Working memory is a system that provides short-term storage of information used in complex cognitive activities such as planning, reasoning, problem-solving, and language. This mental blackboard is a temporary workspace that makes possible the examination, manipulation, and tranformation of internally represented information during these cognitive activities—and also allows its subsequent erasure.

Suppose you ordered three bottles of mineral water at $1.80 a bottle and gave the waiter ten dollars. How much change would you expect? Working this out would likely involve retaining the results of your initial calculations while performing other operations, storing interim results for which you would have no need after arriving at the answer and the details of which would likely escape you upon subsequent inquiry. The temporary storage and manipulation of information required to perform this and many similar tasks is working memory.

Short-Term Versus Working Memory

Researchers have long...