Multi-Store Model

Who made the MSM?

Atkinson & Shiffrin (1968,71)

How does the MSM suggest memory is made up of?

Sensory register, STM, LTM

How does the MSM describe how memory is stored?

Information transfers from one store to another through processing

What is the sensory register?

Immediately processing stimuli from the environment - compromised of five different stores, one for each sense

What is the coding for the sensory register?

Modality-specific: depends on sense → eg echoic memory store is coded acoustically

What is the sensory register’s capacity?

Very high - eg over 100million cells in one eye each store data

What is the sensory register’s duration?

Less than ½ a second

How is information transferred to and from the sensory register?

To: Stimuli from the environment

From: Further into the memory system if you pay attention to the information

What is STM?

The information we have retained from paying attention

How is STM coded?

Acoustically

What is STM’s capacity?

5-9 items

What is STM’s duration?

18 seconds

How can you extend the duration of STM?

Rehearsal of information

How is information transferred to and from STM?

To: Paying attention to information

From: Prolonged rehearsal of information long enough passes it into LTM.

How does information stay in the STM?

Maintenance rehearsal

What is LTM?

Potentially permanent memory store for information that has been rehearsed for a prolonged period

How is LTM coded?

Semantically

What is LTM’s capacity?

Practically unlimited

What is the duration of LTM?

Potentially up to a lifetime

How is information transferred to and from the LTM?

To: Prolonged rehearsal

From: Retrieving the information transfers it back to STM

Strengths of MSM

• Research support for LTM and STM being seperate x2

• Research support on sensory register

Limitations of MSM

• Meaningless stimuli

• Case of KF disproves MSM

• Lack of clarity over how LTM works

• Oversimplified model

What research support is there for the MSM?

• Baddeley (1966) found that we tend to mix up words that sound similar when using the STM, and words with similar meanings using LTM

• Demonstrates them to be separate, independent, memory stores

What other research support is there for the MSM?

• HM underwent brain surgery to relieve his epilepsy

• His hippocampus was removed from both sides of his brain (procedure was in its infancy, not fully understood → now we know that this is central to memory function)

• He thought it was 1953 when it was 1955, and 27 years old when he was 31

• He couldn’t form new long-term memories, but still performed well on tests of immediate memory span (measure of STM)

• Shows STM and LTM to be separate and independent memory stores

What supporting research is there for the duration of the sensory register?

• Sperling (1960) showed participants a tachistoscope of digits and letters for 50 milliseconds

• They were asked to write down as many items as they could remember, and afterwards they heard a tone that would correspond to a row and after the exposure they should write down the row indicated.

• Their recall of the whole thing was poorer than when asked to give one row

• Whole report: 42% (5/12 items)

• Partial report: 75% (3/4 items)

• Supports MSM as it shows the sensor register has a short duration → partial results were higher as they had less to write down

Why is meaningless stimuli a limitation?

• Many studies that support MSM use artificial stimuli: Jacobs’ using digits, Baddeley using words, and Peterson & Peterson using consonant syllables

• This shows MSM to not be a valid model of how everyday memory works with more meaningful information to remember

How does the case of KF show limitations to the MSM?

• Shallice and Warrington (1970)’s client KF had amnesia

• KF’s STM for digits was very poor when they were read to him, but his recall was good when he read them to himself.

• Suggests MSM is wrong in claiming there is just one STM store processing different types of information

How does the MSM lack in explaining how LTM works?

• Craik and Watkins (1973) found that the type of rehearsal is more important than the amount.

• Elaborative rehearsal, linking information to existing knowledge, is needed for LTM

• This means prolonged rehearsal isn’t required → suggests MSM does not fully explain how LTM storage is achieved

How is the MSM an oversimplified explanation of memory?

• Atkinson and Shiffrin based the MSM on research evidence available at the time that showed STM and LTM to be separate and independent

• However, there has been lots of research to show that STM and LTM are not separate, or that there are more memory stores.