y system" (Morris & Conway, 1993, p. xx). The basic conceptualization of the general system of memory, as consisting of sensory registers, or 'buffers,' short-term, or working, memory, and long-term memory, has been widely accepted, but functions primarily as a starting point for other interpretations of the structure of the memory system.
The use of the single term "memory," may suggest that memory is "a unitary system, albeit a complicated one" (Baddeley, 1990, p. 4). But a system is any discrete entity that has inputs and outputs, and internal processes peculiar to the system's functions. Thus, memory "is not one system but many" (Baddeley, 1990, p. 4). These memory systems vary greatly--ranging in storage duration from "fractions of a second up to a lifetime," and possessing storage capacities that range from tiny bits of information in the sensory register to the long-term memory system's enormous capacity, which far exceeds that of any computer in the world (Baddeley, 1990, p. 4). As Cohen noted, however, there are some psychologists who feel that this emphasis on numerous systems of memory has produced "demarcations that are artificial [and they] claim that human behaviour can only be understood as an integrated unitary system" (1989, p. 6). But, even though these various systems "can be understood as separate and independent entities," none of them functions alone, and to speak of a general memory system is accurate, even if it is not particularly useful to researchers (Cohen, 1986, p. 6).
The general memory system can be defined as consisting of three basic components that are involved in three basic, connecting processes. At this minimum level of agreement, therefore, sensory information is taken in and relegated, briefly, to "very short-term, modality specific, memory systems," sometimes known as buffers (Estes, 1987, p. 14). The sensory information in the buffers is then selected for processing into the short...