Working Memory

Conceptualizations of Working Memory

Although researchers agree that working memory is important, different investigators seem to mean slightly different things when they refer to working memory, a point that has caused some confusion in the field. Some researchers include information that comes from any source, even guidelines that one gets from long-term knowledge. An example would be remembering which name goes with which face when one has met several new people. Some of this information will not be held in the conscious mind throughout, say, an hour-long event, but it is newly memorized information that may be easy to retrieve for the time being because one is still in the same context or situation as when the names and faces were first encountered. Other researchers restrict the term working memory to information that is in an active state, that is, in which one is currently thinking of the information, such as when one is currently looking for three kinds of fruit at the grocery store. For some researchers, working memory implies that one is actively doing processing while holding the information in mind. An example is a task in which one must remember the names of five individuals who were presented in a random order but must write the names in alphabetical order. These researchers use the term short-term memory when one is only holding the information, not also carrying out a process or manipulation of it. For other researchers, however, short-term memory and working memory are considered two labels for the same kind of memory, namely, any temporarily held information. This can also be called immediate memory.

Theories of Working Memory

In 1974, Alan Baddeley and Graham Hitch published a book chapter that has been seminal in this field. Previous to their work, authors found it sufficient to think of one mechanism for short-term memory, represented as a box in a flow diagram that represented the progression of information from sensory memory to short-term memory to long-term memory. If that were the case, however, then there should be severe interference if one had to use short-term memory in two ways at once, such as remembering a list of seven numbers while concurrently carrying out a reasoning problem that involved remembering premises and deducing some point from them. Instead, this kind of task produced only minimal interference. Baddeley and Hitch instead found that the conflict between such [Page 1828]tasks was slight. They proposed that the term working memory should be used and that it involves multiple components working together. A phonological store and a visuospatial store (or buffer) were said to be involved in saving verbal and nonverbal and visual materials, respectively. A central executive component was needed to regulate the flow of information between the stores. In 2000, Baddeley added another component to the theory called the episodic buffer, needed to link two different kinds of information together or to hold meanings in working memory.

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