Multi-store model of memory

Question 1

How is memory encoded?

What is the MSM?

A and S proposed this theory in (1968)

Answer 1

Representation of how memory works.
* Consists of how memory is encoded in STM/LTM.
* Proposed by Atkinson and Shriffin (1968)

Question 2

Coding/Capacity/Duration

Describe the STM

Answer 2

• Coded acoustically.
• Disappears unless rehearsed.
  Limited capacity.
• Lasts up to 18 seconds.

Question 3

Describe the LTM

Answer 3

• Coded semantically.
• Unlimited capacity.
• Can last from 2 minutes to 100 years.

Question 4

Think back to diagram of MSM

Describe the MSM diagram.

Answer 4

Starts with an environmental stimulus.
Sensory register obtains information for each of the senses.
Iconic = visual.
Echoic = auditory.
Stored in STM
**Elaborative rehearsal **—> information lead to LTM.
Information can only be recalled from STM not LTM.

Question 5

Coding/Duration/Capacity

What are the features of MSM?

Answer 5

CODING - the format in which information is stored.
DURATION - how long information can be stored in a memory store.
**CAPACITY **- how much data can be stored in a memory store.

Question 6

What was the magic number proposed?

What is the capacity for the STM?

Jacobs and Miller.

Answer 6

**Jacobs (1887)
Digit span test
9.3 digits remembered
7.3 letters remembered
(more letters than words)

Miller (1956)
Everything measured in 7s
Made a rule that roughly absorb 7 pieces of information in STM.
Came up with the magic number 7+-2 as the capacity of STM.
Applies to chunking. —–(grouping of letters and numbers)

Question 7

Evaluation (strengths) of the capacity for the STM.

Answer 7

Historical validity for Jacobs (1887) has been replicated with more controlled studies and findings were validated.
Reliability.

Other studies=confounding variables

Question 8

Evaluation (limitations) of capacity for the STM.

Answer 8

Miller may have overestimated capacity.
Research by Cowan (2001) further backed by Vogel et al (chunking in visual memory) suggests that capacity is only around 4+-1.
Lower half of the magic number rule is more appropriate.

Question 9

Coding in the STM research

Answer 9

Baddeley (1966)
4 lists of words
Acoustically similar/dissimilar
Semantically similar/dissimilar
Participants had to remember the correct order of the the words.

Question 10

What were the findings of his research?

Answer 10

When having to recall the words IMMEDIATELY:
—-> participants struggled to recall acoustically similar words due to acoustic confusion.

When having to recall the words 20 MINUTES AFTER:
——-> participants struggled to recall semantically similar words due to semantic confusion.

Question 11

Evaluation of Baddelely (1966)
(strength)

Answer 11

Provides evidence between the difference LTM/STM and how they are coded.

Idea of STM coding acoustically and LTM coding semantically stood test of time.

Helps to understand MSM.

High internal validity

Question 12

Evaluation of Baddeley (1966)
(limitations)

Answer 12

Uses artificial stimuli which isn’t realistic.
Mundane realism
Does not show how memory is coded in different stores.
20 minutes may not be long enough to test LTM.
Did not take into account visual cues.

When processing meaningful information, some may use semantic coding even for STM.

Question 13

Duration of STM research.

Answer 13

Peterson and Peterson (1959).
24 participants given 8 trials to determine duration of memory.
Given a nonsense trigram to remember after intervals of 3,6,9,12,15,18 seconds and had to count backwards from random numbers to avoid mental rehearsal.

Question 14

What were the findings of P&P (1959)

Answer 14

80% could remember the trigram after 3 seconds however only 3% could remember trigram after 18 seconds.
Therefore STM duration may be 18 seconds.

Question 15

Evaluation of P&P (limitations)

Answer 15

Low external validity, not possible to conduct similar finding in real life.
Trigrams do not reflect most memory activities.

Cannot generalise findings to everyday life.

Question 16

Duration of the LTM

Answer 16

Bahrick (1975)
Used 400 PPTs between ages of 17-74 to research duration of LTM and used high school year book photos as reference.
1) Photo recognition test
90% accurate = PPTs who graduated within 15 years.
70% accurate = PPTs who graduated within 48 years.

2) Free recall task
60% accurate = PPTs who graduated within 15 years.
30% accurate = PPTs who graduated within 48 years.

Question 17

Evaluation of Bahrick (1975)
Strength

Answer 17

High external validity as it uses meaningful memories.
Real estimate as no artificial stimuli was used.
When using memories that were meaningless, recall was lower.

Question 18

Evaluation of Bahrick (1975)
Limitation

Answer 18

Confounding variables were not controlled such as how often they look at their yearbooks.

Question 19

What is the sensory register?

Answer 19

Divided into five stores, one for each of the 5 senses.
Coding is modality specific = depends on the store e.g: iconic store is for visual information.
Capacity is said to be unlimited as it can store lots if information at once.

Question 20

What is the duration of the sensory register?

Answer 20

Sperling (1960)
Tested the iconic seniority register.
Saw a grid of digits and numbers for 50 miliseconds.
Either had to wrote down all 12 items or hear a tone indicating a certain row.

Question 21

What were the findings?

Answer 21

When had to recall all 12 digits, the participants performed poorer (42%).

When had to recall only a row, the participants performed better (75%).

Question 22

What is maintenance rehearsal?

Answer 22

Repetition of information kept in the STM

Question 23

What is prolonged rehearsal?

Answer 23

Repetition over time, allowing information to be stored in the LTM.

Question 24

What is elaborative rehearsal?

Answer 24

More effective way of transferring information to the LTM.

Question 25

Glanzer and Cunitz (1966)

Answer 25

PPTs who memorise long list of words were more likely to remember the first few words (LTM) and the last few words (STM).
middle words = asymptote

Overall, PPTs remember primary and recent information.

Provides evidence to support existence of two memory stores.

Question 26

MSM evaluation (strength)

Answer 26

Supporting evidence form HM (brain damage) that LTM and STM are separate as if one is damaged the other can still function.

Brain surgery to help with his epilepsy.

Removal of his hippocampus which is important for memory function.

Was not able to remember the year or what he ate. Little recall in terms of LTM but performed well on immediate memory span tests (STM)

Question 27

MSM evaluation (strength)

Answer 27

Baddeleys researched suggested that LTM and STM are two different memory stores.

2 different entities.

Counterpoint:
Saturated use of artificial stimuli.
Many studies use artificial stimuli —- lack of mundane realism.

Not generalisable to real life.

Question 28

MSM limitation (evidence of more than one STM store)

Answer 28

KF case study by Shallice and Warrington —-> suffered from amnesia

Recall was worse when digits were read out to him but were better when he read digits to himself.

Suggests that there were 2 STM stores
One for visual learning and one for auditory learning.

Question 29

MSM limitation (weakness)

Answer 29

Prolonged rehearsal not needed for transfer to LTM.
Watkins and Craig found that elaborative rehearsal better for LTM.

MSM doesn’t explain how long term memories are formed