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0:00 What do you do when you just can't figure something out? For zombies, it's pretty simple. They can just keep bashing their brains against the wall. But living brains are a lot more complex. It turns out, though, that if you understand just a little bit of some of the basics about how your brain works, you can learn more easily and be less frustrated. 0:23 Researchers have found that we have two fundamentally different modes of thinking. Here, I'll call them the Focused and the Diffuse modes. 0:34 We're familiar with focusing. It's when you concentrate intently on something you're trying to learn or to understand. But we're not so familiar with diffuse thinking. Turns out that this more relaxed thinking style is related to a set of neural resting states. 0:53 We're going to use an analogy of the game of pinball to help us understand these two thinking modes. Incidentally, both metaphor and analogy are really helpful when you're trying to learn something new. 1:08 If you remember, a pinball game works by, you pull back on the plunger, release it, and a ball goes boinking out, bouncing around on the rubber bumpers, and that's how you get points. So, here's your brain, with the ears right here, and the eyes looking upwards. And we can lay that pinball machine right down inside it. So, there you go. There's the analogy for the focused mode. The blue bumper bumpers here are placed very close to one another. See this orange pattern here towards the top? It represents a familiar thought pattern. Maybe involving something simple like adding some numbers, or more advanced ideas like literary criticism or calculating electromagnetic flows. You think a thought, boom, it takes off, moves smoothly along. And then, as it's bouncing around on the bumpers, you're able to figure out the problem you're trying to solve, or. The concept you're trying to understand that's related to something you're rather familiar with. 2:10 So look at how that thought moves smoothly around on the fuzzy underlying orange neural pathway. In some sense it's as if it's traveling along a familiar, nicely paved road. But what if the problem you're working on needs new ideas or approaches? Concepts you haven't thought of before. That's symbolized here by this neural pattern towards the bottom of the pinball machine area. But if you haven't thought that thought before, you don't even know how that pattern feels or where it is. So how are you going to develop that new thought in the first place? Not only do you not know where the pattern is or what the pattern looks like, but see all the rubber bumpers that are blocking your access whatever direction you do decide to move in? 3:00 To get to this new thought pattern, you need a different way of thinking. And that's represented here, by the diffuse mode. Look at how widely spaced the rubber bumpers are. Thought takes off, look at how it moves widely, bounces around. It could travel a long way before being interrupted by hitting a bumper. In this diffuse mode of thinking, you can look at things broadly from a very different, big-picture perspective. You can make new neural connections traveling along new pathways. You can't focus in as tightly as you often need to, to finalize any kind of problem solving. Or understand the finest aspects of a concept. But you can at least get to the initial place you need to be in to home in on a solution. 3:52 Now as far as neuroscientists know right now, you're either in the focused mode or the diffuse mode of thinking. It seems you can't be in both thinking modes at the same time. It's kind of like a coin. We can see either one side, or the other side of the coin. But not both sides at the same time. Being in one mode seems to limit your access to the other mode's way of thinking. 4:18 In our next video we're going to see how some extraordinary people access their diffuse ways of thinking to do great things. Thanks for learning about learning, I'm Barbara Oakley. [BLANK_AUDIO] Downloads Lecture Videomp4 Subtitles (English)WebVTT Transcript (English)txt Introduction to the Focused and Diffuse Modes.pdfpdf Introduction to the Focused and Diffuse Modes.pptxLink Introduction to the Focused and Diffuse Modes Script.pdfp
0:04 Welcome to learning how to learn. My name is Terry Sejnowski. Let me introduce you to your brain. 0:13 First, some brain surgery. We take off the skull and take out the brain. 0:21 This brain weighs three pounds, but it consumes ten times more energy by weight than the rest of the body, a very expensive organ. It is the most complex device in the known universe. All of your thoughts, your hopes, your fears are in the neurons in this brain. 0:41 We prize our abilities to do chess and math, but it takes years of practice to acquire these skills. And digital computers are much better at it than we are. 0:52 It came as a surprise to discover that what we do so well and take for granted, like seeing, hearing, reaching, running, are all much more complex problems than we thought and way beyond the capability of the world's fastest digital computers. 1:11 What this illustrates is that we are not consciously aware of how our brains work. Brains evolved to help us navigate complex environments, and most of the heavy lifting is done below our level of consciousness. 1:25 And we don't need to know how it's done in order to survive. 1:30 Psychologists who study the unconscious mind have found that influences include thought processes, memory, emotions and motivation. 1:39 We are only aware of a very small fraction of all of the activity in the brain, so we need to rely on brain imaging techniques to guide us. 1:48 Here is the activity map of someone's brain who was asked to lie still, at rest, in a brain imaging scanner. On the left is the side view of the brain and on the right is the view from the midline. 2:00 The colors indicate brain areas whose activities were highly correlated, as shown by the time courses below, color-coded to the brain areas. 2:09 The blue areas are highly active when the subject interacts with the world, but turn off in a resting state. 2:16 The red-orange areas are most active in the resting state and are called the default mode network. Other brain areas are also more active when you are resting, and these areas can be further divided into groups of areas that have common patterns of activity. This is a new and intense area of research, and it will take time to sort out all the resting states and their functions. There are a million billion synapses in your brain where memories are stored. The old view of the brain is that once it matures, the strengths of synapses can be adjusted by learning, but the pattern of connectivity does not change much unless there is brain damage. But now we know that brain connectivity is dynamic and remains so even after it matures. 3:04 With new optical techniques for imaging single connections between neurons called synapses, we can see constant turnover, with new synapses being formed and others disappearing. This raises a puzzle. In the face of so much turnover, how do memories stay stable over so many years? This is a picture of one dendritic branch on a neuron which receives inputs from other neurons. The synapses are on the spiny knobs coming off the dendrite. On the top, the dendrite was imaged before learning. The same dendrite is shown below after learning and after sleep. Multiple synapses that are newly formed together on the same branch are indicated by the white arrowheads. You are looking down into the brain of a live animal. This is really a fantastic new technique. 3:52 Synapses are less than a micron in diameter. In comparison, a human hair is around 20 microns in diameter. 4:00 This new technique allows us to see how learning changes the structure of the brain with a resolution that is near the limit of light microscopy. 4:09 This illustrates that, intriguingly, that you are not the same person you were after a night's sleep or even a nap. It is if you went to bed with one brain and woke up with an upgrade. This is a better deal than you can get from Microsoft. Shakespeare, the great English poet, already knew this. 4:28 Here is Macbeth lamenting his insomnia. 4:33 Sleep that knits up the raveled sleeve of care, the death of each day's life, sore labor's bath, balm of hurt minds, great nature's second course, chief nourisher in life's feast. 4:48 Here Shakespeare is making an analogy between knitted clothes and sleep that knits up the loose threads of experience and concerns during the day and weaves them into the tapestry of your life story. You will learn in this first week how to take advantage of your unconscious mind, and also sleep, to make it easier to learn new things and solve problems. 5:10During the lectures you may ask yourself, how does the brain do this? A good place to find out more about your brain is the website brainfacts.org, brainfacts, one word, .org. You will find a wealth of interesting things about brains and behaviour, and in particular about learning and memory. I am Terry Sejnowski. Happy learning until we meet again.
0:02 When I look back on my childhood or I remember some words from Spanish or from Russian, Здравствуйте, or I bring to mind one of Maxwell's equations, I'm drawing on portions of my brain involved in long term memory. But what I'm trying to hold a few ideas in mind to connect them together so I can understand a concept or solve a problem, I'm using my working memory. Obviously, sometimes I'll bring something from my long term memory into my working memory, so I can think about it. So the two types of memory are related. 0:37 There are lots of different ways to slice our understanding a memory, but for this course on learning, we're going to talk about only these two major memory systems, working memory and long term memory. Working memory is the part of memory that has to do with what you're immediately and consciously processing in your mind. Your working memory is centered out of the prefrontal cortex, although as we'll see later, there are also connections to other parts of your brain ,so you can access long term memories. Researchers used to think that our working memory could hold around seven items or chunks, but now it's widely believed that the working memory is holds only about four chunks of information. We tend to automatically group memory items in to chunks so it seems our working memory is bigger than it actually is. 1:29 Although your working memory is like a blackboard, it's not a very good blackboard. You often need to keep repeating what you are trying to work with so it's stays in your working memory. For example, you'll sometimes repeat a phone number to yourself until you have a chance to write it down. Repetition's needed so that your metabolic vampires, that is, natural dissipating processes, don't suck those memories away. You may find yourself shutting yours eyes to keep any other items from intruding into the limited slots of your working memory as you concentrate. So we know that short term memory is something like an inefficient mental blackboard. The other form of memory, long term memory, is like a storage warehouse. And just like a warehouse, it's distributed over a big area. Different kinds of long term memories are stored in different regions of the brain. Research has shown when you first try to put a short term memory in long term memory, you need to revisit it at least a few times to increase the chances that you'll be able to find later when you might need it. The long term memory storage warehouse is immense. It's got room for billions of items. In fact, there can be so many items they can bury each other, so it can be difficult for you to find the information you need unless you practice and repeat at least a few times. 3:04 Long term memory is important because it's where you store fundamental concepts and techniques that are often involved in whatever you're learning about. When you encounter something new, you often use your working memory to handle it. If you want to move that information into your long term memory, it often takes time and practice. To help with this process, use a technique called spaced repetition. This technique involves repeating what you're trying to retain, but what you want to do is space this repetition out. Repeating a new vocabulary word or a problem solving technique, for example, over a number of days. Extending your practice over several days does make a difference. Research has shown that if you try to glue things into your memory by repeating something 20 times in one evening, for example, it won't stick nearly as well as if you practice it the same number of times over several days. This is like building the brick wall we saw earlier. If you don't leave time for the mortar to dry, that is, time for the synoptic connections to form and strengthen, you won't have a very good structure. 4:20And talk about lasting structure, look at this part of the Acropolis here. Thanks for learning about learning. I'm Barbara Oakley. [BLANK_AUDIO]
0:03 Although living brains are pretty complex, this week we've used metaphor and analogy and zombies to help simplify matters. In essence, people have two fundamentally different modes of thinking that, for the purpose of this course, we've labeled focused and diffuse. We used a simple pinball analogy to help us understand the differences between the modes. The focused mode has tight spacing for the rubber bumpers which seems to, in some sense, help keep your thoughts concentrated. The diffuse mode, on the other hand, has more widely spaced bumpers that allow for more broad ranging ways of thinking. The focused mode is centered more in the prefrontal cortex, and it often seems to involve thinking about things you're somewhat familiar with. For example, if you're familiar with multiplication and you're trying to solve a multiplication problem or you're trying to find a word that rhymes with another word. You're probably stepping along the somewhat familiar pathways of the focused mode. But if you're trying to solve or figure out something new, it often cries out for the more broad ranging perspectives of the diffuse mode. This mode, as it turns out, is representative of the brain's many neural resting states. 1:26 Creative thinkers throughout history, whatever their discipline, have found ways to access the diffuse mode, often more directly and quickly. But we all access this mode quite naturally when we do things like go for a walk or take a shower or even just drift off to sleep. When we find ourselves stuck on a problem, or even if we're unsure of a situation in the course of living our daily life, it's often a good idea, once you've focused directly on the situation, to let things settle back, and take a bit more time. That way, more neural processing can take place, often below conscious awareness in the diffuse mode. The thing is, it often takes time for neural processing to take place, and time as well to build the new neural structures that allow us to learn something new. This is why tackling procrastination is so very important. The easiest way to tackle procrastination is to use the Pomodoro Technique. That brief 25 minute stretch of focused concentration, followed by a bit of mental relaxation. It's through practice and repetition that we can help enhance and strengthen the neural structures we're building as we're learning something new. Practice and repetition is particularly important for more abstract topics. Memory, of course, is an important aspect of learning. There are four slots in our working memory. Things can fall out of those slots unless we keep repeating them to hold them in mind. In that sense, working memory is like a not very good blackboard. Long term memory, on the other hand, is like a storage warehouse. If you practiced and repeated something well enough to get it into long term memory, you can usually call it up later if you need it, although you may need an occasional bit of repetition to freshen the memory up. It's never a good idea to cram your learning by repeating things many times all in one day. Because that's like trying to build muscle by lifting weights all in one day. There's no time for solid structures to grow. We've also learned of the importance of sleep in washing away the toxins that develop during our day's activities. You want to avoid taking tests or doing anything difficult with little sleep the night before, because it's like trying to think with poison on the brain. And just as importantly, exercise is surprisingly valuable in helping improve both our memory and our ability to learn. We've had a lot of fun while learning this week, I'll bet you'll find next week's material to be even more exciting. I'm Barbara Oakley, thanks for learning how to learn. Downloads Lecture Videomp4 Subtitles (English)WebVTT Transcript (English)txt Summing up module 1.pptxLink Summary of module 1.pdfpdf Summary Video for Module 1 Script.pdfpdf