Multistore Model (Research and evaluation) Booklet 5

How did Peterson and Peterson measure the duration of STM?

Got students to remember trigrams at different intervals (prevented rehearsal by having them count backwards in 3s and 4s from a specific number)

What were the key findings of Peterson and Peterson’s research?

The longer the interval, the less accurate the recall.

• At 3 seconds around 80% of the trigrams were correctly recalled

• At 18 seconds only 10% were correctly recalled

How do the findings of Peterson and Peterson’s study support the MSM?

Shows that if we are unable to rehearse information, it will not be passed to long term memory. This supports the MSM having separate memory stores.

Why has Peterson and Peterson’s study been criticised for lacking external validity?

Trigrams are meaningless, whereas everyday life information possesses meaning making it easier keep information in our long term memory (as its coding is semantic).

How did Jacobs measure the capacity of STM?

Digit span technique

• Participants are given sequence of digits/letters

• After shown must write digits/letters down in correct order

• If correct number of digits/letters in sequence increases

What are the key findings of Jacobs’s research?

The capacity of STM memory is limited to 7±2 items

• Mean number of letters in STM: 7.3

• Mean number of numbers in STM: 9.3

How do the findings of Jacob’s study support the MSM?

We can remember more than 7 items so there must be another memory store.

How does Miller’s research support Jacob’s study?

Made observations of 7 in every day practice.

• 7 days of the week

• 7 continents

• 7 deadly sins

• 7 notes in a music scale

How did Baddeley’s study measure coding in STM and LTM?

Participants had to learn and recall the lists either immediately (test of STM) or after 20 minutes (test of LTM).

The lists were either:

• Acoustically similar

• Acoustically dissimilar

• Semantically similar

• Semantically dissimilar

What were the key findings of Baddeley’s research?

• Findings after immediate recall: The worst remembered list was acoustically similar as similar sounding words got mixed up in the STM.

• Findings after 20 minute recall: The worst remembered list was semantically similar as similar semantic words became mixed up in LTM.

How do the key findings of Baddeley’s study support the MSM?

Supports the fact coding is acoustic in STM memory so you get confused by acoustically similar sounds.

How did Bahrick’s study measure the duration of LTM?

Participants were tested on their recall of:

1. Photo recognition from 50 photos of their high school yearbook

2. Free recall where participants recalled any names they could remember from their high school class

What were the key findings of Bahrick’s research?

• 15 years after 90% accuracy of photo recognition, 60% accuracy of free recall

• 48 years after 70% accuracy of photo recognition, 30% accuracy of free recall

How do the findings of Bahrick’s study support the MSM?

Shows that the duration of LTM can last up to a lifetime, contrasting with the duration of STM.

How does the case study of Clive Wearing support MSM?

Proves that there is an existence of two separate stores for the short term and long term memory, because Clive Wearing's long term store was impaired, but his short term works perfectly fine.

What is the problem of maintenance rehearsal in the model and what might be a better way of transferring information from STM to LTM?

• You must repeat information over and over.

• Elaborative rehearsal (give information meaning and make associations between new and pre-existing information)

What is evidence that LTM is not a unitary (single) store as the MSM suggests?

The case of Clive Wearing where his procedural LTM was intact but his semantic and episodic (events) memories were effected.

What is evidence that STM is not a unitary (single) store as the MSM suggests?

The case of KF (damaged his STM in a motorcycle accident). After accident could remember lists of digits when he read them, but not when they were read to him. This suggests we have 2 different types of memory for visual and acoustic information.