Alan Baddeley (b. 1934) is one of the most influential memory researchers, best known for developing the multi-component model of working memory that replaced the earlier concept of a unitary short-term store. His model, first proposed with Graham Hitch in 1974 and refined over subsequent decades, provides the most widely used framework for understanding how the mind temporarily holds and manipulates information during complex cognitive tasks.
The Working Memory Model
Baddeley's model includes four components: the central executive (an attentional control system that directs, coordinates, and manages cognitive resources), the phonological loop (a temporary store for verbal and acoustic information, with a rehearsal process that refreshes decaying traces), the visuospatial sketchpad (a temporary store for visual and spatial information), and the episodic buffer (added in 2000, a limited-capacity store that integrates information from the other components and long-term memory into coherent episodes). Each component has limited capacity and handles different types of information.
Baddeley's model has had enormous practical and theoretical impact. It explains why you can remember a phone number while walking (verbal and spatial tasks use different components) but struggle to remember two phone numbers simultaneously (both compete for the phonological loop). It has been applied to understanding reading comprehension, mental arithmetic, reasoning, language acquisition, and educational achievement. Individual differences in working memory capacity — particularly central executive function — predict academic performance, fluid intelligence, and vulnerability to attentional capture.