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  • This episode is supported by The Great Courses Plus.

  • Hi, I’m Thomas Frank, this is Crash Course Study Skills,

  • and if you happen to be watching this at whatever point in the future that we all get neural implants to let us store our memories on servers in space,

  • what I’m about to tell you is woefully inaccurate.

  • Also, do we have flying cars yet?

  • For those of you who still rely on that mushy gray stuff in your cranium to remember things, though, listen up.

  • Today were digging into how your memory works and how you can make it work better.

  • At least, I think we are.

  • Nick, were not filming those makeup tutorials today, are we?

  • [Theme Music]

  • The science of how memory works is complicated, to say the least.

  • After all, how do we explain how a bunch of nerve cells, chemicals, and electrical jolts

  • somehow let you remember algebra, where you left your car keys, and all the lines to The Dark Knight?

  • Well, it’s simple. We, uh…. rely on Hank from 3 years ago to do it for us.

  • Seriously, there are two whole episodes of Crash Course Psychology that go through the entire process of how memories are formed and retrieved.

  • But just like Xzibit left to his own devices in a car dealership, I can’t resist putting crash courses in your Crash Course.

  • Plus, understanding how your memory works will help you to optimize the way you study.

  • So let’s do a quick review.

  • Your brain turns information into memories by putting it through a few different stages.

  • The first is sensory memory, which processes pretty much everything your senses detect or experience in the real world.

  • That sensory memory has the attention span of a five-year-old at the DMV, though, so most of what it takes in is lost almost immediately.

  • But what does stick moves into your short-term or working memory.

  • This type of memory is sort of like the RAM in your computerthe memories don’t stick around permanently.

  • In fact, unless you continuously rehearse what’s floating around in working memory, itll pull a disappearing act after about 15-30 seconds.

  • This can also happen if you try to cram too much in at once, because your working memory can really only handle 4-7 bits or items of information at a time.

  • Now you can somewhat increase this limit by grouping bits into chunks

  • like splittingFBIKGBCIAinto FBI, KGB, CIA, but there’s still a limit.

  • Now, all this happens primarily in your brain’s prefrontal cortex,

  • but eventually the information has to make its way to other areas of the brain if it’s going to be encoded in long-term memory.

  • To greatly simplify things, itll first head to the hippocampus, which augments it with chemicals called neurotransmitters.

  • Along with many other functions, these transmit details about the informationmetadata, if you will.

  • Eventually, this leads to the formation of new synapses, which are essentially connections between neuronsthough the neurons don’t actually touch.

  • Instead, they prefer to keep a small gap between each other and let more of those neurotransmitters move information between them.

  • The whole process of memory formation causes physical changes within your brain:

  • neurotransmitters shuttle all over the place, neural pathways are forged,

  • and neurons themselves undergo structural improvements using proteins such as brain-derived neurotrophic factor, or BDNF.

  • And, just like the process of strengthening your muscles through exercise, this all takes time

  • which is why cramming for a test doesn’t work, and why you can’t instantly just download jujitsu into your brain like Neo.

  • As Pierce J. Howard noted in his book The Owner’s Manual for the Brain:

  • Work involving higher mental functions, such as analysis and synthesis, needs to be spaced out to allow new neural connections to solidify.

  • New learning drives out old learning when insufficient time intervenes.”

  • Now that you have a bit of an understanding of how your memory works, one crucial tip should be clear:

  • you have to space your learning out over time.

  • But were not going to just leave it at that, becauseas cognitive scientists have known for a long timethe way you do that spacing matters quite a bit.

  • To explain this, let’s start with why we forget things in the first place.

  • Part of the reason is that your brain doesn’t encode all memories equally.

  • During the long-term encoding process, the hippocampus will use different levels of neurotransmitters based on, among other things, how important the information is.

  • And this plays a big role in how strongly it’s embedded in long-term memory.

  • This filtering mechanism is great for survival, as it allows your brain to safely disregard unimportant things,

  • like what you had for breakfast two weeks ago, while paying special attention to what’s important, like that fact that there are ninjas behind you right now.

  • Unfortunately, you can’t always consciously decide what’s important and what’s not,

  • which is why it can be hard to remember all the details from that history chapter you just read.

  • At a primal level, your brain just doesn’t think the details of Genghis Khan’s war with the Quarismian Shah in 1219 are as important as a bear attacking you.

  • However, there are a few tricks you can pull to make it care a bit more.

  • First, understand that your brain latches more readily onto things that are tangible, visual, and uncommon than it does with the abstract or the mundane.

  • Because of this, it can be helpful to develop mnemonics, which are mental devices that help you associate pieces of information in ways that are easier to remember.

  • And mnemonics can take many forms.

  • You can create sayings to remember sequences of letterssuch asErnie Ate Dynamite, GoodBye Ernieto remember the names of the strings on a guitar.

  • Or you can make up weird stories in your head that includes cues to the information youre trying to associate.

  • Like, the way I remember that Helsinki is the capital of Finland is by imagining a giant flaming sinkhole in the ground opening up with a bunch of sharks jumping out of it.

  • Since it’s weird, it’s easy to remember, and it helps me associate the words Hell, Fin, and Sink, which in turn connect Finland and Helsinki.

  • Additionally, the more connections that lead to a memory, the stronger itll beespecially if theyre learned in different contexts.

  • When I first learned about caravels, which were those small ships that Portuguese explorers used to travel down the African coast in the 15th century,

  • I had a hard time remembering that namecaravels.

  • But once I started using them in Civilization V to build my empire

  • and to make sure Ghandi never got far enough to nuke me, the memory became a lot more solid, since I was interacting with it in a new context.

  • Of course, you still have to repeatedly access your new memories once theyre encoded if you want them to stick around.

  • This is pretty much the iron law of memorization:

  • Except in cases where theyre attached to a particularly intense emotional experience, memories fade away unless you repeatedly recall them.

  • Well, sort of. Let’s go to the Thought Bubble.

  • In the 1880’s, a German psychologist named Herman Ebbinghaus wanted to understand how memories decayed over time,

  • and he especially wanted to know how long the process took.

  • He began by running countless tests on his own memory, forcing himself to recall long lists of meaningless letters until eventually, he came up with the Forgetting Curve.

  • While largely hypothetical and simplistic in its details, this model demonstrated how memories decay quickly unless accessed again and again.

  • Since Ebbinghaus’s days, our understanding of how memory decays has come a long way.

  • According to the Forget-to-Learn theory, which is presented in Benedict Carey’s book How We Learn, memories actually have two different strengths:

  • storage strength and retrieval strength.

  • Picture your brain as a library where none of the books ever get stolen or damaged.

  • When a new book is put on a shelf, it’s there for good.

  • This represents storage strength, which, according to the theory, doesn’t weaken.

  • Once a memory is encoded, the neural pattern can only get stronger.

  • Now, unfortunately this library has a particularly lazy librarian who doesn’t do a very good job of keeping the library’s catalog organized.

  • This represents retrieval strength, which does fade with time.

  • Unless you go in and organize the catalogor recall the memoryyoull eventually lose track of it.

  • Thanks, Thought Bubble. Now here’s where it gets good.

  • The more a memory’s retrieval strength has faded, and the greater the difficulty of recalling it, the greater the increase in learning will be.

  • This is called the Spacing Effect.

  • It’s essentially theNo pain, no gain,” of the mental realm;

  • the harder you have to work to recall something, the greater the reward for doing so.

  • There’s an obvious catch, thoughif you wait too long, the retrieval strength diminishes so much that you won’t be able to recall the memory at all.

  • This where the Principle of Desirable Difficulty comes in.

  • To maximize the efficiency of your studying, you want to the find the point right before youre about to forget something.

  • And you can do this by using spaced repetition techniques.

  • The general idea behind spaced repetition is to steadily increase the amount of time in between each study session for any piece of information.

  • So instead of reviewing a fact or concept once every few days,

  • you’d use a schedule like this where you’d wait a day between the first and second sessions, three days between the second and third, and so on.

  • To do this precisely, you need a system that tracks your progress in memorizing each piece of information you need to studysince it never happens evenly.

  • If youve got 100 Japanese kanji to learn, it’s inevitable that youll remember some easier than others.

  • If you use the exact same time delays for every kanji, youll spend too much time studying some, and others won’t ever be learned at all.

  • To solve this problem, you can use the Leitner System.

  • In it, youve got five boxes, each of which represents a specific study interval.

  • Box 1 gets studied every day, Box 2 every three days, Box 3 once a week, and so on.

  • Every fact or term gets its own flash card, and all cards start off in Box 1.

  • Once you get a card right, move it to the next box.

  • And if you get a card wrongno matter what box it’s insend it back to Box 1.

  • If you play by these rules, youll ensure that you maximize your efficiency by spending more time studying the cards you have the weakest grasp on.

  • The increasing time intervals of the boxes also help you leverage the spacing effect and get to close to that point of desirable difficulty.

  • There are also a ton of spaced repetition apps for both computers and smartphones that will let you make this whole process digital.

  • The best known one is probably Anki, which is free on most platforms, but there’s also TinyCards, Quizlet, and many, many others.

  • Now when it comes to subjects that aren’t easily studied through flash cardslike math or even a sport like skateboardingit’s harder to use a rigid spaced repetition algorithm.

  • However, the spacing effect applies here as well, so be sure to space out your practice over time.

  • During any given day’s practice, youll eventually hit a wall where you stop making progress

  • whether it’s learning derivatives in calculus or kickflips in skateboarding

  • but if you come back to it a few days later, everything will be more likely to click into place.

  • In each of these study sessions, make sure youre putting the focus on recalling information from your own memory.

  • As we talked about in our video on reading assignments, there are two main kinds of memoryrecognition and recall.

  • Recognition is what happens when youre exposed to information youve already seen before and remember it.

  • But recall involves dredging the information up from the depths of your memory banks without seeing it,

  • which is exactly what youll have to do in both your exams and in many real-world situations.

  • So when you study, make sure youre focusing on active recall.

  • Don’t just passively read over your notes or slidesuse them to create quizzes for yourself,

  • or challenge yourself to sit down and write out a summary of what youve learned from memory.

  • If youre studying a subject like math or physics, put a huge emphasis on practicing with real problems and actually use the concepts and formulas youve learned.

  • In short, studying should feel like work, and it should challenge your brain.

  • When it does, youll remember more while spending fewer hours at your desk.

  • Thanks for watching, and I’ll see you next week.

  • This episode is brought to you by The Great Courses Plus, an on-demand subscription service

  • where you can get unlimited access to over 7,000 different video lectures about any topic that interests you,

  • including science, literature, history, math, even cooking or photography.

  • The classes are taught by award winning professorsfrom the Ivy League and other top schools around the world.

  • If you're looking to improve your study skills further, you might like this lecture from

  • Professor Steve Joordens, called EncodingOur Gateway into Long-Term Memory where you'll learn more about how to improve your own recall.

  • Right now, The Great Courses Plus is offering Crash Course viewers a free one-month trial.

  • Go to thegreatcoursesplus.com/studyskills, or click on the link in the video description below, to start your free trial today.

  • Crash Course Study Skills is filmed in the Dr. Cheryl C. Kinney Crash Course Studio in Missoula, MT, and it's made with the help of all of these nice people.

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  • Thank you so much for your support.

This episode is supported by The Great Courses Plus.

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Memory: Crash Course Study Skills #3

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    DYY posted on 2017/11/19
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