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

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, Huberman Lab, where he teaches the world about the brain and the human mind. Also, he's a friend and an inspiration and 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 8 sleep a mattress that cools itself and gives me yet another reason to enjoy sleep SEM Rush, the most advanced SEO optimization tool I've ever come across, and Cash App, the app I use to send money to friends. Please check out these sponsors in the description to get a discount and to support 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 meant to be, didn't push on certain points that I should have, was under educated 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 Podcasts, follow on Spotify, support on Patreon, or connect with me on Twitter lexfriedman. 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 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 multi unit signals and we can start seeing some central features of meaning within the brain. And what's interesting is that as trivial as it might seem in listening to it, almost everybody responds to heights and falling from a high virtual place with a very strong stress, if not fear response. And that's because the visual vestibular apparati, the optic flow and how it links to the balanced semicircular canals, 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, excuse me, 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'd study fear by, you know, showing subjects a picture of a bloody arm or a snake or something like that, or. 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 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.

I'm terrified of heights.

It's. It's, you know, when 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 just won't. They actually will hold, get down on the ground and hold onto a virtual beam that doesn't even exist on a flat floor. And so what this really tells us is the power of the brain to enter these virtual states as if they were real. And we really think that anchoring the visual and the vestibular, the balance components of the nervous system are what bring people into that presence so quickly. There's also the potential, and we haven't done this yet, to bring in 360 sound. So the reason we did 360 video is 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 were some interesting moments out there of danger. But it came back with that video and built that for the sharks. And then we realized we need to do this for everything. We need to do it for 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 turned 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'm. And I turn around and then I turn back to you and it's still growling. Yeah, that might seem like more of an impending threat, but. 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, 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 heights.

Heights, yeah. 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 a danger of 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, it was kind of boxy, actually. I mean, it wasn't like ultra realistic simulation. And it's 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 the very, very early stage of visual processing. And incidentally, the way Muller and folks learned 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. I personally don't like snakes at all. I don't mind spiders. We also have a spider stimulus. But like sn snakes, I just don't like them. There's something about the slithering, and it 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 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 we always get the subjective report from the subject of what they experience 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. Exactly. And humans aren't great at explaining how they feel, but. But it's a lot easier to understand what they're saying than a mouse or a macaque monkey is saying. So it's. The best we can do is language plus these physiological and neurophysiological signals.

Is there something you've learned about yourself, about your deepest fears? Like you said, snakes. Is there something that. Like, if I were to torture you. So I'm Russian, so, you know, I always kind of think, how can I murder these people? Then this person entered the room. But also, how. How could I torture you to get some information out of you? What would I go with?

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. Which I'm here, and I had never been to a banya. So, you know, the whole experience of really, really hot sauna.

Yeah.

And what do they call it, the plots? They're hitting you with the leaves, and. And it gets really hot and humid in there. And there were a couple 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, I. 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, 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, heights maybe, but the one I have didn't seem to be connected to. Jumping out of a plane is a very different. Because, 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. 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 it, 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 like, wow. It was the possibility that you can walk on a surface and then at a certain point, there's no surface anymore to walk on. And it's all 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, because it's so fascinating, is, have you learned anything about what it takes to overcome fears?

Yes. And that comes from two, from a 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 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, Lindsey 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 four brain 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 mention 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, you know, the sort of hump shape curve for, you know, at low levels, arousal performance is low and as it increases, performance goes higher and then it drops off as you get really stressed. But there's another bump further out, the distribution where you perform very well under very high levels of stress. And so we've been spending a lot of time in humans and in animals exploring what it takes to get people comfortable, to go to that place, and also to let them experience how there are heightened states of cognition there, there's changes in time perception that allow you to evaluate your environment at a faster frame rate. Essentially this is the matrix, as a lot of people think of it as. 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 into unnecessary risk. But that's where the VR is fun, because you can push people hard without risk of physically injuring them. Them.

And that's like you said, the little bump that, 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 got 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 interoception and exteroception are matched along a couple 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 the pupil dilation, for instance, and movement of the lens essentially changes your optics. 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 kind of drowsy state to be able to. And I don't play music, so I'm guessing here, but sense some of the nuance in the chords or the ways that you're to be relaxed enough that your fingers can follow an external cue. So matching the movement of your fingers to something that's pure exteroception. And so there is no perfect autonomic state for performance. This is why I don't favor terms like flow, because they're not well operationally defined enough. But I do believe that optimal or peak performance is going to arise when internal state is ideally matched to the space time features of the external demands.

So there's some slicing of time that happens and then you're able to adjust slice time more finely or more less. Finally, in order to adjust to the stimulus, the dynamics of the stimulus, what about The. The realm of ideas. So, like, you know, I'm a big believer. This guy named Cal Newport wrote a book about deep work.

Yeah, I love that book.

Yeah, he's great. He. I mean, one of the nice things I've always practiced, deep work, but he. It's always nice to have words put to the. The concepts that you've practiced. It somehow makes them more concrete and allows you to. 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. Like you. You hold it and then you take steps with it. You take further steps, and you. 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 could be applied to the act of thinking as opposed to action?

Well, we haven't done too much work there, but. What. But I think I can comment on it from a neuroscience. Yeah, which is really all I do is. Well, I mean, we do experiments in the lab, but 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. It's 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. But. So apologies in advance for the. 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 twenties. And even you could Say early twenties, sometimes into the late twenties, 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 sort of deep memory and deep memory stores, probably stuff that's moved out of the hippocampus and forebrain and into the cortex and is more 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 kind of 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 mathematics 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 working memory, but we are pushing working memory. When we have people do things like these simple lights out tasks while they're under, 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 it's, 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.

Yeah, 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, this weird, like stepping back, like, is this right? Let's try it this other way. That, that's the most mentally taxing step. It's like you, you've gotten quite good at this particular pattern of how you solve this particular problem. So there's a, 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, 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, you're, it's, you're not querying facts, you're querying like functional things like.

Yes. 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, have 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.

Right.

And I mean, 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. 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 sort of are. We're aiming for precision and accuracy, but we're not going to, 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 determined by the visual system. In humans, we don't walk through space, for instance, like a scent hound would. And look at three dimensional scent plumes. You know, when a scent hound goes out in the environment, they have depth to their odor, 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 is 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 you know, 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 apparati, 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 becomes 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 that the five H2CA2C and two A receptors, which are the main sites for things like LSD and psilocybin and some of the other, the 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 5 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 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 areas 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 sights, 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 what's these are through these so called pons Cheniculate 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 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, right? 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 push my mind in all kinds of directions. I definitely want to, I, I did shrooms a couple of times. I definitely want to figure out how I can experiment with, with psychedelics. I'm talking to Rick Domin. I think Dublin soon aim went back and forth so he.