memory - MSM

Question 1

Who came up with the MSM?

Answer 1

Atkinson and Shiffrin (1968)

Question 2

What is the MSM?

Answer 2

Atkinson and Shiffrin devised the multi-store model (MSM) of memory. It is a cognitive approach that explains memory as information passing through a series of 3 storage systems: the sensory register, then short-term memory, and then long-term memory.

Question 3

What is coding?

Answer 3

The format information is stored as

Question 4

What is capacity?

Answer 4

How much information can be stored

Question 5

What is duration?

Answer 5

How long information is stored for

Question 6

Describe the sensory register

Answer 6

This is where sensory stimuli from the environment is stored, although it only lasts for a fraction of a second unless attention is paid to it.
The store can be divided into different senses, for example iconic for images, echoic for sounds. Coding = modality specific
The capacity for the store is quite large, but the duration is very short (half a second).

Question 7

When would information be passed from the sensory register to STM?

Answer 7

If the individual pays attention to the information coming in via the sensory register, that information is passed on to the short-term memory store, where it may be retained for longer.

Question 8

Describe the STM store

Answer 8

Short term memory receives information from the sensory register by paying attention.

Coding = acoustically (in the form of sound/spoken words)
Capacity = Miller suggested this is small (7 items +/- 2 items) and this can be improved by chunking.
Duration = 18-30 seconds - lost if not rehearsed.

STM passes information to LTM through rehearsal. This is either elaborate rehearsal (linking to info already in LTM) or maintenance rehearsal (repeating the information).

Info can be lost via displacement or decay.

Question 9

How is information transferred from the STM to the LTM?

Answer 9

Extended rehearsal

Question 10

Describe LTM store

Answer 10

Duration - potentially lifetime
Capacity - unlimited, memories are forgotten due to interference or deterioration
Coding - mostly semantically

Memories in LTM can be retrieved into STM.

Question 11

Evaluation of MSM - case studies

Answer 11

The case of HM could be used to support the model.
HM underwent an operation to remove his hippocampus in an attempt to relive symptoms of epilepsy. Afterwards, his STM seemed unaffected, but he was unable to make new long-term memories. His LTM from before the procedure was intact.
This suggests that the link between STM and LTM had been broken, supporting the assumptions of the MSM that the STM and LTM are separate stores.

The case of KF weakens the MSM. KF suffered from amnesia after a motorcycle accident, and was able to recall visual information without difficulty, but had problems recalling verbally presented information.
This suggests there is more than one type of STM store, so the MSM is too simplistic.

Question 12

Evaluation of MSM - low ecological validity

Answer 12

Some research into STM duration has low ecological validity**, as the stimuli participants were asked to remember bear little resemblance to items learned in real life, e.g. Peterson and Peterson (1959) used nonsense trigrams such as ‘XQF’ to investigate STM duration.

Question 13

Evaluation of MSM - recency effect

Answer 13

Study showed that when participants are presented with a list of words, they tend to remember the first few and last few words and are more likely to forget those in the middle of the list, i.e. the serial position effect.

This supports the existence of separate LTM and STM stores because they observed a primacy and recency effect.

Question 14

Outline research into coding

Answer 14

• Baddeley (1966)
• He gave participants one of four word lists to learn. The lists contained words that were either acoustically similar (sounded the same, e.g. hat, cat, bat); acoustically dissimilar (sounded different, e.g. hat, stage, ball); semantically similar (had the same meaning, e.g. big, large); or semantically dissimilar (had different meanings, e.g. gate, big).
• Participants either recalled the list immediately, testing the coding of short-term memory (STM) or after 20 minutes, testing the coding of long-term memory (LTM).
• Participants did worse with acoustically similar words in STM, suggesting that information in STM is coded according to sound, as similar-sounding information conflicted with each other.
  -For LTM, they did worse with semantically similar words, suggesting that information in LTM is coded according to meaning, as information with similar meanings conflicted with each other.

Question 15

Outline research into capacity

Answer 15

• Jacobs (1887)
• He developed the digit-span technique, where a participant has to immediately recall a sequence of letters or numbers, which increased by one letter or number with each trial.
• The mean amount of letters that could be correctly recalled was 7.3, and for numbers it was 9.3.
• Miller concluded that the capacity of STM is 7 plus or minus 2 ‘bits’ of information. He also noted that in order to increase this capacity, people ‘chunk’ information together, for example remembering the area code of a phone number (5 digits) as one chunk. The capacity of LTM is thought to be potentially unlimited.

Question 16

Outline research into duration

Answer 16

• STM duration was investigated by Peterson and Peterson (1959).
• Participants were given a nonsense ‘trigram’ of three syllables, together with a three-digit number (for example, ‘TJF 374’).
• To prevent rehearsal, they had to count backwards in threes from the number until told to stop after either 3, 6, 9, 12, 15 or 18 seconds.
• After the interval, they had to recall the trigram. Recall was generally accurate after 3 seconds (over 80%), but by 18 seconds it declined to around 10%. It was concluded that the duration of STM is around 18-30 seconds, if rehearsal is prevented.