Models of Memory: The multi-store model (MSM)

Question 1

What is “Cognitive” Psychology?

Answer 1

It’s about how our mind deals with information, and our abilities to use that information.

Question 2

What is memory?

Answer 2

The process of storing and retrieving information.

Question 3

What is a model?

Answer 3

It’s not an exact copy, but a representation of something.
Models help us understand how something works.
Models of memory seek to provide a picture of how the whole memory system works, this is by identifying the parts which make up the memory system, indicating what each part does and showing how the parts work together.

Question 4

Who created the multi-store model of memory?

Answer 4

Atkinson and Shiffrin in 1968.

Question 5

What are the key feature of the multi-store model of memory?

Answer 5

There are 3 different types of memory.
The model describes these as “memory stores” = SM (sensory memory, which is also the sensory register), STM, & LTM.
Any stimulus you come across has been in one or more of these stores (in this sequence)
Each store retains a different amount of information (capacity) , in a different way (coding) , and for a different length of time (duration).

Question 6

What is the sensory register?

Answer 6

It receives stimulus from the environment – from the 5 senses.
Coding is modality specific. The two main stores are iconic (visual) and echoic (sound).
The duration is very brief (less than half a second).
High capacity due to million of receptor cells.
Very little goes into STM once passed through the SR – but it will if you pay attention to it.

Question 7

What is short term memory?

Answer 7

A limited capacity and duration store.
Coded acoustically.
We can achieve maintenance rehearsal by repeating information over and over again.
If we rehearse it for long enough it will transfer into our LTM.

Question 8

What is long term memory?

Answer 8

A permanent memory store for information that has been rehearsed for a prolonged period of time.
Unlimited capacity and duration.
Coded semantically.
When we want to recall information from LTM it has to be transferred back into STM, using retrieval.
According to the MSM, no memories are recalled directly from out LTM.

Question 9

What is the process of MSM?

Answer 9

• External information (input) is received through the senses (sound, sight, touch, smell) and enters the sensory register.
• If attention is paid to it, the information is transferred and processed further by the STM store.
• If no attention is paid to it the sensory information is immediately lost or not even processed.
• Material that is rehearsed (maintenance rehearsal) is passed on to the LTM store, where storage takes place.
• When we want to recall information from the LTM it has to be transferred back into the STM, using retrieval.
• Loss can take place from the STM store via decay or displacement, and from the LTM store via decay or interference.

Question 10

How is the sensory register coded?

Answer 10

The SR takes information from one of the sense organs and holds it in that same form.
Iconic memory: Visual information from the eyes – the things you see. Stored as images.
Echoic memory: Auditory input from the ears – the things you hear. Stored as sounds.
Haptic memory: Tactile input from the body – the things you’ve touched. Stored as feelings.

Question 11

What research was done on the duration and capacity of the sensory register?

Answer 11

Sperling (1960):
Presented a grid of letters for less than a second.
People’s recall was poorer when asked to recall the whole table (they only recalled 5 out of 12 items) than when asked to give only one row (they recalled 3 out 4 items).
Info decays before we can report them all.
Duration:
Info decays within about 2 secs (or less).

Question 12

What did Baddeley’s research find about the coding of STM?

Answer 12

Baddeley found that letters which are acoustically similar (that rhyme) are harder to recall from the STM than those which are acoustically dissimilar (non-rhyming).
This suggests that STM mainly encodes things acoustically (as sounds), even though the items were presented visually.

Question 13

What did Miller’s research find about the capacity of STM?

Answer 13

Miller (1956) found that the STM can hold ‘the magic number’ = 7+/-2
On average, the capacity of STM is between 5 and 9 items of information.
Miller found that the capacity of STM could be considerably increased by combining or organising separate ‘bits’ of information, e.g. letters or digits, into larger chunks.
Chunking involves making the info more meaningful, through grouping it with existing knowledge from your LTM.

Question 14

What was Peterson and Peterson’s research on the duration of STM?

Answer 14

Carried out by a married couple Peterson & Peterson in 1959.
They got students to recall combinations of 3 letters (trigrams), after longer and longer intervals (3,6,9,12,15,18 seconds).
During the intervals, students were prevented from rehearsing by a counting task, this was counting backwards from a 3 digit they are given.
After only 3 secs, 80% recalled correctly.
After 18secs, fewer than 10% recalled correctly.
Recall got progressively worse as the intervals
grew longer.

Question 15

What did Baddeley find out about the coding of LTM?

Answer 15

Based on Baddeley’s research (1966).
Presented lists of 10 short words one at a time, some lists were semantically similar, others not.
Ppts were tested after 20 mins.
It was found that after 20 mins, they did poorly on the semantically similar words.
This suggests that we encode the LTM according to what they mean – so we get similar-meaning things confused.
Encoding in LTM is “semantic” (meaning-based).

Question 16

What is the capacity of LTM?

Answer 16

The capacity is potentially unlimited.

Question 17

What is the duration of LTM?

Answer 17

The duration is anything up to a lifetime.
However, it is difficult to test exact duration, but Bahrick et al (1975) tested US graduates.
They were shown photos of their classmates years later and asked recall freely.
90% accuracy for remembering faces & names 34yrs after graduation.
Declined after 48yrs, particularly for faces.

Question 18

What is one piece of supporting evidence (strength) of the MSM?

Answer 18

Their is supporting research evidence.
Research on the nature and structure of the two memories by Baddeley, Peterson, Bahrick and etc, shows that LTM and STM are two separate stores claimed by MSM.
STM and LTM are different stores as they have different characteristics, for example; STM is acoustically coded and LTM is semantically coded.
However, there was criticism as artificial materials were used in supporting studies, this lowers the validity of the Multi Store Model.

Question 19

What is another piece of supporting evidence (strength) of the MSM?

Answer 19

There is supporting neurological evidence, as the STM and LTM are associated with specific areas of the brain.
Brain scans take images of parts of the brain that are active when a person is doing a particular tasks.
Research has found that the prefrontal cortex is active when people work on a task in STM (Beardsley, 1997).
Research has found that the the hippocampus is active when people work on a task in LTM (Squires et al, 1992).
So they must be different stores as they are controlled by different areas of the brain.

Question 20

What is another piece of supporting evidence (strength) of the MSM?

Answer 20

The case of Henry Molaisaon supports the MSM. Henry underwent an operation to remove his hippocampus from both sides of the brain to reduce his severe epilepsy, this caused his brain damage. His personality and intellect remained intact but he couldn’t form new long term memories, though he could remember things from before surgery. His STM was normal (could retain verbal info for about 15 secs without rehearsal and longer with rehearsal). But he couldn’t transfer info into LTM, and if he did he couldn’t retrieve it. He was incapable of remembering any new fact.
This case supports the MSM because he lost his LTM but not his STM, if they were one store he would have lost both, the MSM states that LTM and STM are two different stores.
However, there was criticism as it is a single case, so it has low population validity. However, it has high ecological validity as it is a real life case.

Question 21

What is one piece of challenging evidence (limitation) of the MSM?

Answer 21

The case of KF challenges the MSM (Shallice and Warrington, 1970).
A patient called KF was suffering with amnesia. KF’s 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. Further studies of KF and other people with amnesia showed that there could even be another short term store for non-verbal sounds such as noises.
This case study shows that STM is split into different parts, visual and acoustic. This is because his visual memory was good but his acoustic memory was poor.
This challenges the MSM’s assumptions that STM is one store.
However, there was criticism as it’s a single case study, this means it has low population validity.
But it has high ecological validity as it’s a real life case.

Question 22

What is a strength of the MSM?

Answer 22

The model is simple to understand and informs us about the structure of memory.

Question 23

What is a limitation of the MSM?

Answer 23

There is more than one type of rehearsal. Elaborative rehearsal is needed to maintain information in the LTM, e.g., to link information to existing knowledge.
Not just prolonged rehearsal is required, like the MSM suggests.

Question 24

What is another limitation of the MSM?

Answer 24

The MSM doesn’t explain why we remember some things after only reading about them once . This is due to the level of interest we have about certain things. Things we are interested in, we don’t have to rehearse. The MSM doesn’t explain why this is.

Question 25

What is another limitation of the MSM?

Answer 25

The MSM doesn’t explain ‘flashbulb memory’, this is where the memories pass straight through to the LTM without going through STM and rehearsal. These are memories for events that we can remember without even rehearsing them, for example; the death of someone, we might be able to recall where we were when we heard the news, what we were wearing and etc, but we didn’t rehearse this information, we just remember it. The MSM doesn’t explain why this is.

Question 26

What is the last limitation of the MSM?

Answer 26

There is more than one type of LTM. Tulving says that there are three types of LTM; episodic, sematic and procedural.
Not just one type like the MSM says.