1. as originally described in 1960 by U.S. cognitive psychologist George Armitage Miller, U.S. experimental psychologist Eugene Galanter (1924–  ), and Austrian-born U.S. neuropsychologist Karl H. Pribram, any of various hypothetical systems involved in the brief retention of information in a highly accessible state. The term has evolved, however, to refer primarily to the 1974 model of British cognitive psychologists Alan D. Baddeley (1934–  ) and Graham J. Hitch (1946–  ) for the short-term maintenance and manipulation of information necessary for performing complex cognitive tasks such as learning, reasoning, and comprehension. According to their multicomponent conceptualization, working memory comprises a phonological loop for temporarily manipulating and storing speech-based information and a visuospatial sketchpad that performs a similar function for visual and spatial information. Both are supervised by a limited capacity central executive, a control system responsible for the distribution of attention and general coordination of ongoing processes. A fourth component, the episodic buffer, was added to the model in 2000; it binds together information about the same stimulus or event from the different subsidiary systems to form an integrated representation that is essential to long-term memory storage.

The Baddeley and Hitch working memory model, which introduced an element of assessment and planning into the memory mechanism, has replaced the idea of a unitary short-term memory system and become one of the most influential and well-known concepts within memory psychology, continuing to stimulate research and debate some 40 years after its introduction. Indeed, the model has proved valuable in accounting for experimental data from a wide range of participants under a rich array of task conditions. Current interest focuses most strongly on the link between working memory and long-term memory and on the processes allowing the integration of information from the component subsystems.

2. in animal cognition, a temporally based representation of an object, stimulus, or spatial location that is used within a single trial of an experimental session to guide behavior. Delayed matching to sample, maze running, and various other tasks involving conditional discrimination are commonly used to assess working memory in nonhuman animals. For example, a rat searching a radial maze, the arms of which radiate outward from a center platform like spokes of a wheel, for a single food pellet at the end of each arm relies on working memory to retain information about which arms have already been entered so as to avoid repeating any arm while searching. Compare reference memory. [initially described in 1978 by German-born U.S. psychologist Werner Konstantin Honig (1932–2001) and subsequently elaborated by U.S. physiological psychologist David Stuart Olton (1943–1994) and various colleagues]

3. in computing, see production system.