The Multi-store model

Short term memory, long term memory, sensory memory, The multistore model

What is the coding of short term memory + research/findings?

Acoustic - storing information based on how it sounds. It is the reason why people might confuse words that are similar when recalling them from STM.

Baddeley 1996 - Gave participants a list of acoustically similar and dissimilar words and asked them to recall immediately. Acoustically similar words were harder to recall suggesting STM relies of acoustic coding.

What is the capacity of Short term memory + research/findings?

7± 2 items

Miller 1956 - Reviewed previous research on memory capacity including Jacob’s 1887 research on digit span and found that people could typically remember about 7± 2 items and suggested that people could remember more information by chunking.

What is the Duration of Short term memory + research/findings?

18 -30 Seconds

Peterson and Peterson (1959) - 24 Participants were given a trigram, after seeing the trigram they were asked to countdown in threes from a given number to prevent rehearsal, after different time intervals they were asked to recall. After 3 seconds recall was about 80% correct and after 18 seconds recall dropped to less that 10%. So short term memory is very short, unless rehearsed.

What is the coding of Long term memory + research/findings?

Semantic, storing information based on its meaning.

Baddeley (1996) - Participants were given a list of semantically similar and dissimilar words and asked to recall after 20 minutes to test LTM. LTM was worse for Semantically similar words suggesting that LTM relies on semantic coding.

Short term memory - capacity, coding and duration + researcher

Capacity = 7± 2 Miller 1956

Coding = Acoustic - Baddeley

Duration = 18-30 seconds - Peterson and Peterson

What is the duration of LTM + + research/findings?

Potentially unlimited

Bahrick et al. (1975) - 392 American participants aged 17 -74, tested their memories using photo and free recall tests.

After 15 years - after 48 years : Photo recognition: 90% - 70% Free recall: 60% - 30%

Found that LTM can last a lifetime especially meaningful memories. Recognition is better than free recall suggesting that retrieval failure is the reason for forgetting.

What is the capacity of LTM + + research/findings?

Unlimited

Bahrick et al. (1975) - 392 American participants aged 17 -74, tested their memories using photo and free recall tests.

After 15 years - after 48 years : Photo recognition: 90% - 70% Free recall: 60% - 30%

Found that LTM has a very large capacity since memories can last decades.

What is the coding on sensory memory + researcher?

Modality specific - information is stored in the same form it was received. Sub stores for each sense. (Visual info → iconic store, auditory info → echoic store, touch info → haptic store, taste info → gustatory store, smell info → olfactory info.)

Sperling (1960) - participants were shown a grid of 12 letters for 0.5 seconds and asked to recall as many as possible. One of the conditions → tone was used to recall a specific line. Recall was higher when a tone was used.

Suggests that auditory and visual information is stored seperately.

What is the duration of the sensory register + researcher?

50 ms / 0.5 sec

Sperling (1960) - participants were shown a grid of 12 letters for 0.5 seconds and asked to recall as many as possible. One of the conditions → tone was used to recall a specific line. Recall was higher when a tone was used.

They would quickly forget the letters suggesting that duration was incredibly short

What is the capacity of sensory memory + research/findings?

Very large

Sperling (1960) - participants were shown a grid of 12 letters for 0.5 seconds and asked to recall as many as possible. One of the conditions → tone was used to recall a specific line. Recall was higher when a tone was used.

Lots of information can be stored, it just decays quickly.

Long term memory coding, capacity, duration + researcher:

Coding - semantic - Baddeley

Capacity → unlimited - Bahrick et al

Duration → unlimited - Bahrick et al

Evaluate Baddeley’s research on the capacity of LTM and STM - strength

Supports MSM

Supports the distinction between LTM and STM.

Baddeley found that LTM is stored semantically and STM is stored acoustically

Supports the MSM which states that they are separate stores.

Therefore, the study provides empirical evidence for how memory is structured.

Evaluate Baddeley’s research on the capacity of LTM and STM - strength

Highly controlled

Study was highly controlled

Lab setting → minimised extraneous variables.

Increases internal validity so we can be more confident in encoding difference are due to stm and LTM process and not other factors.

Makes the study reliable and replicable.

Evaluate Baddeley’s research on the capacity of LTM and STM - limitation

Low ecological validity

Study used artificial tasks

Remembering lists of words - doesn’t reflect real life memory/situations.

Lacks ecological validity as memory may differ in an everyday context

Findings may not generalise

Evaluate Millers findings the capacity of STM - strength

Real life application

Research has useful real life application

Concept of chunking is used in phone numbers, number plates ect.

Research has practical benefits for improving memory recall

Study isn’t just theoretical

Evaluate Millers findings the capacity of STM - Limitation

Other research

Miller may have overestimated

Cowan (2001) found that STM is close to 4 chunks

Suggests his finding are too high and STM may be more limited that he claimed

Lacks accuracy

Evaluate Bahrick et al’s research on the duration and capacity of LTM - strength

Ecological validity

High ecological validity

Baddeley utilised real life memories

Meaning finding are more applicable

Study can be generalised

Evaluate Bahrick et al’s research on the duration and capacity of LTM - limitation

Lacks control over extraneous variables

Lacks control over extraneous variables

Participants may have looked over their yearbooks over the years, so memory was rehearsed. Some people may have better memories

Decreases internal validity and doesn’t account for individual differences

May have overestimated, and be an inaccurate representation

Evaluate Bahrick et al’s research on the duration and capacity of LTM - Limitation

Sample bias

Sample bias

Only studied Americans

Findings may not apply to people of different cultures. Lacks population validity

Not universal

Evaluate Peterson and Peterson’s findings on the duration of STM - strength

Controlled

High validity

Took place in a lab where participants were asked to recall letters from a trigram

No extraneous variables present, increasing the internal validity

Meaning the study is reliable and replicable

Evaluate Peterson and Peterson’s findings on the duration of STM - limitation

Artificial stimuli

Artificial stimuli

Trigrams were used which don’t replicate real life scenarios

No meaningful information So it may not apply to real life

Lacks ecological validity

Evaluate Peterson and Peterson’s findings on the duration of STM - Limitation

Other reasons for forgetting

Forgetting could have been due to interference rather than decay

Counting backwards could have meant that retroactive interference took place

Therefore challenging the conclusion that STM fades due to the short duration

Findings may not be accurate

Evaluate Sperlings findings on sensory memory - strength

High internal validity

Lab experiment → controlled conditions

Few extraneous/confounding variables

Replicable and reliable findings.

Evaluate Sperlings findings on sensory memory - Limitation

Ecological validity

Low ecological validity

artificial tasks - grid of 12 letters

Non meaningful information - memory may work differently in real life

Therefore findings may not generalise

Evaluate Sperlings findings on sensory memory - limitation

Demand characteristics

Demand characteristics

People just guessing the letters and getting them correct

Decreases the accuracy of the findings

Limits generalisability and external validity

Memory store model diagram

What is meant by attention?

Moving information from sensory to stm, if information doesn’t receive attention it will decay due to the short duration of STM

What are the 2 types of rehearsal?

Maintenance rehearsal - repeating information to try and remember it (doesn’t guarantee info will move to LTM)

Elaborative rehearsal - linking new info to old info. - more effective in transferring info to LTM

Without rehearsal, information will decay or be displaced to to limited capacity.

What are the 2 types of retrieval?

Recall - information is retrieved without specific cues

Recognition - information is retrieved when prompted by a cue.

Who came up with the multi-store model?

Richard Atkinson

Evaluate the multi store model as a whole - strength

Qualitative differences

Acknowledges the qualitative differences in coding

These are proven by Baddeley

Meaning they are an accurate representation.

However Baddeley lacks ecological validity

Evaluate the multi store model as a whole - limitations

Oversimplified stm

May be oversimplified

Suggests that STM is unitary - shallice and Warrington KF case study → intact visual memory but impaired verbal memory.

STM may have separate subsections

So the multi store model is a limited explanation

Evaluate the multi store model as a whole -limitation

Oversimplified LTM

Oversimplified LTM

Suggests that LTM is unitary → Tulving → 3 separate LTM store supported by HM (impaired episodic.)

Doesn’t account for different LTM stores

Limited explanation