 Alright, simple definition, right off the bat. Any stimulus added or removed, I'm going to use my little cursor here and say, make sure you understand that part, added or removed. So that's going to be our key to negative or positive reinforcement. So any stimulus added or removed, contingent upon a behavior that maintains or increases the strength of the behavior. If you're not familiar with what the term contingent means, then look it up because that is the absolute biggest criteria with regard to reinforcement. So a stimulus is just anything that can be detected, right? So it could be a feeling, it could be an experience that you have, it could be a visual stimulus, it could be a tactile one, it could be an auditory one, it could be a consumatory one. So something like food, right? Food is often used in the animal world and sometimes used in the human world, but we often do anything as a, as a reinforcer, anything that works really. So let's look at how this thing is organized. And it's organized in the form of what we call a three term contingency. So there's that three term contingency. This is going to pop up throughout the quarter. And this is how we actually start to describe behavior as a whole. We have an SD, which as some of you may remember is a discriminative stimulus. We'll talk heavily about discriminative stimuli later, but in reality, what they are is just cues. They're just environmental cues. Oftentimes, it is just the environment as a whole. Then the R, which is your response or the behavior. And an SR, which is notation for reinforcement. So let's read this in a slightly different way. We're going to say a stimulus that discriminates, then a response, then a stimulus that reinforces. So that is our three term contingency in a nutshell. Again, we're going to use that with all sorts of different notation, but that is pretty much how behavior functions. The discriminative stimulus right here will actually signal to the organism that a particular response will be reinforced. So the power of the three term contingency here in terms of which section of it is the most powerful is actually this one, the consequence. So the consequences of behavior are the most important in this three term contingency, right? So this is how operant behavior looks when we put it on to this type of, I don't wanna say graph, but you get the idea if we write it down shorthand, this is how operant behavior is. So operant behavior is, again, kind of paraphrasing your book in previous lectures, is just anything that you do, all right? And by that I mean anything that you do that's a voluntary behavior. Respondent conditioning, the classical conditioning stuff covers the reflexes, but this is a little different than that, all right? Reinforcement is a law, all right? This is one of those things that sometimes people get, sometimes they don't. So I'm gonna beat it over your head a little bit here. We're talking about a law at the level of gravity. People don't argue with gravity. People don't argue with how that stuff works, right? Reinforcement has the same sort of scientific backing behind it. It's that clear. This is what is happening. This is how behavior is being modified. This is what is, again, as the definition says it maintains or increases the strength of a behavior. So we're thinking about the frequency of behavior. We're thinking about whether or not it's gonna continue those types of things. So it is a law, in the past you may have heard of something called the matching law, which is from, what's his name? Thorndike, but he kind of missed the boat on a couple of things. And it's really beyond the scope of this course to look at what he missed the boat on. But this is the law of reinforcement as Skinner discovered it. And I'm not gonna say invented it or wrote it because it was literally more of a discovery through a ton of experimentation. Different types of reinforcers, right? So the first type of reinforcement here is positive reinforcement. Now when we talk about positive and negative reinforcement, remember there is no such thing as good or bad. Positive does not mean good, it has no moral value. Negative does not mean bad, it has no moral value. We are talking about a stimulus being added, which is positive, or a stimulus being removed, which is negative. So the definition of positive reinforcement, contingently adding a stimulus following a behavior to strengthen or maintain a behavior, you can think of this as getting something, right? Now, people often think that reinforcement means you're getting money, you're getting food or something like that. No, this could be as simple as, I'm gonna flip the light switch and the lights come on. When those lights come on, something was added, right? The light, so the light in the room was added. And that strengthens or maintains my behavior of flipping a light switch. Let's also look at negative reinforcement, as you see a nice big negative up there. Contingently removing a stimulus following a behavior to strengthen or maintain the behavior. Notice the only difference between these two is adding or removing. Always, always, always reinforcement strengthens a behavior. That's the only definition of it, it increases behavior. You cannot use reinforcement to remove a behavior, so to speak. And I'm gonna add a little caveat there later on in the quarter when we start talking about how to decrease the behavior using particular reinforcement schedules, but that's a little bit beyond where we're at right now. But reinforcement will always, always, always strengthen a behavior, a particular type of behavior, okay? Again, we're thinking about molar behavior here, so like we talked about, well, today, as you guys remember, we talked about the differences between molecular and molar behavior. So we're thinking about the molar stuff here, the larger behaviors. Flipping a light switch, there's 18 million different ways you can flip a light switch, but any one of those behaviors would be reinforced by the outcome of the light actually coming on. So that's what we're talking about, about positive reinforcement. Negative, a good example of negative reinforcement is like headache. If you've got a headache and you do something and the headache goes away, whatever you did was reinforced by the loss of the headache. We're going to talk more in depth about escape and avoidance later on, which is what negative reinforcement really is. So if you're escaping a stimulus, so you're experiencing something bad, right? And then you do something to get away from that thing, all right? And it's successful, that's a negative reinforcement situation. If you are doing something to avoid something bad happening or something aversive, as we say, then that is a negative reinforcing situation as well, so let's keep moving. Some examples, these are kind of fun. So here's the, again, these are set up as the three term contingency here. So as we go through the slide, you'll see how this works. But this first column here is the SDs, the middle column is the response, and the final column is the consequence. And then the descriptor column is what's actually going on. So let's look at this one. Describe reinforcement is the SD, so that's me saying telling you. So you right now, describe reinforcement. Okay, you're going to make a response. Hopefully you're making it in this gap here, or not. All right, there it is. So an increase in behavior, blah, blah, blah, blah, blah. You provide the right definition, right? So hopefully you just spoke that correct definition for me. Not for the computer here. The consequence is me saying, well done, good job, all right? So well done, you got the definition of that, right? Now is this positive reinforcement, is it negative reinforcement? What do you think? So again, look at the situation. The discriminative stimulus was the command or the request to describe reinforcement. The behavior was you providing a response saying, providing that definition, using a stimulus to increase or using a stimulus to increase or maintain a particular behavior, right? However you wanted to get that exact definition in there. And then my response to you or somebody else's response to you if you got that right would be well done. So positive or negative, something was added, so it is. Say it with me, yeah, here we go, positive, right? So SR plus. Notice there's a little change in notation there. SR and then plus, so a stimulus that reinforces, but this is a positive reinforcer, right? Let's go to the next one, go, wrong button. Or this is getting weird, here, there we go. So your car is not handling well, right? So it's kind of shaking that's your discriminative stimulus, so you take it to the mechanic to get in alignment, that's your behavior is going to the mechanic, right? That's a really molar thing, you gotta drive there and do all that stuff, right? So getting alignment is the behavior. Consequences, the wobble goes away, right? Bear with me here, I have to answer that phone. Okay, I'm back, right? So the car's not handling well, you're going to get an alignment and then that wobble goes away, right? So the consequence of your action is that the wobble goes away. Think about what that consequence is. Is something being added or something being removed? Probably something being removed, right? The wobble itself went away. So what is that going to do to behavior? In the future, if your car is not handling well, right? Then you will likely get an alignment. Again, negative reinforcement. So notice that's not something bad, it's just, that's, you know, this is how you describe that process. It's a negatively reinforcing situation. The wobble went away, you escaped the wobble. Okay, these ones are a little different. We're kind of jumping ahead a few chapters here but I want you to see what's going on in contrast with punishment. So these next two are related to punishers, right? So this one is making curry. So, all right, making curry, but I added too much ginger, right? And it tasted bad. Notice something was added that bad taste. So here we have a new terminology once again, a stimulus that punishes. So this is a positive punisher because you added a stimulus, right? And likely that's going to decrease the behavior of adding too much ginger in the future. So punishers are about decreasing behavior. Reinforcers are about increasing behavior. Sorry about this, hitting the wrong button there. All right, confirm delete. Telling the computer, you know, your computer asks you this all the time. So confirm delete. You press the yes button because you weren't paying attention, right? You lose your paper. That's a negatively punishing situation. You lost something and it's going to reduce the behavior. Hopefully you're going to reduce the behavior, pressing yes, or at least reduce the behavior of not paying attention, you know, something like that. But so again, the first two are the really two that we're focusing on for this chapter but I wanted you to see a little bit about what's coming down the pipe and how things are, how reinforcement is different than punishment. So quick summary, reinforcement strengthens behavior. Does not matter if it's positive reinforcement. Does not matter if it's negative reinforcement. Punishment weakens behavior. Again, doesn't matter if it's positive. Doesn't matter if it's negative, right? So positive reinforcement stimulus is added to strengthen a behavior. Negative reinforcer stimulus is removed to strengthen a behavior.