P Through T: “Short-Term Memory and Long-Term Memory Are Still Different”
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.
Indeed, the big challenge for any model that might be based purely on activation of LTM would be to make it work. The possibility that an STS might be based on pointers rather than copies has a number of interesting implications. If the pointers address representations in LTS then this would greatly complicate the relationship between STS and LTS. However, pointers might also operate within the bounds of a self-contained modality-specific STS. As we will see, the advantage of this option is that it can make very efficient use of the available storage capacity. Far from blurring the lines between STS and LTS, consideration of how a pointer system might work actually reinforces the case for modality-specific short-term stores.
The scientific study of memory is usually traced back to Hermann Ebbinghaus (1885/1913 translation), who examined his own acquisition and forgetting of new information in the form of series of nonsense syllables tested at various periods upto 31 days. Among many important observations, Ebbinghaus noticed that he often had a “first fleeting grasp … of the series in moments of special concentration” (p. 33) but that this immediate memory did not ensure that the series had been memorized in a way that would allow its recall later on. Stable memorization sometimes required further repetitions of the series. Soon afterward, James (1890) proposed a distinction between primary memory, the small amount of information held as the trailing edge of the conscious present, and secondary memory, the vast body of knowledge stored over a lifetime. The primary memory of James is like the first fleeting grasp of Ebbinghaus. The Industrial Revolution made some new demands on what James (1890) called primary memory.
Disease and injury can also have an influence on the ability to store short-term memories as well as convert them into long-term memories. As researchers continue to learn more about factors that influence memory, new ways of enhancing and protecting short-term memory may continue to emerge.
Ebbinghaus H. Translated by H.A. Ruger and C.E. Bussenius. New York: Teachers College, Columbia University; 18851913. Memory: a contribution to experimental psychology.
James W. The Principles of Psychology. New York: Henry Holt; 1890.
Nipher FE. On the distribution of errors in numbers written from memory. Trans. Acad. Sci. St. Louis. 1878;3:ccx–ccxi.
Tzeng OJL. Positive recency effect in a delayed free recall. J. Verbal Learn. Verbal Behav. 1973