Short-Term Memory

This chapter presents an overview of short-term memory. There is a clear limit to the amount of verbal material that can be retained in memory for long enough to reproduce it exactly. This restriction, in what has become known as the span of apprehension, was first investigated in the 19th century. More recently, performance on span tasks has been interpreted as a measure of short-term memory. The evidence from neuropsychological analyses has indicated that there are several dissociable short-term memory systems. Furthermore, selective disorders of these systems have relatively good localizing significance. The following five possible functional roles for auditory–verbal span have been considered: (1) it has been established that short-term memory is not a gateway to the longer-term storage of information, (2) it is not a necessary component of general verbal problem solving abilities, (3) it is not a necessary component of normal fluent language production, (4) the view that the verbatim record provided by span is a necessary component of normal sentence comprehension has been seriously questioned, and (5) it has been suggested that this record may have a role as a backup resource when backtracking over a spoken message is required.