Working memory

What it means

Working memory is the limited-capacity system that temporarily holds and actively works with the information needed for reasoning, comprehension, learning, and planning. In the influential Baddeley and Hitch model it is not a single store but a set of components — a central executive that allocates attention, plus a phonological loop for verbal material and a visuospatial sketchpad for visual and spatial material, later joined by an episodic buffer. Its capacity is famously narrow, often summarized as a handful of 'chunks,' and this bottleneck is one of the central constraints on cognition: when the contents to be juggled exceed capacity, performance on reasoning and self-control degrades. The system distinguishes mere short-term storage from the manipulation of held information, which is why it predicts fluid intelligence and academic achievement better than passive memory span. It is taxed by cognitive load and competes with other demands, which is why distraction and stress impair thinking. It matters because almost every complex task runs through this small workspace, so designs that reduce load — chunking, simplification, external aids — directly improve performance.