2014 Personality Lecture 15: Limbic System & Goals (Biology and Traits)

On Tuesday, I started to talk to you about tradeit Theory, and now I'm going to make a jump to biology. That's a strange jump in some sense because the two levels of analysis are relatively disconnected. But what's happening right now at the sort of outer echelons of Personality research is that the workers at the forefront of the field are trying to integrate what's being established at the statistical level of analysis with what's known at the psychobiological level. This emerging science is known as personality neuroscience.

Um, it's developed in a rather strange way because the traits that were identified that I discussed with you on Tuesday, the big five traits, all emerged as a consequence of the statistical analysis of descriptors characteristic mostly of the English language, although it's been duplicated in other languages. In some sense, it was an a theoretical model, right? It just came out of the linguistic data. So there were no real initial inferences about brain area or neurological activity or anything like that to drive the formulation of the big five model. Instead, the big five model came first, and then people started thinking, "Okay, can this be put into alignment with what we know about the brain?" People have been hitting that pretty hard, I would say, over about the last, it's probably 30 years, something like that.

Because H. Isen and his student Jeffrey Gray were pretty far along on this kind of thinking by, say, 1982, when Gray published his book, "The Neurospsychology of Anxiety." The paper you're reading now, "A Model of the Lyric System and Basal Ganglia: Applications to Anxiety and Schizophrenia," that's a very short summary of the book that Gray published in 1982, which has been incredibly influential. If you're interested in going on in psychology, especially on the scientific end, I would say pretty much regardless, if you're interested in going on in psychology, that's a very useful book to tackle.

There's a newer version; it was published by G.R. McN in, I think, 2000, something like that. It's hard going, and you may have found the paper that way too. Gray was a very, very—unfortunately, he died a few years ago—he was a very, very smart person, and he knew the animal literature on behavior, neuroanatomy, and neuropsychopharmacology inside out and backwards. So whenever he defined a term, he always made sure that the term was intelligible at a behavioral level, at an anatomical level, and at a pharmacological level. The ideas that he was developing had to make sense at these multiple levels of analysis before he would accept them as genuine.

Gray did a remarkable job of extending our knowledge of the biological and evolutionary basis of at least the first two personality traits, say, extroversion and neuroticism, roughly corresponding to positive and negative emotion. That's partly why you're reading Gray. Gray's theory is also cybernetic theory. Cybernetic theory is a variation of a theory developed by an MIT cognitive scientist named Norbert Wiener, who was an early AI artificial intelligence researcher. He proposed that intelligent entities were goal-directed and that they organized their behavior around reducing deviations from a goal while they were approaching it, once they had decided what it would be. That has also proved to be incredibly influential.

We'll talk a fair bit about cybernetic models as we progress. Gray is sort of a combination of artificial intelligence, cybernetic theorizing, and then an incredible amount of data that's come in from animal behavioral research. As far as I'm concerned, most of the things that we know about the brain have been derived from animal research. The animal researchers tended to be extraordinarily careful scientists. They were influenced by B.F. Skinner, who established the initial theoretical basis for understanding how animals learn. We'll talk about that a little bit next class.

So anyway, that's the context within which Gray is working. Leo, these are all papers you're going to read, except for the third one, which is optional. Leo is also an emotional, he's an affective neuroscientist, so he's someone who studies emotions, mostly again in animals, and he has done a lot to sort of add some of the pieces that we're missing in Gray. Gray probably concentrated a little bit too much on a brain area called the hippocampus, which is the brain area that sort of lets you know if it's reasonable to be calm where you're currently situated.

What the hippocampus does, in some sense, is compare what it is that you want to have happen with what is happening. If the two things are the same, then you're calm. So it's a match-mismatch detector and it has access not only to memory but also to formulations of, say, the desired future. Swanson—I had people read the Swanson paper last year; I put it in your reading list as optional—it's worth hacking through if you can manage it; it's a very hard paper though, which is why I took it out of the required reading list.

The reason I like Swanson, we're going to talk a fair bit about him today, is Swanson's not a psychologist; he's actually a developmental neuro—I'm not sure I can never say this properly. He studies developmental anatomy. We'll do that. So he's very interested in how the brain unfolds across time during embryonic development and then up into maturity. He understands the brain differently than a psychologist would because a psychologist tends to analyze the brain as a sort of mature thing, usually in adulthood. For Swanson, it's a much more living and transforming system.

He's trying to set forth a schema for understanding brain anatomy and also associating that with function. You might think that that's a well-advanced science already, that we know how to segment the brain and we know roughly what the pieces do, but we haven't even really managed to establish the terminology properly yet. Neuroscience is a very new field, and there's no limit to the number of things that we don't know about it, including even the basic classification structure. Now, Swanson has put forth a very intelligent basic classification structure, and part of the reason that I think it's so relevant to a personality class is because it maps in a beautiful way onto some of the things that we've already talked about, especially P.J.

There's a nice direct mapping of P.J.'s developmental theory onto Swanson's theory of neural development and then of neural function. That's completely accidental because Swanson never cites P.J., so they're non-overlapping literatures. I kind of like that because if something pops up in one place with one method and pops up in another place with a completely different method, especially if those two places are distinct in terms of their historical development, you might start thinking there's actually something there. It's sort of like seeing something and hearing it at the same time; you've got two independent sources of data. It's like triangulation, in a sense, and so it was very exciting to me to come across this paper by Swanson.

I think he's one of only two scientists I ever wrote a fan letter to. I mean, really, it's a brilliant paper. And then, there's other reasons why it maps onto what we're going to talk about too, because Swanson also points out quite clearly the function of the, he's kind of roughly separates the hypothalamus into two halves, and he points out that they have quite distinct functions. The functions also map onto some of the things that we've been talking about in a very lovely way. So there's a lot of reasons to go through Swanson's paper carefully. You know, it's like 50 pages long, but the guy put in, in some sense, his whole life's work is in those 50 pages.

Even if it takes you 12 hours or 20 hours to read it, that's not too bad if you're going to extract out like 30 years of solid research. Gray's book is the same; like if you read that book, you've got—if you read it and understand it—you've basically got a fair chunk of neuroanatomy, a lot of animal behavioral analysis, behaviorism in general, a lot of psychopharmacology, and a lot of understanding of the functional significance of the brain's major neurotransmitter systems. You can get all that from Gray's book. That's a killer book; you know, if you can extract all that out.

So anyways, Carver and Shire also take a cybernetic perspective. Fundamentally, they're more cognitive scientists. You're going to find their paper a little bit farther down the road, but they're also very interested in how creatures, human beings in particular, select goals and then align themselves with those goals. For our purposes, we're going to talk a fair bit about motivation today, and the distinction between motivation and emotion is not clear. They're both words that sort of function within a linguistic context, but for the sake of argument—of course, all the emotions aren't the same; it's not like there's one circuit that subsumes emotion—there are multiple circuits that subsume emotion, and they're not identical circuits, you know?

It isn't like every emotion is a variant of the same thing; it's not. And it's the same with motivation. So they're very loose groupings, motivation and emotion, but for the purposes of our argument, we're going to make this case: roughly, motivations set goals and roughly, emotions orient you in relationship to those goals. Now, like I said, those categories overlap. Anger is usually considered an emotion and it often has a goal, right? The goal is to hit something or hurt something; that's one possible goal. So emotions can segue quite easily into motivational states.

But whatever you got to use, a category system of some sort to clarify things, and so that's what we're going to pursue. Motivation sets goals; it's actually more complicated than that. You know, I showed you that little oval diagram with the desired future and unbearable present, so to speak. Motivations actually don't just set goals; they also prime behavior and they also set up the perceptual frame within which you interpret the world. So for example, if you're hungry, it isn't just that you're driven to eat.

First of all, eating is a very complex behavior, especially if it's associated with food preparation. Say, the systems that you've used in the past to procure food and then to ingest it are sort of disinhibited by the motivational state, so they're at the ready. And then your sensory system is tuned so that it's going to focus on those things that are relevant to eating and tune out everything else. So the motivational state also does perceptual tuning.

And then there's a felt component of it as well. So it's not reasonable to only say that motivation sets goals or that it drives behavior. It does three things: goal-setting, behavioral driving, plus it provides a perceptual schema within which those other two things make sense. A motivated state, in some sense, is like a little micro personality. It's only got one aim; it's sort of a one-eyed micro personality, you know, so it's only aiming at one thing, but it still has all the other aspects of personality.

For me, that aligns nicely with the psychoanalytic idea that you're a loose aggregation of multiple fragmented personalities. They're sort of coherently tied together at the highest level of analysis, but they can go off and do their own thing. You see that in situations, for example, like eating disorders, where the hunger system itself starts to become almost a spun-off part of the personality, and the rest of the personality then wars with that.

In some sense, that’s like cortex versus hypothalamus. And you never win. Cortex does not win over hypothalamus; the hypothalamus is what keeps you alive. It’s one of the things that keeps you alive. You could do without your cortex, but you cannot do without your hypothalamus. The connections stretching upwards from the hypothalamus, which is a very old brain area, are much more powerful than the connections coming down from the cortex to modulate the hypothalamus.

That's another indication of just exactly who's in charge when the chips are down, you know? And that's why it's so hard for you to override your basic emotions or motivational states. It's like the system evolved to keep you alive, and it's not particularly willing to give up control in a sense, given that your survival is staked on its function. So it's useful to know that because if you pursue psychology and you stay within the human side of psychology, say, instead of wandering off into the animal behavioral research, you'll see that most human psychologists and neuropsychologists are very cortico-centric.

They really like to think that it's the newly evolved parts of the brain that are in charge, and that's just not right. The newly evolved parts of the brain are in charge only when nothing is bothering you. Like if you're not hungry, you're not thirsty, you're not too excited, you're not too curious, you're not too terrified, you're not too cold, you're not too warm—any of those—then the cortex is in charge. But if you deviate substantially across any of those dimensions, the probability that control over your behavioral output and your perceptions is going to devolve down the evolutionary hierarchy to more primordial brain areas is extremely likely, you know?

And you see the same thing happens. You know, maybe you're having a discussion with someone, right? And they exhaust the limits of your rational knowledge, which means basically they out-argue you. Well, what happens? Well, usually what happens is that people cry or they get angry. It's like they're out of cortex; it's bang, right down to the lower and more primary evolutionarily determined systems.

So okay, now we're going to take a look at how the brain functions in general. We're going to start pretty general, and then we're going to go narrow. The first thing that you might want to think about is what problem exactly is the brain wrestling with? The major problem is that reality is so complicated. It has so many layers and so many interconnected causal links that it's complex beyond comprehension, and that's a big problem. I mean, you think about all the subatomic complexity. That's a horrible thing.

Then there's the complexity at the atomic level, and that's, you know, pretty overwhelming. And then there's the molecular level, which makes the atomic level look simple. Then there's all the exceedingly complex structures that emerge out of the molecular level, especially in living organisms. That would be roughly at the organ level of existence, you know? And then there's you as a totality with your brain, which is, and the brain is so much more complex than everything else in the universe that it's not even in the same category.

There are estimates, for example, by Gerard Edelman that there are more connections in your brain, more patterns of connections in your brain, than there are subatomic particles in the universe. So you know, that's one major league complex thing, and there's lots of them around. And you know, they're all integrated into families, and then roughly tribal groupings, some of which get large enough to be nations. And then that's all embedded inside of some biological system and so on and so forth, all the way out to the limits of the cosmos. I mean, this is one complicated place, and you know your job in large part is to understand it, but also not to become overwhelmed by it because you have to simplify it down to the point where you can sort of think about one thing and do one thing.

You have to screen all of that out so that the complexity doesn't overwhelm you when you're attempting to do anything. Anything simple, even to look at yourself in the mirror, which is also a very complicated thing to do. Part of the problem your brain is always facing is what can I ignore? The answer to that is, well, you need to ignore almost everything. And that's a problem because, of course, it's not always obvious what's okay for you to ignore, you know? And that changes on you suddenly too because, you know, because you have imperfect knowledge, you might think something's irrelevant, and it turns out to be of critical importance.

It's a deadly, it's a deadly, deadly difficult problem. One of the ways that we solve this is we're actually pretty blind to almost everything, you know? Our sensory input is limited by our physiological limitations, certainly. So there's like, in terms of vision, we only see a very small little slice of the whole electromagnetic spectrum, and it's the same with sounds. We can only touch things that are basically within our reach, and so that limits things substantially.

Then there are also things we can't detect; like we're not very good at detecting, um, like we don't have the same ability that, say, platypuses and some fish can detect electromagnetic disturbances around them on their skin. There are senses that we don't have, so we're narrowed a fair bit by what it is that we're able to perceive. And we're actually narrowed in what we can perceive far more than anybody ever guessed.

So I'm going to show you a little video here, and hopefully, it'll be loud enough so that you can hear it. The monkey bus solution: count how many times the wearers—the correct answer, 16. Pass. Did you spot the gorilla? For people who haven't seen or heard about a video like this before, about half missed the gorilla. If you knew about the gorilla, you probably saw it. But did you notice the curtain changing color for the player on the black team leaving the game? Here comes the gorilla, and there goes a player and the curtain is changing from red to gold looking for a gorilla.

You can learn more about this illusion in the original gorilla experiment at the invisiblegorilla.com. So how many of you saw the gorilla? No? Let's do the see the gorilla. Okay, how many of you had known about this video beforehand? Yeah? The gorilla part of it? Yeah, so you guys don't count now. And then, you know, I get someone who's seen it before and they still miss the damn gorilla, so that's pretty funny.

But, of course, Simon Dan set this up because his original video got so popular, you know, virally popular that everybody has seen the Invisible Gorilla. And so, you know, now he's showing you that, well, you think you're smart; you've been clued into how blind you are, and it turns out you're not any smarter than you were to begin with, right? So how many people saw all three things that changed? I saw the video before—oh, you've seen it before, so okay. And how many didn't? Yeah? Okay, so the vast majority of you missed one or more of the things that changed, you know? And they're not really trivial things, like the disappearance of a person from six people—that's fairly major.

You know, the whole background changed color, and you might think you'd clue into that. So the weird thing is, even when you're primed to notice what you're supposed to notice, which is to say count the balls, and you know that something weird is going to happen, you're not—still doesn't prime you enough so that you can keep track of all the weird things that are happening. This was an absolutely staggering experiment. When it was first shown, psychologists were just like knocked over by it because the hypothesis up to that point had been always that you could concentrate on what you were concentrating on, but if something anomalous or unexpected happened, your attention would be automatically devoted towards it.

And of course, that's what people would think, right? You'd think that if you're watching people play basketball and a gorilla walks into the area, and it's not small, that of course you'd be surprised and you'd see it, and it turns out that that's just wrong. It tells you a lot about how your nervous system is set up, so you're focusing on counting the balls. For some reason, getting the correct answer to the question of how many times the ball is thrown back and forth turns out to be motivationally significant.

Why? Why did you—you know, you got the instructions, fair enough, but why did you listen to them? Does it narrow your attention to the target? Oh, sure it does, but the question is, why did you even comply with the instructions? Yeah, who said that? Because you wanted to get the answer right. Why did you care if you got the answer right? Well, think about it for a minute. Guess that means you're smart means you're, yeah, that's right.

So that's one possibility. It's like instantly you sort of interpret it as a little cognitive test, maybe, and then you want to see if you can do it, and you know, that taps into your hierarchy of values. Part of your value is, I want to be maybe a smart and competent person, or I want to be at least as smart and competent as everyone else is playing this game. So, you know, the instruction taps into a pre-existent value structure, and then it's motivating.

Compliance, what? Compliance as well! Yes, that's another thing. It's like, you know, the room in some ways is set up to ensure a degree of compliance, right? Because there's an implicit story in the room, which is if I'm at the front of it, and so that sort of makes me at the top of the dominance hierarchy. The fact that you're here means you've already bought into that presupposition, and so it's a logical thing to do to play along with the game. So yes, that is also true.

That's more like the playing a game issue, right? Is that, well, maybe something interesting will happen. Okay, right, right, right. Okay, so there's a variety of reasons why you might listen to the instructions, but the point is the instructions actually tap into your motivation, into your intrinsic motivation enough so that you will in fact attempt to play the game. Then as soon as you play the game, what happens? Well, you focus your very limited attentional resources precisely on what it is that you're supposed to do.

Now, we could talk a little bit about how the visual field is set up. So, you know, you notice that if I'm looking around the room, if I want to see all of you, I can't just stand here and look straight ahead because all you people over here, you're like—I can't see if I'm looking straight ahead. I can't see the faces of anyone past here, and I can only see them sort of as blurs, and unless they move, and if they move up something, then I can see the movement, but I can't—it’s not clear to me what's moving.

It's the same for the people over here. The only person I can really see right now is the woman who's sitting there in the white sweater. All the rest of you are like—and the person to the right, I can more or less—if I look at her, I can more or less see that he's dressed in gray, but I can’t see his face at all. Now he nodded his head, and I could pick that up.

So what's very strange about your visual system and your sensory systems, all your sensory systems are like this—is that you have a tiny little point of focus where the information is rich. That's partly because the center of your eye is the fovea, and it's most densely packed with cells. But more importantly, each of the cells in your fovea, which is the very center of your vision—you can tell when someone's pointing their fovea at you because then you have the sense that they're looking at you. Human beings are unbelievably good at figuring out when someone is pointing their fovea at you.

We can detect eye deviation from direct gaze with an accuracy that's absolutely remarkable. Now, each of those little cells in the fovea is connected—each of the one cells is connected to like 20,000 cells at the first level of the hierarchy of the visual system. The reason that your whole eye isn't fovea is because your head would have to be this big to manage it. So, you know, what's evolved is sort of a compromise is that in the center of your vision, it's—

The center of your vision is very, very detailed. And then what you do is you zip that center around, like snap, snap, snap, snap, snap, snap, and your brain sort of makes an amalgamated picture out of all those little snapshots. Then it weaves it together, so it seems to you like it's a continuous movie of consciousness, even though it's really not. And then the sides of your eyes, the periphery of your eyes, well, they don't have the same potency as the fovea, and so they kind of play a triage game. It's like, "Okay, I can't see if I'm looking straight ahead; I can't see everything. What might I use as an indication that I should move my gaze from where I'm looking to somewhere else?"

One answer to that is movement, so the periphery is pretty good at picking up movement. Often, if you see movement in the periphery, then you'll move your field of vision to where the movement was, and then you know, then you can keep track of what's changing. So what your brain sort of assumes is that when you're looking at something, everything else is irrelevant, and it also sort of fades into the background. That's what's happening with the Gorilla video.

Part of the reason you can't see the damn gorilla is because he's dressed in black like the players. So when you're focusing on the basketball, all the black moving things look the same; there's no distinction between them at all. The background of the curtain—it’s like, well, first of all, why would you be primed to see the curtain change color? Things just don't do that in real life, right? I mean, big objects don't suddenly change color, very seldomly.

And more importantly, the fact that the gorilla shows up, the fact that one player leaves, and the fact that the curtains change color has no bearing whatsoever on whether or not you can complete the task, right? So it doesn't matter if you ignore the information, and that's because it's irrelevant in terms of the interpretive frame, the motivated interpretive frame that you're applying to the scene. So the rule for perception is, don't pay attention to anything that isn't directly relevant to the desired outcome.

Now, exactly how you calculate what you can pay attention to and what you can't, that's very complicated. I mean, you build that knowledge bit by bit over time, and you can be wrong about it too. So the old idea was, you know, well, first of all, that you were very much conscious of the environment, period, which you're not. And then the second idea was, well, while you're being conscious of the environment, if anything changes radically, you will definitely focus your attention on it.

What turned out to be the case is, well, you're not very conscious of the environment, and radical things can happen, and you won't notice them unless they interfere with what you're doing. So something that emerges that interferes with what you're doing that you don't expect, you will instantly orient towards and concentrate on. So it isn't anomaly or novelty that attracts your attention; it's the unexpected disruption of the relationship between your behaviors and the desired outcome of those behaviors.

That's a much narrower claim: only pay attention to things that make you fail. It's something like that, or at least additionally, pay attention to things that make you fail. Generally speaking, that's also associated with an emotional response, you know? So if you're doing something, and you think you know how to do it, and you’re doing it, then all of a sudden something unexpected happens, you're going to have an emotional reaction. We'll talk more about the emotional reactions in the next class, but the emotional reaction partly prepares you for the worst in case this unexpected thing is bigger than you think it is, and it sort of also primes you to be curious and to start to explore to figure out what it is so that you can reconstruct your expectations and desires in accordance with the transforming world.

This slide is an elaboration in some sense of what I was telling you a little bit earlier about the multiple levels of reality. The idea is that the thing that you see, which in this particular schema would be the computer, is nested inside all of these systems or has other systems nested inside of it. That's part of an indication of the complexity of things. Now, you know, one of the things that you might think about, for example, if you're using your computer, one of the things you might ask yourself is, like, why is your computer a black rectangle or like a silver rectangle? It's all smooth and shiny. Why is that?

You know, like, it's not clear—first, it's not transparent, okay? And then it's got this smooth cover, and it wouldn't necessarily have to. Why do you think that's appealing to you? It's familiar, like a book? Okay, so it's familiar, yeah, and that's good. So it's familiar. What else? It's simple, yeah. You don't want to interact with the computer at all; you want to interact with little pictures on the screen, and then you don't even really want to interact with those. You want to interact with some subset of what that picture is doing on the screen, and so you're very, very rarely using the computer, right?

You're just paying attention to, well, let's say the screen and the keyboard. So the computer is whatever is underneath that, and then what that is, is a collection of parts that are so bloody complicated that you don't want to have any to do with them that are nested inside a whole network of things that are so complex you don't want to have anything to do with them. So what happens when you're using a computer is all of a sudden it stops working. Well, then it's a computer. As soon as it stops working, it's a computer. Before that, it was whatever it was you were doing.

As soon as it turns into a computer, what do you do with it? Well, you know, you stupidly hit the on and off button, and maybe you plug it in, and maybe you check your switches to make sure that a fuse didn't burn out or a breaker go. That's pretty much the end of you in terms of your ability to deal with the actual entity, you know? Then you curse with your primate brain, and then you send it out to be fixed.

One of the things that's worth considering because this will also help us understand what happens in terms of brain function as we go along is that as long as things are going according to how you want them to go, you can really pretend that the world is unbelievably simple. All the world consists of is those few things that you're doing in your little bounded perceptual frame, and everything else is zero. Then, unfortunately, now and then, the hypothesis that everything else is zero is radically wrong, like when your computer crashes.

Then you actually, for a while, have to deal with at least some of the complexity that's actually there, and that's usually extremely anxiety-provoking. So, you can imagine the same situation is while you're in your nice smooth car and you're on the highway, and all of a sudden, you hear a horrible grinding noise and smoke comes out of the back, and you're pulled over to the side. Well, what was merely a means of getting from point A to B in comfort, like two seconds ago, is now a collection of extremely troublesome parts, none of which you know anything about, plus it's disrupted your day, plus it's disrupted your pocketbook.

Now you have to deal with a bunch of people who are going to tell you what's wrong with your vehicle and maybe fix it for some completely unknown amount of money and with dubious utility. So, poof, the car turns into that. It's almost impossible to overestimate the degree to which we live within a world that's bounded by our expectations and desires, and how much time we spend keeping everything that's complex away from us so that we don't have to deal with it.

Okay, so now we might want to think about how we do that. I'm going to show you this little schema that might be helpful. So, like, I made this little diagram of dots because I wanted to make an ambiguous figure. I'm hoping that when you look at that figure, what do you see when you look at it? The center? What shape is the center? A cross? Okay, so you can see a cross. What else can you see? It's a rectangle? Yeah, what else can you see? Four squares? It's four squares? Yeah, exactly. So, and what else can you see?

That's a good one. I haven't seen that one; I'll take your word for it, though. What else can you see? I'll show you some of the things you can see. Okay, you can see that, right? You see that, see that? You can see that. Okay, so the first thing that you might note is that the thing in the beginning, the thing in itself, let's say, you can see multiple ways. It's not exactly that you have an opinion about what it is. You know, it's that you can actually see those different things. You can see it manifesting those different perceptual objects.

That's a strange thing because how people always think that arguments are about opinions. There's some facts, and you have one set of opinions about them and you have another, and then you argue about the opin until you get to the facts. Unfortunately, it's a lot worse than that because the facts themselves are often reasonably subject to debate. So you might ask, for example, which of the five ways that you could see that initial thing is the right way to see it.

The answer to that—this is a pragmatic answer—is it depends on what you want to do with your perception. You know, so if you want the highest resolution that captures as much detail as possible, then you want something as close to the thing in itself as possible. That'd probably be object five there. You know, if you want to know the rough area, let's say that's a map of an orchard, you might think about object one if it's an orchard from the top right.

If you want to walk from north to south, you might want to think about it in terms of object three, you know? And so those are different ways you can perceive that object. I would say that what happens at the next level of abstraction, and that's where you've got the numbers and words down here, is that you have the thing in itself, which is complex and can be seen many ways. Then you have the things you see, which are partial sort of low-resolution representations of the thing itself.

Then there are words, which are at least in part references to the image of the thing, and so by the time you get to the word, it's pretty compressed. I really like the metaphor of compression, you know, because a lot of the things you see are sort of like thumbnails. And why are thumbnails useful? You guys have done some image processing, obviously a thumbnail lacks some things that a 16-megabyte—

Is that about right now? How big are cameras? 16 megabytes for a single photo? What's that? Yeah, well, I think the new cameras are up, I think they're up to 16. The newest iteration—so, okay, so why have a thumbnail if you have a 16-megabyte picture? Okay, but why not use the picture, right? That's exactly it. There’s a tradeoff between detailed representation and time utilization, time and resource utilization.

You know, like a computer, you guys have limited time and resources. You don't actually want to see any more than you need to see in order to get what you're supposed to get done, done, because otherwise, it's just a waste of energy. And so what that means is that your brain is always trying to figure out in some sense what's the simplest way I can represent this so that I can undertake whatever it is that I'm planning to undertake next.

That's sort of, again, from a philosophical perspective, that's actually something pragmatic. Okay, so then you might ask yourself: you organize your perceptions in relationship to your goals, and then you might ask yourself, well, where do those goals come from? You know, we've heard from thinkers like, say, Freud, who talked about the ID functions, and the ID is sort of the seat of primordial impulses, right? So you might think about the ID as the producer of primary goals or drives, and Freud did think about them as drives.

So they were things that led to a relatively rigid behavioral algorithm once the state had arisen. Now, as I mentioned before, I think that that's a flawed viewpoint because the motivational state is more than merely a drive, because a drive is something that, say, triggers a pre-programmed sequence of behaviors. A lot of the early behaviors thought about animal behavior in that way, right? They'd say the animal would encounter a stimulus, and the stimulus would produce a response.

Then the responses would get chained together, and then when the animal encountered the stimulus again, then just those chained responses would automatically run. One of the famous experiments that showed that that was wrong was a rat trained to run through a maze. You can sort of train a route pretty quickly if you know, you put them in the maze and there's like, he can go this way or this way, and you put some cheese over here. You do that three or four times; the rat learns to turn right.

Then you add another piece to the maze, and the rat learns to turn left. You can get it turning in an extremely complicated way to walk through the maze, but then what they did was they took a rat and they wrapped up its hind legs, you know, like with tape, so it couldn't use them. Then they put its little rear end on a cart and then had the little rat scoot through the maze on the cart.

It's obvious that a scooting rat and a running rat don't use the same motor output. Not even close. And the rat could still get through the maze. So the idea that all the rat had done was chained together learned automatic responses turned out to be wrong. Rats—it’s more like rats learn what's going on and can generalize from it, just like you do.

So anyway, the notion that the drive just instantiates a sequence of pre-programmed behaviors in most cases—in many cases, especially with complex behavior—turns out to be wrong. There are some limited circumstances under which it's right. Okay, so the first hypothesis we're going to entertain is the idea that you have to frame the world in order to interact with it. This is sort of a little mythological diagram that I whipped up a long time ago, and the bottom thing, that's a uroboros, by the way, which is a dragon that eats its own tail.

It's an ancient symbol of chaos, and chaos is what you see when you don't know what you're looking at. You could say, in some sense, chaos is all the complexity that surrounds you that could possibly intrude on your little safe world. To grasp that chaos, or to operate within it, you have to put it within a framework. So that's the great father there; that's actually God, you see.

God's got the sun behind him because God is like the sun. He's, you know, reliable, and he's associated with consciousness, and then he's ruling over this city. For me, that was a good symbol of culture. In part, culture is what's outside of you, but in part, culture is also the frameworks that you've learned to use by being with other people—the frameworks that you've learned to use to narrow and specify the world.

In my mode of thinking, the framing is associated with security on the one hand because it tells you what you can do and you know makes things safe for you, and tyranny on the other hand because it can get out of control, and it can start to get too rigid. Regardless of the pros and cons of framing, if you see something one way, then you can't see it another. It's harder to see it another, so that's the con side of framing.

The pro side of framing is, well, then you get to do something. If it's unframed, you're in chaos; it's existential anxiety. You're not going to move ahead at all, so you have to frame things. You have to simplify them, and really, in some sense, you even have to oversimplify them. It depends on what you mean by that, but what you're really trying to do is never make your perceptual task any more complex than it has to be in order to get done what you need to get done.

So how do you frame things? Well, the first thing we should point out is that a lot of framing doesn't even happen psychologically. Right? So here you are sitting in this classroom, and you're not overwhelmed by chaos. Well, why? First of all, you're in a city; that's helpful. There's electricity here, and there's natural gas, and there's people to fix all the plumbing.

The fact that you're in a city makes life much simpler right off the bat. There's nothing trying to eat you. You don't have to contend with the fact that it's like us 20 for three months, and you know, so there's a whole bunch of complexity that the civilized world has just taken care of for you. Then, you know, now you're in the university in the city, and that eliminates a whole bunch of other hassles.

You know, there are some things you have to do, but there's a bunch of things you don't have to do. Then you're inside this building, and wow, look at that, there's electric light here, and you know, and the chairs work. There’s not going to be an earthquake. Probably, the whole building isn't going to fall down. By the time you're sitting in your chair here, also with your clothing on, you've screened a lot of complexity out already. So you can sit there fairly calmly, and so that's all external.

Now, part of the reason—and this is worth thinking about—because this isn't only psychological. You guys will hear a fair bit about terror management theories as you progress through your education. Terror management theories are theories that account for why people are, say, patriotic in their beliefs; why they adopt belief systems. The idea is that a belief system protects you from death anxiety.

So Freud sort of said that about religious systems. That was his critique of religion. People are afraid of death, and so they have this infantile desire to have that fear go away, so they turn to religion, and religion says, "Well, death isn't permanent," and that's why people are religious. The extension of that is, well, that's also why they have belief systems in general. They’re trying to protect themselves against this deep shaking anxiety.

To some degree, I suspect that's true, but you should also remember that when you're protecting your culture—say, if you identify with it, you're patriotic or whatever it is—or you think that your culture is worth defending, you're not just defending something psychological. It's like the culture—the functioning culture keeps the lights on, you know? So it doesn't just protect you from death anxiety; it also protects you from death.

That's even more important most of the time than being protected from death anxiety. Now, there’s a psychological component to it too, but you don't ever want to underestimate just the practical utility of being nested inside, you know, what P.J. would consider a relatively functional game. It’s like your world’s a lot simpler, you know? You have to work to maintain it and everything, and that's kind of a drag, maybe—that's the tyrannical element of it—but you know the payoff is pretty big.

Okay, so if you look at medieval cities, this is a well-preserved medieval city in France. There are a lot of medieval cities that still exist in Europe, and you see this is a typical sort of human habitation—it's like inside there's order and outside there's chaos and barbarians, and then there's a couple of walls to keep the chaos and the barbarians out. Inside, you know, there's a dominance hierarchy, and everybody can live their relatively productive and relatively peaceful lives inside of that.

It's all framing, getting rid of unnecessary complexity. Same thing with houses; they do the same thing for you. And then social institutions do the same thing too. It's like, okay, this is—is it Kennedy there? And Obama, I think so. This is part of the transition in power from George Bush to Obama. That's a pretty scary thing to have your leader of your dominance hierarchy replaced by another leader, and you know, among chimpanzees, for example, that's often the occasion for a fair bit of mayhem.

It's also the case often for people that that occurs, and you know, we still have that in the form of political corruption and so on. But all things considered, you know, the power transition from Bush to Obama was far more peaceful than such power transitions generally are if you look across the history of mankind. That means you're also protected by your social institutions; they screen out a lot of potential complexity as well as long as they're functional and, I think, as long as they follow some of the Pji rules.

One of the Pji rules for a playable game is there's some reciprocity. You regard the system, roughly speaking, as either fair or fairer than any other system you can think up. You know, it boils down to the same thing because if it's not fair but you can't come up with a better fantasy, well, it's as good as it can be. The sociological or sociopolitical structures that keep complexity away from us can only operate under a certain limited number of constraints. But still, they perform their function, you know, and very admirably.

It's amazing, I think, because I see people in my clinical practice all the time. Most people that I see—and I think this is true of most people in the world—have at least one serious problem, you know? And it might be they have an illness that's just God awful, or if they don't have an illness, one of their immediate family has an illness that's God awful, or they're really old and they need to be taken care of, or they're suffering from some insane economic problem, or they've just been unemployed or whatever; there's something in their immediate circle that's really difficult to grapple with.

And yet people still go out and maintain their place in the world, and the whole thing roughly works, and to me, that's just a continual source of amazement that people can pull that off, you know? So anyway, a lot of the screening that you do to get rid of that complexity is external. That's part of that is a consequence of good, well-functioning sociological organization.

Then the next thing that sort of screens things out for you is your body. Right? Now look, you kind of naturally see things at a particular level of resolution, right? There's no obvious reason why that should be so. You know, you see the front of people; you can't see the back of them. You see their external covering, their skin and their clothes; you can't see inside them.

When you look closely at them, you can't see their cellular structure or their molecular structure or their atomic structure. You can't really see the social situations that they're embedded in. If I look at you, I can't see your family—you know I presume you have one. I can't really see the political situation that surrounds you, either. I have to know that abstractly. The ecological level is almost completely imperceptible to me.

So part of the way that complexity is screened out is that your body just doesn't allow you to pick a lot of it up. You're just blind to it. So you see at one level of resolution, and that's the human level. You see things of approximately our size; you see things that are approximately the size that we can grip. Those are sort of the things that you're likely to think of as objects.

Clearly, a mountain isn't exactly an object, you know? So usability is part of what defines perceptibility, and so that also screens things out. So you're left with, well, what it is that you have to deal with once everything's been screened out. And then you might ask, well, there's still a lot of complexity left there; like there, say, there's plenty of complexity within the average family, and there's plenty of complexity in the mating domain. You know, to find a partner, to establish a reasonable long-term relationship and to have children and to raise them, there's plenty of complexity left.

The question is, how did biology come to solve those problems, given that they're almost infinite in complexity? How can you do it? The answer to that is fundamentally a Darwinian answer: you start simple. Back in the days of the onell organisms—we have no idea how those things got their start, right? I mean, the actual beginning of Life is a serious mystery, and I'll tell you, it's such a serious mystery, this is completely unbelievable, but one of the people who discovered DNA—I think it was Francis Crick, in fact; I'm virtually certain it was—he actually believed that DNA came from an alien civilization.

He wrote a whole book about that; it's called "Panspermia." He believed, posited, that it's possible for DNA to drift through space for millions of years and to land on planets and to start living. God only knows how old DNA is because he just couldn't figure out at all how it could have possibly evolved. So scientists are a lot weirder than you think when you start to read about what the scientists who discovered things really thought. They're completely, you know, out of their mind.

But whatever, we'll assume that DNA got there somehow and then evolution took over after that. So what does evolution do? It basically says, "Well, here's a terribly complex problem that we've sort of partially solved." Partially solved means we've lived long enough to produce another copy of ourselves. That constitutes the solution; that's it. So we've lived long enough so that we could conceivably duplicate ourselves. How should we do that?

Well, a variety of different ways—that's the answer. We should produce variants. So that might be multiple offspring or it might also be facilitated by random mutation. Hypothetically, the mutations are random. Although there's increasing evidence, by the way, that organisms are much more complex at the genetic level than anyone ever assumed. Bacteria, for example, swap DNA back and forth with other bacteria all the time.

There are experiences that you can have that will change your genetic structure sufficiently so that you will transmit that to your children. So, you know, the idea that everything's purely Darwinian, and it's only mutation that drives randomness—that's clearly likely but not complete; these other mechanisms are clearly there. The issue is that what you do is you start with something that kind of works, and then you produce microvariants of it, and then the world around you changes a little bit.

Hopefully, one of those microvariants manages to do the same thing, and then it produces a bunch of microvariants, and then they manage to do the same thing. What's happening is there's an arms race between the environment, which is always changing, and the organisms that are trying to keep up with it. That arms race just goes on forever, and you know, different life forms proliferate as that occurs.

It's sort of like life is always playing catch-up, and you never get it right. You cannot get it right. The best you can do is get it right long enough to live long enough to reproduce. That constitutes the sum total of your knowledge. What that means, at least in part, is that you guys are all the beneficiary of an evolutionary process that's basically been going on since the beginning of life, and that’s about 3.5 billion years ago.

So, your body, your psychophysiology, has been in an arms race with the transforming environment for three and a half billion years trying to keep up, and poof, you're the stellar consequence of three and a half billion years of effort and death. So, you know, you might thank the cosmos about that. Think about this: every single one of your female ancestors successfully reproduced. It's mind-boggling; you're so unlikely that you would be here that it's almost incalculable.

So good for us; here we are, you know? How successful can you get? So my point is that part of the way that complexity is dealt with is haphazard. It isn't ever really dealt with. That's why you die; you can only manage it to a limited degree. For us, that's like three kids in a hundred years if you're lucky, and that's our knowledge after 3.82 billion years.

So the complexity problem is a rough one. Okay, so that's your body. Now, let's look inside your body. Now, you might think that we have this sort of idea that's kind of leftover Cartesian, that there's a you, and there's your body, and the you is in your brain. Just out of curiosity, how many of you have the subjective sense that the you is in your head?

How many of you would locate you—like for me, I can locate me somewhere; it seems to be about there. I feel like that's where I am. And so how many people think, have like the center of their sense of subjectivity in their head? How many people are like that? Okay, how many people are different than that? Okay, so, oh good, okay, so where? Like, where do you feel the center of your subjectivity?

Where would it be? That's hard to like, um, I have to really think. I was thinking more about how it feels, fair, fair enough. That's perfectly reasonable. I'm thinking of it more as a subjective experience, though. Bra, okay, for me, the heart. So you're kind of located here. How many people would agree with that? Oh, yeah, so quite a few of you, eh?

So that's the same, same for you. I don't know, more like here? Oh, hm, hm, hm. Any other places? Any other places you can talk about? So, yeah, yeah, sorry, any other places? My body? I don't know; it's not like, oh, that's not good. No, I'm kidding, I'm kidding, I'm kidding.

Okay, okay, so we kind of got head and heart, and you know, that's really kind of historically standard. The Greeks seem to have located themselves sort of in their heart, you know? There's some theory that as people became more intellectualized, that that feeling sort of went up to their head, and maybe before the heart, there was the stomach, you know? You might think that you're your stomach if you were hungry all the time, right? I mean, you're just not ever hungry, so like why the hell would you think you were your stomach?

But, you know, that's another way that culture sort of keeps complexity at bay. You don't even—that's almost like a motivational state that modern people don't even have to contend with because you're never really hungry. I mean, how many of you have gone without food for more than 24 hours? Oh, that's pretty good. How many of you involuntarily went without food for more than 24 hours? Oh, yeah? That's rough.

Okay, how about a week? Nobody? How about three days? Okay, well, so you know, there's a couple of people who've gone for reasonable periods of time without eating, but fundamentally, you can tell we kind of got that problem under control. So you don't have to worry too much about your—you being your stomach. But I'll tell you, if you were starving at some point, that's probably where you'd locate yourself.

Okay, so now you're inside the body, and so let's take a look at how the body works inside. You kind of feel that you're in your brain, most of you anyways, but, and you know, you kind of think your brain is in your head, but really, that's not right. I don't really understand ever why we kind of decided that our brains were in our head because, well, look at it. There's the nervous system; it's not in your head; it's distributed throughout your whole body.

There's a lot of it up in your head, but there's the whole spinal cord; that's an important thing. Then it has all these branching nerves that allow you to move your hands and to feel things. Your nervous system is distributed all the way through your body, so it's not reasonable to think about the way that you operate: you see things with your brain and then you do things.

Now, if that's sort of true, but there are important ways that it's not true at all, and it's important to know the ways that it's not true. It helps you understand phenomena that you couldn't otherwise understand. I can give you an example. There are people who experience blindness, but it isn't because their eyes get damaged; it's because they have brain damage.

It damages the visual cortex, and so that's the higher-order part of the brain that's responsible for conscious vision. Okay, so maybe they get, I don't know, they get a tumor or they get hit in the head or they get shot or something, and then poof, they're blind. Then, they tell you they can't see anything, and then you say to them, "Okay, well, that's fine. You can't see anything, but let's play a game."

Okay, I'm going to hold up my left hand or my right hand, and you're going to guess about which I'm holding up. So, you do this, and they go right, and you do this, and they go left, and left, and left, and right, right, and they’re right! You tell them, "You're right," and they say, "Well, I can't be because I don't see anything." So, that's one—that's blindsight.

Okay, so here's another kind of blindsight. So you take the same person, and you set them in front of a screen and you say, "Well, look at the screen." They tell you, "I told you already, I can't see anything." Then, you flash faces at them, and you check for changes in the conductivity of their skin because when people react emotionally, they sweat a little more or a little less, and that changes how electricity passes through their skin.

You show them a smiling face, and there's not much of a change. You know, you show them neutral face, and there's not much of a change. Then you show them a really aggressive or really afraid face, and poof, spikes! You do that a number of times, and you show them—well, as soon as I show you a face of someone who's afraid or a face of someone who's angry, you react to it psychophysiologically.

You think, "Well, how the hell can that happen if they can't see?" The answer to that is you don't just see with your vision; you see with your body. One of the things that you'll find, for example, if you go through Swanson's paper—I'll read you a little bit about this later—is that most of your senses map onto multiple levels of your nervous system.

Some of them map right onto your spine, and that's good because now and then, your eyes should tell your spine to do something before you think because thinking's too slow. So, you know, you've got to understand, like way back when we were frogs, roughly speaking, we had eyes, but we didn't have much of a brain. So like, what the hell were the eyes doing?

It's not like the frog exactly sees. You might think, well, how could eyes inform you about the world if you don't exactly see? Then you've got to kind of think about it in a P.J. sense. Here's an example. You might take an animal like a sponge—pretty simple animal—and it can open and close pores on the outside of its surface according to different changes in the ocean that surrounds it.

Its perception is sort of like the ocean has three states—whatever those might be; maybe it has 10, I don't know, but for the sake of simplicity, we'll say three. The ocean manifests itself in three pattern states. In pattern state one, I do this. In pattern state two, I do this. In pattern state three, I do this. It’s direct pattern onto action mapping.

Animals can use their eyes just to react with—they don't have to see the thing, you know? Because you think you see, and then you act. But why do that? You can just react. You know this already because in a simple way, if you put your hand on a hot stove, you'll go like this, and then you'll feel the pain. What that means is that your body has conserved the relationship between your sensory neurons and your motor neurons at a spinal level.

You perceive the heat—it's not of the heat; it's just mapping a bodily pattern onto a sensory pattern. A lot of really primitive sensory input is exactly that. It's just the sense detects a pattern, and with no intermediary of interpretation, that pattern is translated into a behavioral output. Generally, the first—the simplest cells are sensory motor cells, so they do both. They map the pattern and they react, and then the sensory and the motor cells differentiate, and then neural tissue grows inside them.

What happens is that instead of an outside pattern being mapped immediately onto a behavioral pattern, the neural intermediary says, "Okay, this pattern could mean any of these three things." Then that neural layer grows and grows and grows until, in creatures like us, it's like a whopping layer. We see a pattern, and we go, "That could be this, this, this, this, this, this, this, this." All of those things could be mapped onto this or this or this or this, so, you know, it makes us speedier but more flexible, and slow can be a problem.

Like when you're walking down a pathway and a snake appears, you don't want to be thinking, "You know, snake, rubber hose, stick, whatever," because then you're dead; the snake bites you. What you want to do is catch the snake out of the corner of your eye and jump up into the air before you even know that you saw a snake. You can do that because your eyes can map right onto your spine. They don't just map right onto your spine; they map onto your nervous system at all sorts of levels.

For example, with the blindsight person who's looking at the face—so it's an angry face—the eyes are still mapping information onto the amygdala. The amygdala changes the psychophysiology, you know? It says, "Prepare for threat." That person might feel uneasy, but that's a form of sight. To feel uneasy can be a form of sight.

That’s to say even more clearly that your brain just isn't in your head; it's, like, it's all the way from—and this is a nice pan viewpoint because, you know, in some sense what P.J. says about children is they organize themselves from the spinal level upwards. They learn these little subroutines. First, they have a few subroutines; those are built right into the spine.

Then they start playing with those and chaining them together in flexible ways, and they keep doing that, you know, in more and more complex ways until they're capable of the abstract representation of thought. You can see how this will work as we go through the nervous system. So your brain's in your body. In fact, there's some evidence there are more than one kind of nervous system too, right?

There's the central nervous system that allows you to move voluntarily, and that provides you with sensory feedback, some of which you're conscious of. There's also the autonomic nervous system that runs all the complex machinery that you're too stupid to attend to, you know? Because your consciousness gets little jobs; it doesn't get to run your liver, for example.

You can imagine what your life would be like if you were in charge of your liver; you'd have been dead years ago because what do you know about livers? So you have a whole system, like the autonomic nervous system, which has more neurons than the central nervous system that just runs all that stuff for you, which is, you know, a good thing; then, you don't have to pay attention to it.

So anyways, there's a lot of distribution of neural tissue throughout your body, and there's even some evidence that you have a like, a second brain of sorts in your solar plexus where, you know, that's perhaps part of the reason why you really don't like to get hit there.

There's a tremendous number of serotonergic neurons, for example, in your midsection, and there's increasing evidence that those are associated with things like emotion and mood. The idea that the brain is here, it's like, "No, not really." It's a continuum; you know, your body is a psychophysiological entity. To separate it into body and mind is like—it's not right.

The other thing that seems to be increasingly clear among, say, the robotics guys is you can't even be smart unless you have a body. That's why the advanced advanced intelligence guys are building robots from the bottom up. They're doing it just like P.J. would have suggested. It's like, "Well, build some things that can move, and then chain those things that can move together so that they can move in more complex ways, and then chain them together so they can work in more complex ways."

Once you've got this thing that can do things, then stick a brain on it, and then it'll have things it can do with its brain. If you don't do it that way, you get something that can't function intelligently. It's close to that. So there is the brain, and one way of dividing it into its major subcomponents is represented. There are a variety of ways you can do this.

You can divide it into hemispheres because it's sort of split down the middle. The right hemisphere seems to be kind of specialized for the processing of unknown information, and the left seems to be more comfortable working where you know what's going to happen. The left is generally the linguistic part of the brain—although not always; it's a rough truth; there's lots of exceptions. The linguistic system tends to specialize in the left, and the left sort of insists that it knows what's going on, and the right is always looking out for things that don't fit.

It’s sort of convincing the left slowly and sort of under the table to change its viewpoints, and that seems to happen when you're sleeping and you're dreaming. What might be happening when you're dreaming is that during the day, your cognitive processes are pretty tight and defined. They better be, right? You don't want to be dreaming your schizophrenic dreams in the daytime. That's a bad idea.

So you got to stay kind of focused and narrow in a way during the day, but the problem with that narrowed focus is that you're not paying attention to a lot of things. It kind of looks like your right hemisphere keeps track of the potentially important things that you're not keeping track of. Then at night, your category system sort of broadens and loosens. You can tell that in dreams because they're so weird, and maybe that's when the right hemisphere is sort of tapping some new information into the left and playing with how it might be recategorized without completely overwhelming the left.

You don't want to just—because you learn something new doesn't mean you want to upset yourself totally, right? So it's a real complex dynamic between stability and learning, and it's conceivable that's why you have two hemispheres. So who knows? It's a good theory, though. The guy who came up with it fundamentally, his name is Elkhonon Goldberg; he was a student of Alexander Lurias, who is a great neuropsychologist. So, you know, it's a credible idea.

Here are some rough divisions: you've got your cerebellum. That cerebellum—we don't know what the hell that thing does. If you don't have one, you get all wobbly, but there's more neurons in the cerebellum than there are in the rest of the brain. So like, is it just making you not wobbly? It seems like a tremendous devotion of resources to something that's relatively simple.

Alcohol, when you're a new drinker, is really hard on the cerebellum, which is why you're, you know, totally useless in a motor way and you fall down, and all those things happen. But so that's the cerebellum. We don't know what it does even though it's very complexly branched. It kind of looks like a cauliflower, and it's just packed full of neurons.

Then there's the occipital lobe, and that lets you see, more or less. Then the parietal lobe kind of helps you keep track of who you are from a bodily perspective and sort of where your body's located in space and sort of who you are as an embodied person.

For example, if you lose the right parietal lobe because you have a stroke, then you lose the left side of your body. Even more weirdly, you lose the left side of everything, so all of a sudden, you can't see the left side of anything. Nobody can figure out what that's like because, say, I'm looking at this room and I have this parietal damage.

If I'm looking at the room, do I not see the left side of the room? And then if I look at you, all of a sudden I don't see your left side? Like, we can't figure that out. Like, the left is gone, but then the left is relative to where you happen to be looking. I think one of the ways of understanding it is sort of like, you know how you clearly can see anything behind your head?

It's not black where you can't see, right? It's black if you close your eyes, but there's a difference between what you can't see behind your head and the black you see when you close your eyes because the black sort of seems like nothing, but compared to what's behind your head, it's not nothing at all. I think what happens with people who have neglect parietal damage is that that back part just goes like this.

Instead of, you know, seeing this much of the world and this being just not there at all as far as vision is concerned, it goes like this, so then you've only got like a quarter of the world that you're perceiving. People like that sometimes will throw their own legs out of bed. So they wake up and they think, "Oh my God!" because they can kind of detect the left but not very well, and they're quite freaked out because, you know, do you really want to wake up with a leg in bed with you?

No, so they grab it and throw it out, and that's not so good because they're attached to it. Or, so they'll eat— they only eat half the food on their plate, but if you turn the plate, then they'll eat half of the half that's left. So anyway, that's the parietal lobe. The temporal lobe enables you to hear, roughly speaking. There's a lot of memory there too.

Then the frontal lobe—well, first of all, the frontal lobe seems to allow you to make voluntary movements sort of at the highest level of abstraction. Then the prefrontal cortex, which would be right at the front of the yellow there—it's sort of like the back part of the frontal lobe enables you to make voluntary movements, but the prefrontal cortex enables you to represent the potential motor movements that you might make before you implement them.

It evolved out of the motor strip during the course of evolution. It's sort of like, well, first you learn how to act voluntarily, and then as that grew, and it's particularly big in human beings, that part was able to divorce actions from your body, represent them in an abstract space, run them as simulations, calculate the outcome, and then implement them or not. It's a hit-and-miss business because a lot of you people undoubtedly simulate catastrophic outcomes and then go do whatever it is you were going to do anyways, like, you know, that happens to people all the time, say, when they’re trying to stop drinking or to stop using cocaine or not to binge eat or—so, your prefrontal cortex can whip up these simulations, but other parts of your body can override them quite badly.

That's sort of roughly the brain, at least from, you know, looking at it from the side. Then this is it split down the middle, and you can see that it's not precisely two hemispheres all the way down in the middle; it's just one thing, and then it grows these two things like little hats. As far as I'm concerned, all the important parts of the brain are low down central, old, you know, because people like to think that if it evolved a long time ago, it's primitive.

It's like, "No, if it evolved a long time ago, it's been around a long time; it's really smart." That's why you don't run your liver—the autonomic nervous system runs it because it's been around for an awful long time, and it knows exactly how to do it. So it's really, in some sense, the new parts of the brain are the parts that are primitive. The old parts are extremely necessary and sophisticated.

The areas we're going to concentrate on most particularly are, well, the cortex—we've already talked about the cortex—is probably responsible. People like to think of it as responsible for consciousness, and there's something about that that's right, but it's quite clear that human beings can remain conscious even if they have a substantial amount of damage to the cerebral cortex.

So consciousness is a really weird thing; we're not very good at figuring out where it's localized at all. Cerebral cortex, thalamus—the thalamus is the place where all your sensory information comes together. So you know when you look at the world, it's kind of like a continuum of experience despite the fact that you have these five different sensory inputs, and the thalamus seems to sort of unite all that.

Then it sends the messages that it amalgamates up to the cortex, and the cortex sends them back, and the thalamus sends them back. There's like this loop between the thalamus and the cortex, and maybe that's part of what consciousness is. Rather than being localized in an area, it could easily be a process, and you know, the fact that consciousness sort of turns on in the morning, which is a very weird thing, seems to indicate to me that it’s probably something like that: it’s a loop.

It's the looping interaction between brain areas, and you know if something's looping like that, it gets really weird properties. So that's a positive feedback system. I don't know if you've ever turned a video camera on and hooked it to a TV, and then turned the video camera on the TV. You know, it starts doing extremely weird things; you can get all sorts of unbelievably complex designs and weird phenomena because the TV is recycling its own signal, you know, so there's this circuit in there that's looping.

I suspect consciousness is something like that. The hippocampus is responsible for the movement of short-term information into long-term storage. It’s a very important part of the brain; we'll talk about that more next time. The amygdala is responsible for a lot of emotional responses, and the hypothalamus is responsible for a lot of primordial motivational states.

We'll stop, and we'll start with the hypothalamus on Tuesday. See you soon. [Applause]