What are the stores in the MSM?
Sensory Store, Short Term Memory and Long Term Memory
What is the Coding, Capacity and Duration of the Sensory Store?
Coding - modality specific
Capacity - 9 to 18 items (large)
Duration - approximately 250 milliseconds
What is the Coding, Capacity and Duration of the STM?
Coding - acoustic
Capacity - 5 to 9 items
Duration - 18 to 30 seconds
What is the Coding, Capacity and Duration of the LTM?
Coding - semantic
Capacity - unlimited
Duration - possibly forever
What is the Multi Store Model?
Atkinson and Shiffrin suggested that memory is made up of a series of stores and describe memory as information flowing through a system
Features of each store STM and LTM Encoding - Baddeley
Aim - to investigate encoding in STM and LTM
Procedure - Experimental lists ( acoustically similar and semantically similar) and Control lists ( acoustically dissimilar and semantically dissimilar)
To test STM recall was immediate, LTM was after 10 minutes
Findings - STM - acoustically similar recall was 10% LTM - semantically similar recall 55%
Results - STM encodes acoustically and LTM encodes semantically
Features of each store LTM and STM Encoding - Baddeley EVALUATION
LIMITATIONS
Lacks ecological validity - not a real life task
Method may not be testing LTM as it was only after 10 minutes
STRENGTHS
Lab experiment - high levels of control and can test for cause and effect
Good sample size - 75 ppts means easier to generalise to population
Features of each store Sensory Store Capacity - Sperling
Aim - to investigate the existence of the sensory store
Procedure - participants were presented with a grid of 12 symbols that was shown for less than a second
Condition 1 - recall how many letters they could remember. Condition 2 - asked to recall single row of letters depending on a high medium or low tone
Results - Condition 1 - ppt could recall 4/5 letters Condition 2 - ppt could recall 3 out of 4 letters
Conclusion - the sensory store can retain approximately 76% of all data received
Features of each store - Sensory Store Capacity - Sperling EVALUATION
LIMITATIONS
- lacks ecological validity - not a normal way of remembering information
- ignores other factors that could impact capacity like age
- order effects - boredom, fatigue
STRENGTHS
- Lab study - easy to repeat, high levels of control, easily to test cause and effect
Features of each store - STM duration - Peterson and Peterson
Aim - to investigate the duration of STM
Procedure - 24 psych students had to recall trigrams and to prevent rehearsal they had to count backwards in 3s from a random number till a red light appeared. they had to recall trigrams after increasing intervals of 3 6 9 12 15 18 seconds
Findings - 80% recall after 3s and 10% recall after 18s
Conclusion - the duration of STM is 18 - 30 seconds
Features of each store - STM duration - Peterson and Peterson EVALUATION
LIMITATIONS
- not generalisable -24 psych students
- lacks ecological validity
STRENGTHS
-proves MSM
-reliable - lab study
Features of each store - LTM duration - Bahrik
Aim - to investigate long term memory in a natural setting
Procedure - 392 ppts aged between 17 and 74 had to do 3 tests
1 - free recall - write down names of graduating class
2 - photo recognition - 10 cards of 5 pictures to pick out from year book
3 - name recognition of classmates
Findings - Within 15 years of leaving school - 90% accuracy with faces and names and within 45 years 70% accuracy
Conclusion - LTM has very large duration but cant hold everything forever
Features of each store - LTM duration - Bahrik EVALUATION
LIMITATIONS
- less reliable and hard to control
- not ethnocentric - all American
STRENGTHS
- high ecological validity
- generalisable
- valid test for LTM
Features of each store - STM capacity - Jacobs
Aim - to investigate capacity of STM
Procedure - Serial digit span technique where ppts were presented with increasingly long lists of letters or numbers to recall in the correct order
Findings - average digit span for numbers is 9.3 items and 7.3 items for letters
Conclusion - STM has a capacity of 5-9 items
Features of each store - STM capacity - Jacobs EVALUATION
LIMITATIONS
- lacks ecological validity
- order effects - fatigue
- lacks historical validity
STRENGTHS
- real life application
Millers theory is supported by Jacobs
Evaluation of MSM - Is it an accurate representation of how memory works?
1 Strength - case studies , HM hippocampus removed lost LTM still had STM. Two distinct stores - accurate. However HM is unique cant generalise.
2 Limitation - maintenance rehearsal emphasised. elaborative important. However maintenance is needed so partially correct
3 Limitation - over simplified, STM acoustic and LTM semantic, unitary stores, ignores visual coding and stores within LTM STM - may be incomplete. Working memory more valid.
