The purpose of this paper is to present an in-depth treatment of current theory and research on human memory. In particular, the focus of the paper is on long-term, semantic memory. The treatment begins with a basic definition and delineation of components in human memory systems. After basic terms are defined, the paper presents an explication of current theory and research on semantic memory. In this regard, information on the two basic types of theoretical models of semantic memory are delineated and discussed.
This delineation is followed by a brief review of some empirical investigations of human memory in general and semantic memory in particular, with an emphasis upon information loss or forgetting. This area of the vast body of empirical research was selected because, current thought in the literature held that it was the area most in need of further work, and it is not amply covered by the existing theoretical models of semantic memory.
In 1890, William James observed that there appeared to be two distinct kinds of human memory, a kind that was fleeting and another, more permanent kind:
The stream of thought flows on, but most of its elements fall into the bottomless pit of oblivion. Of some, no element survives the instant of its passage. Of others, it is confined to a few moments, hours, or days. Others, again, leave vestiges which are indestructible, and by means of which may be recalled as long as life endures. Can we explain these differences?
James' observances have now come to be known as short-term and long-term memory systems, where "memory systems" may be defined as those mechanisms and processes that allow an individual to retain information over time (Bourne, Dominowski, Loftus & Healy, 1986).
According to Koch & Leary (1985), memory systems have three basic aspects: (1) encoding which is the way information is stored or represented in the system; (2) retention which is the way informa...