When, psychologists talk about memory, they actually tend to mean it in a much bigger sense, than how we colloquially talk about memory. in the last few lectures I've been, I've been, exploring a kind of memory that is a lot like the one you talk about. You know, how do I make my memory Or a better. And even this notion that I can feel like I have a memory for something that never happened. But, from a psychological perspective memory is at play any time any previous experience affects your current behavior. So if the past affects your present behavior, then we think some form of memory system is underlying that. and what I want to do in, in this lecture and, in fact, the next, is to show you that there's a whole lot more to memory. Than just this sort of conscious memory false or not. There are these influences from the past, that we're going to call familiarity. That can have sometimes kind of weird effects that freak us out. but sometimes they are having effects on us that we're not even aware of. so really cool stuff with familiarity. And just to kind of kick off the familiarity discussion, I'm going to talk about deja vu. that experience that some of us have, most of us have had at least at one point or another. The experience that right now the events unfolding in front of us feel vaguely, oddly, creepily familiar. Almost like we've lived this life before or dreamed these events in a dream or something like that. So It's this disconnect between feeling really familiar but it shouldn't feel familiar. And so, we're trying to understand why that comes about, or, or what it means. So that's deja vu, let's go after it. Alright so, Week 5, Lecture 5, Deja vu and other familiar concepts, all right. So, I want to start by showing you two list of words. I'm going to show them to you pretty quickly. And then I'm going to make them disappear. And then I'll show them to you again. But one of these lists of words should feel familiar and that's really what I want you to experience here is this feeling of familiarity. So, if I ask you which list you think you've seen before and I'm going to show it to you really quickly. So, I'm just going to ask you to make this almost as a kind of gut decision. Which list did you, did you see before? So, either the one on the left or the one on the right. So, think about that, but also kind of think about the basis upon which you're making that decision. Does one of the lists feel different? And heck, if we get really lucky, there even be a sense of deja vu happening, although I can't promise you that. But you should certainly feel familiarity for the one of the lists. Are you ready? Okay, here goes. Maybe that was too fast. I don't know. do you have a sense, left or right? let me do it again but I'll do it a little more slowly this time, I'll, I'll leave the lists up a little bit longer and try again. Here goes, okay? How many of you said left? How many of you said right? Okay, clearly there's a whole lot more left, as well all. Okay You can't see. I can't see either. but here's the list. And I'll just leave it up here now. The reason I didn't want to leave that, but you should still be able to feel that I think that this one feels more familiar than this one. But if I leave it up long enough, you probably could even figure out why this one feels familiar and If you start thinking about these. This is the list that I used to set up your false memories. Alright, so these are the items that you saw the end of one lecture and that we talked about in, in the just passed lecture. so if I show you them long enough you probably would of consciously went oh yeah. I, and so now it doesn't only feel familiar, but you would know why it felt familiar. You would know the source of the familiarity. These are bunch of words I just made up, and so they shouldn't have felt as familiar as these ones that you had thought about, read. And really did experience in a previous demand/g. So one of the concepts that is important to our discussion of de javu is that when we experience something in the past. And then we re-experience it, we can process it a little quicker the second time. There's something about the connection, even just going for the words robber, kick, cocktail, thief, anger, noon. If we've done that before, we kind of learn a little bit about the list structure, how we go from one word to another. And then the next time we see it, we can perceive it more fluently. That's a term that's used in this area, perceptual fluency. The idea is every time you see some object or some person or some word. First time you see it, you have to really look at it in quite a bit of detail to figure out what it, what it is. But with each repeated presentation, your perceptual system becomes more fluent at recognizing what's out there. A build up of perceptual fluency. and the claim is that can cause a feeling of familiarity. Or not, so let's take it the next step. I want to begin with a, with a analogy that's pretty famous in the psychology literature. An analogy first suggested by a scientist named Mandler. And it's called the butcher in the bus analogy. And the, and the idea is this, imagine you're on a bus. So you come on the bus, I guess we came on a back door somewhere over here. We come up on the bus, we expect to see a bunch of strangers. We don't expect anybody to look familiar to use, but let me say this guy right here. We see him and we have that feeling, this won't be deja vu yet, but it can be related. That feeling like I know this guy, I've seen this guy before. But where do I know him from? So the claim in the butcher-in-the-bus is that you really feel that familiarity. When you know, you know somebody or something, but you don't remember where you know them from. Okay, so this guy and why it's called the butcher-on-the-bus is this is the scenario that can cause this, let's say this guy is normally your butcher. if your silly enough to eat meat which I do not condone, nor do I do it myself. But for those of you meat eaters out there you may imagine yourself coming into the butcher shop. And normally you see this guy, but you see him behind the counter, you see him wearing his white aprons with blood all over them. and you, you know, that's the context in which you imagine him. And so you've seen him in that context, and now this context is not one you've ever seen him in before. So because you've seen him, his features do look familiar, they are processed fluently. But the claim is, when we don't know why, when we can't make that connection. We don't recognize him as our butcher. Then what were left with is fluency, without recollection. And then that is when we feel a really strong sense of familiarity. And, you know, we have this behavior. If he were looking at us, we might have this behavior of just kind of stealing a glance at him every now and then. And in our mind, we're thinking, where do I know that guy from? I know, I know him, now, the important difference between this phenomenon and deja vu Is that feeling like, I know, I know him. So in this experience, you have the sense that, you know, I have talked to this guy before. I can figure this out, and once I figure it out, I will know where I know him from. The claim is that some forms of deja vu, and as you'll see there are several. That some reflect the same kind of thing you just, do not believe that you've met the person before or you can't, you don't even try that thought. You become convinced that, I have never met this person before. they're very fluent, but I haven't met them before and it gets creepy. So let's do a more concrete deja vu case here, familiarity with it recollection. Here's one claim. You you might have seen a scene like this. So let's imagine this scene, which is a scene from San Francisco. Let's say as a child, when you were very young, you watched a television show set in San Francsico. So, you know, something like the streets of San Francisco, or something like that, you watched it. And let's say, unbeknownst to you, they shot a lot of their scenes on this road. so that, in fact, you have seen this road before. But you've always seen it while there was some adventure going on, and, your favorite characters were in a car chase. And there was all of this stuff going on, and you were really following the story. You knew nothing about San Francisco. And so, to your mind, they were just driving down some sort of non descript street. But if they use that street a lot for shooting, then you actually have seen that street, even if you never processed it very deeply. Okay, so now let's fast forward. Let's say you watched that show when you were like 10 or 12 or 15 years old, and now you're 30 years old. You decide, I'm going to go to San Francisco, first time I ever go to San Francisco, and so you go to San Francisco. You've never been there before, and you round this corner and you go down the street, and you see this, and it feels really familiar. It's like, woah, I don't know. Somehow seeing that street, everything looks in the right place. This building follows that building, it looks familiar. It feels like I've been here before. But, here's the critical difference in the butcher-in-the-bus. You then say, but I've never been here before. I've never been in San Francisco. Therefore, do, do, do, do, do, do, do, do, creepy feeling, right? Familiarity is like I've been here before, well you kind of were, through the television. But if you can't make that connection, if you don't realize, oh maybe I saw this on TV. And if that never, if that, if a thought like that never enters your mind. If instead you're just overwhelmed by that sense that this is familiar and it shouldn't be, because, I've never seen, I've never been here before. Then the claim is that can cause deja vu. Familiarity without recollection and not just without recollection. So there's without recollection but, but you know oh I should be able to recollect where. And then there's without recollection where you just don't, you become convinced that, ooh this is just creepy, I've never been here. And so you almost don't even try to recollect, okay? Now we want to make an important distinction here across these two situations, to get in the perceptual fluency. The claim with perceptual fluency is, that, that attribution of fluency is important. And what is going on here is you're getting the familiarity, but you have nothing to attribute it to. imagine that this situation has a comparison. Every morning this guy looks himself in the face, in the mirror. So if we think of perceptual fluency, he's seeing himself over and over and over again. and so he should be becoming very fluent at perceiving himself. He can recognize himself very quickly. We can all recognize ourselves very quickly, very fluently. But does this feel like familiarity? Does he look at the mirror and go, ooh, do, do, do, do, do, that guy looks familiar. No, he doesn't. He doesn't have the deja vu feeling, because he knows why this guy looks familiar. He can immediately and effortlessly attribute the fluency to something that makes sense. The fact that he's seeing himself in the mirror over and over. So this is a distinction made strongly by a researcher named Bruce Whittlesea. the, and the point that he makes is that feeling that we associate with deja vu, that subjective state. That requires a, a sort of fluency of processing that you can not attribute to anything. And that's what really causes the feeling of familiarity. Okay, now it doesn't have to be a memory that causes that. There are other kinds of deja vu. So one claim is that it's actually caused by perception without awareness. So I want to try to do this with you a little bit. At least I can give you the feel for the theory, if not, you might not actually feel the, the phenomenon. because it's hard, it's very hard to produce a feeling of deja vu in, in an experimental way. But, here's a scenario that some people talk about. Let's say you're in a room, a classroom and you come out of the classroom and you glance to your left. And I'm going to give you that glance in a second. Okay, but, I want to set this up. You just glance to the left. And at that moment in time, there's a loud explosion, or a loud, something. Okay, let's say that something falls down, and let's not be dramatic and have an explosion. But something falls down in the classroom. Somebody drops a bunch of textbooks. There's a crash, and you can't help but look back. Okay, that happens so quick. You glance and then you look back. Happens so quickly that you are not even aware of glancing. So now you leave the classroom and look to the left again. but you've had a glance that you're not aware of. Okay, so let me try to do that. So we're going to give you a glance and I'm going to take it away. Okay, so you saw that down the hallway, then you look down the hallway again, and you see this, okay? The claim is, that quick glance was enough to begin perceptual processing of the scene. So your perceptual system had just begun, but you got distracted before you were even aware of perceiving anything. But you still had the head start. And so, when you look again, you've got this little head start. And now it takes less information, less time, to process what you're seeing than it should. And that makes it feel fluent. And because you're aware of the quick glance, you don't know why. So, you're left again, with this feeling of fluency, fluent processing that you cannot attribute to anything. And the claim is thats a deja vu, like oh, thats the creepy guy. I looked at him down the hallway and knew these guys were coming towards me. I kind of had a feeling that, that was coming. Yeah, you had a feeling because you had a glance. But if you were not aware of that glance, then that's what's causing the creepiness. Not the fluency, but the fact that it feels more fluent than you think it should given the knowledge that your brain has. And if it doesn't have awareness of the glance, then that can cause it. Let me be one other version, and this is actually my theory, not put to the test. But there's another form of deja vu that I think we all experience, which is, we're in a situation like this, talking, and let's say, during this conversation. these two individuals, whoops these two individuals start talking to one another, and this person's thinking. So he says something, and then when she starts speaking, she's, this woman's thinking I knew she was going to say that. I almost, it's almost like I lived this in the past. Well, here's a claim for that, that If these are her friends, she has formed mental models of who they are, and how they will react. And what they will say in given situations. And she uses these mental models, the theory of mind idea. She used these mental models to predict their behavior. But, the claim is, we expect our predictions to be noisy. We don't expect them to be highly accurate, it's kind of like a weatherman. We expect the weatherman to give us a ballpark idea of what's going to happen. But if the weatherman was exactly right for like ten days in a row, we would all start to think, hey, wait a minute. This guy's got information that other weathermen don't have. This guy's kind of creepy, spiritual, something. He's a witch doctor, right? Well, it could be the same. You're making predictions about their behavior, and most of the time you expect your predictions to be a little bit wrong, and usually they are a little bit wrong. And these predictions could be very low level by the way, sort of subconscious. But every now and then we nail it. We get, we predict what he's going to say and he says it. And then we kind of have a vague prediction of what she's going to say and she says that. And maybe this even goes you know, one, two, three, four times or something like that, and that's when we're getting really creeped out. There's no way I should be accurately predicting this often. And that can once again make us feel like wow everything's going more fluently than it should. And if you don't know why, if you're not actually privy to these predictions being made, that can cause this kind of deja vu, all right. Lot of different kinds of deja vu. My, my, what I'm hoping you get out of this, is the notion that memory, the effect of previous experience on us. Is, is much more dynamic and much more complex and interesting than just, oh, I can relive some past event. These systems are at interplay. Okay, so here's some other this is an interesting little discussion of the, of the link between deja vu and parallel universes. it's a scientific discussion, so I think you'll find it interesting. a lil, a little video on what is deja vu kind of a fun one we can go after. and the reading, this is a reading about someone who has chronic deja vu. They're always feeling this feeling, some people have that, really fascinating. And then another, yet another discussion on deja vu with how stuff works. Again, there's the deja vu side that they're all going to be talking about, but I also want you just to think about all this in terms of the complexity of human memory. and the fact that we have these different systems, dancing. So one system can produce fluency. Another system can either recollect where that fluency came from, or not. And depending on how that plays out, we can either have the strong sense of familiarity, or we don't. As Bruce Whittlesea used to say, when you come down in the morning and you see your spouse, they do not look familiar. Sounds weird, but what he means is you do not go, woah, that person's familiar, they're just your spouse. You expect them to be processed fluently, because you see them all the time. Okay, so, check that out. the, the contrast I'm going to draw from this in the next lecture is, okay deja vu kind of freaks us out. Because we have this feeling that we can't put our finger on, but in fact familiarity can be even more insidious. It can be affecting your behavior without you even being aware that it's doing it. And that will be the subject of our next lecture. I will see you there.
