 The situation is cool. It's about kind of the first thing where you see reflexes changing now. I know some of you are going, well, I saw the reflexes change with the modal action pattern. Well, it's more like they ended. They begin and they end at a certain window, right? So a modal action pattern wasn't there on a particular day and the next week it was. And then five years later, that modal action pattern goes away, right? That's the maturation, right? So we're talking about the reflex itself. So reflexes themselves will actually change. This is the most basic learning response out there. You don't get anything more basic than this in terms of learning. It's the simple modification of reflexes. This is not Pavlovian conditioning, mind you. This is even more simple than that. This is habituation, where you get used to. You habituate to something, right? Salivation example, look at the oranges and the limes. Or lemons and limes, sorry. Lemon, lemon, lemon, lemon, lemon, lemon, lemon. As every time I provide that to you, right? Squirt you with lemon, squirt you with lemon. You can salivate, you can salivate, you can salivate, you can salivate. But every time you can salivate a little less and a little less and a little less. And eventually you're not gonna hardly salivate at all. Then all of a sudden I go and squirt you with the lime or let you smell it and that salivation level goes right back up. I'm even salivating looking at these, which is really annoying when I'm trying to lecture. But maybe I'm still hungry, I don't know. So we're salivating. So the repeated presentations of the lime, well I guess that is an orange. Whatever, it doesn't matter if it's an orange or a lime, but you get the idea, it's a lime in my head. So the lime, then repeated presentations, you will decrease your salivation to that. But it's not that you ran out of saliva or that you're just not hungry anymore and we can test that by just switching the stimuli. So we switch and present the lime, lemon, lemon, lime. Jesus, I put all these oranges and lemons, similar color, right? So those are oranges, maybe they're lemons, I don't know. But then, so we do the lemons over and over and over again and it would present to you the lime and then the salivation will come right back. So the fact that you're changing your reaction to the lemon is an indication that you're habituating to it. So a habituation to that particular stimulus. This is stimulus specific. Again, because it's changing, right? You're decreasing that saliva response, the salivation response to the presentation of that same fruit, right? And then when I just changed the stimulus a little bit I could give you a lime or I could give you a hamburger or something and your salivation levels come right back up. That's habituation, showing you that it's stimulus specific. Habituation, we're gonna come back and revisit this. It is, it plays a role in all sorts of stuff including operant conditioning, which is kind of a surprise. We'll come back and talk about that. Here's another example of habituation. All right, this is not, the one on the right should really be there that you'll see. So the left one, this is a study. So if you present that grid, the one that's the big one that's up there right now to infants, they'll look at it. You present it again and they'll look at it for less amount of time. You present it again and they'll decrease. So with each repeated presentation they decrease the amount of time that they look at that particular stimulus. But if you change the stimulus a little bit and you're probably doing it right now, it's because it's really hard for me not to look at it, you'll tend to stare at that for a bit longer. Interestingly enough, with repeated presentations it actually gets the amount of time that you look at it it gets more intense and then it'll start to decrease. So the more complex the stimulus, the longer it takes to habituate to it. And in fact, you actually go through a sensitization process which is increasing your responding. So it jumps up, the amount of responding that you have increases towards the more complex stimulus and then it decreases. Whereas the other one just simply decreases. It doesn't go through that because it's very simple, very complex. Think about it in terms of arousal. The really tight looking grid there, that one's like it's probably making your eyes a bit wonky, right? It's kind of making your system go, yeah, that bothers me. The other one just like, okay, whatever. That's arousal, it's system arousal. The more we arouse the system, longer it's gonna take things to change and stuff like that. So we'll get back and talk about that stuff later as well. Okay, here's some additional examples of habituation for you. As you might imagine, the grandfather clock is a great example. If you've been around one, they're really annoying. Right, first anyway. And then after a while you just don't hear it anymore. And that's a habituation process. There's tons of examples of these things. Live near some train tracks, dripping water faucet, those types of things. After a while you just don't hear it. It just disappears. It's still there. And if you focus on it, you can attend to it. You can direct your attention and then hear the clock again, that sort of thing. Spontaneous recovery will happen here on occasion. Spontaneous recovery is where the response just jumps right back, okay? Where all of a sudden you can hear the grandfather clock again, this isn't as much to do with times as it has to do with other experiences and things, but your book covers a little bit about that. Spontaneous recovery is just the jumping back of the response, right? That it had once been habituated away, if you will. What affects this? The frequency of the stimuli presentation, the rate of the stimulus presentation. So if I present it to you over and over and over and over again, very fast. Just constantly going after it. You're gonna habituate it pretty quick. If it's just over once in a while, you're not gonna habituate it as fast. You need a lot of repeated exposures in order for this to happen, okay? So there's lots of factors that affect habituation. There's more than what I'm covering here. Oh, excuse me. Just know that it's a pretty cool process and it happens on pretty much every species out there.