Memory

00:05 So Barb, let me tell you. I've been very fortunate to be in some pretty amazing places for my education. But I almost found interesting that wherever I was, there were some of these fellow students who seem really bright and always on the other side that I would help and I was always fascinated by these differences how we all seem to make it but not always as easily. Do you have any insights? How does this happen at the brain level and how can we use that to guide us in our studies? Got plenty there to help us understand learning and the differences between learners. So as it turns out, there are 2 fundamentally different types of learners. The first I'll call the race car learner. And the race car learner gets to the finish line really quickly. They can learn fast. There is another type of learner, however, and that is something I'll call a hiker type learner. I, for example, am a hiker type learner. They can get to the finish line but it's a lot slower. But think about the differences between those 2 different entities, the race car gets to the finish line really fast but everything goes by in a blur. The hiker gets to the finish line very slowly but they can reach out, they can touch the leaves on the trees, they can see the little rabbit trails, hear the birds in the air, completely different experience than the race car and in some ways far richer and deeper. So, there are actual neuroscientific reasons behind why there are these 2 different types of learners. So, a race car may have a better memory and the reason that happens is their little dendritic spines can quickly emerge and fix into place so that helps them learn very quickly. For the hiker, their dendritic spines can emerge but it takes them longer to fix into place. The difference between these 2, however, meaning that the race car learns swiftly but once they've learned it they can be less flexible with what they've learned. The hiker can learn more slowly but they can be more accurate and more flexible about what they've learned. So 2 very different learning processes and you can't say one is better than the other even though we would all love to have wonderfully swift memories. Now, that's talking about long-term memory but I should also give you some insight into working memory.

03:19 It's kind of like short-term memory. And it means that it's that temporary information that you're holding in mind. For example if I asked you to remember 74392 something like that. You'd hold it temporarily in working memory in the prefrontal cortex. So, I like to imagine this prefrontal cortex working memory as an octopus. And this octopus can hold certain amounts of information, typically it can hold 4 pieces of information. If it can hold more it's because it's grouped that information together. Now, what your working memory does is it helps you put together links that are stored in long-term memory. So then whenever you need a fact or a skill, you can pull that information from those sets of links in long-term memory, pull them into mind, and then you've got the memory or the information readily at hand. So, to better understand this, for once I won't use a metaphor.

04:36 Instead, I'll introduce you to my daughter. This is our younger daughter and she is going to model for us what it felt like when she was first learning to back up a car.

04:51 So when she was first learning to back up a car, well, she didn't know which mirror to look at, I mean do you look on the front, do you look in the back, and of course then off she goes into a ditch. The thing is when she was first learning to back up a car, she had nothing in long-term memory. So, she would try to work with sets of links in working memory. She couldn't hold much in mind and that meant she had a heavy cognitive load, all of the arms of her attentional octopus or quadrupus with 4 arms were taken up with trying to learn to back up the car. So, word of the wise, don't speak with someone when they're trying to learn to back up a car because they don't have any arms left on their attentional octopus to process whatever you're saying to them. But once you've learned to back up a car as with Rachel here, she can just pull that set of links to mind "I wanna back up a car and off she goes, no problem at all, and she even has extra arms on her attentional octopus that she could use to think about other things like what's on the radio or is her seatbelt buckled. So, the key idea here is that when you're learning you want to create sets of links that are stored almost like in a locker of long-term memory and then whenever you need to, for example you're sitting down to a test your working memory kind of hops right up and it can pull sets of links from long-term memory, put ideas together, and help you solve problems. But if you don't actually put those sets of links in long-term memory, so for example you haven't studied effectively, then what can happen is you sit down to a test, you open it up, and you realize there's no sets of links there and you panic, you may think "I have test anxiety" because you are sure you knew it before. But if you hadn't used retrieval practice, you don't necessarily know that you had put that information in long-term memory. So this is why testing yourself with retrieving that information is so important, it puts those sets of links in long-term memory. Now, if we just look, for example, here is a typical octopus of working memory, it has 4 arms so it's a quadropus. And what this octopus is doing is it can reach up into long-term memory and grab sets of links as you need to know some information now or process some skill. And as long as you got those links there, all works well. But one thing to be aware of is that people have different sizes of working memory capacity.

08:22 Some people have, maybe on average, it's 4 sets of arms in working memory, some people have 8 or 9 or 10, others like me may have 3 arms in working memory.

08:37 And the way these different people learn is kind of like the race car versus the hiker. So, bigger working memory capacity you can, in some sense, leap tall buildings with a single bound. You can learn very difficult material perhaps more swiftly because you can hold more in working memory. But if you have lesser capacity working memory, you can still learn exactly the same information, it's just that you need to learn it in smaller pieces and it can be then put in long-term memory and combine together in a process called consolidation that we'll talk about later. And that will help you to learn just as effectively if you're a hiker type learner as the race car learner. So, breaking things into chunks, that's a key idea and this brings me actually to my favorite scientist of all times. His name was Santiago Ramon y Cajal. And Cajal was the epitome, it was the perfect example of the terrible learner. He flunked out of several schools and he just couldn't get things into his long-term memory very easily, in fact he got a really poor working memory. But Cajal decided when he was about in his 20s, he was going to try to become a professor of anatomy. He worked really hard and he took the tests.

10:30 First year he took the test he flunked. Second year he took the test, he flunked.

10:36 Third year he took the test, that's the last year he could take it, he passed.

10:41 He became a professor of anatomy. But that's not all. Then, his studies of how neurons actually function led him to win the Nobel Prize. And that's not all.

10:59 Then he is now known as the Father of Modern Neuroscience. So, he was asked once "How did you become such a great discoverer and how did you make all these terrific inventions and discoveries?" And he said, "You know I was no genius." And he was no genius. But he said "I have worked with many geniuses.

11:29 And the challenge with geniuses is they're very smart, they jump to conclusions, and when they're wrong they can't change their mind, they will instead use their genius to intellectually justify why they must have been right after all." So, again, there we go with the race car who can be fast but inflexible versus the hiker who is slow but can be much more flexible. So if you, like Cajal, are not a genius, rejoice because you can also do something even geniuses cannot. Thank you.

12:18 So, Barb what a great example and I remember studying and hearing of Cajal and his work when I was in medical school and I have to frankly say as a fellow hiker boy that's great to know I didn't know those things about, you know, his challenges and limitations and I hope for all everyone once you missed you can see that you can really make a lot of your capabilities if you apply them appropriately and that's really the heart of this course is to figure out how to maximize your potential and be a doctor. As doctors we don't have to be geniuses, we have to be good compassionate people and know our basics and apply them.

13:11 So, really helpful Barb. Thank you so much.