Working Memory and How to Overcome Its Limitations Through Practice

Summary of key facts about working memory

1. Working memory is what we can keep active in the mind while we perform mental operations.
2. There are only a limited number of chunks of information we can keep in working memory at one time (between 4 and 10). When new ones are added, old ones are pushed out.
3. The size of the chunks is not limited. In fact, sometimes making them bigger makes it easier, particularly, if we increase their size by making them more meaningful to us.

What is working memory and why it matters for good performance

Working memory is the small mental buffer you use to keep things on top of mind so that you can do something with them. You need working memory when you do mental calculations, compare ideas, recognise faces, drive a car, or when you write a sentence. Without it, we would be too slow at doing any of these things.

There are many things we don’t know for certain about working memory but we are sure, it is very limited. It can only hold about 7 discrete items at once (some people say it’s even less but definitely no more than 10).

A good simple example is writing down a phone number someone is dictating to you. Unless you focus, you can usually only do it a few digits at a time and nobody can do a whole 10 digit phone number. Just remembering each digit individually and then writing them down one by one is impossible without some mental tricks. And it’s these sort of tricks that we can learn from.

The very simplest mental trick is to chunk the numbers. So instead of putting 2 3 5 6 7 8 9 1 9 3 6 into your working memory buffer one by one, you can do 2356 7789 1936. Now you only have three chunks in working memory. This is easier but the chunks don’t mean anything, so it will still be a challenge. So instead, you can decide to chunk the numbers in a way that has some meaning. 23 (how old your cousin is) 5677 (a house number) 89 (number of a road you travel on) 1936 (date in history). All of a sudden, it’s much easier to quickly put the numbers into your working memory and keep them there. (The world record holder can use this approach to memorise 514 digits in 5 minutes.)

So what we did was:

1. Create chunks
2. Make the chunks bigger and richer by adding meaning

This seems like a paradox. If working memory is limited, how can we make it easier to think when we put more in? That is the second thing we are sure about when it comes to working memory. Even though the number of chunks we can keep in it is limited, the size of the chunks is not. Chunks, by the way, is the technical term in the research, so we will use this here, as well.

Working memory in practice

How does this work in practice? We use working memory for much more than just writing down phone numbers. It is involved in everything we do. Working memory is fundamental to speaking, reading and writing. Here is another example. Take this English sentence:

Books are often very expensive.

It probably took you less than a second to read and understand. (Assuming you are a native speaker who does not have dyslexia or some other difficulty that slows down processing.)

Let’s take a similar sentence in another language. Let’s say Czech. You probably don’t speak Czech but, it should be very easy to translate, if I give you all the words first.

Here is an alphabetical list of the four words that will appear in the sentence.

Now, how long does it take you to read and understand this sentence?

Staré knihy jsou támhle.

Probably at least 10 seconds. Why? You have to look up every single word in the list and then put them together in your mind. But all those words are unfamiliar and they take up a lot of space in your working memory. So it is possible that even after you put them all together you have no mental capacity to do anything else with that sentence. Such as make it into a question by swapping the verb and the subject. It is very simple:

Jsou staré knihy támhle?

But you probably couldn’t do it without a lot of effort. What are some strategies you could use to translate and transform the sentence. There are essentially three:

(1) First, you would probably want to remove everything else that may be taking up space in your working memory. This means focusing just on the sentence. Removing visual distractions such as not looking anywhere else, minimising other audio input such as turning down music, remove thoughts of other things by trying to focus on just the task at hand.

(2) Second, you would want to offload some of the load from your working memory somewhere else. The best way to do that is to write down each individual word as you translate it on a piece of paper. And when I ask you to switch the subject and verb, you may want to circle the two words that constitute the subject (old books) and underline the verb (jsou).

But none of these methods are sustainable in the long term. You could not translate very many sentences doing this. And you would never be able to have a conversation in the language. Looking up every word of a sentence in a dictionary is not how you speak, read or write a language. So this leads us to the next strategy that lies at the heart of this programme.

(3) Third, combine the words into meaningful chunks in your mind. You could try to find some surface similarities to create a mnemonic devices. For example, staré sounds kind of like starry and you could associate knihy with knights who go high. But this is very hard to do quickly and only works for recalling the words, not doing something with them.

(4) So you are left with the only other option and that is to practice the language. This would involve repeating different combinations of words many times to create chunks that you can use in working memory. But it would also require that you think about how the words are put together and also about the ways of trying to learn them. And, most importantly, you would need to make sure that what you are saying has real meaning to you.

This has been called deliberate practice and it lies at the heart of the Writing Boot Up. Deliberate practice is like any other practice. You repeat actions until you can perform them with ease. But the core of deliberate practice is that this repetition involves focus and reflection. And these are aimed explicitly at helping you overcome the limitations of working memory by developing ‘bigger chunks’ and storing them for later use as mental representations.

Reflective repetition as a way of overcoming working memory limitations and performance plateaus

To get better at anything, we need to practice. We cannot just think about how to do something, we have to try it first. And usually we have to repeat it many times before we get better at it. Just think about how long it took you to learn to drive. There are many steps to just getting started and simply thinking about them is not enough. You have to practice in small chunks and slowly it becomes easy.

But very soon, we stop getting better no matter how many times we repeat something. This means we reach a plateau. To break through a plateau, we need to reflect on what it is that we’re doing, what gets in the way and what else we could try to improve with the next round of repetitions. As we reach close to the limit of what is possible, more reflection and more focused repetition is needed. As you get closer to being the best you can be, you may have to do a lot of this for relatively small gains. But initially, adding reflection to repetition can help us make great strides.

To summarise the key principle behind this approach, we can say:

We get better at many things after doing them a few times. But after a while we stop improving. So we have to be more focused on how we repeat things. It is best if what we are trying to learn has a nice programme of step by step improvement we can follow such as Couch to 5K. But if there is not one, you can still improve by focusing on what you are practicing.

The key principle behind our reflection should be: