What Is Working Memory? When You Notice It Slipping

In 1974 the British psychologists Alan Baddeley and Graham Hitch published a chapter called “Working Memory”. It described the ability to hold information briefly while using it to think, as a system made of several parts. The term “working memory” came into wide use from there.

You walk into the kitchen and cannot remember what you came for. You hear a phone number, start typing it, and lose it halfway. Many people feel this happens more with age. In this post I go through what working memory is and what research has found, and then some things you can do in daily life.

One thing first. If forgetfulness is getting in the way of work or daily life, or people around you have started to mention it, please see a doctor before trying to work around it.

What working memory is

Working memory is sometimes compared to a notepad in your head. The difference from a plain notepad is that you do not only write things down on it, you work with what is written there.

When you add 47 and 38 in your head, for example, you hold on to the fact that 7 and 8 make 15, and the 1 you carry, while you add the tens. When someone asks you a question in a meeting, you keep the question in mind while you put an answer together. In both cases you are holding on and thinking at the same time.

In Baddeley and Hitch’s model, working memory has a part that briefly holds words and sounds (the phonological loop), a part that holds shapes and positions you have seen (the visuospatial sketchpad), and a control centre that directs attention between them (the central executive). In a 2000 paper, Baddeley added a part that binds this information together and holds it as a single episode (the episodic buffer).

How it differs from short-term memory

A similar term is “short-term memory”. Researchers use the words slightly differently, but a common distinction is that short-term memory means holding information as it is for a short time, while working memory also includes doing something with it.

In testing, repeating a list of digits in the order you heard them is used as a short-term memory task, and repeating them backwards as a working memory task. To say them backwards you have to rearrange them in your head.

How much it can hold

In 1956 George Miller wrote, in “The magical number seven, plus or minus two”, that the number of items people can handle at once is around seven. “Seven plus or minus two” is well known, but later research has pointed to a smaller number. In a 2001 paper, Nelson Cowan argued that once you take away tricks such as rehearsing or grouping, people can hold about four chunks at a time.

Remembering a phone number in groups of three or four digits is a way of making good use of that limited space.

How it changes with age

In 2002 Denise Park and her colleagues published a study of 345 adults across a wide age range, from their twenties into old age, measuring processing speed, working memory, long-term memory and more. Scores on these processing-heavy tasks fell steadily with age from the twenties onwards. Verbal knowledge, such as vocabulary, was if anything higher in older people.

This study compared people of different ages at one point in time; it did not follow the same people as they aged. It also shows averages, and people differ a great deal. I wrote more about how different abilities change with age in How to Think Faster.

“What did I come in here for?”

On the feeling of walking into a room and forgetting why, Gabriel Radvansky and his colleagues reported in 2011 that walking through a doorway made it harder to recall what had been learned in the previous room. Their explanation was that a doorway acts as a boundary between events, and memory gets filed into separate episodes.

However, in four replication experiments published in 2021, there was no clear doorway effect overall. Only when people were also doing another task in their head while they moved did memory become more open to interference. So it cannot be said that doorways themselves make us forget. One way to take it: when you are holding something in mind and something else grabs your attention, what you were holding is easily pushed out.

Can working memory be trained?

This question has a long history of argument.

In 2008 Susanne Jaeggi and her colleagues published a paper in PNAS reporting that training on a dual n-back task, doing two n-back tasks at once, raised scores on a test of reasoning. It drew a lot of attention. But in a 2013 study by Thomas Redick and his colleagues, which used a stricter design where the comparison group also trained on a different task, no effect on intelligence tests was found.

In 2016 Monica Melby-Lervåg and her colleagues published a meta-analysis of 87 publications and 145 comparisons. Right after training, scores on working memory tasks close to the trained ones did go up. But there was no convincing evidence that the gains spread to more distant abilities such as intelligence, reading comprehension or arithmetic.

In short, practising working memory tasks makes you better at those tasks and at similar ones. Current research does not show that it will stop you forgetting why you went into the kitchen. I summarised the research on brain training as a whole in Does Brain Training Work?

Everyday fixes

What follows are some ideas based on the research above. They are not methods that have been tested in studies.

Get it out of your head. If working memory holds about four chunks, there is no need to keep everything in it. Write the shopping list on paper or your phone, put pills in a box sorted by time of day, keep your keys in one place. Handing memory over to things outside your head is called “cognitive offloading”, and it is discussed in detail in a 2016 review by Risko and Gilbert.

Say it in a few words before you stand up. Before going to another room, say quietly to yourself “getting the scissors”, and then stand up. With what you need to remember packed into one phrase, it may be easier to get back to it if your attention drifts on the way.

One thing at a time. Being on the phone while looking for a note and checking a notification in between means all of these compete for the same limited space. I also wrote about noting your next step before you stop a task in Can’t Stay Focused? A 10-Minute Daily Practice for Adults.

Make chunks. Remember numbers and items in groups of three or four. Building meaningful chunks makes things easier to remember, as I also mentioned in How to Improve Your Memory as an Adult.

Sleep well. Many studies show that lack of sleep weakens attention. If you feel more forgetful than usual for a while, sleep is worth looking at first.

About BrainDojo

BrainDojo is an iPhone and iPad app for keeping up daily brain training with short mini-games.

The Memory Boost lane in the training list has games that use working memory. N-Back Image Memory and N-Back Light are n-back tasks, where you answer whether the current picture or lit square matches the one a few steps back. In Position Memory you remember the numbers in a grid and recall the hidden ones. In Pair Memory you remember cards and find matching pairs. Triple Task has you steer around obstacles while solving sums and keeping count of what you saw. Version 1.7.0 added new trainings that use working memory too: Reverse Recall, where you remember digits shown one at a time and write them in reverse order; Path Trace, where you remember the route a light takes across a grid and trace it; and Bus Count, where you follow people getting on and off at each stop and say how many are left on the bus.

The daily Brain Dojo Check has three areas, Processing Speed, Inhibitory Control and Working Memory. For Working Memory, one task is chosen from a set that includes remembering positions shown in sequence and entering digits in reverse order. The tasks are simplified app versions of tasks used in research, and the result is not a medical diagnosis. Your score should go up as you keep doing it, but as the research above suggests, most of that likely comes from getting used to the tasks. It can serve as a gauge of how you are doing day to day.

Every training except the newest ones is free to play, and so are Today’s Training, the Brain Dojo Check once a day, and a calendar where you stamp the days you trained. The free version shows ads. BrainDojo Plus removes them and opens the new trainings anytime. When a new training appears in Today’s Training, you can play it free that day.

Getting Started with BrainDojo walks through the first session, and BrainDojo Free vs Plus compares the two plans.