Hey guys, how you doing? Time for some side dish videos. I hope to post a couple today. This one will be a pretty brief one but I did want to jump off one of the discussions that is going on in the discussion forum. And just kind of, I think, add an exclamation point to it by giving you a couple of clear examples. So, specifically, one of you guys commented on being really interested in the brain and finding this all really fascinating, everything that you had learned about the brain. But the comment was, now that I understand how complex the brain is, I have a better understanding of why it can run into problems. And in fact, I think he said something like, it's amazing that so many brains work as well as they do, given their complexity. And I read that and went, yeah, 100%. There was a time when people used to think mental illness was some sort of weird thing or people were faking everything. But we're now very much at a point where we're starting to understand what looks like very bizarre abnormal behavior. But we're really starting to understand the biological basis of that behavior. And stories are emerging that kind of make sense. So I want to tell you two of these stories, so that you can start to see that concrete link between the brain and what may seem like bizarre behavior. Okay, so first story. We're going to talk about some of these later in the course in detail, but for now, just to get your appetite whet, I guess, let's consider something called panic attacks. So let's go right to this. Okay, so let's start, go back into the brain and let's talk about one of the systems in the brain. And specifically I almost want to talk about one little thing, so let me bump up this picture a little bit. It's not a very big picture, but it doesn't really need to be. Notice the amygdala here. So we have this hippocampal formation, and the hippocampus, as we'll talk about in detail more in the memory section, is really important for memory. But right on the very tip of the hippocampus on each side we have these things called the amygdala. The amygdala, again, are kind of our spider sense. They tingle when there's danger around. So literally our brain is keeping track of potential dangers. Notice this is linked to the memory system. Any time we've been in danger, when our sympathetic system got kicked up because we were in danger, our hippocampus also got kicked up and tried to basically remember everything about that situation. Now so one of the things that we can talk about, by the way, is this is the system that underlies posttraumatic stress disorder. If somebody is in a stressful situation, their amygdala triggers that they're under attack, something terrible is happening to them. The brain records those memories in detail, not just of the attack, but of the events that were occurring prior to it, any cues, any sounds, any feelings, any sights get encoded. Why? Because the brain wants to make sure you don't find yourself in that situation again. Or basically, it wants to be able to predict the attack. So the brain works in all these memories, all this information, about when we're in potential danger, so that in the future, if we're in some situation, we're looking around our world, we're hearing things, we're seeing things. It's possible that the things that are out there can trigger our amygdala and warn us before the danger actually is in our face, that we might want to get ready for that danger. So, cool. This system is really useful for us most of the time, alerts us, gets us ready, makes us react. But here's the case of panic disorder. A slight malfunction in that system can lead to very bizarre problematic behavior. So let's do the chain of events. Let's imagine somebody who's on, let's say, a subway, underground on a train underground. And for various reasons or for unexpected reasons, their amygdala becomes stimulated, not because of anything that's happening in their world, but because the brain is always stimulating parts, and some people's amygdalas become stimulated for no good reason. What does this person feel? They feel danger. They feel like they are in danger, and so what do they do? They look around, they look, they listen, they try to figure out where's the danger? Now for you or I, were that to happen, there's probably something that triggered that. There was probably that sort of scruffy-looking dude over there, or something weird, somebody with their hand in their pocket in a way that maybe suggests they might have a weapon or something like that. But this person, their amygdala was not triggered by that. It was triggered internally. So as they look around, they can't find any source of danger. If there's anything worse than feeling danger because that dude over there is looking at you weird, it's feeling like you're in danger and not knowing where the source of the danger is. So these people will become more and more anxious as they try to identify the source of the danger. And if they can't, then what may happen is the next stop, when the doors open, this person is bolting to get out of the subway. I have to get out of here, I have to get out of here, my life's in danger, they're pushing by everybody, they're acting crazy. And in fact, it can snowball, because if this happens to somebody on a regular basis, well, they get pretty embarrassed by these. They feel like idiots when there really wasn't any danger there but they reacted in such an extreme way. And so they can get something called anticipatory disorder, where they worry about a panic attack happening. I don't want to go anywhere because a panic attack could happen. That can lead to something that we call agoraphobia where we generally talk about it as the fear of open spaces. It's not really the fear of open spaces. It's the fear of leaving your house and because you worry something might happen, and that's one example. You worry you'll have a panic attack, so you don't want to go on a subway. You don't want to go in any enclosed space. You don't want to leave your house. All of this chain of events, the panic attack itself, the anticipatory anxiety that you get, and potentially the agorophobia could all be caused simply because somebody's amygdala was a little too active. It fired when it shouldn't. So that shows the sensitivity of something like the amygdala. You want it to be sensitive when it has to be but not when it doesn't. And if that line is crossed, then problems can happen. Let's talk about another one, to give you the breadth of this sort of issue. Let's talk about schizophrenia. Now I'm going to flip over here to the language sides of the brain, and I'll bump this one up as our main one that we're going to talk about here. We didn't talk a whole lot about the angular gyrus, more about Wernicke's and Broca's and we'll kind of keep these kind of things going here. Broca, the area that helps us produce speech, Wernicke, the area that helps us understand speech. Now you've probably heard that one of the dominant characteristics of schizophrenia is that people hear voices in their head. Now I always find it funny when people say that, they just go, whoo, you hear voices in your head. There's nothing weird about hearing voices in your head. I hear voices in my head. I have whole conversations in my head. I have conversations with rock stars, me and Slash chat every now and then. [LAUGH] I think all of us have voices in our head. I hope I'm not revealing too much. The really weird thing, though, about schizophrenia is, well, is it weird about them or weird about us? It's hard to know. When I hear voices in my head, I ultimately assume that it's me somehow that's behind all these voices. I take ownership of the voices. Even though I may be conversing with my mum in my head, I still know that that's my mum but I'm kind of controlling the simulation, I guess it were, of my mum. So I somehow hold onto that as my own. For a schizophrenic, they think these voices that they're hearing are coming from an external source, not from an internal source, and that what's make it so problematic for them. Somebody else is talking to them in their head. So it's really that non-ownership of those vocal sounds that leads to a lot of bizarre behavior. Now let's think about that. Well, all of us every day kind of battle between the world inside our head and the world outside our head, and we can all be confused by things. I'm sure you've said to people, Jeez, there's something I wanted to tell you. Did I tell you this already or did I just think about telling you? I've certainly been there. Or we might say something like, Jeez, there was something that I'm remembering now, but did that thing actually happen or did I just dream it happened, or did I just think about it happening? So any one of us can have trouble distinguishing events in our head from events in the real world. In fact, you've probably had an experience similar to the schizophrenic experience. I certainly have. I've been laying in bed at night, and I hear a voice, and I'm almost certain that voice came from the room. I wake up, I look around. There's nobody talking to me in the room. I probably tell myself, okay, it was really in your head. You heard that in your head. It wasn't really in the room. But for a moment there, I believe that voice that I heard was an external event. How do we know the difference? So let's focus on Wernicke's area here. This is the area that understands things that are spoken to us. It also, by the way, when we're internally thinking to ourselves these areas are lit up. But they're lit up just a little bit. They're a little active. When someone is speaking to us from the outside world, they're more active. And it's something about that relative activity that tells us whether a voice we're hearing is ours in our head or external. So in something like schizophrenia, all that has to happen, almost like the story I just told you about panic attacks, is if Wernicke's area reacts a little too strongly to internal stimulation, it will seem to the person as though that stimulation is coming from somewhere else, like somebody else is talking to them. That little bit of extra activation is all it would take from you to hear the voices as an external source and make you feel like someone is talking to you in your head. And that can give rise to all sorts of bizarre behavior. So again, I want to give you those examples just to kind of give you the sense of how fine a line your brain is walking all the time and how smooth this functioning has to be, mostly so that you don't feel so surprised when you see people who are having difficulties. It's almost more surprising that it doesn't happen more often than it does. Our brains are cool. You're learning that, that's very neat. So that's what I want to give you today, just a little more food for thought in the side dish. This analogy's going too far sometimes. But cool, hope you continue to enjoy the course. Talk to you soon. Bye-bye.
