Jonathan Peelle 0:03 Hello, and welcome to The Brain Made Plain. I'm your host, Jonathan Peelle. Each episode I talk to a different brain scientist about their research. Joining me today is Dr. Taraz Lee. Taraz, thanks for joining me today. Taraz Lee 0:16 Thanks for having me. Glad to be here. Jonathan Peelle 0:18 I wonder to start with if you could just give a little overview of the research going on in your lab right now. Taraz Lee 0:24 Sure. So, in my lab, we're primarily interested in a process called cognitive control. So how we act in the service of our goals, and how processes that support that like attention and working memory interface with things like motivation, and the learning of skills, and specifically motor skills or movement skills. So we do a whole bunch of different kinds of studies, using a variety of techniques, including neuroimaging, and behavioral studies, and brain stimulation studies to try to get a handle on both how all these processes interact to produce behavior, and also how the brain supports the processes. Jonathan Peelle 1:01 I wonder if you could give an example of how cognitive control interfaces with with goal directed behavior, or even just like at a basic level, like what an example of a goal someone might be trying to accomplish? Taraz Lee 1:14 Sure. So an example I like to use is just, let's say driving a car. So over time, you learn to be pretty good at driving a car, if you have a lot of practice. But let's imagine you go to England or somewhere where they drive on the left side of the road. In that case, you're gonna have to override all a lot of your-, you're gonna have to override a lot of your automatic tendencies in terms of where you're looking where you are attending to in space. So you know, maybe when you're making a left turn, and you look at a particular part of space to check for cars, you're gonna have to overcome that and kind of change your actions and what you're doing in the service of this new goal. And this new rule, driving the left side of the road. So things like shifting attention, maintaining what the rule is. So keeping in mind driving on the left side of the road, these kinds of processes are what we collectively referred to as cognitive control in cognitive psychology and cognitive neuroscience, often, Jonathan Peelle 2:09 Is it fair to say that sort of like, and I don't want to, maybe this is obvious to people, but but your goals can be sort of like big goals and small goals, right? So like a big goal if you're driving on the side of the road you're not used to is like not to hit a car not to hit a tree. But it could also be like, if I'm reaching for something, and I'm going to I'm not going to get it the way that I think I am I have to kind of use some awareness of my situation to correct that reach. And is that also that kind of like awareness or interrupting automatic action? Does that also kind of fall under cognitive control? Taraz Lee 2:42 Sure, yeah, I think that's where it gets tricky, specifically with the interface with movement and motor control. So you have a lot of actually automatic processes that can do this online error correction. So if you're reaching out to a coffee mug, and you know, someone bumps the table, that could be pretty in the moment automatic. But if you know ahead of time, you have a goal of oh, I want to maybe my, you know, index finger hurts. So I want to pick this up with my middle finger and my thumb or something like that, then that's a new goal. It's different than how you normally pick up a cup. And that is kind of gold, but you're definitely right, that you can have kind of like larger goals, like, you know, don't hit a car, or you can have more minute goals, like I'm a little bit late, I'm gonna try to go a little bit faster. Right, and that's gonna probably change your actions that you pick, say, if you have a morning meeting that you don't want to. Hopefully that makes a little bit more clear. Jonathan Peelle 3:39 Yeah, that's good. What got you interested in this area originally? Taraz Lee 3:45 That's a good question. It was probably in when I was an undergraduate student, I knew I always want to take psychology, I was always interested in how people think and solve problems. And I think my first was either brain and behavior class or intro to cognitive psychology class. And we talked about memory. And I somehow got really interested in attention and working memory specifically. And as I kept going through undergrad and also doing some research on the side as a research assistant, I started getting more and more interested in just how it is that we kind of over overcome our automatic tendencies. How does that process work exactly? I should also mention, given some interests, I think I always loved sports and played a lot of sports growing up. And there's always this interplay between kind of your automatic overtrained actions and what the goal is in the moment. And I think that inner plays always kind of been in the back of my mind, even from the start after graduate school that I started looking at the melding of these two things before but I think even way back then it kind of motivated some of my interest in cognitive control more broadly. Jonathan Peelle 4:55 And at what point in that did you start to start thinking about the brain, you know, specifically from more of like a cognitive neuroscience perspective, as opposed to maybe more of a behavioral psychology perspective. Taraz Lee 5:06 Sure, yeah, I think around that same time, actually, I think I was just fascinated by the fact that we could identify the neural underpinning of any of these kinds of processes. I don't, it didn't occur to me at that time that that was something that one could do. You know, I don't know how many people have experienced or any contact with neuroscience or psychology for that matter. In grade school or high school. I definitely didn't have much at all. Jonathan Peelle 5:34 Right. Taraz Lee 5:35 So I never really realized that you could connect behavior in neuroscience like that. I thought that was very exciting. And just seemed cool. You know, everybody likes cool brain pictures. And I think I got wrapped up in it as well. And it made it seem, I think a lot of people report this or Cog neuro scientists, and even lay people, but it made it seem more real if it was grounded in biology, I think. So I do think of myself as both a cognitive psychologist and a cognitive neuroscientist. And I talk about how those, you know, the merits of both and the pitfalls of both. But yeah, I think it's just it seemed cool. It seemed more real to me at this from the start, even. And I still, I still love doing both honestly, Jonathan Peelle 6:17 In the kind of in the context of thinking about brain systems. I wonder, can you give sort of a brief overview of what the main parts of the brain are that you think about either for cognitive control or for some of the related processes that you study? Taraz Lee 6:34 Sure, yeah, I think for more or less my entire career, a lot of my research, my cognitive neuroscience research has been focused on the prefrontal cortex. So that's the part of your brain that's basically right behind your forehead, often talked about as the part of the brain that is controlling attention or controlling, is responsible for working memory and keeping your goals online. So in the context of my work, part of the brain that we focus on often is the dorsolateral, prefrontal cortex. So dorsal meaning top and lateral meaning side, so the side top of the prefrontal cortex, I would say. And this area has been implicated in through a lot of neuroscience studies and cognitive neuroscience studies and animal studies, in controlling attention and sending signals back to other parts of the brain, kind of, I hesitate to say, the top of the control, because I think that's a tricky topic in and of itself, but often thought about that way that is kind of directing what's going on. So in my work, we often focus on prefrontal cortex, we also look at times at the interface between this lateral frontal cortex area and motor regions like motor cortex. So primary motor cortex, for example, is involved in actually sending signals down to your muscles down the spinal cord to your muscles, about how to move, right. And there's a whole host of other motor planning regions in between. So kind of this whole pathway in between these frontal cortex areas and these motor areas, and how they interface amongst other regions, as well, obviously, it always gets more complicated the further down you go. Jonathan Peelle 8:18 Right. Well, kind of in that context, I'm going to ask you sort of like a very detailed in the weeds question that people can feel free to ignore if they're not interested. But one of the challenges, I think, for all of us, depending on what our favorite region of the brain is, but it's sort of, you know, clearly defining it. So. So your definition of dorsal lateral prefrontal cortex was great. But if I wanted to situate that in the context of the main gyri in the frontal lobe, so there's the inferior frontal gyrus, the middle frontal gyrus, the superior frontal gyrus, is it is it mostly middle frontal gyrus? Is it inferior frontal sulcus? Does it matter? Like, how do you kind of operationally define DLPFC? Taraz Lee 9:05 Right. Yeah, I think that in and of itself, about how to fractionate DLPFC, is a large question... Jonathan Peelle 9:11 You didn't know is going to put you on the spot with this. Taraz Lee 9:12 Yeah, it's a it's a large question. No, it's a good one. It's a really good one, though. So for in the context of my work, at least—and especially when, you know, looking at interfaces with motor control—often the region that keeps coming up over and over again, is kind of this bit of the inferior frontal sulcus that is pretty far back close to inferior frontal junction. Sometimes in fMRI studies, activation bleeds up into middle frontal gyrus as well. And it seems, actually, recently I had a study that we're trying to stimulate this region and we got the coordinates, so to speak of where to stimulate people's brains from a meta analysis that was looking at attention to action specifically, and it seems in a whole host of studies, the same regions coming up over and over. And so one of the things that we tried to do in my lab is try to figure out what this region is actually doing. Right? So in the context of different tasks, how this region changes levels of activity? What are the kinds of things, the kinds of information that we can read out from that brain region? And also, when we use different brain stimulation techniques, what happens if we disrupt that area of the brain for a short amount of time? What does that cause people to have deficits? So if I kind of take that offline for a little while, how do people react? And what what does that actually hurt when people are doing these kinds of tasks? Jonathan Peelle 10:31 Yeah, I wonder maybe you could talk a little bit about, you know, the brain stimulation approaches you use and then and then maybe an example of how you use that. Taraz Lee 10:39 So the brain stimulation technique that we use in my lab is called transcranial magnetic stimulation. And so the idea behind this technique is that you have a magnetic coil that has some wires running through it. And when you pass current through that coil, you can induce a magnetic field. And so given the relationship between electricity and magnetism, you can create magnetic fields by passing current through some wires, basically. And that magnetic field can cross the skull and make neurons in the brain fire. And so depending on the pattern of firing that you induce in the brain, you can either make a certain part of the very focal part of the brain, maybe a centimeter or two, you can make that part of the brain either more excitable or less excitable. So some people like to say that you can use TMS or transcranial magnetic stimulation to kind of temporarily knock out a region and see what the effects are. You can use this technique for a lot of other things as well, it's often used in motor control studies, because if you use even a single pulse, it's called if you pass this current really quickly through that coil over to your motor cortex that controls your muscles, you can actually make those muscles fire. So the way we've been calibrated for each individual is we put this coil over motor cortex, and we change our settings and intensities. So that we can elicit finger movements just by the use of the coils. So it can feel kind of funny for people to have the experiments or make their fingers jump. But it is a it is a pretty cool and powerful technique. And I've used it in the past and quite a few studies at this point, usually to test predictions about the importance of a brain region in a particular function. Jonathan Peelle 12:22 So what is the function of that region? How does that change behavior? And then you can sort of draw some conclusions about what it was doing when it was functioning. Okay. Taraz Lee 12:31 Right, exactly. So I can give an example from one of the studies in my graduate work where so there's a lot of evidence that the prefrontal cortex might be sending signals back to visual cortex to either ramp up excitability in the relevant areas of visual cortex or kind of tamp down and ignore some other kinds. And so what we did is that we used this TMS technique to disrupt an area of the prefrontal cortex, just before people did one of these attention tasks in the fMRI scanner, actually, and so we could see that disrupting activity there made people worse at this attention task. And also, we could see that the activity in those visual regions that I was talking about that are important for the task also get altered by disrupting prefrontal activity. So we were able to show that, you know, you can actually affect brain regions far away from the site of stimulation, depending on the task. Jonathan Peelle 13:33 And this kind of, like, correct me if I'm wrong, but sort of in the this overall framework of cognitive control, right? So what you're saying is that normally, dorsal lateral prefrontal cortex can affect other regions like like primary sensory and motor regions, for example, if by helping you attend, so if you're paying attention to part of your environment, it may improve the processing for that part of the environment, helping you achieve your goal, whatever that is. And then now, by disrupting it, you've sort of disrupted that mechanism of cognitive control. And so it has less less control over those lower regions. I hate to call them "lower regions", but... Taraz Lee 14:11 Right, yeah, that's, I think that's exactly right. Yeah. So I, your listeners may be aware that you have different parts of your brain that we felt, you know, you said primary regions right? So you have primary motor cortex, primary auditory cortex, primary visual cortex. And so those regions are the first cortical sites, at least that information from the outside world gets into your brain, right? And so the prefrontal cortex can have what's called modulate activity in those regions or make them more excitable, more reactive to what they see and hear and feel if you want to anthropomorphize them, or less reactive in just exactly what you said. If you disrupt your frontal cortex, it turns out it ruins those modulations. So now, they those areas, in some sense, don't care as much about what you're supposed to be attending to anymore, and they just react to everything. Jonathan Peelle 15:03 I wonder if you could talk a little bit about the role of motivation in this whole kind of cognitive control goal directed endeavor? Is that something that you've also been interested in? Taraz Lee 15:15 Sure yeah, so I got interested in that even before I got to graduate school, I think I was interested in reward motivation. I had played a lot of poker, before grad school actually Jonathan Peelle 15:31 Were you any good? Taraz Lee 15:32 Yeah, actually, I was. That's how I supported myself for a couple years, actually, after undergrad, I didn't really know where I was going to go, or what I was going to do, and I was making pretty good money. And so I decided to keep doing that until I could figure it out. So I, you know, I spent a lot of time thinking about reward and decision making. And, but I didn't get really interested in it from a research standpoint, and i didn't start doing it until a lot more recently. But it turns out that there's a lot of evidence at this point, coming from quite a wide variety of labs, showing that when you're motivated, you can actually increase a lot of these cognitive control capabilities. And, you know, intuitively smack makes sense, right? So I used that example, earlier of, you know, you, you're driving your car, and you don't want to miss a meeting. Let's say you're driving your car, in, you know, England, again, we're on the left side of the road, and it's not normal place for you to drive, you may be better able to maintain that rule and overcome your automatic actions when you're motivated. So, you know, real world context has a lot of reasons to be motivated. Often, the lab will use monetary rewards. So we have people play our little video games for $5, $10, $50, things like that. And generally, what you see is that people tend to increase control, and increase their ability to attend to the right thing, when they're more motivated in specifically what's called control. So kind of planing and forward planning tends to be a little bit better when motivated. And, you know, one of the things I'm interested in is kind of this interplay between these cognitive control processes and motor control processes, because you know, sometimes paying more attention and taking more control isn't exactly great for let's say, a golf swing, for example, maybe maybe you should, maybe you don't know what you should be focusing on. It's just kind of "just do it" as Nike used to say, right. So one of things I'm interested in is actually the kind of the inner, the back and forth between that, you know, being motivated is good, increasing cognitive control is good, but maybe it's not, and how does that work exactly? And so kind of the pluses and minuses, the good and the bad of cognitive control, I think, is one of the things that has motivated me for the past 6, 7, 8 years at this point. Jonathan Peelle 17:54 And that's really interesting because I feel like my default, you know, position, I don't know, just as like, as a cognitive neuroscientist, who doesn't specialize in cognitive control. You know, I, my instinct is just like, well, more cognitive control is better, right? Like, you should always do better if you're using these, like, you know, highly evolved regions of your frontal lobe, you know, like that, that's always better, right. But as you're, as you're talking, I'm thinking to, you know, what comes to mind really is more motor things, you know, kind of getting to your examples of what now so, So full disclosure, I was never a great athlete, I played in the little league, my favorite, my favorite embarrassing moment from Little League was we, you know, if you had, if you're up to bat and you had four balls, instead of getting a walk to first you got to hit the ball off the tee. And I, so I got four balls, I got to hit the ball off the tee, which should be very easy because the ball is stationary. And I kept asking them to lower the tee to the lowest possible. I kept lining my bat up, and then I swung with all my might, and I hit the tee halfway to the pitcher, but I totally missed the ball anyway. But I feel like as a slightly older person, I've done a little bit of bowling, although not for years. Never golf, but you know, there are these sort of, I guess I have this like, intuitive sense of this memory of of overthinking a lot of these movements. And when I'm able to, to kind of relax and not overthink it, then I do better. And I wonder if that sort of, you know, the disengagement of these cognitive control frontal systems? And maybe, you know, does that let, as you were talking earlier about these sort of built in motor feedback, or motor control systems kind of do their thing, right, like, maybe we don't have to interrupt them if they already know how to do this stuff. Taraz Lee 19:48 Right. I think that's more or less exactly how I think about it. And there's, you know, there's a lot of experimental evidence for this too. In that early on. When you're learning this skill. Often you need a lot of these processes to occur. So let's say, you know, you're learning how to juggle or something like that you've never done it before. Someone might give you a few rules, you know, right hand then left hand or something like that. Or in the context of golf, try to keep your left arm straight. And that'll help your golf swing. Over time you have other systems in the brain that tend to learn over a longer time scale. Specifically, doesn't have to be motor control. Even language often often works like this grammar works like this. But it takes a long time for these systems to learn, but they pretty much learn autonomously and automatically from the errors they get. So over time, they learned the right thing to do. And in the context of motor control, you don't have access to your muscles consciously, right? Like, if you're riding a bike, you can tell me how you fire your oblique muscles, so you don't fall down. And you just kind of you just kind of know that's muscle memory. Right? Right. And at that stage, what I think is going on at least is that you have these systems that know how to do that task really well. And you actually don't have access to what you should be doing necessarily. So yes, cognitive control is good. And you will do the thing that you're trying to do, but that may not be good for what your task is, right? So let's say riding the bike example, maybe you think what helps you balance is that your legs are a certain way, right? So you can have this top down goal, I'll keep my legs a little bit further apart. But that may not be the right thing. So you'll do that. But you might fall down more, right. So I think cognitive control can be good if it's focused on the right thing. So you know, if you're riding a bike, you should be paying attention to where you're going. And you might be wanting to scan out there in the environment where the cars are coming, or pedestrians are there. But you probably don't want to be paying attention to and really trying to control how you're p edaling, or what your abs are doing. Right. So I do think of cognitive control as this kind of higher order thing where you can always take control and change what you're doing. But maybe that's not good. Maybe you don't know exactly consciously what you should be doing, you should just let your body go. And so like I mentioned, there is a lot of experiment evidence. This is the case specifically for experts. So there's a lot of work showing that expert musicians and expert athletes, if you ask them to pay attention to what their body is doing, their performance is actually worse than if you ask them to pay attention to what's going on. So between, you know, throwing darts or hitting a baseball or playing the piano piece. If you pay attention to your sensory feedback in the environment. So what, say you're playing baseball, where does your bat go? Where does the ball go? And looking at the ball that's coming toward you, that usually leads to better performance and outcomes, especially for experts then paying attention to what your arms should be doing. So I think you still need cognitive control, but you need to be deployed to the right place. And often we put it in the wrong place. Or not. Maybe not maybe not that often, I should say. But I'm interested in the cases where you put in the wrong place and how that actually works. Right. Jonathan Peelle 23:06 So let's talk about one—I know we've we've talked about a lot of a lot of your studies, actually—But let's talk about one in particular. This is a 2015 paper in NeuroImage: "Out of control: diminished prefrontal activity coincides with impaired motor performance due to choking under pressure". And I'll include a link to this in the show notes. But I love this idea of choking under pressure. And I'm guessing that everyone like has had that experience. But, how would you how would you define that as a scientist? What's choking under pressure? Taraz Lee 23:40 Yeah, that's a good question. So the way that I usually define it is doing worse than you would expect in neutral conditions, specifically because of some external stressor. So I know there's a lot of reasons people might be worse, you might have an injury. But in the context of our lab studies, we can get a sense of someone's baseline performance, and then put them in different pressure situations and see how the performance is and if performance is worse in pressure situations. And the performance is worse specifically because of the pressure situation, I would say that you're choking. I do think that often. Colloquially, we talk about it as missing an easy shot or easy pot or something like that in sports. But basically, failing under pressure, doing worse than you'd expect, because you're under pressure now is what I would define as choking. Jonathan Peelle 24:34 And I guess in the in any way in the lab, you know, what position what situation you're putting people in and so you can sort of have a good idea about whether they're under a higher pressure or lower pressure situation. Taraz Lee 24:46 Yeah, yeah, I think like I was saying with everything it can get pretty complicated, but in the context of my work, typically we try to use reward. So we use very large rewards and specifically very rare large rewards. So certain certain trials, you may say, "Hey, this is the jackpot trial" for some people. And if those are rare enough, and those are large enough, often people do much worse in those trials than they would on a trial that's worth a middling amount of money. So, in my lab, we usually or exclusively I should say, used reward. So the advantage of that is we get to see, you know, the good things about motivation, when the reward gets a little bigger people are better. And also if it's really big. Yeah, people do a little bit worse often. So you can look at both sides of that coin. As you might imagine, there's a lot of individual differences in how people react to rewards. So other labs have kind of combined reward and money pressure with social pressure, and that really has peope feeling pressure. So you can do things like, "hey, now you're playing for cash bonuses, you're playing with a partner, in order to win the money, you guys both have to do great, they already went and they did awesome. Oh, by the way, we're also going to be videotaping you, oh, by the way, I'm training a new research assistant, they're just gonna be standing next to watching your performance." And so if you, the more the kinds of sources of pressure you load on, the worse people do. For me, it's, as a scientist, you know, you want to draw some lines between specific manipulations and people's behavior. So I've kind of taken tack of trying to minimize how many we use, but it does make choking less likely to occur, the fewer that you have seen before, there's a lot of influences how people react. But you can use those in research as well, a lot of people do. Jonathan Peelle 26:33 That sounds kind of fun! I feel bad but... Taraz Lee 26:35 I know. Well, you know what, like we actually ordered, so we have some little webcams that we have, we have some lab coats in lab, because we were planning on doing some of these kinds of studies to kind of really load up social pressure, we haven't actually gotten a chance to get to it yet, both because of COVID and one of the, my lab manager moved on to another position at some point. So we've kind of paused on that, but I'm actually really interested in, you know, is there some evidence that social pressure might be a little different than monetary pressure, reward pressure, in terms of kinds of the impairments that they might produce Jonathan Peelle 27:10 I mean it is really interesting. This is like really getting off topic, and then we'll get back on topic. But anecdotally, so for the work that I do, which is more, you know, language and speech research. You know, anecdotally, on a lot of tasks, people seem to perform better if the researcher's in the room, right? So we have them listening to a bunch of sentences and pressing a key. And you know, some, some people will do it and sort of say, okay, just do your thing and pop out, pop your head out the door, when you're done, let me know and other people will be very conscientious and sit in there and try not to be obtrusive, and try not to provide, you know, too much pressure, but kind of be there. And low and behold, people perform better, typically, when there's a person there. So I do think- Taraz Lee 27:52 Social facilitation. Jonathan Peelle 27:53 Exactly, yeah. And so that's like a good, you know, for us, that's a good, good motivational constraint. Taraz Lee 28:02 Actually, there's a lot of cool work trying to look at specifically that interplay. So it depends on what the, so the context and the setting is, it often depends on what the participant thinks that person's in the room for. If you tell them, if you tell the participant, "hey, this person's gonna be in the room, they're gonna be evaluating your performance," or, you know, judging you or something like that. Often people do worse. But you know, people- Jonathan Peelle 28:28 like having a clipboard, and they're kind of Taraz Lee 28:29 Yeah, exactly, exactly, exactly. You can you have this image of like, you know, a person with glasses on the end of their nose looking down at you and, you know, writing notes furiously as you do a task, that kind of thing. But I do think it's the case, you know, especially a lot of these lab studies that might be boring. And there is, you know, demand characteristics. So you want to perform well for the experimenter. So being around often helps as well, so. There are again, like, like a lot of things we've been talking, there's kind of two sides of the same coin. Right? It depends exactly on the nature of it exactly how its presented, I think. Jonathan Peelle 29:01 Yeah. Taraz Lee 29:02 It's, it's tricky, but it's fun, right? Jonathan Peelle 29:04 Yeah. Yeah, totally. So for this choking under pressure study, can you like walk us through, you know, the specific task, and then sort of Taraz Lee 29:14 Sure Jonathan Peelle 29:14 And how people performed and what you found? Taraz Lee 29:16 Sure, sure. So might be helpful to talk a little bit about the background and motivation of the study. So like I had mentioned, there had been a decent amount of behavioral studies looking at pressure. And this has kind of led to two different theories of why choking- people choke under pressure. So this has led to two different theories of why people choke under pressure. So the first and both of these theories make appeals to this cognitive control process that we've been talking about. So One theory suggests that what's going on when you're choking under pressure is, you know, it's the big moment and instead of thinking about the task that you're doing, you are now distracted away and thinking about failing or what people might think. So these are kind of distraction theories of choking under pressure. So instead of using your cognitive control in the service of the task, it's now distracted away and you're thinking about other things, you're not focusing enough. On the other hand, we have this other class of theories that sometimes called monitoring theories or explicit monitoring theories that suggests, well, you know what, maybe what's going on is that when you're in this high pressure environment, specifically for motor skills, you really try to take control of what you're doing. But that's not actually good if it's an automatic. So go back to that example of golf, if you're Tiger Woods, maybe you don't exactly want to be focusing on what your elbows doing in that moment, because you've done a golf swing a thousand times, right? And there, again, like I mentioned before, there's a lot of evidence that specifically when experts do that kind of, or when experts have that kind of attention to their body that can be- so the motivation behind this study was that I wanted to see if that in a particular situation, we can use neuroimaging to kind of tease apart which one of these theories is more explanatory. In the context of-. So I kind of alluded to this before a little bit. But the task, I kind of designed this new task from scratch because I want people to not have any experience with the motor task. And so I don't know if any of your listeners have ever played that old game snake on a cell phone where you're trying to control a snake and have to eat an apple and it gets longer and longer. So kind of started with that task. And I kind of modified it a bit. So instead of a little snake eating a little tiny apple, it was a little snake that you have to just navigate over to this large apple on the other side of the screen. And instead of growing, you just had different trials where you just have to get that snake over there to the apple under a certain time limit. And people had two little mouse scroll wheels that they were using to control this snake, one wheel would control the speed of the snake and the other would do some steer. So it's really tricky, what's called bimanual, two handed motor task where you have to learn to coordinate your hands together to get there under the time limit. But if you went too fast, it said, you're going too fast, you know, so we had people come in on one day and kind of play the, this little game for about an hour or so in the fMRI scanner. And then a couple days later, they came back and they played for cash bonuses. So in the context of this study, I believe we gave them on different trials, you were playing for either $5 $10 or $40. And so we wanted to see how performance and how brain activity would change as a function of that. So we want to see what brain areas kind of changed their activity. And how does performance differ when you go from $5 to $10? And then what happens when you get to these big reward trials, these $40 trials, do people do worse? And if they do, are there any hints of what's going on the brain that might be contributing to this course. And, you know, I do want to make a point that just giving people money, you might not get choking under pressure, but we kind of did a lot of experiments early on in pilots tried to figure out the exact kinds of reward schemes and how to make those large jackpot trials rare enough. And if they're back to back, for example, if you put a bunch of $40 trials in the row people get used to it right. So you have to kind of make them rare, and surprising, like oh, man, this is a big one, and then Jonathan Peelle 33:21 big enough that people sort of, you know, remark on it internally. Taraz Lee 33:26 Exactly. Exactly. Jonathan Peelle 33:27 And just a note for people, I think. So just a note, you didn't actually pay people like hundreds of dollars for the study. Right? Yeah. You pay some subset... Taraz Lee 33:39 yeah. So the way we typically use... So the way we typically use rewards in the lab is we say a trial is worth $5, this trial is worth $10. This trial is worth $40. And at the end of the experiment, we pick one trial at random. And if they got that trial, right, they win that associated dollar amount. So one of the things that we try to guard against is people earning money throughout the task. So let's say you had a bunch of $10 trials and got it right. And by the end of the experiment, let's say you've already won $300, well, then $40 might not mean as much anymore, right? So in order to kind of keep each trial independent, you only get one of those, but you never know which one of those so you kind of have to be trying the whole time, Jonathan Peelle 34:18 right? Because this trial could be the one that gets picked and you're going to get zero or $40, which is a big difference. Taraz Lee 34:25 Exactly. Exactly. Exactly. So. Jonathan Peelle 34:32 And then did you say this already? Were they rewarded on every trial? Or were there some trials where there was no reward? Taraz Lee 34:39 So in this experiment, there was always some level of reward related to each trial. So we had basically low, medium and high reward trials. So what we found is maybe what you'd expect, given the conversation is that on $5 trials, people did all right. They did a little bit better on $10 trials, but at these big $40 trials, they did a little bit worse than they did on other trials. Specifically, in the first half experiment when all these money trials were new, they tended to do a lot worse for the $40 trials than those median value trials. And so what we did with the neuro imaging is we were really interested in Okay, well, ultimately, when people aren't moving and doing this game, often motor cortex is sending the signals down to your muscles. So we want to take a look at what other brain areas are communicating with motor cortex. And how does that differ when you're choking under pressure. So when we're doing neuroimaging, we can use an analysis called a functional connectivity analysis to try to make this inference. And basically, the the rationale behind the functional connectivity analysis is that you can look over time at the overall activity of certain brain areas. So in our case, we have motor cortex and dorsal lateral cortex. And we can look over time on a trial by trial basis, what's the activity level in each of these regions separately? And then what we can do is say, Okay, over time, what areas seem to be going up and down together? So what areas on a trial by trial basis seem to be raising and lowering their activity levels at the same rate. And the inference you make in neuroimaging often is that if we find two areas that are kind of singing along together through time like this, that they are communicating in the network, and they're speaking to each other, talking to each other, and they're functionally related. So what we did in this study was we looked at $10 trial specifically, and so okay, what areas are kind of singing along with motor cortex on these $10 trials? Then separately, we could look at $40 trials and say, Okay, are there any other areas that seem to be seeing along with motor cortex only on these $40 trials. And so what we found, when we looked at the difference between these connectivity maps, we're gonna call them, of who's talking to the motor cortex and at what time? We did find this region of the prefrontal cortex that I was talking about earlier, this dorsolateral prefrontal cortex region that seemed to be communicating with motor cortex more on these $40 trials when people were tuning in. And so we followed up with that because we thought that was pretty interesting. Okay, so it does look like potentially some of these cognitive control processes might be involved given what we know, about, or the dorsolateral cortex. And what we saw specifically was that those people who were choking under pressure were those who couldn't increase this communication between prefrontal cortex and motor cortex. So the people who were doing just fine, really showed this increase in communication between motor cortex and prefrontal cortex. And the people who ended up choking under pressure were the ones who were doing that. So we kind of took this as evidence for distraction. So these $40 trials, you know, you know, they're really important. And potentially, this makes you distracted away from the task a little bit. And what you need to do to stay on task potentially, is increase your control over your motor behavior, increase communication to induce a lot, prefrontal cortex and motor cortex. And if you're able to do that, well, you do just fine. If you can't, if you can't resist this distraction, potentially you're the ones who choke under pressure. So, in the context of this study, at least, we really thought the support of this distraction account that, okay, when you're in these high pressure moments, you really need to focus even more on the task that you're doing, because you're so susceptible to distraction. But I do want to make a note that this is people who are pretty new to the task, right? These are novices. So you might imagine this might change, the story might change a little bit, if we look at experts. If I had these people play this game for months, instead of, you know, a couple hours, the story might be a little bit different. But I do think it was a cool study to be able to, to be able to see some evidence for why why people were choking under pressure, even if it was just novices. Jonathan Peelle 38:46 Yeah, well, I mean, a lot of us do. I mean, anyway, we're all learning new things all the time, whether it's motor skills or, or other stuff. And so I think it is super applicable. I mean, we're not all professional athletes. Right? Taraz Lee 38:59 Exactly. Jonathan Peelle 39:01 So do you think? Yeah, I guess I'm trying to put together then. So we've got motivation. And of course you can manipulate that with with monetary reward, cognitive control, the motor system for whatever task you're doing, you know, is there maybe maybe maybe another way to ask this is sort of like, is there anything else you're going to throw into the mix? Because it gets pretty complex, right? I mean, this yeah, here is like multi-faceted... Taraz Lee 39:30 This is kind of my curse is that I, there are people who devote their whole life to studying one small part of the prefrontal cortex and the people who very tightly and very carefully study a very specific motor skill for a long time. And I think that work is awesome and very rigorous and amazing. But it turns out my interests are how these things all relate together. So my experiments do tend to be a little bit complicated cuz I want to see how these pieces fit together a little bit. So do I add anything else? We're starting to look at the cerebellum, which is a whole nother can of worms, I should say, I think. But no, no other manipulation. Jonathan Peelle 40:17 I think that you know the importance about looking at these things together. So if you've shown that there's interactions between them, then kind of like, necessarily, if you only look at one region or one part of the puzzle, you're going to miss that, that effect, right? So if you only look at motor cortex, and you never look at how its interacting with cognitive control regions, then you're gonna, you are gonna miss part of it, even if you really understand that one, you know, that one part of the story really well. So this seems like, important work. But I wonder, then, you know, maybe just in closing a little bit, but do you see any, you know, path for some of the things you've been working on, to to affect, you know, rehabilitation? Taraz Lee 41:00 Actually, this is something I've been thinking about a lot more as I've become an Assistant Professor. I actually have a couple collaborations open right now with folks who do research into Parkinson's disease. Specifically because Parkinson's disease is thought of as a movement disorder. But it turns out, they often, Parkinson patients also have a lot of motivational issues as well. They don't really react to rewards as one expects. So actually, right now, we are, again, paused by COVID. But hopefully, bringing it up again, soon. I'm trying to take a look at how this coupling between motivation and action is impaired in Parkinsons. So one idea is that Parkinson's patients have trouble translating their motivation into actions. So it's not necessarily that they have trouble walking. It's the case that they have trouble getting motivated to walk, and translating their goals in this goal directed we've talking about so much. translating those goals into action. And those, that connection may be somewhat imperative. So, we're actually looking at that right now. And hopefully, we have some compelling results into giving us clues about what the deficits are, and kind of what kinds of strategies and rehabilitation strategies might be the most effective. So you might imagine if the problem is actually attentional goals or control ones, you might have different kinds of strategies and trainings that you'd give someone relative to if it was just a motor problem. So to relearn how to use your- So yeah, I'm really excited about that avenue of research that we have going on now as well, and hopefully that will continue. Jonathan Peelle 42:31 Yeah, that's great. Well, Taraz, thanks so much for joining me today. And it was just really great to hear about your work. Taraz Lee 42:38 It's my pleasure. Thanks for having me. Always glad to chat. Jonathan Peelle 42:42 All right. Bye, everybody. If you enjoyed this podcast, please subscribe so you don't miss any new episodes. Tell a friend who might enjoy it. And leave us a rating on Apple podcasts to help other people find it. You can also support The Brain Made Plain on Patreon and get access to longer interviews and other goodies. Go to patreon.com/brainmadeplain. 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