Working memory is the system that holds and manipulates information for a few seconds while you use it, for example when doing mental arithmetic or following directions. A working memory test measures how much of it you can use.
The Baddeley and Hitch model
Proposed in 1974, it splits working memory into a central executive that directs attention and two stores: the phonological loop for verbal material and the visuospatial sketchpad for images and positions. Baddeley added the episodic buffer in 2000.
How much fits?
Miller wrote of “7 ± 2” items in 1956. Today the estimate is about 4 when rehearsal and grouping are not possible. On digit span, a young adult repeats about 6 to 7 digits forwards and 5 backwards.
How to test it
The classic tasks are digit span and Corsi blocks, forwards and backwards. Try them in our memory test, compared with age norms.
How much it holds
In 1956 George Miller wrote of “the magical number seven, plus or minus two”. We now know that figure included tricks such as chunking; without them, capacity is about four items, according to Nelson Cowan’s 2001 review.
Working memory in daily life
- Doing a sum in your head.
- Remembering a phone number while you dial it.
- Following a conversation while planning your reply.
- Reading a long paragraph without losing the thread.
Can you train it?
Training programmes improve the task you practise but transfer little to other abilities. What does help is cutting distractions, sleeping well and using notes when the task allows.
Frequently asked questions
Can working memory be trained?
Practice improves the trained tasks, but meta-analyses find little transfer to other abilities.
How many items can working memory hold?
About four without strategies such as chunking; Miller’s “seven plus or minus two” included those strategies.
Sources
- Baddeley, A. D. & Hitch, G. (1974). Working memory. Psychology of Learning and Motivation, 8, 47–89.
- Miller, G. A. (1956). The magical number seven, plus or minus two. Psychological Review, 63(2), 81–97.
- Cowan, N. (2001). The magical number 4 in short-term memory. Behavioral and Brain Sciences, 24(1), 87–114.