STM + LTM=features of each store:coding,capacity and duration Flashcards
Baddeley(1966) what is the coding of the STM?
The STM is acoustic , this means acoustically(sound similar)similar words(cat,cab)are harder to recall but acoustically dissimilar words are easier to recall(pit,cow).
Miller(1956) what is the capacity of the STM?
The span of the STM is about 7 items(+2 or -2),it’s increased by chunking-grouping sets of digits/letters into units.
Peterson and Peterson(1959)What is the duration of the STM?
24 students were given a consonant syllable (e.g. C,G) to recall and a
3-digit number to count backwards from. Retention interval was varied: 3, 6, 9, 12, 15 or 18 seconds.
After 3 seconds - average recall was 80%. After 18 seconds it was 3%. STM duration without rehearsal is up to 18 seconds.
Baddeley (1966) what is the coding of the LTM?
The LTM is semantic , this means semantically(definition)similar
words(great,big)are harder to recall but semantically dissimilar words are easier to recall(good,huge).
What is the capacity of the LTM
unlimited
What is the duration of the LTM?
It’s how long an individual can keep information in their head.
What study was conducted to find out the duration of the LTM?
Bahrick et al.(1975) Participants were 392 Americans aged 17-74.
1.Recognition test - 50 photos from high school yearbooks.
2.Free recall test - Participants listed names of their graduating class
Recognition test - 90% accurate after 15 years, 70% after 48 years.Free recall test - 60% recall after 15 years, 30% after 48 years.
How many memory stores did baddeley identify through his work?
Two,the LTM and the STM.Later research showed the LTM is mostly semantic and the STM is mostly acoustic.Baddeleys work led to the development of the MSM.
What was a limitation of Baddeley’s study?
Used artificial stimuli, The words used had no personal meaning to the participants so tells us little about coding for everyday memory tasks. When processing more meaningful information,people use semantic coding even for STM. This means the findings of this study have limited application.
What was a limitation of millers research?
Overestimates STM capacity.Cowan(2001) concluded that the capacity of STM was only about 4 (plus or minus 1) chunks. This suggests that the lower end of Miller’s estimate (5 items) is more appropriate than 7 items.
What’s a limitation of Peterson and Peterson’s study?
Meaningless stimuli. We sometimes try to recall meaningless things so the study isn’t completely irrelevant. But recall of consonant syllables (C,G) aren’t meaningful everyday memory tasks,the study lacked external validity.
What’s a strength of Bahrick et al’s study?
High external validity. Everyday meaningful memories (e.g. of people’s faces and names) were studied. When lab studies were done with meaningless pictures to be remembered, recall rates were lower. This means that Bahrick et al’s findings reflect a more ‘real’ estimate of the duration of LTM.
