophobia.

And what's missing still is 360 sound where 360 sound would be, for instance, if I were to turn around and there was a, like a giant attack dog there, the moment I would turn around and see it, the dog would growl.

But if I turned back toward you, then it would be silent.

So, and that brings a very real element to one's own behavior, where you don't know what's gonna happen if you turn a corner.

Whereas if there's a dog growling behind me and I turn around and then I turn back to you and it's still growling, that might seem like more of an impending threat, unsustained threat, but actually it's when you start linking your own body movements to the experience.

So when it's closed loop, where my movements and choices are starting to influence things and they're getting scarier and scarier, that's when you can really drive people's nervous system down these paths of high states of stress and fear.

Now we don't want to traumatize people obviously, but we also study a number of tools that allow them to calm themselves in these environments.

Well, from a psychology and from a neuroscience perspective, this whole construction that you've developed is fascinating.

We did this a little bit with autonomous vehicles.

So to try to understand the decision making process of a pedestrian when they cross the road and trying to create an experience of a car, you know, that can run you over.

I was so surprised how real that whole world was.

And the graphics that we built wasn't ultra realistic or anything, but I was still afraid of being hit by a car.

Everybody we tested were really afraid of being hit by that car.

I mean, it wasn't like ultra realistic simulation.

So any kind of depth, we're just programmed to not necessarily recoil, but to be cautious about that edge and that depth.

And then looms, things coming at us that are getting larger.

There are looming sensing neurons even in the retina at a very, very early stage of visual processing.

And incidentally, the way Muller and folks learn how to not get eaten by great white sharks when you're swimming outside the cage is as they start lumbering in, you swim toward them.

And they get very confused when you loom on them because clearly you're smaller, clearly they could eat you if they wanted to, but there's something about forward movement toward any creature that that creature questions whether or not it would be a good idea to generate forward movement toward you.

And so that's actually the survival tool of these cage exit white shark divers.

Are you playing around with, like, 1 of the critical things for the autonomous vehicle research is you couldn't do 360 video because there's a game theoretic, there's an interactive element that's really necessary.

So maybe people realize this, maybe they don't, but 360 video, you obviously, well it's actually not that obvious to people, but you can't change the reality that you're watching.

So, but you find that that's like, is there something fundamental about fear and stress that the interactive element is essential for?

Or do you find you can, you can arouse people with just the video?

We also have a spider stimulus, but like snakes, I just don't like them.

There's something about the slithering and it just creates a visceral response for me.

Some people, not so much, and they have lower levels of stress and fear in there.

But 1 way that we can get them to feel more of that is to use mixed reality where we have an actual physical bat and they have to stomp out the snake as opposed to just walk to a little safe corner which then makes the snake disappear.

That tends to be not as stressful as if they have a physical weapon.

And so you've got people in there, you know, banging on the floor against this thing.

And there's something about engaging that makes it more of a threat.

Now, I should also mention, we always get the subjective report from the subject of what they experienced because we never want to project our own ideas about what they were feeling.

But that's the beauty of working with humans is you can ask them how they feel.

And humans aren't great at explaining how they feel, but it's a lot easier to understand what they're saying than a mouse or a macaque monkey is saying.

So it's the best we can do is language plus these physiological and neurophysiological signals.

Is there something you've learned about yourself about your deepest fears?

Like you said, snakes, is there something that, like if I were to torture you, so I'm Russian, so, you know, I always kind of think, how could I murder this person that entered the room?

But also how could I torture you to get some information out of you?

It's interesting you should say that I never considered myself claustrophobic, but, cause I don't mind small environments provided they're well ventilated, but I, before COVID, I started going to this Russian banya, you know, and then we jumped here.

So, you know, the whole experience of really, really hot sauna.

The plaza, they're hitting you with the leaves.

And it gets really hot and humid in there.

And there were a couple of times where I thought, okay, this thing is below ground.

It's in a city where there are a lot of earthquakes.

Like if this place crumbled and we were stuck in here and I'd start getting a little panicky and I realized I'm like, I don't like small confined spaces with poor ventilation.

So I realized, I think I have some claustrophobia and I wasn't aware of that before.

So I put myself into our own claustrophobia stimulus, which involves getting into an elevator and with a bunch of people, virtual people, and the elevator gets stalled.

But then as we start modulating the environment and we actually can control levels of oxygen in the environment if we want to, it is really uncomfortable for me.

And I never would have thought, you know, I fly, I'm comfortable in planes, but it is really uncomfortable.

And so I think I've unhatched a bit of a claustrophobia.

So I went to skydiving to try to overcome the fear of heights, but that didn't help.

Yeah, I jumped out, but it was fundamentally different experience than, I guess there could be a lot of different flavors of fear of heights maybe, but the 1 I have didn't seem to be connected to jumping out of a plane.

It's a very different, because once you accept that you're going to jump, then it's a different thing.

I think what I'm afraid of is the moments before it is the scariest part.

And I don't think that's emphasized in the skydiving experience as much.

And also just the acceptance of the fact that it's going to happen.

So once you accept it is going to happen, it's not as scary.

It's the fact that it's not supposed to happen and it might, that's the scary part.

I guess I'm not being eloquent in this description, but there's something about skydiving that was actually philosophically liberating.

I was like, wow, it was the possibility that you can walk on a surface and then at a certain point, there's no surface anymore to walk on.

And it's all of a sudden the world becomes 3 dimensional.

And there's this freedom of floating that the concept of like of earth disappears for a brief few seconds.

I don't know those those while that was wild but I'm still terrified of heights.

So, I mean, 1 thing I want to ask just on fear, because it's so fascinating is, have you learned anything about what

Yes, and that comes from 2, from a research study standpoint, 2 parallel tracks of research.

1 was done actually in mice, because we have a mouse lab also where we can probe around in different brain areas and try and figure out what interesting brain areas we might want to probe around into humans.

And a graduate student in my lab, she's now at Caltech, Lindsey Sillay, published a paper back in 2018 showing that what at first might seem a little bit obvious, but the mechanisms are not, which is that there are really 3 responses to fear.

You can pause, you can freeze essentially.

You can retreat, you can back up, or you can go forward.

And there's a single hub of neurons in the midbrain, it's actually not the midbrain, but it's in the middle of the thalamus, which is a forebrain structure.

And depending on which neurons are active there, there's a much higher probability that a mouse, or it turns out, or a human will advance in the face of fear or will pause or will retreat.

Now that just assigns a neural structure to a behavioral phenomenon.

But what's interesting is that it turns out that the lowest level of stress or autonomic arousal is actually associated with the pausing and freezing response.

Then as the threat becomes more impending and we used visual looms in this case, the retreat response has a slightly higher level of autonomic arousal and stress.

So think about playing hide and go seek and you're trying to stay quiet in a closet that you're hiding.

If you're very calm, it's easy to stay quiet and still.

As your level of stress goes up, it's harder to maintain that level of quiet and stillness.

You see this also in animals that are stalking, a cat will chatter its teeth.

That's actually sort of top-down inhibition and trying to restrain behavior.

So the freeze response is actually an active response, but it's fairly low stress.

And what was interesting to us is that the highest level of autonomic arousal was associated with the forward movement toward the threat.

So in your case, jumping out of the plane, however, the forward movement in the face of threat was linked to the activation of what we call collateral, which means just a side connection, literally a wire in the brain that connects to the dopamine circuits for reward.

And so when 1 safely and adaptively, meaning you survive, moves through a threat or toward a threat, it's rewarded as a positive experience.

And so the key, it actually maps very well to cognitive behavioral therapy and a lot of the existing treatments for trauma is that you have to confront the thing that makes you afraid.

So otherwise you exist in this very low level of reverberatory circuit activity where the circuits for autonomic arousal are humming and they're humming more and more and more.

And we have to remember that stress and fear and threat were designed to agitate us so that we actually move.

So the reason I mentioned this is I think a lot of times people think that the maximum, you know, stress response or fear response is to freeze and to lock up.

But that's actually not the maximum stress response.

The maximum stress response is to advance, but it's associated with reward.

So there's this kind of, everyone always thinks about the bell shape, you know, the sort of hump shape curve for, you know, at low levels of arousal performance is low.

And as it increases, performance goes higher.

And then it drops off as you get really stressed.

But there's another bump further out the distribution where you perform very well under very high levels of stress.

And so we've been spending a lot of time in humans and in animals exploring what it takes to get people comfortable to go to that place And also to let them experience how there are heightened states of cognition there.

There's changes in time perception that allow you to evaluate your environment in fast, at a faster frame rate, essentially.

This is the matrix as a lot of people think of it.

But we tend to think about fear as all the low level stuff where things aren't worked out.

But there are many, there are a lot of different features to the fear response.

And so we think about it quantitatively and we think about it from a circuit perspective in terms of outcomes.

And we try and weigh that against the threat.

So we never want people to put themselves in unnecessary risk, but that's where the VR is fun because you can push people hard without risk of physically injuring them.

And that's, like you said, the little bump, that seems to be a very small fraction of the human experience, right?

So it's kind of fascinating to study it because most of us move through life without ever experiencing that kind of focus.

Well, everything's in a peak state there.

I really think that's where optimal performance lies.

There's so many interesting words here, but what's performance and what's optimal performance?

We're talking about mental ability to what?

To perceive the environment quickly, to make actions quickly, what's optimal performance?

Yeah, well, it's very subjective and it varies depending on task and environment.

So 1 way we can make it a little bit more operational and concrete is to say, there is a sweet spot, if you will, where the level of internal autonomic arousal, aka stress or alertness, whatever you want to call it, is ideally matched to the speed of whatever challenge you have to be facing in the outside world.

So we all have perception of the outside world as exteroception and the perception of our internal real estate interoception.

And when those 2 things, when interoception and exteroception are matched along a couple of dimensions, performance tends to increase or tends to be in an optimal range.

So for instance, if you're, I don't play guitar, but I know you play guitar.

So let's say you're trying to learn something new on the guitar.

I'm not saying that being in these super high states of activation are the best place for you to be in order to learn.

It may be that your internal arousal needs to be at a level where your analysis of space and time has to be well-matched to the information coming in and what you're trying to do in terms of performance, in terms of playing chords and notes and so forth.

Now, in these cases of high threat where things are coming in quickly and animals and humans need to react very quickly, the higher your state of autonomic arousal, the better.

Because you're slicing time more finely just because of the way the autonomic system works.

The pupil dilation, for instance, and movement of the lens essentially changes your optics.

But with the change in optics is a change in how you bin time and slice time, which allows you to get more frames per second readout.

With the guitar learning, for instance, it might actually be that you want to be almost sleepy, almost in a kind of drowsy state to be able to, and I don't play music, so I'm guessing here, but sense some of the nuance in the chords or the ways that you're, to be relaxed enough that your fingers can follow an external cue.

So matching the movement of your fingers to something that's pure exteroception.

And so there is no perfect autonomic state for performance.

This is why I don't favor terms like flow because they're not well operationally defined enough.

But I do believe that optimal or peak performance is going to arise when internal state is ideally matched to the space-time features of the external demands.

So there's some slicing of time that happens and then you're able to adjust, so slice time more finely or more, less finely in order to adjust to the stimulus, the dynamics of the stimulus.

There's a guy named Cal Newport who wrote a book about deep work.

1 of the nice things, I've always practiced deep work, but it's always nice to have words put to the concepts that you've practiced.

It somehow makes them more concrete and allows you to get better.

It turns it into a skill that you can get better at.

But I also value deep thinking, where you think, it's almost meditative.

You think about a particular concept for long periods of time.

The programming you have to do that kind of thing for.

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Andrew Huberman: Neuroscience of Optimal Performance | Lex Fridman Podcast #139