Memory: Coding, capacity, duration Flashcards
What is coding?
The format in which information is stored in the various memory stores
Who studied coding?
Baddeley
What procedure did Baddeley use to study coding?
Ppts were given a list of acoustically similar words or acoustically disimilar words
Semantantically similar or dissimilar words
What were the findings from Baddeley’s coding study?
Immediate recall worse with acoustically similar words so STM is acoustic
Recall after 20 minutes worse with semantically similar words, LTM is semantic
What is a strength of Baddeley’s coding study?
It identified two memory stores.
Even though later studies showed that there are exceptions to Baddeley’s findings, STM is mostly acoustic and LTM is mostly semantic
Led to the development of MSM
What is a limitation of Baddeley’s coding study?
It used artificial stimuli
The words used had no personal meaning to the ppts so tells us little about coding for everyday memory tasks
When processing more meaningful tasks people use semantic coding even for STM, limited application
What is capacity?
Amount of information that can be held in memory before new incoming information displaces it
Who studied capacity?
Jacobs
Miller
What was the procedure of Jacob’s digit span?
Gave participants several sequences of digits or letters asking them to repeat after each sequence in correct order
Sequence increased in size by 1 each time
What were the findings of Jacob’s digit span study?
9.3 digits or 7.3 letters at once can be held in STM
What is Miller’s magic number study?
Reviewed psychological research studies and concluded span of STM is 7 (+/-) 2
What is chunking according to Miller?
grouping large amounts of information into smaller meaningful units so more can be remembered
What is a strength of Jacobs study?
Has been replicated
Old study with confounding variables but later studies (Bopp + Verhaegen) confirmed findings
Valid measure of digit span
What is a limitation of Miller’s study?
Overestimates STM capacity
Cowan - suggested more lile 4+- 1 chunks
Lower end of millers estimate more appropriate
What is duration?
Amount of time that information can be held in a memory store before it is lost due to decay
Who studied duration?
Peterson + Peterson
Bahrick et al
Who studied STM duration?
Peterson + Peterson
What was the procedure of Peterson + Peterson’s study?
Ppts were given 3 letters to remember and then had to count down from a random 3 digit number they were given until told to stop.
What were the findings of Peterson + Peterson’s study?
Recall after 3s was 80% but recall after 18s was 3%
STM duration without rehersal is up to 18 secs
What is a limitation of Peterson + Peterson’s study?
There is meaningless stimuli, sometimes recall meaningless irl so not completely irrelevant but doesn’t entirely reflect normal life
Lack of external validity
Who studied LTM duration?
Bahrick et al
What was Bahrick et al’s procedure?
392 Americans aged between 17 and 74
Recognition test - 50 photos from high school books and say names
Free recall test - ppts listed names from their graduating class
What were the findings from Bahrick et al’s study?
Recognition test - 90% accurate after 15 years, 70% after 48 years
Free recall test - 60% accurate after 15 years, 30% after 48 years
What is a strength of Bahrick et al’s study?
High external validity, meaningful memories were studied
Shepard, meaningless photos produce less recall
Predict a more ‘real’ estimate of the LTM duration
How is STM coded?
Acoustically
How is LTM coded?
Semantically
What is the capacity of STM?
7 plus minus 2
What is the capacity of LTM?
Potentially unlimited
What is the duration of STM?
about 18s
What is the duration of LTM?
Potentially up to a lifetime
