What is working memory? It is the mental workspace that holds a few pieces of information while you use them, like keeping a total in your head while you add the next number. Psychologist Nelson Cowan calls it "the few temporarily active thoughts," with a core limit of about 3 to 5 meaningful items in young adults.
Picture a small desk next to a big filing cabinet. The filing cabinet is your long-term memory: your address, how to ride a bike, the plot of a favorite film. The desk is your working memory, where you lay out the few things you need for the job in front of you right now.
The desk is small, and things slide off it quickly when you get interrupted. That is why you can forget a phone number between reading it and dialing it, or lose the thread of a sentence when someone calls your name.
It is also not the same for everyone. Cowan's review notes that working memory capacity varies among people and changes across the life span.
Cowan gives three classic examples. Each one is a moment where you must hold something in mind while doing something else with it:
Understanding language: keeping the ideas from the start of a long sentence so they make sense when the end arrives.
Mental math: carrying a digit from the ones column to the tens column while remembering the other numbers.
Planning: working out the best order to visit the bank, the library and the grocery store.
You use it all day in other small ways too:
Typing a six-digit sign-in code from one app into another.
Following spoken directions, like "left at the light, then the second right."
Cooking while you track which ingredients are already in the bowl.
Holding your point in a meeting while someone else finishes talking.
A famous 1956 paper by George Miller suggested people can repeat back about seven items. Later research told a more modest story. Cowan's review explains that young adults can recall only 3 or 4 longer chunks, such as idioms or short sentences, and that the central limit looks like about 3 to 5 meaningful items when tricks like silent repeating and grouping are blocked.
The good news is that a "chunk" can be bigger than one item. Grouping things lets more fit into each slot. Cowan's example: to remember to buy bread, milk and pepper, picture bread floating in peppery milk. Phone numbers work the same way. Ten loose digits are hard, but three groups of numbers are easier.
Many apps and programs promise to boost working memory. A 2016 meta-analysis by Melby-Lervåg, Redick and Hulme looked at 87 publications with 145 experimental comparisons. Right after training, people reliably improved on other working memory tests. But for "far transfer" measures, such as reading comprehension, arithmetic, and verbal and nonverbal ability, there was no convincing evidence of reliable gains compared with an active control group.
The authors concluded that working memory training programs appear to produce short-term, specific effects that do not carry over to real-world thinking skills. In plain English: you get better at the game. That does not mean you will remember shopping lists better. Play memory games because you enjoy them, not as a fix.
Because the workspace is small, the most reliable strategy is to ask less of it:
Write it down right away. A note on paper or your phone frees up a slot. Our sister site's guide to doing a brain dump shows how to clear your head fast.
Do one thing at a time. The American Psychological Association reports that the mental blocks created by shifting between tasks can cost as much as 40 percent of someone's productive time. Every switch also means remembering where you were.
Break tasks into written steps. A checklist holds the plan so your head does not have to.
Chunk and picture it. Group numbers, and turn lists into one silly image.
Repeat it back. Saying "So, left at the light, then second right?" gives you a second pass and a chance to catch mistakes.
Protect your sleep. The National Heart, Lung, and Blood Institute (NHLBI) says sleep deficiency can bring trouble making decisions, solving problems and remembering things.
Example desk routine for a busy day: keep a notepad by your keyboard, write down any task the moment it pops up, finish the current step, then check the pad. This is an example only, so adapt it to your work.
This is general information, not medical advice. Talk to your doctor or pharmacist about your own situation. Everyone loses track sometimes. If forgetting instructions, losing your place in conversations or juggling steps is getting in the way of work, school or home life, talk to a doctor or another qualified professional who can help work out what is going on.
Adding numbers in your head while carrying a digit, holding the start of a long sentence until the end, or planning the order of your errands. Typing a code you just read is another everyday example.
The old estimate was about seven. Cowan's review points to a core limit of about 3 to 5 meaningful items, or chunks, in young adults. Chunking lets you pack more into each one.
They can raise scores on similar memory tasks right after training. A 2016 meta-analysis found no convincing evidence that the gains carried over to things like reading comprehension or arithmetic.
Poor sleep affects thinking in general. The NHLBI says sleep deficiency can cause problems with learning, focusing and reacting, along with trouble remembering things.
If you enjoy short memory and logic challenges, SkillArena: Focus Training offers a free daily session of four short games in about four minutes, drawn from thirteen games covering attention, memory, logic, numbers, reading and wording. Its skill ratings are not an IQ score or a medical or clinical assessment, so treat it as a fun daily game rather than a working memory fix. There is no account and no ads, and your progress stays on your device.
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Multitasking: Switching costs (American Psychological Association)
Sleep Deprivation and Deficiency: How Sleep Affects Your Health (NHLBI)