Sensory and Working Memory

Memory researchers traditionally distinguish between two types of transient memory: Sensory memory and short-term (or working) memory. Sensory memories are faithful, veridical, records of original events. They represent literal persistence—the same sensory event simply removed in time. Short-term memories are the active, but analyzed, contents of mind—the stuff of conscious awareness. This chapter reviews the major empirical properties of sensory and short-term memory and discusses the various methodologies that are used to study each. Sensory memories—measured through synchrony judgment tasks, backward masking techniques, or by the Sperling partial report task—last for only a few hundred milliseconds and may accrue as a simple by-product of neural dynamics. Short-term memories—measured through Brown-Peterson distractor task and immediate serial recall—probably last for a second or two but can be maintained indefinitely through rehearsal. Traditional accounts of short-term storage—e.g., the working memory model—have come under attack in recent years. Increasingly, researchers are concluding that remembering over the short-term is cue-driven, much like long-term memory, and that simple notions of rehearsal and decay are unlikely to explain the particulars of short-term forgetting. Keywords: decay; interference; retrieval; sensory memory; short-term memory; temporal distinctiveness; working memory