 All right, everyone. Welcome back. It's Veronica Howard. So we're going to talk today about contingency schedules. And this is all part of that idea of how you use reinforcement effectively. You have to understand contingency schedules because they produce a very specific effect on a person's behavior on the way in which they behave. And I want to just return us now to that idea of Skinner's quote about reinforcement. Remember, the way positive reinforcement is carried out is far more important than the amount of reinforcement. There's a lot of clinical, artful application here that we want to be paying attention to when we're using reinforcement. So when we're talking about schedules, remember that schedules are incredibly important because they produce specific patterns in response. And those patterns themselves are another important tool in understanding human behavior. They can help explain some irrational human behavior like drug abuse. Why is it that a person would choose to engage in consuming a substance that could be harmful? Why is it that people continue consuming food even well after they're full and become obese? Why is it that despite knowing that procrastination is bad, why do people still procrastinate? All of these can be at least partially understood by talking about schedules of reinforcement. And understanding schedules also helps us better be able to motivate clients to help meet their goals. So when we talk about schedules of reinforcement, I want you to bear in mind that we have categories that we describe schedules as. We can talk in a very generic way about these schedules that we can refer to continuous reinforcement or intermittent reinforcement or extinction. We've previously introduced extinction as a clinical procedure, but extinction also is used to refer to a schedule of reinforcement where no reinforcers are delivered. We can also talk about schedules in a very specific way. We can talk about fixed or variable ratio schedules of reinforcement, fixed or variable interval schedules of reinforcement, and even an advanced concept known as limited hold. But let's begin by talking about those very basic generic schedules. Continuous reinforcement refers to this idea of reinforcing every single response. Every response, every target behavior that occurs contacts the reinforcer. In this case, we're talking about every response earns the reinforcer, but we also have this wide swath of intermittent reinforcement, which means that some but not all responses contact reinforcement, and that can be like every other response or 99% of responses will contact reinforcement. It could also be a very lean lean schedule where incredibly few responses contact reinforcement. Finally, remember that extinction refers to a schedule reinforcement where no responses are reinforced. There are some benefits to these different schedules. So in a continuous schedule, this is really effective for teaching, for shaping new behavior. But continuous schedule reinforcement is really problematic because the client earns a lot of the reinforcer, and so then they satiate very quickly. They're no longer going to give you the behavior because they've earned enough of the reinforcer where it loses its value. We also see that continuous schedules of reinforcement, though they are effective at teaching new behavior, continuous schedules of reinforcement are not very resistant to extinction. So what will happen is if you have a client on a continuous schedule reinforcement, and then suddenly something happens with the reinforcer, it's not delivered with fidelity, you could find that response is very shaky and may disappear entirely. There are then some advantages to using intermittent reinforcement. Intermittent reinforcement is a pretty great way of maintaining a behavior over a long time, and the reinforcement is effective for longer because the client's less likely to have had a lot of it. It maintains that response, it makes it resistant to extinction, but the disadvantage of an intermittent schedule is it's very, very bad at teaching a new response. Intermittent schedules, if you don't reinforce every single response like you would with an intermittent schedule, it means that you can kind of have something called superstitious reinforcement develop where it's unclear what specific response is meant to be emitted to contact the reinforcer. Okay, so let's move now to extinction. So remember that I said before that extinction is both a procedure and a schedule. Let's talk about extinction as a schedule. Remember that we have to bear in mind that extinction has as part of its side effects this idea of the extinction burst. And when we understand that that kind of variability and the change of magnitude, the emotional responding that all of those phenomenon occur with extinction. We can also apply that knowledge to understand what happens when we are not careful with our schedules. Clients who go from a very thick or a very heavy schedule reinforcement to a very thin schedule reinforcement. Clients who were earning a lot of reinforcement who suddenly then earn quite a bit less reinforcement are going to experience a phenomenon known as ratio strain. So with ratio strain, what we're talking about here is the idea that you're going to get some behavioral variability, you'll get some kind of intermittent responses, some unusual responses, some weak responses, some strange behavior. And ratio strain is very, very similar to extinction, because fundamentally at their core, we're looking at responses that are kind of similar. They're strange behavior that develops as a function of the fact that the behavior is kind of on this proto extinction schedule. What I mean by that is, from the perspective of the learner, if you go from say a very rich schedule reinforcement to a super super lean schedule reinforcement, there's almost no difference. How would you be able to tell the difference between lots of reinforcement, very little reinforcement, it seems like extinction. So we always want to be watching for this phenomenon is ratio strain, it tells us that we've leaned our schedule or we find it out that we're delivering to little reinforcement, and you want to be careful about that. So coming back, we're going to be talking in the rest of our material this topic about the different schedules specific schedules of reinforcement we're going to talk about ratio, both fixed and variable ratio. We're going to talk about the class of time based schedules, which would include a fixed interval, variable interval, as well as something called a limited whole, which is a deadline schedule. Coming back, we'll talk about that and I look forward to seeing you next time.