What is working memory?

Definition

Working memory is the cognitive system that holds a small amount of information in mind for a few seconds at a time and lets you do something with it. Holding a phone number in your head while you walk to a different room to write it down is working memory. Holding the start of a sentence in mind while you read the end is working memory. Mental arithmetic is working memory.

It is sometimes confused with short-term memory, but the two are not the same thing. Short-term memory is closer to passive storage; working memory adds the manipulation. Most modern cognitive scientists treat working memory as the active, executive subset of short-term memory rather than as a separate store.

Capacity is small. Most adults can hold roughly four to seven items at once, with the exact number depending on the type of information, your level of fatigue, and what else is competing for attention. The famous "magical number seven, plus or minus two" (Miller, 1956) is the classical reference, though later research has refined the picture.

Why it matters

Working memory is one of the strongest individual predictors of academic achievement (Alloway and Alloway, 2010), correlates substantially with measures of fluid intelligence, and is closely connected to attention. When people describe walking into a room and forgetting why, or losing their place mid-paragraph, working-memory load is a big part of what is happening underneath.

It is also the cognitive function most directly affected by sleep deprivation, stress, and certain conditions including ADHD. Most people notice working memory failures more than any other kind of cognitive lapse because they happen so visibly in the middle of doing something.

How it works in the brain

The standard model of working memory (Baddeley and Hitch, 1974, with later updates) identifies a few subsystems. The phonological loop holds verbal information for a couple of seconds while you rehearse it. The visuospatial sketchpad holds visual and spatial information. The central executive coordinates them and decides what gets attention. A later addition, the episodic buffer, integrates information across these subsystems and links them to long-term memory.

The hardware sits primarily in the prefrontal cortex (especially dorsolateral prefrontal cortex), with parietal and temporal regions doing the storage work for the different content types. Imaging studies consistently show prefrontal activity scales with working-memory load.

How to improve working memory

Working memory is moderately trainable on the specific tasks you train (Klingberg, 2010). Focused practice on tasks like n-back, complex span, or visuospatial recall reliably improves performance on those tasks and on closely related ones. The catch, summarized in the Simons and colleagues (2016) review, is that the gains do not transfer broadly to general intelligence or unrelated skills. Train it for what it specifically does.

The other half of the picture is the boring but powerful one: sleep, exercise, hydration, and stress management all measurably affect working memory in the short term. The fastest way to lose three points of working-memory capacity is to lose two hours of sleep.

Train this with Blanked

Blanked is a free visual memory game built around focused daily practice. Two minutes a day. Six modes that target different visual-memory dimensions. Try the free visual memory test to set a baseline first.

Frequently asked questions

Related terms

• Miller (1956), "The Magical Number Seven, Plus or Minus Two"
• Baddeley & Hitch (1974), "Working Memory"
• Alloway & Alloway (2010), "Investigating the predictive roles of working memory and IQ in academic attainment"
• Klingberg (2010), "Training and plasticity of working memory", Trends in Cognitive Sciences
• Simons et al. (2016), "Do Brain-Training Programs Work?", Psychological Science in the Public Interest