[MUSIC, Title: "Race Cars, Hikers and Intellectual Humility"] [Barb] Have you ever met a person like this post? An inflexible thinker who's as stiff as this post in their thinking? We all have a certain amount of inflexibility. But to become good, critical thinkers, and avoid being like this post right here, we can get a little help from our friendly neighborhood neuroscientist. Terry? [Terry] Mental flexibility? That's an interesting topic, and a very important one. It might be best to start by talking about the training that interns receive on their way to becoming a medical doctor. After a group of interns might examine the patient, they're then quizzed in front of others about the potential diagnosis. There is often one doctor-to-be in the group with an extraordinary memory. These memory superstars can be amazing. After seeing the patient— without checking any textbooks— they can blurt out a diagnosis complete with a dazzling array of supporting details. Racecars indeed! But in the end, these racecar learners with their keen memories are not necessarily the best at diagnosing diseases. But how can that be? Isn't a medical diagnosis just a question of remembering all the key facets of a disease and detecting a match with a patient's symptoms? [Barb] Previously in Uncommon Sense Teaching... we described the differences between race car and hiker learners. Race cars like the dazzling doctors-to-be with extraordinary memories, can learn quickly, while hikers learn more slowly. Both can get to the finish line and learn the material— they just do so differently. Part of the differences between race cars and hikers can relate to differences in working memory capacity. A large working memory capacity often means learning comes more swiftly. While a smaller working memory capacity— like I have—often means a slower approach to learning. But let's look at another factor that can be involved in faster versus slower learning. Remember that the declarative learning pathway goes from working memory, through the hippocampus, and onto long-term memory in the neocortex. We already know that if the octopus of working memory has fewer arms, it means that learning proceeds more slowly. In some sense, with fewer arms to work with, it takes longer for links to be put together by working memory for storage in long-term memory. But it seems there's another way that learning through the declarative pathway can go more slowly. And that is, if neurons in the hippocampus are weaker. In other words, they don't latch onto their links as easily. Let's remember what the hippocampus does. Good old Hip reminds Neo, the neocortex, over and over again about which links should hook together and be strengthened in order to more permanently remember a fact, an idea, a relationship, or whatever. For example, you may have a set of links in long-term memory about what someone looks like, and another set of links about that person's name. The hippocampus helps you connect the name and the face together. [Beth] Remember that Hip's neural links are meant to be temporary. They're meant to last long enough to reinforce the links in the neocortex that are supposed to remain together. However, if Hip's dendritic spines are washed away more easily, a person can end up with a weaker hippocampal system. They might need to repeatedly study and practice with the material. [Terry] It may be that the doctor with a superb memory who was diagnosing a worrisome patient, is like a photographer trying to see which picture is closest to the picture in his mind. This doctor trusts his memory because it is indeed an unfailingly good memory. When he searches his memory for a good diagnostic fit and finds one, BINGO! He's done. There's no need to rethink things, because he's not used to being wrong. His memory, after all, is much better than most others'. And indeed, the neural bath of chemicals that provides for an exceptionally good memory CAN, it seems, sometimes make it more difficult to LET GO OF a decision in order to rethink the diagnosis. That strong memory bath of neurochemicals helps dendritic spines lock into place, so the doctor can remember more easily than other people. But that same bath of neurochemicals also makes it harder to loosen up dendritic spines. The spines remain more permanently in place, making it hard to rethink an idea or be more flexible when considering a new idea. It's like tall, strong trees that grow sturdily in place, as opposed to the bendable prairie grass. The top of a tall tree may seem to give you the best overall view, but where would you rather be standing when conditions change and a big storm blows in? Ultimately, the doctor with a poor declarative memory, may be more like an artist trying to paint rather than photograph a scene. This doctor can't remember the scene perfectly, and she knows this to be true about herself. So, she re-checks the scene— that is the symptoms—again and again to see how they compare with possible diagnoses. She may think about what she's seen over several days and sleep on it over several nights. Instead of being locked into her first guess by firm neural links, she may instead be continuously changing neural connections here and there, searching for new hypotheses. Only after carefully sifting through all of the facts, checking and re-checking over several days, does she come to her conclusions. And her conclusions, although slowly coming, are more likely to be correct. [MUSIC, Title: "An Evolutionary Perspective on Race Car and Hiker Learners"] [Barb] Let's take a big step back for a moment and look at matters from an evolutionary perspective. It seems like, as this paper says, "Group living enables species to come up with solutions that each individual would not have accomplished alone." What does this mean in practice? Let's say you have a school of fish. Some fish are going to be fast, but inaccurate learners. And some slow, but more accurate. A fast, but inaccurate learner for example, might spot a bit of drifting seaweed and ignore it. A pretty safe assumption in most cases. A slower, but more accurate learner, on the other hand, may be slower at detecting whether something is an actual piece of seaweed. But that's because they're also trying to determine whether the supposed seaweed is in reality, a deadly scorpion fish that is evolved to LOOK like a seaweed. The school of fish as a whole relies on different types of learners, depending on which type leads to more successful strategies in a given situation. It seems that in fish, birds, people, and perhaps any social creatures, there's a mixture of both fast, but inaccurate, and slow, but more accurate, learners. What's particularly interesting is that within these groups, the fast leaners tend to be inflexible and less accurate, while the slow learners tend to be more flexible, but more accurate. [Beth] As we mentioned, research evidence supports the idea that fast is often INflexible, but slow is often MORE flexible. This idea is true even in humans. Interestingly, individuals who are shier are also often more flexible in their thinking— perhaps a reason why that quiet person sitting in the back of the classroom or boardroom can sometimes weigh in with the most insightful ideas. Is there something you can do as a teacher to help fast learners be more flexible? Are there other reasons that people can be inflexible? Does flexibility have anything to do with critical thinking? In the next videos, you'll find out. In the meantime, head over onto the discussion forum and talk about what kind of things YOU do to support both racecars and hikers in your classroom. [Beth] I'm Beth Rogowsky. [Barb] I'm Barb Oakley. [Terry] I'm Terry Sejnowski. [All] Learn it, link it, let's do it!