The Passion Brain | Erin Bigler

Look deep into nature and you will understand everything better. That is advice that Einstein gave us many years ago and guided his research. If we accept the basic premise that the brain is the master organ of behavior, then if we look deep into understanding the brain, its structure and function, we will understand behavior. We will not only understand behavior, we'll understand the aspects that go into behavior like reward and passion. Passion, we saw great examples just a few weeks ago in the Olympics. We saw those athletes dedicated, motivated, inspired, driven to accomplish. There's an entire industry out there that is devoted to tapping passion, motivational speakers, how it engages one in business. There's a unifying theme for all Nobel laureates and that is the passion that they have for their field, regardless of what it may be. These are the wonders of passion, the good side of passion. There is a dark side. There's a negative aspect of passion, crime of passion. That is the mens rea argument in a legal sense that something was done because emotions went awry. It wasn't premeditated. The person was not responsible for those actions because they just came. Something went awry. What does that mean in terms of emotional disorders? Well, if we think of emotional disorders as behaviors and behaviors are guided, directed and related to brain function, these are brain disorders and we need to understand the brain in the most fundamental ways that we can. So how do we do that now? We do that with brain imaging. I want to share with you my passion for understanding human behavior by understanding brain structure and function and take you on a little journey for just a moment. A little over 40 years ago, I finished my doctoral studies. I finished them before there was brain imaging as we know it today. I was actually doing very basic animal electrophysiology work, putting electrodes in animals and studying the brain because I thought that was the only way we could do it. But then along came computerized axial tomography, CAT scan is what it used to be called. And there for the first time, I was able to see an individual in a scanner and we could make out the images. They were very grainy, very poor, but we could make out the images that something was wrong with the brain. The first patient I saw was a patient that had a brain tumor. This was astonishing. It was amazing. It was thrilling. And at that moment, the passion in me to study the brain and human behavior was ignited. I realized I didn't have to study animal models. I could study humans. But we had to measure the brain. We had to study it in some way. We had to evaluate it and we had to relate it to behavior. So how do we do that? We do that with brain imaging. There are many techniques now. These have revolutionized how we can study human behavior. I'm going to show you magnetic resonance imaging. But why not look at my brain? When was the last time that you saw your speaker's brain? Never. As I think about it, maybe we should look at our politicians' brains. But that's a different lecture. We won't do it tonight. So let's start with my brain. So here is my brain. So on the right-hand side is my brain, my magnetic resonance imaging brain. I've sectioned it at about the ear level. And you're looking at it as you would look at me on the stage. On the left-hand side is a post-mortem brain that we have sectioned and matched with the MRI. You can run your eyes back and forth here, and you can see that the general anatomy of the brain at post-mortem can be seen in the living individual. Now, just to point out a couple of very key characteristics here, this is the gray matter of the brain. You can see it's gray on this MRI. The white matter, the internal structure of the brain where there's connections made up of axons. Then we see the subcortical areas of the brain deep inside the brain. Over on the right-hand side, you see a colorized image of my brain. Well, if we look at this scan on a grayscale, there are various shades of gray. And we can extract that information out and create and generate a three-dimensional model of the brain. And so here we have a three-dimensional model of me. You're looking at me. And so now we're going to actually look at my head. Now, in the magnetic resonance world, none of us have hair, so everyone is hairless. In just a moment, I'm going to strip away the skull, the skin, the skull, and the covering of the brain, the meninges, and we're going to see my brain. Now, this is not an artist's rendition of my brain. This is my brain. In fact, I have here, you may have wondered what I brought out. This is my brain. I could have a little Hamlet moment here and hold it out. It's not Urich, but Aaron, I knew him well. But actually, I know him very well. This is my brain. I am holding my brain. I can study this in an amazing way, and we can create a 3D tangible model. So let's look at this in some different ways here. So now this is a surface rendering of the brain. So we're looking at all the surface areas of the brain, and we're just sort of tilting and turning it around here. So you can see it in different angles. We can peer inside and look at the inner surface as well as the top surface of the brain. This right here is now we've stripped away the outer mantle of the brain, so this is the white matter of the brain. And now we're going to, when this little clip ends, we're going to look at the subcortical areas of the brain. So now we're looking through the cortex and into the subcortical areas. The subcortical areas are the non-conscious areas of the brain, the conscious areas of the brain that we experience. That is the outer cortex that we're looking through here. So we can now go into the subcortical areas. Again, this is my brain. Everything that you see there, we can measure, we can assess the size, the shape, the contour of it, but this is only part of the story. No matter how beautiful this anatomy appears, it has to be connected for it to work. And this is diffusion tensor imaging showing the aggregate pathways of my brain. Those colors that you see are important. The blues are vertically oriented color, the red and oranges are back and forth, pathways that go side to side, and the green represents front and back oriented pathways. One thing to point out is you look at this, see these strands right here? Those strands are made up of tens of thousands to hundreds of thousands of axons. So we're only looking at a very molar view of the brain, yet we can study brain pathways and connections. What about the reward centers of the brain? Reward ties into passion. Reward centers. Let's go back to our introductory psychology class. You all saw this illustration. This is the rat experiment where the electrode was placed in a reward center in the brain. The rat presses the lever to receive the reward and will do this at the exclusion of everything else. Will not eat, will not rest, will not sleep, will actually do this until exhaustion. That's how powerful the reward centers are. So where are the reward centers in the human brain? Let's go back to my original illustration here. That red circle surrounds the basic reward centers of the brain. The first thing you notice, that's a very small area. The cerebral cortex is large. So if I ask you to imagine something that's rewarding, you can recall that. Your memory can pull that up. That's a cortical function. But something that drives reward is this subcortical function. And this is what we call a bottom-up stimulation. This is top-down control. So this bottom-up, top-down control is a very big issue with regards to reward and passion and how it functions in the brain. So let's look at a reward center in the brain. What you're looking at now is a cutaway that I've done. So we've removed the left hemisphere and you're looking at the subcortical areas of my brain. And now we're going to put this into motion. You're gonna see it move here and it's going to tilt back just a little bit and it's going to stop. And I'm going to point to this area right here. That area right there is a brain structure called the nucleus accumbens. That is one of the reward centers of the brain. That is activated when reward occurs. I have a brain model of that. Look at this. Isn't that astonishing? This is a 3D printout of my brain and you are looking at the reward center right here. It's this little tiny, tiny area of the brain. Very small. Very tiny. Incredibly powerful. Look at, you have this enormous cerebral cortex yet this very small center of the brain that regulates reward from this bottom-up perspective. So let's see if we can understand this a little bit better, this interplay between the top-down and the bottom-up. So we're gonna return to this view right here. And if you look at this particular view right here, you actually see the intricate nature of these pathways in the brain. So if you're doing something that's involving the cerebral cortex and an active memory and thinking cognitive process, you're involving this network that you see right here. In contrast, if you're doing something that involves reward, it's involving these areas, these subcortical areas here. The white areas represent the pathways. You notice something very, very quickly. They're short. They're not these long, intricate areas of integration that happens when we're doing something that involves cortical processing. So our challenge is to understand the relationship between these very basic areas of the brain involved in reward and passion. And to illustrate how small this is, I've created my nucleus accumbens that I hold in my hand right here. It's the size of a bean. And so we have this enormous cerebral cortex here, thinking, cognition, decision-making. And we have this little reward center here that if it goes awry, this cerebral cortex doesn't necessarily dampen down what occurs at this level here. We've got to understand this level if we're going to understand these disorders that affect the human condition, particularly disorders like drug and substance abuse that involves this area of the brain here. We now have that technology, and as Einstein said, we need to look deep into the nature of things. Einstein knew that he needed to understand molecules and atoms to understand the cosmos. If we're gonna understand the human condition and understand emotional functioning, we've got to understand the brain at the most fundamental level and understand these small areas of the brain that have powerful influences on human behavior. Thank you.