The multi-store model of memory

Multi-store model was described my Atkinson and Shriffin (1968). It consists of 3 stores, the sensory memory, short-term memory & long-term memory. 
The sensory store is collects information which is collected by your eyes, ears, nose, fingers, tongue and etc. Information is retainted for a very brief amount of time. It stores information for about 0.5 seconds. 

STM:

• Information in STM will decay quickly if it isn't rehearsed.
• It will also disappear if new information enters the STM, therefore displacing the orginal information, this is because STM has a limited capacity. (7±2 chunks)
• Information is kept in STM throughout maintenance rehearsal which is usually verbal. 

STM to LTM:

• Information is transferred to LTM throughout elabroative rehearsal.

Multi-store model is a description of how memonry works in terms of three 'unitary' stores; your sensory memory, short-term memory and long-term memory. Attention and rehearsal is how information is transferred.  

There is strong evidence for thre seperate stores.

The sensory memory/store:

• Evidence to show the duration of the sensory store was collected in a study by Sperling (1960).
• Participants were shown a grid of digits and letters for 50 milliseconds.
• When they were asked to recall the whole thing in order, recall was poorer than when asked to give one row only.
• This showed that information decays quickly in the sensory store. 

The serial position effect:

• Research which was conducted showed that words from the start of the list (primacy effect) and the words from the end of the list (recency effect) were much easier to recall then words in the middle. 
• The primacy effect occurs because the first words were best rehearsed.
• The recency effect occurs because these words are in STM when you start recalling the list  

Case Study of patient HM:

• Scoville and Milner (1957) conducted research on patient HM who suffered brain damage.
• His brain damage was caused by an operation to remove the hippocampus.
• HM's personality and intelect remained the same as before but he couldn't form any new long term memories.
• This suggeseted that the hippocampis may function as a memory 'gateway' through which new memories must pass before entering long-term memory storage. 

Another strength of MSM is that the model provides an account of memory in both structure and process. The structure is the 3 stores, and the processes are attention and verbal rehearsal.

Thirdly, the MSM shows clear predictions about memory which means psychologists can conduct studies to test it.  

Main cricism of the MSM is that it oversimplifies memory structures and processes.

Structures: STM and LTM are not unitary stores:

• Case study of KF (1970); KF suffered brain damage which resulted in difficulty in dealing with verbal information in STM but a normal ability to process visual information. This suggests that STM is not a unitary store.
• MSM describes LTM as one single store whereas evidence from patients with amnesia indicates that there are different kinds of long-term memory. Schachter et al (2000) have suggested there are 4 long-term memory stores.

Processes: Rehearsal verssus processing. :

• Research has also show maintenance rehearsal (repeating things) is not the only way long-term memories are made.
• Craik and Tulving (1975) gave participants a list of nouns and asked a question about each word.There were 3 kinds of questions. Shallow processing, phonemic processing or semantic proccesing. 
• Participants remembered most from semantic processing and least from shallow proccesing.

Craik and Lochart has led the MSM replacing 'maintenance rehearsal' with 'elaborative rehearsal'. Maintenance rehearsal involves repeating things, where as elaborative rehearsal involves eeper or more semantic analysis. 

Research (Glenberg et al) has shown that maintenance rehearsal does have some effect of enduring memories but not as much as elaborative rehearsal.