[MUSIC] Okay. So with operational learning we can facilitate, we can make a really tight connection between a stimulus and an action. And we know that that action's going to have a good outcome. It has to have a good outcome in the past. And then we can see that the next action also leads to that good outcome. And we can chain together one action with another action, with another action. And so, we can actually group these three actions into a chunk, and in fact we are able to group lots of actions into a chunk. Consider brushing your teeth. You brush your teeth, you brush your teeth. If you had to actually bring your, toothbrush down and then bring it back up. If each of those were a separate movement, what would happen? Well, brushing your teeth would take a lot longer. It would take a lot more motivated thought, it would or deliberate thought. And in fact we don't do that, we don't say we don't make that, those component movement of brushing our teeth separate. We use them as one chunk and chunking is a very important function of the Basal ganglia. You do that whenever you learn some new movement, you've done it since when you were a baby. When you were a baby you started to look at faces and you move your eyes, you move your eyes around that face. And that enables you to recognize who that person is. And the way you move your eyes, it has a lot of separate components. You go from one eye to the other eye down to the mouth, back to the eyes, across, across, around the perimeter of the face. Those are all separate movements but they all get chucked into this one movement that is scanning an individual's face. So, we, we chunk a lot of movements, movements that we do all the time. You are maybe more aware, you're probably not aware of the fact that you've chunked scanning faces because we do it all the time we've been doing it since we were babies and we don't think about it. But you, if you learned a complex movement such as driving, you'll know that when you first started to drive, every piece of driving felt like a, a very complex and difficult task. So just steering and putting on the windshield wipers and putting on a turn signal and glancing in the rearview mirror or the side mirror, those all felt like separate movements. But after you've driven for five years or ten years or 30 years, they all feel like one big chunk. It's the driving chunk. Okay. So that's the advantage of dr, of chunking. It makes things, number one, way faster. Way faster. And number two, it makes it so you don't have to concentrate on every component movement. One of the most common examples of a habit is when you're typing. Say you're trying to type THE, and instead you type TJE. So, here are you're two options. You can go in here. And replace that J with an H or you can just retype the whole thing. Which is faster? And I'm pretty sure that you will agree with me, that this retyping three letters is way faster in going in there and correcting one letter. Why? Because this is a habit and this takes thought and deliberate action. So, habits are things that we do all the time. Chunking is, is a, is the thing that makes our life actually flow a little faster. Is there a disadvantage to chunking? Yes. There is a disadvantage to chunking, which is that once you start it, you go through the whole thing. Moreover, that chunk will happen regardless of the outcome. It is outcome-independent. When you started it, it was outcome dependent but once you continue to chunk something, once you continue to do it. If it is a chunk it is in fact also another word for this it's a habit. And habits are outcome independent it doesn't matter what the outcome is. You just do it. Habits are fast but they're inflexible. And doing things deliberately is slow but flexible. Slow but flexible. So think about what, what's a, a situation where we do something by habit? Well, the biggest habit that probably afflicts the most people in modern society is drug abuse. And in drug abuse. [SOUND]. The habit gets triggered and it's outcome independent. So a person continues to take a drug that originally made them feel very, very good, and that's how the habit got started. There's operational learning. They put heroin into their system or cocaine into their system and that felt really good. But once it becomes a habit, it doesn't matter of whether it makes them feel good or whether it makes them feel miserable, they are going to continue to do it. And that is why people interested in treating substance abuse, are very interested in Basal Ganglia. We're trying to figure out how we can break this habit. Break the habit of drug addiction. Okay, in the next segment, we are gong to look at Parkinson's.