Short + Long Term Memory Flashcards
what is the capacity, duration and coding of the STM?
C: 7+-2
D: <18s
C: acoustic
what is the capacity, duration and coding of the LTM?
C: unlimited
D: lifetime
C: semantic
what study tested the capacity of STM?
the digit span; Jacobs found the average capacity for digits was 9.3 and 7.3 for letters - he suggests this is because there are 9 digits but 26 letters.
what was the study for the duration of STM?
- trigrams
- Peterson + Peterson gave participants a constant syllable and a three digit number, the pp were asked to recall the consonant syllable after retention intervals of 3,6,9,12,15 or 18 seconds. During the interval they counted back from their three digit number.
- results: 90% for 3s, 20% for 9s and 2% for 18s
what was the study for the duration of LTM?
- Bahrick et al. tested 400 by asking them to complete a photo-recognition test of 50 photos from their year book and a free-recall test of listing names they could remember from they class.
- results: photo-recognition = 15yrs, 90%, 48yrs, 70%
free recall = 15yrs, 60%, 48yrs, 30%
what was the study for the coding of LTM + STM?
Baddeley used word lists of either acoustically similar but semantically different or semantically similar, acoustically different.
He found Pp had difficulty remembering acoustically similar words in STM but not in LTM and that semantically similar words had no issues in the STM.
- this suggests the STM is largely coded acoustically and the LTM is coded semantically
why is it suggested the capacity of STM may be more limited? (evaluation of capacity)
Millers original findings have not be replicated, other psychologists have suggested that the STM is likely to have a capacity of 4 chunks.
why is it suggested the size of the chunks of information matter? (evaluation of capacity)
Simon found that people had a shorter memory span for larger chunks of information, such as eight word phrases, than smaller chunks of say one-syllable words.
why is it suggested that the testing of STM was artificial? (evaluation of duration)
Trying to memorise consonant syllables does not truly reflect everyday activities where what we are trying to remember is meaningful. However sometimes we memorise meaningful things such as phone numbers.
why is it suggested STM results where due to displacement? (evaluation of duration)
In Petersons study, pp were counting the numbers in their STM and this many displace/overwrite the syllables to be remembered. Reitman used auditory tones instead of numbers foe that displacement wouldn’t occur and found the duration of STM was longer.
why is it suggested that the STM may not be exclusively acoustic? (evaluation of coding)
some experiences have some that visual codes are also used in STM. e.g. brandimore found that pp used visual coding in STM if they were giving a visual task and prevented any verbal reasoning in the retention interval.
why is it suggested that the LTM may not be exclusively semantic? (evaluation of coding)
in general LTM often appears to be semantic but frost showed that long-term recall was related to visual as well as semantic categories.
