[MUSIC] Okay, so we're going to talk about what does Cerebellum do. What does it do for motor function and it really we can boil it down to a couple of, of, features. One is Motor Learning and the other one is Motor Coordination. We could actually say motor learning, and then, motor execution. So, what do I mean by that? What I mean is, let's, let's think about walking. I used to think that when babies were very squirmy at the age of one, between one and two. That they, I don't know, I thought they were kind of annoying by being squirmy. But the fact is that the babies are biologically programmed to teach themselves how to walk. They take so, I, I calculated how many steps they take and, and, how much they would walk if their steps actually, were adult size and the distance that a baby walk, would walk if they actually had our stride. Is in the, I think it's around seven miles 11 kilometers, something like that. So it's they're really, they're really trucking. And why are they doing it? They're practicing, they're practicing over and over and over again. And so, in fact, we practice gait. We practice steps. Probably, in our lifetime, billions of times. And, we practice staying upright, against gravity, postural sway. We practice that trillions of time. So, this young girl has already practiced, postural sway, probably a few million times. And she, she's looking like she got no problem standing up against gravity. And in fact we, we have this biological program to, stand up against gravity. To, to walk and to explore our environment. And, once we, once we learn how to do that we don't forget it. It's, it is Motor Memories are basically impossible to forget. Once we've learned that basic move, movement pattern. Then, we're just, we're continuously checking it. Making sure that we're doing it right. Making sure that it's going smoothly. Now, let's take a different type of movement. Let's take a movement that not everyone learns how to do. Everyone learns how to stand up if they can. Everyone learns how to walk if they can. Let's take a a different movement, let's take say juggling. I can't juggle, but if I were to juggle, if I juggled say five times that's not a motor memory that is on a par with, with walking. But if I juggled and I did it say, 100 times a day, then I could take of five days and I probably could come back to it and within a few repetitions get back into it. If I have practiced something, whatever it is, a few, 100,000 times, hundreds or thousands of times, then I can take years off. I actually played the flute as a, as a kid and I took it back up a few years ago and I immediately, without looking at anything, I immediately knew the notes. That's a motor memory. So it depends a little bit on, on how much you've done it. Well, it depends a lot on how much you've done it but those motor memories, they stay. And you, you, you can't you cannot forget this motor memory. Just like, and, and this is people say it all the time, you can't forget how to ride a bike. Once you've learned how to ride a bike, you can't forget to how to ride a bike. More appropriate would be, you can't forget how to walk. Now, the point of the cerebellum is not just to teach you how to walk and how to stand, but also to adapt your movements to changes, either in your own body or changes in the environment. So, I break my leg, I have to walk in a different way for some time. When my leg recovers I need to go back to my old way of walking. Cerebellum's going to be perfect for that kind of short term learning. The, the spinal cord reflexes don't do that. They don't feed forward and the memories don't last that long but the Cerebellum is very good for that. And let's take a different example, where the environment changes rather than my body changes. Let's say that I go on to a ship. Not going to happen, but let's say that I did go onto a ship. Now my walking has to be different. Even if I go onto the beach, if I walk from the sidewalk, from a concrete sidewalk to the beach,. My walking has to be different and the cerebellum adapts my motor program to a changing environment seamlessly. Okay, so that's essentially what the cerebellum is doing. And, now we're going to look at the different parts of the cerebellum and how they, handled different types of movements.
