Multi-store model of memory Flashcards
Everything to do with the MSM including STM, LTM and their evaluations, the sneery register and overall evaluation of the MSM.
How is memory encoded?
What is the MSM?
A and S proposed this theory in (1968)
Representation of how memory works.
Memories form sequentially.
- Consists of how memory is encoded in STM/LTM.
- Proposed by Atkinson and Shriffin (1968)
Coding/Capacity/Duration
Describe the STM
- Coded acoustically.
- Disappears unless rehearsed.
Limited capacity. - Lasts up to 18 seconds.
Describe the LTM
- Coded semantically.
- Unlimited capacity.
- Can last from 2 minutes to 100 years.
Think back to diagram of MSM
Describe the MSM diagram.
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.
Coding/Duration/Capacity
What are the features of MSM?
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.
What was the magic number proposed?
What is the capacity for the STM?
Jacobs and Miller.
**Jacobs (1887)
Digit span test
9.3 digits remembered
7.3 letters remembered
(more letters than digits)
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)
Evaluation (strengths) of the capacity for the STM.
Historical validity for Jacobs (1887) has been replicated with more controlled studies and findings were validated.
Reliability.
More contemporary and better controlled = stood test of time.
Valid
Other studies=confounding variables
Evaluation (limitations) of capacity for the STM.
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.
Coding in the STM research
Baddeley (1966)
4 lists of words
Acoustically similar/dissimilar
Semantically similar/dissimilar
Participants had to remember the correct order of the the words.
What were the findings of his research?
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.
Evaluation of Baddelely (1966)
(strength)
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
Evaluation of Baddeley (1966)
(limitations)
Uses artificial stimuli which isn’t realistic.
Word list had no personal meaning to ppts.
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.
Limited application to the real world
Duration of STM research.
Peterson and Peterson (1959).
24 participants given 8 trials to determine duration of memory.
Given a nonsense trigram to remember after retention intervals of 3,6,9,12,15,18 seconds and had to count backwards from random numbers to avoid mental rehearsal.
What were the findings of P&P (1959)
80% could remember the trigram after 3 seconds however only 3% could remember trigram after 18 seconds.
Therefore STM duration may be 18 seconds.
Evaluation of P&P (limitations)
Low external ecological validity, not possible to conduct similar finding in real life.
Trigrams do not reflect most memory activities. –> memorising meaningless material
Cannot generalise findings to everyday life.
Duration of the LTM
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.
Evaluation of Bahrick (1975)
Strength
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.
More real reflection on duration of LTM
Evaluation of Bahrick (1975)
Limitation
Confounding variables were not controlled such as how often they look at their yearbooks/whether they are still in contact with people in year book.
Could skew results of data.
What is the sensory register?
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.
What is the duration of the sensory register?
Sperling (1960)
Tested the iconic sensory 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.
What were the findings?
When had to recall all 12 digits, the participants performed poorer (42%).
When had to recall only a row, the participants performed better (75%).
What is maintenance rehearsal?
Repetition of information kept in the STM
What is prolonged rehearsal?
Repetition over time, allowing information to be stored in the LTM.
What is elaborative rehearsal?
More effective way of transferring information to the LTM.
Glanzer and Cunitz (1966)
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.
MSM evaluation (strength)
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)
MSM evaluation (strength)
Research support
Baddeleys research 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.
MSM limitation (evidence of more than one STM store)
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.
Challenges STM –> not just 1 unitary store
MSM limitation (weakness)
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
Outdated model –> LTM memory more complex
