That Neuroscience Guy - The Neurosciene of Executive Control

Episode Date: July 29, 2024

Why are kids more single-minded and impulsive than adults? In today's episode of That Neuroscience Guy, we discuss executive control, the cognitive process we use to control decision-making, memory, and other high-level functions. 

Hi, my name is Olof Kregolsen, and I'm a neuroscientist at the University of Victoria. And in my spare time, I'm that neuroscience guy. Welcome to the podcast. So there's this phrase that we use in cognitive psychology and cognitive neuroscience, and it's executive control. And if you just hear that phrase and you don't know anything about cognitive neuroscience or cognitive psychology, you might even picture like a business where the executives are in control. And funnily enough, that's kind of what I'm talking about. One of the key roles of the human prefrontal cortex is executive control. The question is, what is that? Now, we've talked about Phineas Gage

before, but I just want to give you a quick reminder. Phineas Gage was a railway supervisor who on the job had a railway spike that blew up and there was an explosion of some sort and it shot up and it went through his eye socket and up through his brain and it basically took out and damaged a large chunk of his prefrontal cortex. Even though this was in the 1800s, Phineas Gage miraculously survived. But what was interesting is prior to this incident, Phineas Gage miraculously survived. But what was interesting is prior to this incident, Phineas Gage was a supervisor. He was an outgoing person. He did lots of things. He engaged with other people. And afterwards, Phineas Gage basically spent the rest of his

life sitting on the couch. He lost his job. He just didn't seem to be able to engage and do things. What Phineas Gage had lost was executive control. So let's pull apart what that really means. It basically means that the prefrontal cortex is the part of the brain that governs the high level stuff. And I'm going to give you some very specific examples, but this is why as humans, we're ahead of cats and dogs and monkeys and chimpanzees because our prefrontal cortex is larger proportionally than these other animals. And as a result, we have greater executive control capabilities. Now, the parts of the prefrontal cortex I'm talking about are the orbital frontal cortex, which is right on the bottom part of the brain, right at the front. It's the dorsolateral

prefrontal cortex, which is off to the sides on the left and right, but again, at the front of the brain. It's the ventral lateral prefrontal cortex, which is just below that. So if you were going to sort of go up from your eyes, the edge of your eyes, the outer edges, and just push up towards your brain, you'd be into the ventral lateral and the dorsolateral prefrontal cortex. Now, studies using neuroimaging have seen that these areas of the brain are active when you're sort of thinking about your own or others' mental states. So you're wondering what's going on in other people's heads, what we call theory of mind, when you're performing two or more tasks, when you're trying to remember things, pull things out of long-term memory, and a whole myriad of other things.

But the key features that the executive control system is responsible for are, number one, the control of working memory. Now, we've talked about memory quite a bit, but basically, if you think of what memory is, and just a quick flashback here, we have sensory information all around us, and it goes into working memory or short-term memory, right? So let's say someone tells you their name, okay? You're standing, you know, you meet someone and they say, hey, my name is Bob Smith. Well, that sensory information goes into working memory. And if you get distracted, working memory can't hold onto it and it disappears, right? But if you rehearse it, you say it a few times over and over again, or it happens to be an emotional event, and we've

talked about the amygdala way too much, then guess what? That information goes into long-term memory. But where it also plays a role is when you pull things out of long-term memory. So let's say I say, what's the capital of New Zealand? All right, you're going to pull that out of long-term memory, and it's going to come into working memory. So what the central executive does, and that's another phrase for our executive control system, is it controls working memory. Another thing that executive control is responsible for is planning, coming

up with plans. Now this is tied to another function that it's responsible for, which is goal setting. So our ability to set goals, you know, I want to go for a walk today. That is part of what the executive control system does. And then at the same time, it's also the part of the brain that comes up with your plan. Where am I going to go for a walk? When am I going to go for a walk? What am I going to wear when I go walking? Should I ask someone to walk with me? That's all part of the executive control system. Again, all located within the prefrontal cortex. Another key function of the executive control system is task switching. Our ability to switch between one task and another.

Let's say you're sitting down having lunch and the doorbell rings. Without this ability to switch tasks, eating lunch to answering the door, you would get stuck eating lunch and you'd miss who's at the door. And that's what your executive control system does. It's able to prioritize and say, okay, put down lunch, answer door. Young children can be bad at this. You'll find that young children can get stuck on one task and they have a hard time switching away. And it's just because their central executive or their executive control system isn't fully developed yet. The last function of the executive control system I'm going to talk about is response inhibition. It's quite common that our brain throws out an idea and says, hey,

let's try this. All right. This is something we should try and do, all right? But then you realize it might be inappropriate or it might not be the right time to do it. So your executive control system is the thing that puts on the brakes. This is why people that have damage to the prefrontal cortex have a hard time stopping their responses. They might blurt things out.

And this is actually the problem we have with our teenagers. Teenagers, especially young males, their executive control system is one of the last things to fully develop, which is why they just do dumb things because their brain throws out the idea and says, hey, let's do this. Let's jump off the roof of the house. And the executive control system isn't fully developed, so it might not stop that response. All right, response inhibition. And if you're a teenager or younger and you do something silly, just look at your parents and say, hey, guess what?

My central executive, my executive control system isn't fully developed, yet you can't hold me responsible. Now, when we study these things, there's a couple of different ways to do this. All right. A key way to study the working memory system is called the NBAC task. And I just thought I'd take you through some of these things and give you some examples just so you can see these things. Now, if you want to try the NBAC task, well, one, I'm going to walk you through it right now, but you can also just Google. Now, if you want to try the NBAC task, well, one, I'm going to walk you through it right now, but you can also just Google it. If you open up Google and put in NBAC

task, you're going to find some online version that you can play. There's iPhone apps that allow you to play the NBAC task. And in fact, with some of these games I'm going to tell you about, they're tied to the executive control system. This is what Luminosity is based on. They're all just psychology games. Now in the NBAC task, it's pretty straightforward, but I'm going to tell you what's going to happen. You're just going to listen to me say a bunch of numbers. All right. And when, what I want you to do is if you hear two numbers in a row, I just want you to realize you've heard two numbers in a row. That's a one back task. So you want to detect the've heard two numbers in a row. That's a one-back task. So you want to detect the presence of two numbers in a row.

So let's go. Three. Five. One. Nine. Four. Four. Boom.

You should have said, okay, that's two numbers in a row. Most people can do an NBAC task of one. But let's try a trickier one. The NBAC task is used to push the central executive. So let's try a two-back. So what you're looking for is not two numbers in a row, but for the second number to match. So if I went 4, 1, 4, that's a two-back because there's a four, then there's a space, and then

there's a four. So let's try that one out. Three, two, eight, five, zero, six, zero. Now that should have triggered you a two back because you heard a zero, then a space, then a zero. And why we use this to study the central executive is your working memory system has to keep updating all the time and has to say, okay, let's forget about something because I don't need that anymore. And let's add this to our little memory buffer that we hold on to. And people do three back. They do four back. I've heard of people doing five and six back. All right. And it's just a test of the central executive. We actually use it in my own lab when

we look at mild cognitive impairment and dementia. People that have mild cognitive impairment or dementia really struggle with the NBAC task, especially when you get to two back and three back. Younger kids have trouble with this as well because their central executive isn't fully developed. Now, there are other tasks that are out there. This one, I can't really walk you through. But if you want to see a central executive task that, you know, makes that executive control system really work, find the Towers of Hanoi. Some people call it the Towers of London, but originally it's the Towers of Hanoi. And again, if you Google this, Towers of Hanoi, you will find online versions. There's iPad or an iPhone versions where you can try it. Basically,

to describe it, there's three pegs and there's a bunch of circular discs on the first peg, and they're sorted by size. The biggest one is at the bottom and it goes up to a smaller one. And the goal is to move all of the discs from the first peg to the third peg. But there's a crucial rule. You can never put a bigger disc on a smaller disc. Now, most people start with three discs and it's a little bit challenging, but it can be done. three disks, and it's a little bit challenging, but it can be done. All right. And then you go to four disks and five disks. Try it out. What's interesting about the Towers of Hanoi is it's a mathematically solvable problem, which there are computer algorithms that can play this and always get it right, even with crazy amounts of disks. All right. But you try it yourself. And the further you can go, the better you are in terms of

your central executive, your executive control system, because that means you're good at goal setting and planning. All right. Another one you can test is your ability to do task switching. And the classic one for this is the Wisconsin card sorting task. And the way the Wisconsin card sorting task works is you get a deck of cards. And I'm going to use a simple example. Imagine there's a deck of cards that are comprised of squares and circles. That's all you see on the card. And the squares can either be red or blue. And the circles can either be red or blue.

And then I give you a rule. Sort the cards by shape. So you start turning over cards and you put squares on one pile and circles on the other pile. You get the idea? Turn it over, you see a circle, you put it on one pile, you see a square, you put it on the other pile. And at some point I'll say, okay, the rule is now color. So then you turn over the next card and you have to put blue on the left and red on the right. But the problem is you've turned over the card, and it's a blue circle,

and you might want to put it on the right where you are putting circles, but you're actually supposed to put it on the left. And what you do to test your ability for task switching is, again, you switch this up regularly. You keep changing the rules, And this is a great one. If you go on YouTube and put on Wisconsin card sorting task in kids, you'll see some hilarious examples of kids that can't do this. They can't switch rules because their central executive isn't fully developed.

And again, as we get older and cognitive impairment becomes an issue, then this Wisconsin card sorting task can be used even with adults, because if you struggle with this, it's a sign that your central executive or your executive control system is impaired. So again, you can Google this, you can try it. There's JavaScript games, there's iPad games. It's the Wisconsin card sorting task. And it's, you know, it's a fun one to play and there's advanced versions of it. There's simplified versions for kids. All right. And it's, it's, it's a good one. I'd try it out just for fun. Try it at a party sometimes, maybe if you've had a few too many glasses of milk,

you get the idea. Now, the last one I'll tell you about is the last feature of the central executive, the executive control system that I told you about, which is the response inhibition aspect of the central executive. The most common way to test this, and there's lots of ways for all these things, is something called the Stroop task. Now, again, I'm just going to describe this, but you can go, again, you can Google the Stroop task and you can try it out. And there's a million different versions of the Stroop task. But the basic version of this is you're going to see a list of color names. So you're going to see like green and blue and red.

But your instruction is to recite the color that the word is written in. So if you see the word red and it's written in red, well, that's easy. You say red, right? But you're saying red, not because the word reads red, but because the color of the word is red. And what the Stroop effect is very simply is if you see the word blue, but it's written in red, some people are slow to respond because they want to go blue and then they go red because you're supposed to be saying the color of the word is written in red. Some people are slow to respond because they want to go blue and then they go red because you're supposed to be saying the color of the word is written in. And again, young children struggle with this. They just read the word. People with impairments, like I've said a few

times now to the central executive, they struggle with this because quite simply, they just want to read the word. Their central executive is impaired. So again, you can Google that and try that out. That's the Stroop task, and it's called the Stroop effect, and it's a way to test the central executive or your executive control system. Anyway, I hope you found that interesting. If nothing else, I've given you a couple of cool games to play, and if you're into luminosity and these kind of things, you might start thinking about those games and what they're probing because they're typically probing your central executive or your executive control system in different ways. All right. That's all I've got for this podcast on the executive control system. Do not forget, we still have our website,

thatneuroscienceguy.com. We do have our t-shirts up on our Etsy store. We haven't made any new designs. We keep saying we're going to. It's been years now. I'll actually shout this out to you. If you have an idea for a cool t-shirt design that's a neuroscience theme, please let us know. There's Patreon, of course, where you can support us. Thanks to those of you that did. I was able to give Matt some money the other day because we pulled money out of our Patreon account. So for all the hard work he does and the fact he's a graduate student,

thank you for supporting Matt and other graduate students in the Craig Olson Lab at the University of Victoria. Remember, a dollar a week, a dollar a month, it all adds up. And of course, if you have ideas, we're winding down the summer season. We got a couple episodes to go, but we're going to make one big push in September. And we want to know

what you want to know about the neuroscience of daily life at that neuroscience guy on threads and X, or just email us that neuroscience guy at gmail.com. We do read them. We can't respond to everybody because we get a lot, but we really do want to know what you want to know about the neuroscience of daily life. And of course the podcast. We haven't been as consistent as we want to be over the summer. Matt and I have both been traveling and being quite busy with work, but we try the best we can. So thank you for listening. I'm sorry we're not consistent week to week. We'll try and do better, but please subscribe if you haven't already. And thank you so much one more time for listening. My name is Olof Kregolsen,

and I'm that neuroscience guy. I'll see you soon for another episode of the podcast.