The Need for an Explanation of Human Memory
Discuss the need for an explanation of human memory, which proposes that memory is a set of stages, rather than a single process.
This essay is going to discuss the need for an explanation of human memory, which proposes that memory is a set of stages rather than a single process. Flanagan (1997) defines memory as "the mental function of retaining data, the storage system holding the data, and the data which is retained." It is evident from reviewing the literature that an explanation of memory as a set of stages proves to be more understandable than as a single process, the theories of memory all providing information about how memory is structured and organised and the findings from the research studies inevitably pointing in the direction of memory existing as a set of stages rather than a single process. Therefore these are the areas which are to be outlined in this essay in order to understand the need to explain human memory as a set of stages.
The nature of memory can be explained as a set of stages that are necessary but not sufficient for memory to have taken place. These involve "input" -registering or encoding information, where a memory trace is formed from translating the sensory data, "storage" which is either temporary or permanent and "output" which involves retrieval - memories would be useless unless they could be retrieved. It is these stages that form the fundamental characteristics of the process of memory and in order for this to occur it is necessary for the data to become engaged in the memory structure. Memory structure can be separated into three distinct categories, sensory memory (input store) where the sensory data remains unchanged in the mind for a brief time but is rapidly lost through decay; short -term memory- which has a relatively limited capacity (approximately seven items) with rapid decay being prevented through rehearsal and finally long-term memory which is a relatively permanent storage system with an apparent unlimited capacity with information being held in enactive, iconic or symbolic form. The evidence for separate stores comes from empirical studies of duration, capacity, coding differences, serial position effect, brain damage and forgetting.
In regard to duration there have been several studies that indicate separate stages, Sperling (1960) briefly showed participants a display of twelve letters organised in three rows and asked them to immediately recall the letters. It was found that if a tone was presented after the display signalling which row to report "recall was three times better demonstrating that available information disappears very rapidly". This study demonstrates the existence of a sensory memory system where the information is lost through decay. Peterson and Peterson (1959) found that delayed recall of trigams reduces performance from 80% after 3 seconds to 10% after 18 seconds, this is significant in that participants were...