MSM of memory

What is the MSM?

First described by Atkinson and Shiffrin (1968) with the key feature of the model being 3 different stores that differ in capacity, duration and encoding.
Sensory - information collected by the senses. Most of the time, informaiton does not get attention and remains in the sensory store for a breif period. If attention is payed, the data is transfered to the STM.
STM - for events in the present or immediate past. Informaiton held here disappears very quickly if it is not rehersed. The more something is rehersed the more lasting the memory is. If new information enters, original data will be displaced. Has limited capacity of 4-7 chunks.
LTM - for events that have happened in the more distant past. Direct relationshop between rehersal in STM and strength of LTM (the more it is rehersed, the better it will be remembered).

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Peterson and Peterson (1958) - testsed duration of STM using costant slylales followed by a 3 digit number. Immediately after hearing participants had to count down in 3s then asked to recall the constant syllable. Participants remembered 90% when had 3 second interval and 2% when there was a 18 second interval. Led to conclusion that STM lasts around 20 seconds.
However, not valid. Low ecological validty causing participants to behave differently to normal. Therefore results may not be reliable and accurate to use as a basis for other studies.
Bahrick et al (1975) - conducted natural experiment to test duraiton of LTM. Asked participants of various ages to put names to faces in their high school year book; 48 years later about 70% of people were accurate. Due to being meaningful.
Study is valid as has high ecological validity from being a NE, however, variables are not closely controlled. May still be in contant with most people from school.

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Simon (1974) - found that the size of the 'chunk' in STM does effect memory; remember better if they are short.
To demonstate existance of seperate stores is to link specific memory to different parts of the brain.
Beardsley (1997) - found that the prefrontal cortex is active when individuals work on STM task.
Squire et al (1992) - hippocampus is involved when LTM is engaged.
Both studies can be reliable as use brain scanning. However, depends on how the partcipants were gathered, e.g. if a volunteer example, it will be biased.

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Logie (1999) - STM actually relies on LTM so cannot 'come first' as suggested in MSM.
May oversimplify memory process. For example, research evidence shows that LTM can be split into several types such as semantic, episodic and procedural.
In conclusion, MSM has supportive and contridictory evidence. It was the first testible model of memory however, critics claim it is too simple.

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