STM+LTM+SR RESEARCH ANAYLSIS Flashcards
What is memory?
Process in which information is retained about the past.
What are the three types?
Sensory register, Short-term memory, Long-term memory.
What is capacity?
How much data can be held in a memory store.
What is duration?
The length of time information remains in memory.
What is coding?
The way in which information is changed so that it can be stored.
What is the capacity of the STM?
7+/-2 miller
What is the capacity of the SR?
Huge e.g. the number of cells in a retina.
What is the capacity of the LTM?
Unlimited
What is the duration of the STM? * and who proposed this?
Less than 18 seconds.* Peterson and Peterson.
What is the duration of the SR?
250 milliseconds
What is the duration of the LTM?
Unlimited (2 mins-100 years).
what is the coding of the SR?
depends on organ, MODALITY SPECIFIC
what is the coding of the STM?
acoustic (form of sounds).
what is the coding of the LTM?
semantic (form of meaning).
what did M suggest?
what did J also find?
research into the capacity of STM x 2 ?
digit spans test Jacobs (1887) digits 9.3 items 7.3 letters- Jacobs suggested only 9 digits 26 letters.
Miller (1956) concluded STM 7+/-2 items. Dots flashed ppts accurate recall with 7 dots not 18.
Ppts recalled 5 words as well as 5 letters.- chunking (group letters/ digits into meaningful units).
research into duration of STM?
Peterson+ Peterson, 24 ppts, 8 trials, given a constant syllable and 3 digit number. Asked to recall the syllable after retention interval of 3-18 secs,during the interval count back from 3 digit no 90% correct of constant syllables after 3 secs, 20% 9 secs but 2% correct after 18 secs. (short if verbal rehearsal prevented).
research into duration of LTM ?
Bharick (1975) 400 ppts of various ages- memory classmates. photo -recognition 50 photos within 15 years 90% accurate after 48 yrs 70%. Free recall 60% to 30%.
What does it suggest?
research into coding of STM?+ LTM?
Baddeley (1966) had 4 groups learn diff word lists: A ACOUSTICALLY SIM (cab can cat), B:ACOUSTICALLY DISSIMILAR(pit few pew), C: SEMANTICALLY SIMILAR (big large huge), D: SEMANTICALLY DISSIMILAR (good huge hot). when STM tested A had worst recall, LTM 20 mins later C had worst recall.
suggests STM acoustic and LTM semantic
evaluation of capacity of STM
may be even more limited.
criticism of research into STM is miller’s finding not replicated. Cowan reviewed studies on capacity STM concluded 4 rather than 7 chunks.
suggests STM not as extensive as 7+/-2 items.
evaluation of capacity of STM
the size of the chunk matters.
research shown size of chunk affects no of chunks that can be remembered.
Simon (1974) found ppl smaller memory span for larger chunks (multi-syllable words vs single - takes longer to rehearse).
supports view STM memory has a limited capacity despite benefits chunking.
evaluation of duration STM.
testing STM is artificial
and however.
criticism of STM research - takes place in artificial situations e.g remembering meaningless syllables. Does not reflect how we use memory in real life, where info is more useful.low mundane realism
however some material we remember like postcode meaningless so research has some relevance to real life.
(researchers p+p)
who found something else?
suggests…
evaluation of duration STM.
STM results due to displacement
criticism of Peterson and Peterson research is it didn’t measure what it set out to measure. counting back in no. displaced syllables to be remembered. Reitman used auditory tones rather than no. and found duration of STM longer.
suggests forgetting in P+P study was due to displacement than decay.
evaluation of coding STM
STM not exclusively acoustic.
studies found visual code also used STM. Brandimote (1992) found ppts used visual coding when given pics to remember and prevented from verbally rehearsing.
suggests there multiple types of coding in STM not exclusively acoustic.
evaluation of coding LTM
LTM not exclusively semantic.
general semantic but frost (1972) showed L-T recall was related to visual and semantic categories. Furthermore Nelson and Rothbart (1972) found evidence for acoustic coding in LTM. Suggests LTM codes acoustic visual semantic info depending on type of info being remembered.
