– A representation of how memory works based on three separate memory stores (sensory register, short term memory and long term memory) and how information is processed between these stores
DESCRIPTION
– Richard Atkinson and Richard Shiffrin (1968) presented the concept of the multi-store model which describes how information flows through the memory system.
– The model suggests the memory is made up of three stores linked by processing.
SENSORY REGISTER
– The ‘sensory store’
– A stimulus from the environment will pass into the sensory register where it will be sorted into one of five stores.
– One of two main stores are called iconic memory where visual information is coded visually
– The second is echoic memory where auditory information is encoded acoustically
– The duration is less than half a second
– Very high capacity
– Very little of the sensory register goes further into the memory system unless you pay attention
Attention
– If a person’s attention is focused on one of the sensory stores, the data is transferred to STM
– Attention is the first step in remembering something
SHORT TERM MEMORY
– STM is known as a limited capacity store, because it can only contain between 5 to 9 items of information before forgetting takes place. (Unless rehearsal takes place)
– Information will disappear from the STM when new information enters the STM, displacing the original information
– Information in STM is coded acoustically and lasts about 30 seconds unless it is rehearsed.
– Information is held in STM to help with immediate tasks
Maintenance Rehearsal
– Repetition keeps information in the STM but can also create a long term memory
– Atkinson and Shiffrin proposed a direct relationship between rehearsal in STM and the strength of the LTM
– The more information that is rehearsed, the better it is remembered
LONG TERM MEMORY
– LTM is a potentially permanent store for information that has been rehearsed for a prolonged time and so its capacity is unlimited.
– LTMs tend to be coded semantically which means in terms of meaning.
Retrieval
-When we want to recall material that has been stored in LTM, it has to be transferred back into STM by a process called retrieval.
-According to the multi-store model, none of our memories can be recalled directly from LTM, it has to be through the STM
EVALUATION OF THE MSM
STRENGTH
Research Support
– Research shows that STM and LTM are qualitatively different
– For example, Baddeley showed that we tend to mix up words that sound similar in our STM. But we mix up words that have similar meanings in our LTM.
– This clearly shows that coding in STM is acoustic and in LTM it is semantic.
– So, they are different which supports the idea that in the multi-store memory model the two memory stores are separate and independent.
Case Study Support – HM
– Psychologists have also shown that different areas of the brain are involved in STM and LTM from their study of individuals with brain damage
– One case was a man referred to as HM
– His brain damage was caused by an operation to remove the hippocampus from both sides of his brain to reduce the severe epilepsy he had suffered.
– HM’s personality and intellect remained intact but he could not form new long-term memories
– Although he could remember things from before the surgery.
– This provides support for the MSM’s notion of separate stores, as he was unable to transfer information from his STM to his LTM but was able to retrieve information from before his surgery from his LTM into his STM
LIMITATIONS
There is more than one type of STM
– The multi-store model states that there is only one type of STM.
– However, evidence from people suffering from amnesia show that this cannot be true.
– For example, a patient called KF who had amnesia.
– Psychologists found that his STM for digits was very poor when they read them out loud to him.
– But his recall was much better when he was able to read the digits to himself.
– This suggests that there must be one store to process visual information and another for auditory information and therefore a limitation of the MSM.
There is more than one type of rehearsal
– According to the MSM, what matters in rehearsal is the amount of it that you do.
– However, psychologists found that what matters is actually the type of rehearsal. They discovered that there are two types of rehearsals.
– Maintenance is the type described in the MSM but this does not transfer information into LTM, it just maintains it in STM.
– Elaborative rehearsal is needed for long-term storage, which occurs when you link information to your existing knowledge.
– This is a limitation of the MSM because it is another research finding that cannot be explained by the model.