Short-term memory and long-term memory are still different

Abstract

A commonly expressed view is that short-term memory (STM) is nothing more than activated long-term memory. If true, this would overturn a central tenet of cognitive psychology-the idea that there are functionally and neurobiologically distinct short- and long-term stores. Here I present an updated case for a separation between short- and long-term stores, focusing on the computational demands placed on any STM system. STM must support memory for previously unencountered information, the storage of multiple tokens of the same type, and variable binding. None of these can be achieved simply by activating long-term memory. For example, even a simple sequence of digits such as "1, 3, 1" where there are 2 tokens of the digit "1" cannot be stored in the correct order simply by activating the representations of the digits "1" and "3" in LTM. I also review recent neuroimaging data that has been presented as evidence that STM is activated LTM and show that these data are exactly what one would expect to see based on a conventional 2-store view. (PsycINFO Database Record

Figure 1

(A) Atkinson and Shiffrin’s (1971) model of STM. (B) Baddeley and Hitch’s working memory model (Baddeley, 2000). (C) Cowan’s (1988) model of memory and attention. (D) Oberauer’s (2002) model of working memory. Nodes and lines correspond to long-term memory representations. Black nodes are activated. Nodes within the large oval are in the direct access region. One node is in the focus of attention.