Free 860 words essay on HUMAN MEMORY for school and college students.
This paper is a discussion of various aspects of the human memory. Human memory is one of the things that have baffled psychologists for eons. However, researches have been intense, and some light has been thrown into this area. This has generated a lot of insight, with resultant theories, models and approaches being advanced to attempt an explanation of the working of the human memory. This paper will look at two models- the multi store memory model proposing possibility of segmentation of the human memory into short and long term, and the working memory model. There are three concepts that will be explained before we proceed. Encoding is the transformation of information so that it can be kept or stored in the memory. Duration refers to the time span that information remains stored in the memory, while capacity refers to how much information can be stored in the memory.
1.Multi-Store Memory Model
- Short-term Memory
This is the memory that is concerned with ephemeral recall of information that is being processed. In other words, it acts as a scratch pad for information waiting processing. In terms of duration, it has short span of operation, and decays very fast in about 300 milliseconds. However, skills such as chunking can lengthen the span of information storage. Chunking means the process of breaking down information into smaller parts, making it easier to remember. Encoding is mainly visual or acoustic. The capacity is 7 (+/-2) items.
- Long–term Memory
This is the part is the part that is concerned with long term memory of information. Information is transferred from the working memory into it every few seconds. In this, there is appreciably little decay of information. Encoding is basically semantic, and the duration is over 100years. The capacity however, has no upper limit. Anderson conducted some experiments in which his subjects were to memorize sentences. Some of the sentences were to be studied longer than others. They were also required to discriminate those sentences that they memorized from distractions. In each sentence they were to be tested more times than one, with distractions of other sentences. It was found that the length of study and time of access from the time the material was learnt affect learning. The length of study, however, only mattered in as far the information was accessed after a long period.
Some of the strengths of this model include the fact the suggestion of existence of separate stores makes us understand why some parts of the brain can be damaged without affecting the operation of others. Additionally, we are able to tell why some people remember some things more easily than others. Finally the primacy and recency effect lends support to it.
However, some of the weaknesses include its oversimplification on account of the fact that other research suggests existence of other short term memory stores, and also many long term memory stores. Also, the phenomenon of flashbulb memories is not addressed by this model. Finally, the fact that most experiments are done in the lab set up raises the question of the ecological validity of this model.
2. Working Memory Model
This model was described by Graham Hitch and Allan Baddeley in 1974. It was an improvement of the Atkinson-Shiffin multi-store model which the duo believed lacked in detail specifically the short term memory store. The model consists of four major sections. These are divided into two systems i.e. the supervisory system which is the central executive, and the slave systems consisting of three i.e. the Visuo-Spatial sketch-pad, the Phonological Loop and the Episodic Buffer.
The Phonological Loop is comprised of the articulatory control system and the phonological store-what are referred to as the inner voice and the inner ear respectively (These are not the physical anatomical ear canals). The articulatory control system brings revival of the memory cues with auditory stimuli perceived to enter directly to the phonological store. This store keeps information through a sound code which decays within a few seconds (2 seconds). This input generates from LTM.
In terms of strengths, it is more realistic in the sense that it creates provision for manipulation of information especially in the face of problems and challenges. Secondly it can be argued to be more plausible than the multi-store memory model in which the short term memory is considered a stationary store. In contrast, this model brings out the short term memory as a dynamic process. This model begins with a process in which visualization of every window corresponding with the visual-spatial sketchpad. This brings into focus the phonological loop, whilst the central executive is mandated with the action of making all co-ordination in this activity.
However, this model has a number of weaknesses too. To begin with, the central executive, the primary area of operation in this model is obscurely explained and is not well understood. The functions thus are difficult to test. Secondly, the proponents of this theory state that the central executive only has a limited capacity, but it is not possible to separate it so that a conclusive result can be arrived at. Finally, the Episodic Buffer is not clear enough on how it integrates information from STM and STM.