Short-Term Memory as a Processing Shift

Abstract

Models of memory processing were investigated in three experiments on free recall. The results suggest a shift to short-term processing as the amount of information presented is perceived to exceed the capacity of long-term processing. Short-term memory appeared to function as temporary maintenance storage rather than as a necessary initial phase of a sequential processing of information from short-term to long-term memory. The appropriateness of a distinction between short- and long-term memory, the characteristics of short-term memory, and the relationship between short- and long-term memory have been researched and described in terms of information-processing models of memory. The most widely referenced of these models are those of Waugh and Norman (1965) and Atkinson and Shiffrin (1968). These models suggest that information enters a temporary short-term store of limited capacity from which it may be processed into a more permanent long-term store. After the limited capacity of the short-term store is reached, new items enter by displacing older items. Thus, short-term memory is seen as a preliminary stage in a sequential processing of information from short- to longterm memory. Rehearsal can maintain information in short-term memory, but unrehearsed information is rapidly lost. Rehearsal ends during recall, resulting in rapid forgetting from short-term memory. In free recall, the most recently presented information tends to be recalled first, leading to the marked recency peak of the serial-position curve among practiced subjects. That is, the most recently presented items represent recall from the short-term store, and items presented in early and middle serial positions are thought to represent recall from the long-term store. Results from a variety of studies have been offered to support such two-store interpretations of serial-position effects. Although there is research consistent with the models that propose multiple processes, the evidence does not compel an automatic, sequential relationship between short- and long-term memory. Logically, in a