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

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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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this podcast. 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 misspoke in some parts, was more critical on occasion than I’m meant to be,

didn’t push on certain points that I should’ve, 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 one or two statements from a three 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, at least I know I can’t.

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. I promise to work my ass off to improve. Whether I’m successful at that or not, we shall

see. If you enjoy this thing, subscribe on YouTube, review it with five stars on Apple Podcast, 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 one 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 the fears? 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? Because you can, without going too far

down the rabbit hole of defining these things, 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 we can start playing the word game.

And that actually is one 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 orbitofrontal cortex down beneath the skull. So these are

chronically implanted electrodes. We’re getting multiunit 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 apparatus,

right? The optic flow and how it links to the 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 suddenly you’re sweating, even though you’re not afraid

of falling off this virtual platform, but you feel as if you’re falling because of the optic flow.

That one 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. Oh, so this is actually 360 video.

360 video. And this was important to us, right? 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 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 forgetting they’re in a laboratory. And so heights will always do it. And if people

want to challenge me on this, I like to point to that movie, Free Solo, which was wild because

it’s an 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. So heights always does it. 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

going to 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, but heights gets them

every time. Yeah. And I’m terrified of heights. We have you step off a platform, virtual platform,

and it’s a flat floor in my lab, but 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 one 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 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

two buildings. And then we encourage them or we cue them by talking to them through a microphone

to continue across that platform to continue the game. And some people, they actually will

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 when we started all this back in 2016,

a lot of the VR was pretty lame, frankly, it was CGI, it just wasn’t real enough. 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 a lot of fun. There’s

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 heights. 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 giant attack dog there,

the moment I would turn around and see it, the dog would growl. But if I turn back toward you,

then it would be silent. And that brings a very real element to one’s own behavior where you

don’t know what’s going to 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 and sustained 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. So the short answer is height. 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

could run you over. So there’s the danger there. 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.

Even though it was all a simulation.

It was all a simulation. It was kind of boxy actually. I mean, it wasn’t like ultra realistic

simulation. It was fascinating. Looms and heights. 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 one 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. That’s right. 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? Great question. It works best to use mixed

reality. So we have a snake stimulus that I personally don’t like snakes at all. I don’t

mind spiders. We also have a spider stimulus, but like snakes, I just don’t like them. There’s

something about the, the slithering and the, 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 one 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, more of a threat. Now,

I should also mention that we, 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, I’m, so I’m

Russian. So, you know, I always kind of think, how can I murder this people that this person

entered the room, but also how, how can I torture you to get some information out of you? What would

I go with? Hmm. It’s interesting. You should say that I never considered myself claustrophobic,

but because 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, and I had never been

to a banya. So, you know, the whole experience of really, really hot sauna and what are they

called? The plots. 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’ve 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. And at first you’re fine. You feel fine. 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. Yeah. Yeah. Yeah. For me as well, probably that one, that one is pretty

bad. The heights I tried to overcome. So I went to skydiving to try to overcome the fear of heights,

but that didn’t help. Did you jump out? Yeah. Yeah. I jumped out, but it was, it was a,

it was fundamentally different experience. And I guess there could be a lot of different flavors

of fear of heights maybe, but the one I have didn’t seem to be connected to jumping out of a

plane is a very different, cause like once you accept that you’re going to jump, then it’s,

it’s a different thing. I think what I’m afraid of is the moments before it is the scariest part.

Absolutely. 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 that

it’s 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 that I guess I’m not being eloquent in this description,

but there’s something about skydiving that was actually philosophically liberating. I was,

I was like, wow, it, 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

three 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. That was, that was wild. That was wild,

but I’m still terrified of heights. So, I mean, one, one thing I want to ask just on fear,

cause it’s so fascinating is have you learned anything about what it takes to overcome fears?

Yes. And that comes from two, from a, you know, research study standpoint,

two parallel tracks of research. One 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 in humans. And a graduate student in my lab,

she’s now at Caltech, Lindsay Saleh, 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 three

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 seeking, 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 one 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 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. It has positive valence. 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 arousal performance is low

and as the increases performance goes higher and then it drops off as you get really stressed.

But there’s another bump further out that 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 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 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 one 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 two 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 and that’s obvious. 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 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 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, slice

time more finely or more, less finely in order to adjust to the stimulus, the dynamics of the

stimulus. What about the realm of ideas? So like, you know, I’m a big believer, this guy named

Cal Newport who wrote a book about deep work. Yeah, I love that book. Yeah, he’s great. I mean,

one 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, you know, 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. You just

have to hold this concept, like you hold it and then you take steps with it. You take further

steps and you’re holding relatively complicated things in your mind as you’re thinking about them.

And there’s a lot of, I mean, the hardest part is there’s frustrating things like you take a step

and it turns out to be the wrong direction. So you have to calmly turn around and take a step back.

And then it’s, you kind of like exploring through the space of ideas. Is there something about

your study of optimal performance that can be applied to the act of thinking as opposed to

action? Well, we haven’t done too much work there, but I think I can comment on it from a neuroscience

perspective, which is really all I do is, well, I mean, we do experiments in the lab, but I’m

looking at things through the lens of neuroscience. So what you’re describing can be mapped fairly

well to working memory, just keeping things online and updating them as they change in information

is coming back into your brain. Jack Feldman, who I’m a huge fan of and fortunate to be friends

with is a professor at UCLA, works on respiration and breathing, but he has a physics background.

And so he thinks about respiration and breathing in terms of ground states and how they modulate

other states. Very, very interesting and I think important work. Jack has an answer to your

question. So I’m not going to get this exactly right because this is lifted from a coffee

conversation that we had about a month ago. So apologies in advance, but I think I can get mostly

right. So we were talking about this, about how the brain updates cognitive states depending on

demands and thinking in particular. And he used an interesting example. I’d be curious to know if you

agree or disagree. He said, most great mathematics is done by people in their late teens and 20s,

and even you could say early 20s, sometimes into the late 20s, but not much further on. Maybe I

just insulted some mathematicians. No, that’s true. And I think that it demands, his argument

was there’s a tremendous demand on working memory to work out theorems in math and to keep a number

of plates spinning, so to speak mentally and run back and forth between them, updating them.

In physics, Jack said, and I think this makes sense to me too, that there’s a reliance on

working memory, but an increased reliance on some deep memory and deep memory stores,

probably stuff that’s moved out of the hippocampus and forebrain and into the cortex and is some

episodic and declarative stuff, but really, so you’re pulling from your library, basically. It’s

not all RAM, it’s not all working memory. And then in biology, and physicists tend to have

very active careers into their 30s and 40s and 50s and so forth, sometimes later. And then in

biology, you see careers that have a much longer arc, these protracted careers often, people still

in their 60s and 70s doing really terrific work, not always doing it with their own hands because

people in the labs are doing them, of course. And that work does tend to rely on insights

gained from having a very deep knowledge base where you can remember a paper or maybe a figure

in a paper, you could go look it up if you wanted to, but it’s very different than the working

memory of the mathematician. And so when you’re talking about coding or being in that tunnel of

thought and trying to iterate and keeping a lot of plates spinning, it speaks directly to working

memory. My lab hasn’t done too much of that. But we are pushing working memory when we have people

do things like these simple lights out tasks. We can increase the cognitive load by increasing the

level of autonomic arousal to the point where they start doing less well. And everyone has a cliff.

This is what’s kind of fun. We’ve had SEAL team operators come to the lab. We’ve had people from

other units in the military. We’ve had a range of intellects and backgrounds and all sorts of things

and everyone has a cliff. And those cliffs sometimes show up as a function of the demands of

speed of processing or how many things you need to keep online. I mean, we’re all limited at some

point in the number of things we can keep online. So what you’re describing is very interesting

because I think it has to do with how narrow or broad the information set is. And I’m not an

active programmer, so this is a regime I don’t really fully know. So I don’t want to comment

about it in any way that doesn’t suggest that. But I think that what you’re talking about is

top down control. So this is prefrontal cortex keeping every bit of reflexive circuitry at bay,

the one that makes you want to get up and use the restroom, the one that makes you want to check

your phone, all of that, but also running these anterior thalamus to prefrontal cortex loops,

which we know are very important for working memory. Let me try to think through this a little

bit. So reducing the process of thinking to working memory access is tricky. It’s probably

ultimately correct. But if I were to say some of the most challenging things that an engineer has

to do, and a scientific thinker, I would say it’s kind of depressing to think that we do that best

in our 20s, but is this kind of first principles thinking step of saying you’re accessing the

things that you know, and then saying, well, let me, how do I do this differently than I’ve done

it before? This weird like stepping back, like, is this right? Let’s try it this other way. That’s

the most mentally taxing step is like, you’ve gotten quite good at this particular pattern of

how you solve this particular problem. So there’s a pattern recognition first. You’re like, okay,

I know how to build a thing that solves this particular problem in programming, say. And then

the question is, but can I do it much better? And I don’t know if that’s, I don’t know what

the hell that is. I don’t know if that’s accessing working memory. That’s almost access. Maybe it is

accessing memory in a sense. It’s trying to find similar patterns in a totally different place that

it could be projected onto this. But you’re not querying facts. You’re querying like functional

things like. Yeah, it’s patterns. I mean, you’re running out, you’re testing algorithms. Yeah.

Right. You’re testing algorithms. So I want to just, because I know some of the people listening

to this and you have a basis in scientific training and have scientific training. So I

want to be clear. I think we can be correct about some things like the role of working memory in

these kinds of processes without being exhaustive. We’re not saying they’re the only thing. We can be

correct, but not assume that that’s the only thing involved. And neuroscience, let’s face it,

is still in its infancy. I mean, we probably know 1% of what there is to know about the brain.

I mean, we’ve learned so much and yet there may be global states that underlie this that

make prefrontal circuitry work differently than it would in a different regime or even time of day.

I mean, there’s a lot of mysteries about this. So I just want to make sure that we’re aiming for

precision and accuracy, but we’re not going to be exhausted. So there’s a difference there. And I

think sometimes in the vastness of the internet, that gets forgotten. So the other is that

we think about these operations at really focused, keeping a lot of things online.

But what you were describing is actually, it speaks to the very real possibility probably

that with certainty, there’s another element to all this, which is when you’re trying out lots

of things, in particular, lots of different algorithms, you don’t want to be in a state of

very high autonomic arousal. That’s not what you want, because the higher level of autonomic

arousal and stress in the system, the more rigidly you’re going to analyze space and time. And what

you’re talking about is playing with space time dimensionality. And I want to be very clear. I’m

the son of a physicist. I am not a physicist. When I talk about space and time, I’m literally

talking about visual space and how long it takes for my finger to move from this point to this

point. You are facing a tiger and trying to figure out how to avoid being eaten by the tiger.

And that’s primarily going to be determined by the visual system in humans. We don’t walk through

space, for instance, like a cent hound would and look at three dimensional scent plumes. When a

scent hound goes out in the environment, they have depth to the odor trails they’re following.

And they don’t think about them. We don’t think about odor trails. You might say,

oh, well, the smell’s getting more intense. Aha. But they actually have three dimensional odor

trails. So they see a cone of odor, see, of course, with their nose, with their olfactory cortex.

We do that with our visual system. And we parse time, often subconsciously, mainly with our visual

system, also with our auditory system. And this shows up for the musicians out there. Metronomes

are a great way to play with this. Bass drumming, when the frequency of bass drumming changes,

your perception of time changes quite a lot. So in any event, space and time are linked

through the sensory apparatus, through the eyes and ears and nose, and probably through taste too,

and through touch for us, but mainly through vision. So when you drop into some coding or

iterating through a creative process or trying to solve something hard,

you can’t really do that well if you’re in a rigid, high level of autonomic arousal because

you’re plugging in algorithms that are in this space regime, this time regime matches. It’s

space time matched. Whereas creativity, I always think the lava lamp is actually a pretty good

example, even though it has these counterculture, new agey connotations, because you actually don’t

know which direction things are going to change. And so in drowsy states, sleeping and drowsy

states, space and time become dislodged from one another somewhat, and they’re very fluid.

And I think that’s why a lot of solutions come to people after sleep and naps. And this could

even take us into a discussion, if you like, about psychedelics and what we now know, for instance,

that people thought that psychedelics work by just creating spontaneous bursting of neurons

and hallucinations. But the 5H2C and 2A receptors, which are the main sites for things like LSD and

psilocybin and some of the other ones that create hallucinations, the drugs that create hallucinations,

most of those receptors are actually in the collection of neurons that encase the thalamus,

which is where all the sensory information goes into, a structure called the thalamic

reticular nucleus. And it’s an inhibitory structure that makes sure that when we’re

sitting here talking, that I’m mainly focused on whatever I’m seeing visually, that I’m essentially

eliminating a lot of sensory information. Under conditions where people take psychedelics and

these particular serotonin receptors are activated, that inhibitory shell, it’s literally shaped like

a shell, starts losing its ability to inhibit the passage of sensory information. But mostly

the effects of psychedelics are because the lateral connectivity in layer five of cortex

across cortical areas is increased. And what that does is that means that the space time relationship

for vision, like moving my finger from here to here, very rigid space time relationship,

right? If I slow it down, it’s slower, obviously, but there’s a prediction that can be made based on

the neurons in the retina and the cortex. On psychedelics, this could be a very strange

experience. But the auditory system has one that’s slightly different space time, and they’re matched

to one another in deeper circuits in the brain. The olfactory system has a different space time

relationship to it. So under conditions of these increased activation of these serotonin receptors,

space and time across sensory area starts being fluid. So I’m no longer running the algorithm for

moving my finger from here to here and making a prediction based on vision alone. I’m now,

this is where people talk about hearing sites, right? You start linking, this might actually

make a sound in a psychedelic state. Now I’m not suggesting people run out and do psychedelics

because it’s very disorganized, but essentially what you’re doing is you’re mixing the algorithms.

And so when you talk about being able to access new solutions, you don’t need to rely on

psychedelics. If people choose to do that, that’s their business. But in drowsy states, this lateral

connectivity is increased as well. The shell of the thalamus shuts down. And these are through

these so called pons chiniculate occipital waves. And what’s happening is you’re getting whole brain

activation at a level that you start mixing algorithms. And so sometimes I think solutions

come not from being in that narrow tunnel of space time and strong activation of working memory and

trying to well iterate if this, then this very strong, deductive and inductive thinking and

working from first principles, but also from states where something that was an algorithm

that you never had in existence before suddenly gets lumped with another algorithm. And all of a

sudden a new possibility comes to mind. And so space and time need to be fluid and space and

time need to be rigid in order to come up with something meaningful. And I realize I’m riffing

long on this, but this is why I think, you know, there was so much interest a few years ago with

Michael Pollan’s book and other things happening about psychedelics as a pathway to exploration and

all this kind of thing. But the real question is what you export back from those experiences,

because dreams are amazing, but if you can’t bring anything back from them, they’re just amazing.

I wonder how to experiment with the mind without, without any medical assistance

first. Like, you know, I, I pushed my mind in all kinds of directions. I definitely want to,

I did, uh, shrooms a couple of times. I definitely want to, uh, figure out how I can experiment with,

um, with psychedelics. I’m talking to, uh, Rick Doblin, uh, soon. I even went back and forth. So

he does all these studies on psychedelics and he keeps ignoring the parts of my email that asks,

like, how do I participate in these studies? Well, there are some legality issues. I mean,

conversation, I want to be very clear. I’m not saying that anyone should go out and do psychedelics.

I think that drowsy states and sleep states are super interesting for accessing some of

these more creative states of mind. Hypnosis is something that my colleague, David Spiegel,

associate chair of psychiatry at Stanford works on where also, again, it’s a unique state because

you have narrow context. So this is very, um, kind of tunnel vision and yet deeply relaxed,

excuse me, deeply relaxed where new algorithms, if you will, can start to surface, um, strong

state for inducing neuroplasticity. And I think, you know, so if I had a, um, I’m part of a group,

um, that, uh, it’s called the liminal collective as a group of people that get together and talk

about, um, just wild ideas, but they try and implement. Um, and it’s a, it’s a really interesting

group. Some people from a military, from a logitech and some other backgrounds, academic

backgrounds. And I was asked, you know, what would be, um, if you could create a tool,

you just had a tool like your magic wand wish for the day, what would it be? I thought it’d

be really interesting if someone could develop psychedelics that have, um, on off switches.

So you could go into a psychedelic state very deeply for 10 minutes, but you could launch

yourself out of that state and place yourself into a linear real world state very quickly

so that you could extract whatever it was that happened in that experience. And then go back

in if you wanted, because the problem with psychedelic states and dream states is that

first of all, a lot of the reason people do them is they’re lying. They say they want plasticity

and they want all this stuff. They want a peak experience inside of an amplified experience.

So they’re kind of seeking something unusual. And I think we should just be honest about that

because a lot of times they’re not trying to make their brain better. They’re just trying

to experience something really amazing. But the problem is space and time are so unlocked

in these states, just like they are in dreams, that you can really end up with a whole lot of

nothing. You can have an amazing amplified experience housed in an amplified experience

and come out of that thinking you had a meaningful experience when you didn’t bring anything back.

You didn’t bring anything back. All you have is a fuzzy memory of having a transformational

experience, but you don’t actually have tools to bring back, sorry, actually concrete ideas to

bring back. Yeah, it’s interesting. I wonder if it’s possible to do that with a mind to be able to

hop back and forth. I think that’s where the real power of adjusting states is going to be. It

probably will be with devices. I mean, maybe it will be done through pharmacology. It’s just that

it’s hard to do on off switches in human pharmacology that we have them for animals.

I mean, we have Cree flip recombinases and we have channel opsins and halo root opsins and

all these kinds of things. But to do that work in humans is tricky, but I think you could do it

with virtual reality, augmented reality and other devices that bring more of the somatic experience

into it. You’re of course, a scientist who’s studying humans as a collective. I tend to be

just a one person scientist of just looking at myself and I play when these deep thinking,

deep work sessions, I’m very cognizant in the morning that there’s times when my mind is so

eloquent at being able to jump around from ideas and hold them all together. I’m almost like I

step back from a third person perspective and enjoy that, whatever that mind is doing,

I do not waste those moments. I’m very conscious of this little creature that woke up that’s only

awake for, if we’re being honest, maybe a couple hours a day. Early part of the day for you.

Early part of the day. Not always. Well, early part of the day for me is a very fluid concept.

You’re one of those.

Yeah, I’m one.

Yeah, you’re one of those.

Being single, one of the problems, single and no meetings. I don’t schedule any meetings.

I’ve been living at like a 28 hour day. So it drifts. So it’s all over the place. But

after a traditionally defined full night’s sleep, whatever the heck that means, I find that in those

moments, there’s a clarity of mind that’s just, everything is effortless. And it’s the deepest

dives intellectually that I make. And I’m cognizant of it. And I try to bring that to the other parts

of the day that don’t have it and treasure them even more in those moments because they only last

like five or 10 minutes. Because of course, in those moments you want to do all kinds of stupid

stuff that are completely is worthless, like check social media or something like that.

But those are the most precious things in intellectual life is those mental moments

of clarity. And I wonder, I’m learning how to control them. I think caffeine is somehow involved.

I’m not sure exactly.

Sure. Well, because if you learn how to titrate caffeine,

and everyone’s slightly different with this, what they need, but if you learn to titrate caffeine

with time of day and the kind of work that you’re trying to do, you can bring that autonomic arousal

state into a close to perfect place. And then you can tune it in with, sometimes people want a little

bit of background music. Sometimes they want less, these kinds of things. The early part of the day

is interesting because the one thing that’s not often discussed is this transition out of sleep.

So there’s a book, I think it’s called Winston Churchill’s Nap. And it’s about

naps and the transition between wake and sleep as a valuable period. A long time ago,

someone who I respect a lot was mentoring me said, be very careful about bringing in

someone else’s sensory experience early in the day. So when I wake up, I’m very drowsy. I sleep

well, but I don’t emerge from that very quickly. I need a lot of caffeine to wake up and whatnot.

But there’s this concept of getting the download from sleep, which is in sleep, you were essentially

expunging the things that you don’t need, the stuff that is meaningless from the previous day,

but you were also running variations on these algorithms of whatever it is you’re trying to

work out in life on short timescales like the previous day and long timescales like your whole

life. And those lateral connections in layer five of the neocortex are very robustly active and

across sensory areas. And you’re running an algorithm or it’s a brain state that will be

useless in waking. You wouldn’t get anything done. You’d be the person talking to yourself

in the hallway or something about something that no one else can see. But in those states,

the theory is that you arrive at certain solutions and those solutions will reveal

themselves in the early part of the day, unless you interfere with them by bringing in,

social media is a good example of you immediately enter somebody else’s

space time sensory relationship. Someone is the conductor of your thoughts in that case.

And so many people have written about this. What I’m saying isn’t entirely new, but allowing the

download to occur in the early part of the day and asking the question, am I more in my head

or am I more of an interoceptive or exteroceptive mode? And depending on the kind of work you need

to do, if it sounds like for you, it’s very interoceptive and you’ve got a lot of thinking

going on and a lot of computing going on, allowing yourself to transition out of that sleep state and

arrive with those solutions from sleep and plug into the work really deeply. And only then allowing

things like music, news, social media, doesn’t mean you shouldn’t talk to loved ones and see

faces and things like that. But some people have taken this to the extreme. When I was a graduate

student at Berkeley, there was a guy there, a professor, brilliant, odd, but brilliant,

who was so fixated on this concept that he wouldn’t look at faces in the early part of the

day because he just didn’t want anything else to impact him. Now he didn’t have the most rounded

life, I suppose. But if you’re talking about cognitive performance, this could actually be

very beneficial. You said so many brilliant things. So one, if you read books that describe

the habits of brilliant people like writers, they do control that sensory experience in the

hours after wake. Like many writers, you know, they have a particular habit of several hours

early in the morning of actual writing. They don’t do anything else for the rest of the day,

but they control, they’re very sensitive to noises and so on. I think they make it very difficult to

live with them. I try to, I’m definitely like that. Like I could, I love to control the sensory

how much information is coming in. There’s something about the peaceful, just everything

being peaceful. At the same time, and we were talking to a mutual friend of Whitney Cummings,

who has a mansion, a castle on top of a cliff in the middle of nowhere. She actually purchased her

own island. She wants silence. She wants to control how much sound is coming in.

She’s very sensitive to sound and environment. Beautiful home and environment, but like clearly

puts a lot of attention into details. Yeah. And very creative.

Yeah. And that’s, yeah, that allows for creativity to flourish. I’m also, I don’t like that feels

like a slippery slope. So I enjoy introducing the noises and signals and training my mind to

be able to tune them out. Cause I feel like you can’t always control the environment so perfectly

because, cause your mind gets comfortable with that. I think it’s a skill that you want to learn

to be able to shut it off. Like I often go to like back before COVID to a coffee shop.

It really annoys me when there’s sounds and voices and so on, but I feel like I can train my mind

to, to block them out. So it’s, it’s a balance, I think.

Yeah. And I think you know, two things come to mind as you’re saying this first of all,

yeah. I mean, we’re talking about what’s best for work is not always what’s best for, you know,

completeness of life. I mean, you know, autism is probably many things like when you hit autism,

just like feet, there are probably 50 ways to get a fever. There are probably 50 ways to,

that the brain can create what looks like autism or what people call autism.

There’s an interesting set of studies that have come out of David Ginty’s lab at Harvard med,

looking at these are mouse mutants where these are models for autism, where nothing is disrupted

in the brain proper and in the central nervous system, but the sensory app, the sensory neurons,

the ones that innervate the skin and the ears and everything are, are hypersensitive. And this maps

to a mutation in certain forms of human autism. So this means that the, the overload of sensory

information and sensory experience that a lot of autistics feel, they’re like that they can’t

tolerate things. And then they get the stereotype behaviors, the rocking and the kind of the

shouting it, you know, we always thought of that as a brain problem. In some cases it might be,

but in many cases it’s because they just can’t, they, they seem to have a, it’s like turning the

volume up on every sense. And so they’re overwhelmed and none of us want to become like

that. I think it’s very hard for them and it’s hard for their parents and so forth. So I, I like

the coffee shop example because the way I think about trying to build up resilience, you know,

physically or mentally or otherwise is one of I guess we could call it limb. I like to call it

limbic friction. That’s not a real scientific term. And I acknowledge that I’m making it up

now because I think it captures the concept, which is that, you know, we always hear about

resilience. It makes it sound like, oh, you know, under stress where everything’s coming at you,

you’re going to stay calm, but there’s another, you know, so limbic, the limbic system wants to

pull you in some direction, typically in the direction of reflexive behavior and the prefrontal

cortex through top down mechanisms has to suppress that and say, no, we’re not going to respond to

the banging of the coffee cups behind me, or I’m going to keep focusing. That’s pure top down

control. So limbic friction is high in that environment. You’ve put yourself into a high

limbic friction environment, meaning that the prefrontal cortex has to work really hard.

But there’s another side to limbic friction too, which is when you’re very sleepy,

there’s nothing incoming. It can be completely silent and it’s hard to engage and focus because

you’re drifting off and you’re getting sleepy. So their limbic friction is high, but for the

opposite reason, autonomic arousal is too low. So they’re turning on Netflix in the background or

looping a song might boost your level of alertness that will allow top down control to be in exactly

the sweet spot you want it. So this is why earlier I was saying it’s all about how we feel inside

relative to what’s going on on the outside. We’re constantly in this, I guess one way you

could envision it spatially, especially if people are listening to this just on audio,

is I like to think about it kind of like a glass barbell where one sphere of perception and

attention can be on what’s going on with me. And one sphere of attention can be on what’s going on

with you or something else in the room or in my environment. But this barbell isn’t rigid. It’s

not really glass. Would plasma work here? I don’t know anything about plasma. Sorry. I don’t know.

So imagine that this thing can contort the size of the globes at the end of this barbell can get

bigger or smaller. So let’s say I close my eyes and I bring all my experience into what’s going on

through interoception internally. Now it’s as if I’ve got two orbs of perception just on my

internal state, but I can also do the opposite and bring both orbs of perception outside me.

I’m not thinking about my heart rate or my breathing. I’m just thinking about something

I see. And what you’ll start to realize as you kind of use this spatial model is that two things.

One is that it’s very dynamic and that the more relaxed we are, the more these two orbs of

attention, the two ends of the barbell can move around freely. The more alert we are,

the more rigid they’re going to be tethered in place. And that was designed so that if I have

a threat in my environment, it’s tethered to that threat. If something’s coming to attack me, I’m not

going to be like, oh, my breathing cadence is a little bit quick. That’s not how it works. Why?

Because both orbs are linked to that threat. And so my behavior is now actually being driven by

something external, even though I think it’s internal. And so I don’t want to get too abstract

here because I’m a neuroscientist. I’m not a theorist. But when you start thinking about

models of how the brain works, there are only really three things that neurons do. They’re

either sensory neurons, they’re motor neurons, or they’re modulating things. And the models of

attention and perception that we have now, 2020, tell us that we’ve got interoception

and exteroception. They’re strongly modulated by levels of autonomic arousal. And that if we want

to form the optimal relationship to some task or some pressure or some thing, whether or not it’s

sleep, an impending threat, or coding, we need to adjust our internal space time relationship with

the external space time relationship. And I realize I’m repeating what I said earlier.

But we can actually assign circuitry to this stuff. It mostly has to do with how much limbic

friction there is, how much you’re being pulled to some source. That source could be internal.

If I have pain, physical pain in my body, I’m going to be much more interoceptive than I am

exteroceptive. You could be talking to me and I’m just going to be thinking about that pain. It’s

very hard. And the other thing that we can link it to is top down control, meaning anything in

our environment that has a lot of salience will tend to bring us into more exteroception than

interoception. And again, I don’t want to litter the conversation with just a bunch of terms, but

what I think it can be useful for people is to do what essentially you’ve done,

Lex, is to start developing an awareness. When I wake up, am I mostly in a mode of interoception

or exteroception? When I work well, what does working well look like from the perspective of

autonomic arousal? How alert or calm am I? What kind of balance between internal focus and external

focus is there? And to sort of watch this process throughout the day. Can you linger just briefly

on, because you use this term a lot and it’d be nice to try to get a little more color to it,

which is interoception and exteroception. What are we exactly talking about? So like

what’s included in each category and how much overlap is there? Interoception would be an

awareness of anything that’s within the confines or on the surface of my skin that I’m sensing.

So literally physiological. Physiologically, like within the boundaries of my skin

and probably touched to the skin as well. Exteroception would be perception of anything

that’s beyond the reach of my skin. So that bottle of water, a scent, a sound, and this

can change dramatically actually. If you have headphones in, you tend to hear things in your

head as opposed to a speaker in the room. This is actually the basis of ventriloquism.

So there are beautiful experiments done by Greg Reckenzone up at UC Davis, looking at how auditory

and visual cues are matched and you have an array of speakers and this will become obvious as I say

it, but obviously the ventriloquist doesn’t throw their voice. What they do is they direct your

vision to a particular location and you think the sound is coming from that location. And there are

beautiful experiments that Greg and his colleagues have done where they suddenly introduce an

auditory visual mismatch and it freaks people out because you can actually make it seem from a

perception standpoint as if the sound arrived from the corner of the room and hit you physically and

people will recoil. And so sounds aren’t getting thrown across the room. They’re still coming from

a defined location, an array of speakers, but this is the way the brain creates these internal

representations. And again, I don’t want to go down a rabbit hole, but I’m sure the listeners

appreciate this, but everything in the brain is an abstraction, right? I mean, the sensory

apparatus, there are the eyes and ears and nose and skin and taste and all that are taking

information and with interoception, taking information from sensors inside the body,

the enteric nervous system for the gut. I’ve got sensory neurons that innervate my liver,

um, et cetera, taking all that. And the brain is abstracting that in the same way that if I

took a picture of your face and I handed it to you and I’d say, that’s you, you’d say, yeah, that’s

me. But if I were an abstract artist, I’d be doing a little bit more of what the brain does, where if

I took a pen, pad and paper, maybe I could do this because I’m a terrible artist and I could just

mix it up. And I, let’s say I would make your eyes like water bottles, but I’d flip them upside down

and I’d start assigning fruits and objects to the different features of your face. And I show it to

you, I say, Lex, that’s you say, well, that’s not me. And I’d say, no, but that’s my abstraction

of you. But that’s what the brain does. The space time relationship of the neurons that fire that

encode your face has have no resemblance to your face. Right. And I think people don’t really,

I don’t know if people have fully internalized that, but the day that I, and I’m not sure I

fully internalized that because it’s weird to think about, but all neurons can do is fire in

space and in time, different neurons in different sequences, perhaps with different intensities.

It’s not clear. The action potential is all or none. Although people, neuroscientists don’t like

to talk about that, even though it’s been published in nature a couple of times, the

action potential for a given neuron doesn’t always have the exact same waveform. People,

it’s in all the textbooks, but you can modify that waveform.

Well, I mean, there’s a lot of fascinating stuff with neuroscience about the fuzziness of all the,

of the transfer of information from neuron to neuron. I mean, we certainly touch upon it every

time we at all try to think about the difference between artificial neural networks and biological

neural networks. But can we maybe linger a little bit on this, on the circuitry that you’re getting

at? So the brain is just a bunch of stuff firing and it forms abstractions that are fascinating

and beautiful, like layers upon layers upon layers of abstraction. And I think it, just like

when you’re programming, you know, I’m programming in Python, it’s awe inspiring to think that

underneath it all, it ends up being zeros and ones. And the computer doesn’t know about, you know,

stupid Python or Windows or Linux. It only knows about the zeros and ones. In the same way with

the brain, is there something interesting to you or fundamental to you about the circuitry of the

brain that allows for the magic that’s in our mind to emerge? How much do we understand? I mean,

maybe even focusing on the vision system, is, is there something specific about the structure of

the vision system, the circuitry of it that allows for the complexity of the vision system to emerge?

Or is it all just the complete chaotic mess that we don’t understand?

It’s definitely not all a chaotic mess that we don’t understand, if we’re talking about vision.

And that’s not just because I’m a vision scientist.

Let’s stick to vision.

Let’s stick to vision. Well, because in the beauty of the visual system, the reason David Hubel and

Torrance and Wiesel won the Nobel prize was because they were brilliant and forward thinking and

adventurous and all that good stuff. But the reason that the visual system is such a great

model for addressing these kinds of questions and other systems are hard, is we can control

the stimuli. We can adjust spatial frequency, how finer the gratings are, thick gratings,

thin gratings. We can adjust temporal frequency, how fast things are moving. We can use cone

isolating stimuli. We can use it. There’s so many things that you can do in a controlled way.

Whereas if we were talking about cognitive encoding, like encoding the space of concepts

or something. I, like you, if I may, am drawn to the big questions.

The big questions in neuroscience. But I confess in part because of some good advice I got early

in my career and in part because I’m not perhaps smart enough to go after the really high level

stuff. I also like to address things that are tractable and we need to address what we can

stand to make some ground on at a given time.

There you can construct brilliant controlled experiments to study, to really literally

answer questions about, yeah.

Yeah. I mean, I’m happy to have a talk about consciousness, but it’s a scary talk. And I

think most people don’t want to hear what I have to say, which is, we can save that for later,


I mean, it’s an interesting question of, we talk about psychedelics. We can talk about

consciousness. We can talk about cognition. Can experiments in neuroscience be constructed

to shed any kind of light on these questions?

So, I mean, it’s cool that vision, I mean, to me, vision is probably one of the most beautiful

things about human beings. Also from the AI side, computer vision has some of the most

exciting applications of neural networks is in computer vision. But it feels like that’s a

that’s a neighbor of cognition and consciousness. It’s just that we maybe haven’t come up with

experiments to study those yet.

Yeah. The visual system is amazing. We’re mostly visual animals to navigate,

survive. Humans mainly rely on vision, not smell or something else, but it’s a filter

for cognition and it’s a, it’s a strong driver of cognition. Maybe just cause it came up and

then we’re moving to higher level concepts. Just the way the visual system works can be

summarized in it in a few relatively succinct statements. Unlike most of what I’ve said,

which has not been succinct at all.

Let’s go there.

You know, the retina, yeah. So the retina is this three layers of neuron structure at the

back of your eye. It’s about as thick as a credit card. It is a piece of your brain.

And sometimes people think I’m kind of wriggling by out of a reality by saying that it is,

it’s absolutely a piece of the brain. It’s, it’s a forebrain structure that in the first

trimester, there’s a genetic program that made sure that that neural retina, which is part of

your central nervous system was squeezed out into what’s called the embryonic eye cups.

And that the bone formed with a little hole where the optic nerve is going to connect

it to the rest of the brain. And those, that window into the world is the only window into

the world for a, for a mammal, which has a thick skull. Birds have a thin skull. So their pineal

gland sits and lizards too, and snakes actually have a hole so that light can make it down into

the pineal directly. And in train melatonin rhythms for time of day and time of year,

humans have to do all that through the eyes. So three layers of neurons that are a piece of your

brain, their central nervous system, and the optic nerve connects to the rest of the brain,

the neurons in the eye, somewhat just care about luminance, just how bright or dim it is.

And they inform the brain about time of day. And then the central circadian clock informs every

cell in your body about time of day and make sure that all sorts of good stuff happens. If you’re

getting light in your eyes at the right times and all sorts of bad things happen. If you are getting

light randomly throughout the 24 hour cycle, we could talk about all that, but this is a good

incentive for keeping a relatively normal schedule, consistent schedule, light exposure,

consistent schedule, try and keep a consistent schedule. When you’re young, it’s easy to go off

schedule and recover. As you get older, it gets harder, but you see everything from outcomes in

cancer patients to diabetes improves when people are getting light at a particular time of day and

getting darkness at a particular phase of the 24 hour cycle. We were designed to get light and

dark at different times of the circadian cycle. All that information is coming in through

specialized type of neuron in the retina called the melanopsin intrinsically photosensitive

ganglion cell discovered by David Berson at Brown University. That’s not spatial information. It’s

subconscious. You don’t think, Oh, it’s daytime. Even if you’re looking at the sun, it doesn’t

matter. It’s a photon counter. It’s literally counting photons. And it’s saying, Oh, even

though it’s a cloudy day, lots of photons coming in at winter in Boston, it must be winter. And

your system is a little depressed. It’s spring. You feel alert. That’s not a coincidence. That’s

these melanopsin cells signaling the circadian clock. There are a bunch of other neurons in the

eye that signal to the brain and they mainly signal the presence of things that are lighter

than background or darker than background. So a black objects would be darker than background,

a light object lighter than background. And that all come, it’s mainly it’s looking at pixels.

Mainly it’s they look at circles and those neurons have receptive fields,

which not everyone will understand, but those neurons respond best to little circles of dark

light or little circles of bright light, little circles of red light versus little circles of

green light or blue light. And so it sounds very basic. It’s like red, green, blue and circles

brighter or dimmer than what’s next to it. But that’s basically the only information that sent

down the optic nerve. And when we say information, we can be very precise. I don’t mean little bits

of red traveling down the optic nerve. I mean, spikes neural action potentials in space and time,

which for you is like makes total sense. But I think for a lot of people, it’s actually beautiful

to think about all that information in the outside world is converted into a language

that’s very simple. It’s just like a few syllables, if you will. And those syllables

are being shouted down the optic nerve, converted into a totally different language, like Morse code

goes into the brain. And then the thalamus essentially responds in the same way that

the retina does, except the thalamus is also waiting things. It’s saying, you know what,

that thing was moving faster than everything else, or it’s brighter than everything else.

So that signal I’m going to get up, I’m going to allow up to cortex or that signal is much

redder than it is green. So I’m going to let that signal go through that signal as much.

It’s kind of more like the red next to it. Throw that out. The information just doesn’t get up into

your cortex. And then in cortex, of course, is where perceptions happen. And in V1, if you will,

visual area one, but also some neighboring areas, you start getting representations of

things like oriented lines. So there’s a neuron that responds to this angle of my hand versus

vertical. This is the defining work of Hubel and Wiesel’s Nobel. And it’s a very systematic map

of orientation, line orientation, direction of movement, and so forth. And that’s pretty much,

and color, and that’s how the visual system is organized all the way up to the cortex.

So it’s hierarchical. I want to be clear. It’s hierarchical because you don’t build up that line

by suddenly having a neuron that responds to lines in some random way. It responds to lines

by taking all the dots that are aligned in a vertical stack, and they all converge on one

neuron. And then that neuron responds to vertical lines. So it’s not random. There’s no abstraction

at that point, in fact. In fact, if I showed you a black line, I could be sure that if I

were imaging V1, that I would see a representation of that black line as a vertical line somewhere in

your cortex. So at that point, it’s absolutely concrete. It’s not abstract. But then things get

really mysterious. Some of that information travels further up into the cortex and goes from

one visual area to the next, to the next, to the next, so that by time you get into an area that

Nancy Kanwisher at MIT has studied much of her career, the fusiform face area, you start finding

single neurons that respond only to your father’s face or to Joe Rogan’s face, regardless of the

orientation of his face. I’m sure if you saw Joe, because you know him well, from across the room

and you just saw his profile, you’d be like, oh, that’s Joe. Walk over and say hello.

The orientation of his face isn’t there. You wouldn’t even see his eyes necessarily,

but he’s represented in some abstract way by a neuron that actually would be called the Joe

Rogan neuron. He might have limits. I might not recognize him if he was upside down or

something like that. It’d be fascinating to see what the limits of that Joe Rogan concept is.

So Nancy’s lab has done that because early on she was challenged by people that said

there aren’t face neurons. There are neurons that they only respond to space and time,

shapes and things like that, moving in particular directions and orientations. It turns out

Nancy was right. They use these stimuli called greeble stimuli, which any computer programmer

would appreciate, which kind of morphs a face into something gradually that eventually just

looks like this alien thing they call the greeble. The neurons don’t respond to greebles.

In most cases, they only respond to faces and familiar faces. Anyway, I’m summarizing a lot

of literature and forgive me, Nancy, and for those of the greeble people, if they’re ours,

they’re like, don’t come after me with pitchforks. Actually, you know what? Come after me with

pitchforks. I think you know what I’m trying to do here. So the point is that in the visual system,

it’s very concrete up until about visual area four, which has color pinwheels and seems to

respond to pinwheels of colors. And so the stimuli become more and more elaborate, but at some point

you depart that concrete representation and you start getting abstract representations that can’t

be explained by simple point to point wiring. And to take a leap out of the visual system to

the higher level concepts, what we talked about in the visual system maps to the auditory system

where you’re encoding what? Frequency of tone sweeps. So this is going to sound weird to do,

but you know, like a Doppler, like hearing something, a car passing by, for instance,

but at some point you get into motifs of music that can’t be mapped to just a, what they call a

tonotopic map of frequency. You start abstracting. And if you start thinking about concepts of

creativity and love and memory, like what is the map of memory space? Well, your memories are very

different than mine, but presumably there’s enough structure at the early stages of memory processing

or at the early stages of emotional processing or at the earlier stages of creative processing

that you have the building blocks, your zeros and ones, if you will,

but you depart from that eventually. Now the exception to this, and I want to be really clear

because I was just mainly talking about neocortex, the six layered structure on the outside of the

brain that explains a lot of human abilities, other animals have them too, is that subcortical

structures are a lot more like machines. It’s more plug and chug. And what I’m talking about

is the machinery that controls heart rate and breathing and receptive fields, neurons that

respond to things like temperature on the top of my left hand. I came into neuroscience from

more of a perspective initially of psychology, but one of the reasons I forced upon myself to learn

some electrophysiology, not a ton, but enough, and some molecular biology and about circuitry

is that one of the most beautiful experiences you can have in life, I’m convinced, is to lower

an electrode into the cortex and to show a person or an animal, we do this ethically of course,

stimulus like an oriented line or a face. And you can convert the recordings coming off of

that electrode into an audio signal or an audio monitor, and you can hear what they call hash.

It’s not the hash you smoke, it’s the hash you hear. And it sounds like, it just sounds like

noise. And in the cortex, eventually you find a stimulus that gets the neuron to spike and

fire action potentials that are converted into an auditory stimulus that are very concrete,

crack, crack, crack, sounds like a bat cracking, like home runs or outfield balls.

When you drop electrodes deeper into the thalamus or into the hypothalamus or into the brainstem

areas that control breathing, it’s like a machine. You never hear hash. You drop the electrode down.

This could be like a grungy old Tugston electrode, not high fidelity electrode, as long as it’s got

a little bit of insulation on it. You plug it into an audio monitor, it’s picking up electricity.

And if it’s a visual neuron and it’s in the thalamus or the retina and you walk in front

of that animal or person, that neuron goes, and then you walk away and it stops. And you put your

hand in front of the eye again and it goes, and you could do that for two days. And that neuron

will just, every time there’s a stimulus, it fires. So whereas before, it’s a question of

how much information is getting up to cortex. And then these abstractions happening where

you’re creating these ideas, when you go subcortical, everything is.

There’s no abstraction.

It’s two plus two equals four. There’s no abstractions. And this is why I know we have

some common friends at Neuralink and I love the demonstration they did recently. I’m a huge fan

of what they’re doing and where they’re headed. And no, I don’t get paid to say that. And I have

no business relationship to them. I’m just a huge fan of the people in the mission.

But my question was to some of them, when are you going to go subcortical? Because if you want to

control an animal, you don’t do it in the cortex. The cortex is like the abstract painting I made

of your face. Removing one piece or changing something may or may not matter for the abstraction.

But when you are in the subcortical areas of the brain, a stimulating electrode can

evoke an entire behavior or an entire state. And so the brain, if we’re going to have a

discussion about the brain and how the brain works, we need to really be clear which brain,

because everyone loves neocortex. It’s like, oh, canonical circuits in cortex. We’re going to get

the cortical connectome. And sure, necessary, but not sufficient. Not to be able to plug in

patterns of electrical stimulation and get behavior. Eventually we’ll get there. But if

you’re talking subcortical circuits, that’s where the action is. That’s where you could potentially

cure Parkinson’s by stimulating the subthalamic nucleus, because we know that it gates motor

activation patterns in very predictable ways. So I think for those that are interested in

neuroscience, it pays to pay attention to like, is this a circuit that abstracts the sensory

information? Or is it just one that builds up hierarchical models in a very predictable way?

And there’s a huge chasm in neuroscience right now, because there’s no conceptual

leadership. No one knows which way to go. And this is why I think Neuralink has captured an

amazing opportunity, which was, okay, well, while all you academic research labs are figuring all

this stuff out, we’re going to pick a very specific goal and make the goal, the end point. And some

academic laboratories do that, but I think that’s a beautiful way to attack this whole thing about

the brain, because it’s very concrete. Let’s restore motion to the Parkinsonian patient.

Academic labs want to do that too, of course. Let’s restore speech to the stroke patient.

But there’s nothing abstract about that. That’s about figuring out the solution to a particular

problem. So anyway, those are my… And I admit I’ve mixed in a lot of opinion there,

but having spent some time, like 25 years digging around in the brain and listening to neurons

firing and looking at them anatomically, I think given it’s 2020, we need to ask the right… The

way to get better answers is ask better questions. And the really high level stuff is fun. It makes

for good conversation and it has brought enormous interest. But I think the questions about

consciousness and dreaming and stuff, they’re fascinating, but I don’t know that we’re there yet.

So you’re saying there might be a chasm in the two views of the power of the brain arising from

the circuitry that forms abstractions or the power of the brain arising from the majority

of the circuitry that’s just doing very brute force, dumb things that don’t have any fancy

kind of stuff going on. That’s really interesting to think about.

And which one to go after first. And here I’m poaching badly from someone I’ve never met,

but whose work I follow, which is, and it was actually on your podcast. I think Elon Musk

said, basically the brain is a, I want to say a monkey brain with a supercomputer on top.

And I thought that’s actually probably the best description of the brain I’ve ever heard because

it captures a lot of important features like limbic friction. But we think of like, oh,

when we’re making plans, we’re using the prefrontal cortex and we’re executive function

and all this kind of stuff. But think about the drug addict who’s driven to go pursue

heroin or cocaine. They make plans. So clearly they use their frontal cortex. It’s just that

it’s been hijacked by the limbic system and all the monkey brain as he referred to. It’s really

not fair to monkeys though, Elon, because actually monkeys can make plans. They just don’t make plans

as sophisticated as us. I’ve spent a lot of time with monkeys, but I’ve also spent a lot of time

with humans. Anyway, you’re saying like, there’s a lot of value to focusing on the monkey brain

or whatever the heck you call it. I do because let’s say I had an ability to place a chip anywhere

I wanted in the brain today and activate it or inhibit that area. I’m not sure I would put that

chip in neocortex, except maybe to just kind of have some fun and see what happens. The reason

is it’s an abstraction machine. And especially if I wanted to make a mass production tool,

a tool in mass production that I could give to a lot of people, because it’s quite possible that

your abstractions are different enough than mine that I wouldn’t know what patterns of firing to

induce. But if I want, let’s say I want to increase my level of focus and creativity. Well, then I

would love to be able to, for instance, control my level of limbic friction. I would love to be

able to wake up and go, Oh, you know what? I have an eight o clock appointment. I wake up slowly.

So between seven, eight, but I want to do a lot of linear thinking. So you know what? I’m going to

just, I’m going to turn down the limbic friction and or ramp up prefrontal cortexes activation.

So there’s a lot of stuff that can happen in the thalamus with sensory gating. For instance,

you could shut down that shell around the thalamus and allow more creative thinking by allowing more

lateral connections. These would be some of the, those would be the experiments I’d want to do.

So they’re in the subcortical quote unquote monkey brain, but you could then look at what sorts of

abstract thoughts and behaviors would arise from that rather than, and here I’m not pointing my

finger at neural link at all, but there’s this obsession with neocortex, but I, I’m going to,

well, I might lose a few friends, but I’ll hopefully gain a few. And also one of the

reasons people spend so much time in neocortex. Yes. I have a fact and an opinion. One fact is

that you can image there and you can record there right now, the two photon and one photon microscopy

methods that allow you to image deep into the brain still don’t allow you to image down really

deep unless you’re jamming prisms in there and endoscopes. And then the endoscopes are very

narrow. So you’re getting very, you know, it’s like looking at the bottom of the ocean through a,

through a spotlight. And so you much easier look at the waves up on top. Right. So let’s face it,

folks. A lot of the reasons why there’s so many recordings in layer two, three of cortex with all

this advanced microscopy is because it’s very hard to image deeper. Now the microscopes are getting

better and thanks to the amazing work, mainly of engineers and chemists and physicists. Let’s face

it. They’re the ones who brought this revolution to neuroscience in the last 10 years or so.

You can image deeper, but we don’t really, that’s why you see so many reports on layer two, three.

The other thing, which is purely opinion, and I’m not going after anybody here, but is that

as long as there’s no clear right answer, it becomes a little easier to do creative work

in a structure where no one really knows how it works. So it’s fun to probe around because anything

you see is novel. If you’re going to work in the thalamus or the pulvinar or the hypothalamus or

these structures that have been known about since the sixties and seventies, and really since the,

you know, centuries ago, you are dealing with existing, you have to combat existing models.

And whereas in cortex, no one knows how the thing works, the neocortex, six layer cortex.

And so there’s a lot more room for discovery. There’s a lot more room for discovery and I’m

not calling anyone out. I love cortex. We’ve published some papers on cortex. It’s super

interesting. But I think with the tools that are available nowadays and where people are trying

ahead of, of not just reading from the brain, monitoring activity, but writing to the brain,

I think we really have to be careful and we need to be thoughtful about what are we trying to write?

What script are we trying to write? Because there are many brain structures for which we already

know what scripts they write. And I think there’s tremendous value there. I don’t think it’s boring.

The fact that they act like machines makes them predictable. Those are your zeros and ones.

Let’s start there. But let the, what they’re, what’s sort of happening in this field of writing

to the brain is there’s this idea. And again, I want to be clear. I’m not pointing at Neuralink.

I’m mainly pointing at the neocortical jockeys out there that you go and you observe patterns.

And then you think replaying those patterns is going to give rise to something interesting.

Yeah. I should call out one experiment or two experiments, which were done by Susumu

Tonagawa, Nobel prize winner from MIT, done important work in memory and immunology,

of course, is where he got his Nobel as well as Mark Mayford’s lab at UC San Diego.

They did an experiment where they monitored a bunch of neurons while an animal learned something.

Then they captured those neurons through some molecular tricks so they could replay the neurons.

So now there’s like perfect case scenario. It’s like, okay,

you monitor the neurons in your brain. Then I say, okay, neurons one through 100 were played

in the particular sequence. So, you know, the space time, you know, the keys on the piano that

were played that gave rise to the song, which was the behavior. And then you go back and you

reactivate those neurons, except you reactivate them all at once, like slamming on all the keys

once on the piano and you get the exact same behavior. So the space time code

may be meaningless for some structures. Now that’s freaky. That’s a scary thing because what that

means is that all the space time firing in cortex, the space part may matter more than the time part.

So, you know, rate codes and space time codes, we don’t know. And, you know, I’d rather have,

I’d rather deliver more answers in this discussion questions, but I think it’s an important

consideration. You’re saying some of the magic is in the early stages of what the closer to the

raw information. I believe so. You know, the stimulus, you know, the neuron that encodes

that stimulus. So, you know, the transformation. When I say this for those who don’t think about

sensory transformations, it’s like, I can show you a red circle. And then I look at how many times

the neuron fires in response to that red circle. And then I could show the red circle a bunch of

times, green circle, see if it changes. And then essentially the number of times that is the

transformation. You’ve converted red circle into like three action potentials, you know, beep, beep,

beep, or whatever you want to call it, you know, for those that think in sound space.

So that’s what you’ve created, you know, the transformation and you march up the,

it’s called the neuro axis as you go from the periphery up into the cortex. And we know that,

and I know Lisa Feldman Barrett, or is it Barrett Feldman? Barrett Feldman, excuse me,

Lisa, that talked a lot about this, that, you know, birds can do sophisticated things and whatnot as

well, but humans, there’s a strong, what we call cephalization. A lot of the processing

has moved up into the cortex and out of these subcortical areas, but it happens nonetheless.

And so as long as you know the transformations, you are in a perfect place to build machines

or add machines to the brain that exactly mimic what the brain wants to do, which is take events

in the environment and turn them into internal firing of neurons.

So the mastery of the brain can happen at their early level. You know, another perspective of it

is you saying this means that humans aren’t that special. If we look at the evolutionary time scale,

the leap to intelligence is not that special. So like the extra layers of abstraction

isn’t where most of the magic happens of intelligence, which gives me hope that maybe,

if that’s true, that means the evolution of intelligence is not that rare of an event.

I certainly hope not.

Oh, so you hope there’s…

I hope there are other forms of intelligence. I mean, I think what humans are really good at,

and here I want to be clear that this is not a formal model, but what humans are really good at

is taking that plasma barbell that we were talking about earlier and not just using it for analysis

of space, like the intermediate environment, but also using historical information. Like I can read

a book today about the history of medicine. I happen to be doing that lately for some stuff

I’m researching and I can take that information and if I want, I can inject it into my plans for

the future. Other animals don’t seem to do that over the same time scales that we do. Now,

it may be that the chipmunks are all hiding little notebooks everywhere in the form of little dirt

castles or something that we don’t understand. I mean, the waggle dance of the bee is in the most

famous example. Bees come back to the hive, they orient relative to the honeycomb and they waggle.

There’s a guy down in Australia named Serena Vasson who studied this. It’s really interesting.

No one really understands it except he understands it best. The bee waggles in a couple of ways

relative to the orientation of the honeycomb and then all the other bees see that it’s visual and

they go out and they know the exact coordinate system to get to the source of whatever it was,

the food and bring it back. He’s done it where they isolate the bees, he’s changed the visual

flight environment, all this stuff. They are communicating and they’re communicating something

about something they saw recently, but it doesn’t extend over very long periods of time.

The same way that you and I can both read a book or you can recommend something to me and then we

could converge on a set of ideas later. And in fairness, because she was the one that said it

and I didn’t and I hadn’t even thought of it, when you talk to Lisa on your podcast,

she brought up something beautiful, which is that it never really occurred to me and I was

sort of embarrassed that it hadn’t, but it’s really beautiful and brilliant, which is that

we don’t just encode senses in the form of like color and light and sound waves and taste,

but ideas become a form of sensory mapping. And that’s where the really, really cool and

exciting stuff is, but we just don’t understand what the receptive fields are for ideas. What’s

an idea receptive field? And how they’re communicated

between humans because we seem to be able to encode those ideas in some kind of way.

You’d be able to encode those ideas in some kind of way. Yes, it’s taking all the raw information

and the internal physical states, that sensory information put into this concept blob that we

cut in the store and then we’re able to communicate that. Yeah, your abstractions are different than

mine. I actually think the comment section on social media is a beautiful example of where

the abstractions are different for different people. So much of the misunderstanding of the

world is because of these idea receptive fields, they’re not the same. Whereas I can look at a

photoreceptor neuron or olfactory neuron or a V1 neuron, and I am certain, I would bet my life

that yours look and respond exactly the same way that Lisa’s do and mine do. But once you get

beyond there, it gets tricky. And so when you say something or I say something and somebody gets

upset about it or even happy about it, their concept of that might be quite a bit different.

They don’t really know what you mean. They only know what it means to them.

Yeah. So from a neural link perspective, it makes sense to optimize the control and the

augmentation of the more primitive circuitry. So like the stuff that is closer to the raw sensory

information. Go deeper. If they, I think, go deeper into the brain. And to be fair,

so Matt McDougall, who’s a neurosurgeon at Neuralink and also a clinical nurse, a great guy,

brilliant. They have amazing people. I have to give it to them. They’ve been very cryptic in

recent years. Their website was just like nothing there. They really know how to do things with

style. And they’ve upset a lot of people, but that’s good too. But Matt is there. I know Matt,

he actually came up through my lab at Stanford, although he was a neurosurgery resume. He spent

time in our lab. He actually came out on the shark dive and did great white shark diving with my lab

to collect the VR that we use in our fear stuff. I’ve talked to Matt and I think he and other folks

there are hungry for the deeper brain structures. The problem is that damn vasculature, all that

blood supply. It’s not trivial to get through and down into the brain without damaging the

vasculature in the neocortex, which is on the outer crust. But once you start getting into

the thalamus and closer to some of the main arterial sources, you really risk getting massive

bleeds. And so it’s an issue that can be worked out. It just is hard. Maybe it’d be nice to educate.

I’m sure my ignorance. So the smart stuff is on the surface. So I didn’t realize this. I didn’t

quite realize because you keep saying deep. Yeah. So like the early stages are deep.

Yeah. So in actual, physically in the brain. Yeah. So the way that, of course you got your

deep brain structures, they’re involved in breathing and heart rate and kind of lizard

brain stuff. And then on top of that, this is the model of the brain that no one really subscribes

to anymore, but anatomically it works. And then on top in mammals. And then on top of that,

you have the limbic structures, which gate sensory information and decide whether or not

you’re going to listen to something more than you’re going to look at it, or you’re going to

split your attention to both kind of sensory allocation stuff. And then the neocortex is on

the outside. And that is where you get a lot of this abstraction stuff. And now not all cortical

areas are doing abstraction. Some like visual area one, auditory area one, they’re just doing

concrete representations. But as you get into the higher order stuff, that when you start hearing

names like inferoparietal cortex, and when you start hearing multiple names in the same, then

you’re talking about higher order areas. But actually there’s an important experiment that

drives a lot of what people want to do with brain machine interface. And that’s the work of Bill

Newsome, who is at Stanford and Tony Movshin, who runs the Center for Neuroscience at NYU.

This is a wild experiment. And I think it might freak a few people out if they really think about

it too deeply. But anyway, here it goes. There’s an area called MT in the cortex. And if I showed

you a bunch of dots all moving up, and this is what Tony and Bill and some of the other people

in that lab did way back when, is they show a bunch of dots moving up. Somewhere in MT,

there’s some neurons that respond. They fire when the neurons move up. And then what they did is

they started varying the coherence of that motion. So they made it so only 50% of the dots moved up

and the rest move randomly. And that neuron fires a little less. And eventually it’s random and that

neuron stops firing because it’s just kind of dots moving everywhere. It’s awesome. And there’s a

systematic map so that other neurons are responding and things moving down and other things responding

left and other things moving right. Okay. So there’s a map of direction space. Okay, well,

that’s great. You could lesion MT, animals lose the ability to do these kind of coherence

discrimination or direction discrimination. But the amazing experiment, the one that just

is kind of eerie is that they lowered a stimulating electrode into MT, found a neuron

that responds to when dots go up, but then they silence that neuron. And sure enough,

the animal doesn’t recognize the neurons are going up and then they move the dots down.

They stimulate the neuron that responds to things moving up and the animal responds because it can’t

speak. It responds by doing a lever press, which says the dots are moving up. So in other words,

the sensory, the dots are moving down in reality on the computer screen. They’re stimulating the

neuron that responds to dots moving up. And the perception of the animal is that dots are moving

up, which tells you that your perception of external reality absolutely has to be a neuronal

abstraction. It is not tacked to the movement of the dots in any absolute way. Your perception

of the outside world depends entirely on the activation patterns of neurons in the brain.

And you can hear that and say, well, duh, because if I stimulate the stretch reflex and you kick or

something or whatever, the knee reflex and you kick, of course, there’s a neuron that triggers

that, but it didn’t have to be that way. Because A, the animal had prior experience, B, you’re way

up in the higher order cortical areas. What this means is that, and I generally try and avoid

conversations about this kind of thing, but what this means is that we are constructing our reality

with this space time firing the zeros and ones. And it doesn’t have to have anything to do with

the actual reality. And the animal or person can be absolutely convinced that that’s what’s

happening. Are you familiar with the work of Donald Hoffman? So he makes an evolutionary argument

that’s not important of that. We, our brains are completely detached from reality in the sense that

he makes a radical case that we have no idea what physical reality is. And in fact,

it’s drastically different than what we think it is. So he goes, that’s scary. So he doesn’t say

like there’s just, cause you’re kind of implying there’s a gap. There might be a gap with constructing

an illusion and then maybe using communication to maybe create a consistency that’s sufficient for

human collaboration or whatever, or mammal, you know, just maybe even just life forms constructing

a consistent reality that’s maybe detached. I mean, that’s really cool that neurons are constructing

that, like that you can prove that this is when neuroscience at its best vision science. But he

says that like our brain is actually just lost its shit on the, on the, on the path of evolution to

where we’re normal. We’re just playing games with each other in constructing realities that allow

our survival. But it’s, it’s, it’s completely detached from physical reality. We’re missing a

lot. We’re missing like most of it, if not all of it. Well, this was, it’s, it’s fascinating because

I just saw the Oliver Sacks documentary. There’s a new documentary out about his life. And there’s

this one part where he’s like, I’ve spent part of my life trying to imagine what it would like to be,

be, to be a bat or something, to see the world through the life, the sensory apparatus of a bat.

And he did this with his, these patients that were locked into these horrible syndromes that

to pull out some of the, the beauty of their experience as well, not just communicate the

suffering, although the suffering too. And as I was listening to him talk about this,

I started to realize it’s like, well, what, you know, like they’re these mantis shrimps that can

see 60 shades of pink or something. And they, they see this stuff all the time and animals,

they can see UV light. Every time I learn about an animal that can sense other things in the

environment that I can’t like heat sensing, well, not, I don’t crave that experience the same way

Sacks talked about craving that experience, but it does throw another penny in the jar for what

you’re saying, which is that it could be that most, if not all of what I perceive and believe

is just a neural fabrication and that for better, for worse, we all agree on enough

of the same neural fabrications in the same time and place that we’re able to function.

Not only that, but we agree with the things that are trying to eat us

enough to where we don’t, they don’t eat us. Meaning like that it’s not just us humans,

you know, right?

I see. Because it’s interactive.

It’s interactive. So like, so like now I think it’s a really nice thought experiment.

I think because Donald really frames it in a scientific, like he makes a hard,

like as hard as our discussion has been now, he makes a hard scientific case that

we don’t know shit about reality. I think that’s a little bit hardcore, but I think it’s,

I think it’s hardcore, but I think it’s a good thought experiment that kind of cleanses the

palette of the confidence we might have about, because we are operating in this abstraction

space, you know, and, you know, the sensory space, it might be something very different.

And it’s kind of interesting to think about if you start to go into the realm of Neuralink or

start to talk about just everything that you’ve been talking about with dream states and

psychedelics and stuff like that, which part of the, which layer can we control and play

around with to maybe look into a different slice of reality?

I just got to do the experiment. The key is to just do the experiment in the most ethical way

possible. You just, I mean, that’s the beauty of experiments. This is why, you know, there’s

wonderful theoretical neuroscience happening now to make predictions. But that’s why experimental

science is so wonderful. You can go into the laboratory and poke around in there and be a

brain explorer and listen to and write to neurons. And when you do that, you get answers. You don’t

always get the answers you want, but that’s, you know, that’s the beauty of it. When you were

saying this thing about reality and the Donald Hoffman model, I was thinking about children,

you know, like when I have an older sister, she’s very sane. But when she was a kid, she had an

imaginary friend and she would play with this imaginary friend. And it had, there was this

whole, there was a consistency. This friend was like, it was Larry lived in a purple house.

Larry was a girl. It was like all this stuff that a child, a young child wouldn’t have any issue

with. And then one day she announced that Larry had died. Right. And it wasn’t traumatic or

traumatic and that was it. And she just stopped. And I always wonder what that neuro developmental

event was that kept her out of a psychiatric ward had she kept that imaginary friend. But it’s also,

there was something kind of sad to it. I think the way it was told to me, cause I’m the younger

brother, I didn’t, I wasn’t around for that. But my, my dad told me that, you know, there was a

kind of a sadness because it was this beautiful reality that had been constructed. And so we kind

of won. I wonder as you’re telling me this, whether or not, you know, as adults, we try and

create as much reality for children as we can so that they can make predictions and feel safe

because the ability to make predictions is a lot of what keeps our autonomic arousal in check. I

mean, we go to sleep every night and we give up total control and that should frighten us deeply.

But you know, unfortunately, autonomic arousal, the yanks us down under and we don’t negotiate

too much. So you sleep sooner or later. I don’t know. I was a little worried. We get into

discussions about the nature of reality because I’m I it’s interesting in the laboratory. I’m a

very much like, what’s the experiment? What would the, you know, what’s the analysis going to look

like? What mutant mouse are we going to use? What, what, what experience are we going to put

someone through? But I think it’s wonderful that in 2020, we can finally have discussions about

this stuff and look, kind of peek around the corner and say, well, Neuralink and people,

others who are doing similar things are going to figure it out. They’re going to,

the answers will show up and we just have to be open to interpretation.

Do you think there could be an experiment centered around consciousness? I mean,

you’re plugged into the neuroscience community. I think for the longest time, the quote unquote

C word was totally not, was almost anti scientific, but now more and more people are

talking about consciousness. Elon is talking about consciousness. AI folks are talking about

consciousness. It’s, it’s still nobody knows anything, but it feels like a legitimate domain

of inquiry. That’s hungry for a real experiment. So I have fortunately three short answers to

this. The first one is, I’m not, I’m not particularly succinct. I agree that the joke

I always tell is there are two things you never want to say to a scientist. One is what do you

do? And the second one is take as much time as you need. And you definitely don’t want to say

them in the same sentence. I have three short answers to it. So there’s a, there’s a cynical

answer kind of, and it’s not one I enjoy giving, which is that if you look into the seventies and

eight back at the 1970s and 1980s, and even into the early two thousands, there were some very

dynamic, very impressive speakers who are very smart in the field of neuroscience and related

fields who thought hard about the consciousness problem and fell in love with the problem,

but overlook the fact that the technology wasn’t there. So I admire them for falling in love with

the problem, but they gleaned tremendous taxpayer resources essentially for nothing. And these

people know who they are. Some of them are alive. Some of them aren’t. I’m not referring to Francis

Crick, who was brilliant by the way, and thought the claustrum was involved in consciousness,

which I think is a great idea. It’s this obscure structure that no one’s really studied. People

are now starting to study it. So I think Francis was brilliant and wonderful, but there it, you

know, there were books written about it. It makes for great television stuff and thought

around the table or after a couple of glasses of wine or whatever. It’s an important problem

nonetheless. And so I think, I do think the consciousness, the issue is it’s not operationally

defined, right? That psychologists are much smarter than a lot of hard scientists in that

for the following reason, they put operational definitions. They know that psychology, if we’re

talking about motivation, for instance, they know they need to put operational definitions on that

so that two laboratories can know they’re studying the same thing. The problem with consciousness is

no one can agree on what that is. And this was a problem for attention when I was coming up. So in

the early two thousands, people would argue, what is attention? Is it spatial attention,

auditory attention? Is it, and finally people were like, you know what, we agree.

Have they agreed on that one?

Sort of.

I remember hearing people scream about attention.

Right. They couldn’t even agree on attention. So I was coming up as a young graduate student,

I’m thinking like, I’m definitely not going to work on attention and I’m definitely not

going to work on consciousness. And I wanted something that I could solve or figure out.

I want to be able to see the circuit or the neurons. I want to be able to hear it on the

audio. I want to record from it. And then I want to do gain a function and loss a function,

take it away, see something change, put it back, see something change in a systematic way.

And that takes you down into the depths of some stuff that’s pretty plug and chug, you know,

but you know, I’ll borrow from something in the military because I’m fortunate to do some work

with units from special operations and they have beautiful language around things because their

world is not abstract. And they talk about three meter targets, 10 meter targets and 100 meter

targets. And it’s not an issue of picking the 100 meter target because it’s more beautiful

or because it’s more interesting. If you don’t take down the three meter targets and the 10

meter targets first, you’re dead. So that’s, I think scientists could pay to, you know, adopt

a more kind of military thinking in that, in that sense. The other thing that is really important is

that just because somebody conceived of something and can talk about it beautifully and can glean a

lot of resources for it, doesn’t mean that it’s led anywhere. So this isn’t just true of the

consciousness issue. And I don’t want to sound cynical, but I could pull up some names of

molecules that occupied hundreds of articles in the very premier journals that then were later

discovered to be totally moot for that process. And biotech companies folded everyone in the lab

pivots and starts doing something different with that molecule. And nobody talks about it because

as long as you’re in the game, we have this thing called anonymous peer review. You can’t afford to

piss off anybody too much, unless you have some other funding stream. And I have avoided battles

most of my career, but I pay attention to all of it. And I’ve watched this and I don’t think it’s

ego driven. I think it’s that people fall in love with an idea. I don’t think there’s any,

there’s not enough money in science for people to sit back there rubbing their hands together,

you know, the beauty of what Neuralink and Elon and team, cause obviously he’s very impressive,

but the team as a whole is really what gives me great confidence in their mission is that he’s

already got enough money. So it can’t be about that. He doesn’t seem to need it at a level of,

I don’t know him, but it doesn’t, he doesn’t seem to need it at a kind of an ego level or something.

I think it’s driven by genuine curiosity and the team that he’s assembled include people that are

very kind of abstract neuro neocortex, space time coding people. There are people like Matt,

who is a neurosurgeon. You can’t, I mean, you know, you can’t BS neurosurgery. Failures in

neurosurgery are not tolerated. So you have to be very good to exceptional to even get through the

gate. And he’s exceptional. And then they’ve got people like Dan Adams, who was at UCSF for a long

time as a good friend and a known him for years, who is very concrete studied the vasculature in

the eye and how it maps to the vasculature and cortex. When you get a team like that together,

you’re going to have dissenters. You’re going to have people that are high level thinkers,

people that are coders. When you get a team like that, it no longer looks like an academic laboratory

or even a field in science. And so I think they’re going to solve some really hard problems.

And again, I’m not here. They don’t, you know, I have nothing at stake with them, but I think

that’s the solution. You need a bunch of people who don’t need first author papers,

who don’t need to complete their PhD, who aren’t relying on outside funding, who have a clear

mission. And you have a bunch of people who are basically will adapt to solve the problem.

I like the analogy of the three meter target and the a hundred meter target.

So the folks at Neuralink are basically many of them are some of the best people in the world at

the three meter target. Like you mentioned Matt and neurosurgery, like they’re solving real problems.

There’s no BS, philosophical smokes and weed and look back and look at the stars. But

so both on Elon and because I think like this, I think it’s really important to think about

the hundred meter and the hundred meter is not even a hundred meter, but like

like the stuff behind the hill that’s too far away, which is where I put consciousness. Maybe

I tend to believe that consciousness can be engineered. I mean, part of the reason,

part of the business I want to build leverages that idea that consciousness is a lot simpler

than we’ve been talking about. Well, if someone can simplify the problem,

right, that will be wonderful. I mean, the reason we can talk about something as abstract as face

representations, infusive form face area is because Nancy Kanwisher had the brilliance

to tie it to the kind of lower level statistics of visual scenes. It wasn’t because she was like,

oh, I bet it’s there. That wouldn’t have been interesting. So people like her understand how

to bridge that gap and they put a tractable definition. So I, so I just, I, that’s what

I’m begging for in science is a tractable definition. This is what, but I want people

to sit in the, I want people who are really uncomfortable with woo woo, like consciousness,

like high level stuff to sit in that topic and sit uncomfortably because it forces them

to then try to ground and simplify it into something that’s concrete because too many

people are just uncomfortable to sit in the consciousness room because there’s no definitions.

It’s like attention or, or intelligence in the artificial intelligence community. But the reality

is it’s easy to avoid that room altogether, which is what, I mean, there’s analogies to everything

you’ve said with the artificial intelligence community with Minsky and even Alan Turing that

talked about intelligence a lot. And then they drew a lot of funding and then it crashed because

they really didn’t do anything with it. And it was a lot of force of personality and so on. But that

doesn’t mean the topic of the Turing test and intelligence isn’t something we should sit on

and think like, think like, what is, well, first of all, Turing actually attempted this with the

Turing test. He tried to make concrete this very question of intelligence. It doesn’t mean that

we shouldn’t linger on it. And we shouldn’t forget that ultimately that is what our efforts are all

about in the artificial intelligence community. And in the people, whether it’s neuroscience or

whatever bigger umbrella you want to use for understanding the mind, the goal is not just

about understanding layer two or three of the vision. It’s, it’s to understand consciousness

and intelligence and maybe create it or just all the possible biggest questions of our universe.

That’s, that’s ultimately the dream. Absolutely. And I think what I really

appreciate about what you’re saying is that everybody, whether or not they’re working on a

kind of a low level synapse, that’s like a reflex and the musculature or something very high level

abstract can benefit from looking at those who prefer three, you know, everyone’s going after a

three meter, 10 meter and a hundred meter targets in some sense, but to be able to tolerate the

discomfort of being in a conversation where there are real answers, where the zeros and ones are,

are known zeros and ones are those, the equivalent of that in the nervous system.

And also, as you said, for the people that are very much like, Oh, I can only trust what I can

see and touch. Those people need to put themselves into the discomfort of the high level conversation

because what’s missing is conversation and conceptualization of things at multiple levels.

I think one of the, this is, um, I don’t gripe about my life’s been fortunate. We’ve been funded

from the start and we’ve been happy, um, in that, in that regard and lucky, and we’re grateful for

that. But I think one of the challenges of research being so expensive is that there isn’t a lot of

time, especially nowadays for people to just convene around a topic because there’s so much

emphasis on productivity. Um, and so there, there are actually, believe it or not, there aren’t that

many concepts, formal concepts in neuroscience right now. The last 10 years has been this huge

influx of tools. And so people in neural circuits and probing around and connect homes, it’s been

wonderful, but w you know, 10, 20 years ago, when the consciousness stuff was more prominent,

the C word, as you said, um, what was good about that time is that people would go to meetings and

actually discuss ideas and models. Now it’s sort of like, it’s sort of like demonstration day at

the school science fair where everyone’s got their thing and some stuff is cooler than others.

But, um, I think we’re going to see a shift. I’m grateful that we have so many computer scientists

and theoreticians and, um, or theorists, I think they call themselves. Um, and somebody tell me

what the difference is someday. Um, and you know, psychology and even dare I say philosophy,

you know, these things are starting to converge. We, you know, neuroscience that the name

neuroscience, there wasn’t even such a thing when I started graduate school or as a postdoc,

it was neurophysiology or you were a neuro anatomist or what now every it’s sort of

everybody’s invited and that’s beautiful. That means that something’s useful is going to come

of all this. And there’s also tremendous work of course happening on it for the treatment of disease

and we shouldn’t overlook that. That’s where, you know, endings, you know, eliminating,

reducing suffering is also a huge initiative in neuroscience. So there’s a lot of beauty in the

field, but the consciousness thing continues to be a, uh, it’s like an exotic bird. It’s like,

no one really quite knows how to handle it and it dies very easily.

Well, yeah, I think also from the AI perspective, I, uh, so I view the brain as less sacred. Uh,

I think from a neuroscience perspective, you’re a little bit more sensitive to BS,

like BS narratives about the brain or whatever. I’m a little bit more, uh, comfortable with just

poetic BS about the brain as long as it helps engineer intelligence systems. Well, you know

what I mean? Well, and I have to, you know, I confess, um, ignorance when it comes to,

you know, most things about coding and I’m, I’m have some quantitative ability,

but I don’t have strong quantitative leanings. And so I know my limitations too. And so I,

I think the next generation coming up, you know, a lot of the students at Stanford are really

interested in quantitative models and theory and AI. And I remember when I was coming up, um,

a lot of the people who were doing work ahead of me, I kind of rolled my eyes at some of the stuff

they were doing, um, including some of their personalities, although I have many great,

um, senior colleagues, uh, everywhere in the world. So it’s the way of the world. So nobody

knows what it’s like to be a, you know, a young graduate student in 2020, except the young graduate

students. So I, I know what I, I’m, I know there are a lot of things I don’t know. And, um, in

addition to wanting to do a lot of public education, increased scientific literacy and

neuroscientific thinking, et cetera, a big goal of mine is to try and at least pave the way so that

these really brilliant and forward thinking, um, younger scientists can make the biggest

possible dent and make what will eventually be all us old guys and gals look stupid. I mean,

that’s, that’s what we were all trying to do. That’s what we were trying to do. So yeah.

Yeah. So from the highest possible topic of consciousness to the, to the lowest level,

uh, topic of David Goggins, uh, let’s go.

I don’t know if it’s low, low level. He’s high performance.

High performance, but like low, like there’s no, I don’t think David has any time for philosophy.

Let’s just put it this way. Uh,

well, it’s, I mean, I think we can tack it to what we were just saying in a, in a,

in a meaningful way, which is whatever goes on in that abstraction part of the brain,

he’s figured, you know, he’s figured out how to dig down in whatever the limbic friction.


He’s figured out how to grab ahold of that,

scruff it and send it in the direction that he’s decided it needs to go. And what’s wild is that

he’s, what we’re talking about is him doing that to himself, right? He’s, it’s like he’s scruffing

himself and directing himself in a particular direction and sending himself down that trajectory.

And he, what’s beautiful is that he acknowledges that that process is not pretty. It doesn’t feel

good. It’s kind of horrible at every level, but he’s created this rewarding element to it. And I

think that’s, what’s so it, it’s so admirable. And it’s what so many people crave, which is

regulation of the self at that level.

And he practices, I mean, there’s a ritual to it. There’s a, every single day, like no exceptions.

There’s a practice aspect to the suffering that he goes through.

It’s principled suffering.

Principled suffering.

It is.

I mean, I just, I mean, I admire all aspects of it, including him and his girlfriend slash wife.

I’m not sure. She’ll probably know this.

I don’t know.


Wonderful person.

I’m not asking him.

No, no. We’ve only communicated, I’ve only communicated with her by text about some stuff

I was asking David, but yeah, they clearly formed a powerful team.

And it’s a beautiful thing to see people working in that kind of synergy.

And it’s inspiring to me, same as with Elon, that a guy like David Goggins can find love.

That you find a thing that works, which gives me hope that like whatever,

whatever flavor of crazy I am, you can always find another thing that works with that.

But I, I’ve had the, so maybe let’s trade Goggins stories.

Uh, you from a neuroscience perspective, me from a, uh, self inflicted pain perspective,

I somehow found myself in communication with David about some challenges that I was undergoing.

One of which is we were communicating every single day, email, phone,

about a particular 30 day challenge that I did.

That stretched for longer of, uh, pushups and pullups.

And you made a call out on social media.

Yeah. Social media was dumb.

Actually, I think that was the point I, I knew of you before,

but that’s where I started tracking some of what you were doing with these physical challenges.

And I, um, well, no, I think I actually, I don’t often comment on people’s stuff,

but I think I commented something like, uh, neuroplasticity loves a nonnegotiable rule.

No, I said a nonnegotiable contract because at the point where neuroplasticity really loves a

nonnegotiable contract, because, you know, and I’ve said this before, so forgive me,

but you know, the brain is doing analysis of duration, path and outcome.

And that’s a lot of work for the brain. And the more that it can pass off duration,

path and outcome to just reflex, the more energy and it can allocate to other things.

So if you decide there’s no negotiation about how many pushups, how far I’m going to run,

how many days, how many pullups, et cetera, you actually have more energy for pushups,

running and pullups.

And when you say neuroplasticity, you mean like the brain, once the decision is made,

it’ll start rewiring stuff to, to make sure that this, we can actually make this happen.

That’s right. I mean, so much of what we do is reflexive at the level of just

core circuitry, breathing, heart rate, all that, that boring stuff, digestion.

But then there’s a lot of reflexive stuff, like how you drink out of a mug of coffee

that’s reflexive too, but that you had to learn at some point in your life earlier

when you were very little, analyzing duration, path and outcome.

And that involves a lot of top down processing with the prefrontal cortex,

but through plasticity mechanisms, you now do it. So when you take on a challenge,

provided that you understand the core mechanics of how to run pushups and pullups and whatever

else you decided to do, once you set the number and the duration and all that,

then you, all you have to do is just go, but people get caught in that tide pool of just,

well, do I really have to do it? How do I not do that? What if I get injured? What if I,

you know, can I sneak a this or that, you know? And that’s work. And to some extent,

I look, I not David Goggins, obviously, nor, nor do I claim to understand his process

partially, you know, but maybe a little bit, which is that it’s clear that by making the decision,

there’s more resources to devote to the effort of the actual execution.

Well, that’s a really, like what you’re saying was not a lesson that was obvious to me. And

it’s still not obvious. It’s something I really work at, which is there is always an option to

quit. And I mean, that’s something I really struggle with. I mean, I’ve quit some things

in my life, sick, stupid stuff. And, uh, one lesson I’ve learned is if you quit once,

it opens the door that like, it’s really valuable to trick your brain into thinking

that you’re, you’re going to have to die before you quit. Like it’s actually really convenient.

So actually what you’re saying is very profound, but you shouldn’t intellectualize it. Like

it took me time to develop like psychologically in ways that I think it would be another

conversation, cause I’m not sure how to put it into words, but it’s really tough on me to, uh,

to do certain parts of that challenge, which is a huge, you know, is a huge output. The number,

the number that I was, I thought it would be, the number would be hard, but it’s not. It’s

the entirety of it. Uh, especially in the early days was just spending a kind of embarrassed to

say how many hours this took. So I didn’t say publicly how many hours, cause people,

I knew people would be like, don’t you, aren’t you supposed to do other stuff?

Well, it’s, um, again, I don’t want to speculate too much, but occasionally David has said this

publicly where people will be like, don’t you sleep or something. And his process used to just

be that he would just block delete, you know, like gone, but it’s, it’s actually, um, it’s,

it’s a super interesting topic. And because self control and directing our actions and the role of

emotion and quitting, these are, these are vital to the human experience and they’re vital to

performing well at anything. And at a high, obviously at a super high level, being able to

understand this about the self is crucial. Um, so I have a friend who was also in the teams.

His name is Pat Dossett. He did nine years in the seal teams. Um, and in a similar way,

there’s, there’s a lore about him among team guys, um, because of a kind of funny challenge he gave

himself, which was, so he and I swim together, although he swims for a long time. Um, and he

doesn’t swim together, although he swims further up front than I do. Um, and he’s very patient. Um,

but you know, he was on a, uh, he was assigned when he was in the teams to a position that gave

him a little more time behind a desk than he wanted. And it’s not as much time out out and

deployments, although he did deployments. Um, so he didn’t know what to do at that time,

but he thought about it and he asked himself, what, what does he hate the most? And it turns

out the thing that he hated doing the most was bear crawls, you know, walking on your hands and

so he decided to bear crawl for a mile for time. So he was bear crawling a mile a day.

Right. And I thought that was an interesting example that he gave because, you know, like

why pick the thing you hate the most? And I think it maps right back to limbic friction.

It’s the thing that creates the most limbic friction. And so if you can overcome that,

then there’s carry over. And I think the notion of carry over has been talked about psychologically

and in kind of in the self help space, like, Oh, if you run a marathon, it’s going to help you in

other areas of life, but will it really will it? Well, I think it depends on whether or not there’s

a lot of limbic friction because if there is what you’re exercising is not a circuit for bear crawls

or a circuit for pull ups. What you’re doing is you’re exercising a circuit for top down control

and that circuit was not designed to be for bear crawls or pull ups or coding

or waking up in the middle of the night to do something hard. That circuit was designed to

override limbic friction. And so neural circuits were designed to generalize, right? The stress

response to an incoming threat that’s a physical threat was designed to feel the same way and be

the same response internally as the threat to an impending exam or divorce or marriage or whatever

it is that’s stressing somebody out. And so neural circuits are not designed to be for one particular

action or purpose. So if you can, as you did, if you can train up top down control under conditions

of the highest limbic friction that when the desire to quit is at its utmost, either because

of fatigue or hyper arousal, being too stressed or too tired, you’re learning how to engage a

circuit and that circuit is forever with you. And if you don’t engage it, it sits there, but it’s

atrophied. It’s like a plant that doesn’t get any water. And a lot of this has been discussed in

self help and growth mindset and all these kinds of ideas that circle the internet and social media.

But when you start to think about how they map to neural circuits, I think there’s some utility

because what it means is that the limbic friction that you’ll experience in, I don’t know, maybe

some future relationship to something or someone, it’s a category of neural processing that should

immediately click into place. It’s just like the limbic friction you experienced trying to engage

in the God knows how many pushups, pull ups and running runs you were doing.

25,000. Who’s counting?

So folks, if Lex does this again, more comments, more likes. This is the problem with you getting

more followers is you’re going to get more. Actually, I should say that’s the benefit.

I don’t know. Maybe it’s not politically correct for me to ask, but there is this

a stereotype about Russians being like being really durable. And I started going to that

Russian banya that way back before COVID and they could tolerate a lot of heat and they would sit

very stoic. No one was going, oh, it’s hot in here. They’re just kind of like ease into it.

So maybe there’s something there, who knows?

Might be something there, but it could be also just personal. I just have some, I found myself,

everyone’s different, but I’ve found myself to be able to do something unpleasant for very long

periods of time. Like I’m able to shut off the mind and I don’t think that’s been fully tested.

Monkey mind or the supercomputer?

Well, it’s interesting. I mean, which mind tells you to quit exactly?

Limbic. Limbic friction tells you.

Well, limbic friction is the source of that, but who are you talking with exactly?

So there’s a, we can put something very concrete to that. So there’s a

paper published in Cell, super top tier journal, two years ago, looking at effort.

And this was in a visual environment of trying to swim forward toward a target and a reward.

And it was a really cool experiment because they manipulated virtually the visual environment. So

the same amount of effort was being expended every time. But sometimes the perception was

you’re making forward progress. And sometimes the perception was you’re making no progress

because stuff wasn’t drifting by meant no progress. So you can be swimming and swimming

and swimming and not making progress. And it turns out that with each bout of effort, there’s epinephrine

and norepinephrine is being released in the brainstem and glia, what traditionally were

thought of as support cells for the neurons, but they do a lot of things actively too,

are measuring the amount of epinephrine and norepinephrine in that circuit.

And when it exceeds a certain threshold, the glia send inhibitory signals that shut down

top down control. They literally it’s the quit. You stop. There’s no more. It’s you quit enduring.

It can be rescued. Endurance can be rescued with dopamine. So that’s where the subjective part

really comes into play. So you quit because you’ve learned how to turn that off or you’ve

learned how to, some people will reward the pain process so much that friction becomes the reward.

And when you talk about people like Goggins and other people I know from special operations and

people have gone through cancer treatments three times, you hear about, just when you hear about

people, the Viktor Frankl stories, I mean, you hear about Nelson Mandela, you hear about these

stories. I’m sure the same process is involved. Again, this speaks to the generalizability of

these processes as opposed to a neural circuit for a particular action or cognitive function.

So I think you have to learn to subjectively self reward in a way that replenishes you.

Goggins talks about eating souls. It’s a very dramatic example in his mind, apparently that’s

a form of reward, but it’s not just a form of reward where it’s like you’re picking up a trophy

or something. It’s actually, it gives you energy. It’s a reward that gives more neural energy. And

I’m defining that as more dopamine to suppress the noradrenaline adrenaline circuits in the

brainstem. So ultimately maps to that. Yeah. He creates enemies. He’s always fighting enemies.

I never, I think I have enemies, but there are usually just versions of me inside my head. So

I thought about through that 30 day challenge, I tried to come up with like fake enemies. It wasn’t

working. The only enemy I came up with is David. Well, now you have a, you certainly have a form

formidable adversary in this one. I don’t care. I’m David. I’m willing to die on this one. So let’s

go there. Well, let’s hope you both survive this one. My problem is the physical. So everything

we’ve been talking about in the mind, there’s a physical aspect that’s just practically difficult,

which is like, I can’t like, you know, when you injure yourself at a certain point, like you just

can’t function or you’re doing more damage. Yeah. Talking about it, taking yourself out of running

for the rest of your life potentially, or like, you know, or did it for years. So, you know,

I’d love to avoid that, right? There’s just like stupid physical stuff that you just want to avoid.

You want to keep it purely in the mental. And if it’s purely in the mental, that’s when the race

is interesting. But yeah, the problem with these physical challenges as David has experienced,

I mean, it has a toll on your body. I tend to think of the mind is limitless and the body is

kind of unfortunately quite limited. Well, I think the key is to dynamically control your output.

And that can be done by reducing effort, which doesn’t work for throughout, but also by

restoring through these subjective reward processes. And we don’t want to go down the

rabbit hole of why this all works, but these are ancient pathways that were designed to

bring resources to an animal or to a person through foraging for hunting or mates or water,

all these things. And they work so well because they’re down in those circuits where we know the

zeros and ones. And that’s great because it can be subjective at the level of, oh, I reached this

one milestone, this one horizon, this one three meter target. But if you don’t reward it, it’s

just effort. If you do self reward it, it’s effort minus one in terms of the adrenaline output.

I have to ask you about this. You’re one of the great communicators in science. I’m really a big

fan of yours, enjoying in terms of the educational stuff you’re putting on neuroscience.

Thank you.

What’s the, do you have a philosophy behind it or is it just an instinct,

unstoppable force? Do you have, like, what’s your thinking? Because it’s rare and it’s exciting.

I’m excited that, you know, somebody from Stanford. So I, okay, I’m in multiple places

in the sense of like where my interests lie. And one, you know, politically speaking, academic

institutions are under fire, you know, for many reasons we don’t need to get into. I get into it

in a lot of other places, but I believe in places like Stanford and places like MIT as one of the

most magical institutions for inspiring people to dream, people to build the future. I mean,

it’s, I believe that it is a really special, these universities are really special places.

And so it’s always exciting to me when somebody as inspiring as you represents those places. So

it makes me proud that somebody from Stanford is like, somebody like you is representing Stanford.

So maybe you could speak to what’s, how did you come to be who you are in being a communicator?

Well, first of all, thanks for the kind words, especially coming from you. I think Stanford is

an amazing place as is MIT and it’s such a. MIT is better by the way. I’ll let it out. Anything

you say at this point. I have many friends at MIT. Yeah. Smarter friends. Yeah. Ed Boyden is

among the best in class. There’s some people, not me that can hold a candle to him, but not many,

maybe one or two. I think the great benefit of being in a place like MIT or Stanford is that

when you look around, the average is very high. You have many best in class among the one or two

or three best in the world at what they do. And it’s a wonderful privilege to be there. And one

thing that I think also makes them and other universities like them very special is that

there’s an emphasis on what gets exported out of the university, not keeping it ivory tower and

really trying to keep an eye on what’s needed in the world and trying to do something useful.

And I think the proximity to industry and Silicon Valley and in the Boston area and Cambridge also

lends itself well to that. And there are other institutions too, of course. So the reason I got

involved in educating on social media was actually because of Pat Dossett, the mile bear call guy.

It was at the turn of 2018 to 2019. We had formed a good friendship and he talked me into doing these

early morning cold water swims. I was learning a lot about pain and suffering, but also the beauty

of cold water swims. And we were talking one morning and he said, so what are you going to

do to serve the world in 2019? It’s like, that’s the way that like a Texan former seal talks.

Like we’re just literally like, what are you going to do to serve the world in 2019?

Like, well, I’ve run my lab. It’s like, no, no, what are you going to do? That’s new.

And he wasn’t forceful in it, but I was like, that’s interesting question. I said, well,

if I had my way, I would just teach people, everyone about the brain. Because I think

it’s amazing. He goes, we’ll do it. I go, all right. He goes, shake on it. So we did it, you

know? And so I started putting out these posts and it’s grown into, to include a variety of things,

but you asked about a governing philosophy. So I want to increase interest in the brain and in the

nervous system and in biology generally, that’s one major goal. I’d like to increase scientific

literacy, which can’t be rammed down people’s throats of talking about how to look at a graph

and statistics and Z scores and P values and genetics. It has to be done gradually, in my

opinion. I want to put valuable tools into the world, mainly tools that map to things that we’re

doing in our lab. So these will be tools centered around how to understand and direct one’s states

of mind and body. So reduce stress, raise one’s stress threshold. So it’s not always just about

being calm. Sometimes it’s about learning how to tolerate being not calm, raise awareness for

mental health. There’s a ton of micro missions in this, but it all really maps back to, you know,

like the eight and 10 year old version of me, which is I used to spend my weekends when I was

a kid reading about weird animals. And I had this obsession with like medieval weapons and stuff

like catapults. And then I used to come into school on Monday and I would ask if I could talk

about it to the class and teach. And I just, it’s really, I promise, and some people might

not believe me, but it’s really, I don’t really like being the point of focus. I just get so

excited about these gems of that I find in the world in books and in experiments and in

discussions with colleagues and discussions with people like you and around the universe.

And I can’t just compulsively, I got to tell people about it. So I try and package it into

a form that people can access. You know, I think if I’ve, I think the reception has been really

wonderful. Stanford has been very supportive, thankfully. I’ve done some podcasts even with

them and they’ve reposted some stuff on social media. It’s a precarious place to put yourself

out there as a research academic. I think some of my colleagues, both locally and elsewhere,

probably wonder if I’m still serious about research, which I absolutely am. And I also

acknowledge that their research and the research coming out of the field needs to be talked about

and not all scientists are good at translating that into a language that people can access.

And I don’t like the phrase dumb it down. What I like to do is take a concept that I think people

will find interesting and useful and offer it sort of like you would offer food to somebody visiting

your home. You’re not going to cram foie gras in their face. You’re going to say, like, do you want

a cracker? And they say, yeah. And like, do you want something on that cracker? Like, do you like

cheese? Like, yeah. Like, do you want Swiss cheese or you want that really like stinky, like French?

I don’t like cheese much. Or do you want foie gras? Like, what’s that? Like, so you’re trying,

the best information prompts more questions of interest, not questions of confusion,

but questions of interest. And so I feel like one door opens, then another door opens,

then another door opens. And pretty soon, the image in my mind is you create a bunch of

neuroscientists who are thinking about themselves neuroscientifically. And I don’t begin to think

that I have all the answers at all. I cast a neuroscience, sometimes a little bit of a psychology

lens onto what I think are interesting topics. And someday I’m going to go into the ground or

the ocean or wherever it is I end up. And I’m very comfortable with the fact that not everyone’s

going to be happy with how I deliver the information, but I would hope that people

would feel like some of it was useful and meaningful and got them to think a little bit

harder. Since you mentioned going into the ground and Victor Frankl, Man’s Search for Meaning,

I reread that book quite often. Let me ask the big ridiculous question about life. What do you

think is the meaning of it all? And maybe why do you, do you mention that book from a psychologist

perspective, which Victor Frankl was, or do you ever think about the bigger philosophical questions

that raises about meaning? What’s the meaning of it all? One of the great challenges in assigning a

good, you know, giving a good answer to the question of like, what’s the meaning of life is,

um, I think illustrated best by the Victor Frankl example, although there are other examples too,

which is that our sense of meaning is very elastic in time and space. And I’m, I’m,

uh, we talked a little bit about this earlier, but it’s amazing to me that somebody locked in a cell

or a concentration camp can bring the horizon in close enough that they can then micro slice their

environment so that they can find rewards and meaning and power and beauty, even in a little

square box or, or a horrible situation. And I think this is really speaks to one of the most

important features of the human mind, which is we could do, let’s take two opposite extremes.

One would be, let’s say the alarm went off right now in this building and the building started

shaking our vision, our hearing, everything would be tuned to this space, time bubble for those

moments and everything that we were processed, all that would matter. The only meaning would be

get out of here, safe, figure out what’s going on, contact loved ones, et cetera.

If we were to sit back, totally relaxed, we could do the, you know, I think it’s called pale blue

dot thing or whatever, where we could imagine ourselves in this room. And then they were in

the United States and this continent and the earth, and then it’s peering down us. And all of

a sudden you get back, it can seem so big that all of a sudden it’s meaningless, right? If you

see yourself as just one brief glimmer in all of time and all of space, you go to, I don’t matter.

And if you go to, oh, every little thing that happens in this text thread or this, you know,

comment section on YouTube or Instagram, your space time bubble is tiny, then everything seems

inflated and the brain will contract and dilate its space, time, vision and time, but also sense

of meaning. And that’s beautiful. And it’s what allows us to be so dynamic in different environments

and we can pull from the past and the present and future. It’s why examples like Nelson Mandela and

Viktor Frankl had to include, it makes sense that it wasn’t just about grinding it out. They had to

find those dopamine rewards, even in those little boxes they were forced into. So I’m not trying to

dodge an answer, but for me personally, and I think about this a lot because I have this complicated

history in science where my undergraduate, graduate advisor and postdoctoral advisor all died young.

So, you know, and they were wonderful people and had immense importance in my life. But what I

realized is that we can get so fixated on the thing that we’re experiencing, holding tremendous

meaning, but it only holds that meaning for as long as we’re in that space, time regime.

And this is important because what really gives meaning is the understanding that you can move

between these different space, time dimensionalities. And I’m not trying to sound like a

theoretical physicist or anyone that thinks about the cosmos and saying that it’s really the fact

that sometimes we’d say and do and think things and it feels so important. And then two days later,

like what happened? Well, you had a different brain processing algorithm entirely. You were in a

completely different state. And so what I want to do in this lifetime is I want to engage in as many

different levels of contraction and dilation of meaning as possible. I want to go to the micro.

I sometimes think about this. I’m like, if I just pulled over the side of the road, I bet you there’s

an anthill there and their whole world is fascinating. You can’t stay there. And you also

can’t stay staring up at the clouds and just think about how we’re just these little beings and it

doesn’t matter. The key is the journey back and forth, up and down that staircase, back and forth

and back and forth. And my goal is to get as many trips up and down that staircase as I can before

the reaper comes for me. Oh, beautiful. So the, the, the dance of dilation of meaning,

contraction between the different space, zoom in, zoom out, and get as many steps in on that

staircase. That’s, that’s my goal anyway. And I’ve watched people die. I watched my postdoc advisor

die wither away. My graduate, it was tragic, but they found beauty in these closing moments

because their bubble was their kids in one case, or like one of them was a Giants fan and like got

to see a Giants game, you know, in her last moments and like, and you just realize like it’s a Giants

game, but not in that moment because time is closing. And so those time bins feel huge because

she’s slicing things so differently. So I think, um, learning how to do that better and more fluidly,

recognizing where one is and not getting too taxed to the idea that there’s one correct answer,

like that’s what brings meaning. That’s my goal anyway. I don’t think there’s a better way to end

it. Andrew, I really appreciate that you would, uh, come down and contract your space time and

focus on this conversation for a few hours. Uh, is a huge honor. I’m a huge fan of yours. As I told

you, I hope you keep growing and educating the world about the human mind. Thanks for talking

today. Thank you. I really appreciate the invitation to be here. And people might think I’m

saying it just cause I’m here, but I’m a huge fan of yours. I send your podcasts to my colleagues

and other people. And I think what you’re doing is, isn’t just, uh, amazing. It’s important. And

so thank you. Thanks for listening to this conversation with Andrew Huberman. And thank

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And now let me leave you with some words from Carl Jung. I am not what happened to me.

I am what I choose to become. Thank you for listening and hope to see you next time.