Working Memory
By: Stephen M. Ryan
CEFR Level: A2+
Word Count: 824 words
The Brain in Simplified English
If I tell you my street address, can you remember it long enough to go and get some paper and write it down? I warn you, my address is very long. What do you think? Can you do it?
The answer is probably “No,” especially if it takes you more than a few seconds to find some paper. But why is this? You can remember what you did last week. You can remember basic math you learnt in elementary school. Why can’t you remember my address for more than a few seconds?
The answer is that your brain stores information you just heard (or saw) in a different way from those other memories. This kind of memory is called short-term memory. “Short-term” means “for a short time,” so you can use it to remember things for just a few seconds, or even less time if something else comes along that you want to remember. That’s the other problem with short-term memory: it can keep only a small amount of information at one time. You can only remember about seven things at once. So, your short-term memory is not only short, but it is also small.
Of course, there are ways to solve these problems. When you go to get the piece of paper, you can repeat my address to yourself, either by speaking or just saying it inside your mind. When you do this, you are refreshing your short-term memory, so that the timer starts from zero again: in a short time, you will forget me saying my address, but, if you have repeated it, you will remember you repeating it. Until you forget that, too, so you had better repeat it again. Repeating like this does not make your memory longer; it just means that you put the information back into your short-term memory more times.
The other way you can trick your short-term memory goes like this: If I say “Station Road,” that’s two pieces of information to remember. But if you think of it as one piece “StationRoad,” it’s only one. In this way, you can make each piece of information bigger, although the limit on the number of pieces will still be about seven. That’s why, if somebody asks for my telephone number, I don’t say “0-5-1-7-6-4-9-9-2-6.” That’s 11 pieces of information to remember: too many! I say “051-764-9926.” That’s only three pieces of information.
But, why do we have a memory that can’t remember very much, and soon forgets even those few things? The other name for “short-term memory” is “working memory.” This name can help us to answer that question. Imagine you had a workshop where you wanted to make something. Let’s say you want to make a chair out of wood. You need to buy the wood at the woodstore, but you already have some nails and some glue. You carry the wood to your workshop and you take the nails and glue from the place where you keep them. In the workshop, you put them together and make the chair. Working memory is like that: you take some things you just got and some things you already had and put them together.
Let’s go back to me telling you my address. When you hear my address, you hold it in your working memory for a few seconds (that’s the thing you just got). Then you think about what you already know about my town. You realise that my house is near the post office and say “Oh, is that near the post office?” knowing about my town was the thing you already had. You put the new information together with the old information (in your working memory) and you understand where I live.
This is why you have working memory: to put new information together with information you already know so that you can do something with it. Let’s look at another example. Your teacher gives you a story in English to read. You can understand the story because you know the words in the story. The story is the new information. The words are what you already know. After you understand each sentence, you do not need to remember all the words of the story. You only need to remember the story. That’s why your working memory forgets the words very soon after you read them.
You use your working memory all the time. Every time you do something—like getting out of bed, reading a book, talking to your sister, or solving a math problem)—it is putting together things you know with things you just saw (or heard) so that you can think, understand, and take action.
So, your working memory is very important, but it is not designed for you to remember things for a long time. Your brain has other ways of remembering things that might be important for your future. This is good news if you have a test tomorrow!
