Guide
Working memory: what it is and how it works
Working memory is the mind’s workbench: where you keep a few pieces of information active for a few seconds while you use them. Working out change, following directions, repeating a phone number until you write it down. All of it goes through working memory.
What working memory is
The term was popularised by psychologists Alan Baddeley and Graham Hitch in 1974. Their model has three parts: a phonological loop that holds sounds and words (the inner voice repeating a number), a visuospatial sketchpad that holds images and positions (where the button was, which shape lit up), and a central executive that divides attention between them. In 2000, Baddeley added an episodic buffer that binds information together and links it to long-term memory.
When you play Simon or take the memory test, you mainly use the visuospatial sketchpad. If you name the shapes in your head, the phonological loop joins in.
How much fits: 7 or 4?
The famous “7 plus or minus 2” comes from a 1956 paper by George Miller. More recent estimates (Cowan, 2001) show that when people cannot rehearse or group information, real capacity is closer to 3–5 items.
The difference is chunking. “FBI-CIA-NASA” is 11 letters but only 3 chunks for someone who knows them. Experts seem to have huge working memory in their field because they chunk better, not because they have “more room”.
Working memory vs short-term vs long-term memory
| Type | What it does | How long it lasts |
|---|---|---|
| Short-term memory | Passively holds a few items | Seconds |
| Working memory | Holds and processes: compare, calculate, reorder | Seconds, while in use |
| Long-term memory | Stores facts, events, skills | Hours to a lifetime |
In practice, the line between short-term and working memory is not strict. Many researchers use the terms almost interchangeably, with “working” stressing that the information is also being processed.
How it is measured
- Digit span: repeat a string of digits forwards or backwards.
- Corsi test: the examiner taps a series of blocks and you repeat the order. The typical span is about 5–6.
- N-back: say whether the current item matches the one N steps back.
- Complex span: remember a list while solving another task between items.
Memory Flash uses the structure of a span test: the sequence grows until your first mistake. It is not a clinical test, but it shows, on the same principle, how far you can go.
Where you use it every day
- Holding a code from a text message until you type it.
- Following a recipe without checking every step.
- Doing mental arithmetic at the shops.
- Following a conversation and holding your point until it is your turn to speak.
- At school: reading comprehension, maths problems, taking notes while listening.
Can working memory be trained?
Yes and no. Practising a working-memory task clearly makes you better at it and at very similar tasks. This is near transfer, and a meta-analysis of 47 studies (Schwaighofer et al., 2015) confirmed it.
Far transfer, meaning higher intelligence, better grades or better memory in general, is small or absent in well-controlled studies (Melby-Lervåg et al., 2016). So a memory game is a good way to measure and practise working memory, not a shortcut to a “better brain”. For that, sleep, exercise and active learning have stronger evidence.
What affects it
- Stress and anxiety fill part of working memory with worries.
- Too little sleep lowers attention and, with it, how much you can hold.
- Multitasking splits capacity between tasks and makes all of them worse.
- Age: capacity grows through childhood and adolescence and declines slowly after 60, with big differences between people.
Frequently asked questions
What is the difference between working memory and short-term memory?
Short-term memory just holds a few items for a few seconds. Working memory holds them and processes them: you compare, calculate, reorder.
How many items can working memory hold?
Around 3–5 chunks by current estimates. With grouping and rehearsal you can hold longer strings, which is where the classic figure of 7±2 comes from.
Does poor working memory mean ADHD or dyslexia?
Not necessarily. Working-memory difficulties are common in ADHD and some learning disorders, but a low score in a game is not a diagnosis. Assessment is done by a specialist.
How can I test my working memory?
Online, you can try a span-style test such as the memory test on this site. A clinical assessment uses standardised tests given by a psychologist.
Sources
- Baddeley & Hitch (1974). Working memory. Psychology of Learning and Motivation, 8.
- Baddeley (2000). The episodic buffer: a new component of working memory? Trends in Cognitive Sciences, 4(11).
- Miller (1956). The magical number seven, plus or minus two. Psychological Review, 63(2).
- Cowan (2001). The magical number 4 in short-term memory. Behavioral and Brain Sciences, 24(1).
- Kessels, van Zandvoort, Postma, Kappelle & de Haan (2000). The Corsi Block-Tapping Task: standardization and normative data. Applied Neuropsychology, 7(4).
- Schwaighofer, Fischer & Bühner (2015). Does working memory training transfer? A meta-analysis including training conditions as moderators. Educational Psychologist, 50(2).
- Melby-Lervåg, Redick & Hulme (2016). Working memory training does not improve performance on measures of intelligence or other measures of “far transfer”. Perspectives on Psychological Science, 11(4).