AS MEMORY - MULTI STORE MODEL Flashcards
Describe the multi store model of memory
1) Info flows from the env into the sensory register which has 5 diff stores. It’s an automatic response to the perception of env.al stimuli by the sensory organs.
2) Paying attention brings info from SR into the STM (an active store containing info currently being thought about). From STM stems response (i.e. remembering); remembering has to come from STM. Maintenance rehearsal refreshes the info and keeps it in the STM.
3) Through prolonged rehearsal info can be sent to LTM (a potentially permanent store). When we want to remember/ recall info it must be taken back to STM using the process of retrieval.
Who put forward the MSM?
Atkinson and Shiffrin (1968)
Describe the coding of sensory register
Sensory register has a modality specific coding system; there are 5 separate stores (one for each sense) and info is stored raw and unprocessed.
Describe the capacity of sensory register.
SR has very large memory stores but due to the fact that they last for v little amounts of time, it is difficult to quantify.
Sperling (1960) showed this by flashing a 3x4 grid of letters onto a screen for 1/20 sec and then sounded a tone to indicate which row he wanted the ppts to recall. Recall of the desired row was high, showing that all of the env.al info from the grid was taken in by the SR. This shows that the SR has v large stores of env.al info.
Describe the duration of SR
SR has a v small duration ie env.al info fades quite quickly. Sperling (1960) showed this by flashing a 3x4 grid of letters onto a screen for 1/20 sec and then sounded a tone to indicate which row he wanted the ppts to recall. Although recall was high here showing large capacity, when asked to just write down the whole grid, ppts couldn’t get past 4 or 5 letters, showing that the info in SR fades very quickly, i.e. extremely short duration.
Describe the coding of STM
Coding for STM is mainly acoustic. This has been shown by Baddeley (1966). C1 were given acoustically similar words, C2 given acoustically dissimilar words, C3 given semantically similar words, C4 given semantically dissimilar words. Ppts asked to recall the list of words they’d been given.
When asked to recall immediately (i.e. STM), C1 performed worst, and when asked to recall after 20 mins (i.e. LTM), C3 performed worst.
This suggests that STM codes acoustically, because the acoustically similar info all seems the same to the STM so it’s harder to separate out and recall.
Describe the capacity of STM
STM has a capacity of 7 +/- 2 items, as shown by Miller (1956), who gave ppts a list of either no.s, letters, words or tones, and asked them to recall as many as possible. Found that ppts could recall 7 +/- 2 items through the chunking process, ie 7 +/- 2 words, letters, no.s etc; just so long as they were items they could chunk.
Describe the duration of STM
STM is thought to have a duration of up to 30 secs, as shown by Peterson and Peterson (1959), who gave ppts trigrams (3 letter combos e.g. XPJ, ZFN etc).
C1 listened to the trigrams and then immediately recalled them, whilst C2 counted backwards in threes for 18 secs and then recalled them, to prevent rehearsal. C1 had an average recall rate of 75% whilst C2 had just 6%.
Atkinson and Shiffrin (who put forward the MSM) said we keep info in the STM by maintenance rehearsal; C2 were prevented from doing so.
Describe the coding for LTM
LTM is coded for semantically, as shown by Baddeley (1966). C1 were given acoustically similar words, C2 given acoustically dissimilar words, C3 given semantically similar words, C4 given semantically dissimilar words. Ppts asked to recall the list of words they’d been given.
When asked to recall immediately (i.e. STM), C1 performed worst, and when asked to recall after 20 mins (i.e. LTM), C3 performed worst.
This semantic confusion shows that LTM is coded semantically; the semantically similar info is harder to separate out and recall as it all seems the same to the LTM.
Describe the capacity for LTM
The capacity of the LTM is thought to be limitless, although this is difficult to objectively prove through experiment. Although forgetting does occur, this is through other processes e.g. retrieval failure and interference theory, not due to capacity limitations.
Describe the duration of LTM
LTM duration is thought to be lifetime, or at least for a very long time. Bahrick (1975) got ppts between 17 and 74 to recall their classmates via photo recognition and also name recall.
For photo recognition, ppts interviewed 15 yrs after graduation had a 90% accuracy rate, dropping to 70% after 48 yrs.
For name recall, ppts interviewed 15 yrs after graduation had a 60% accuracy rate, dropping to 30% after 48 yrs.
Shows LTM lasts a v long time
Evaluate the MSM
(-) MSM only accounts for maintenance rehearsal but ignores other types of rehearsal e.g. elaborative rehearsal (when info is linked to existing knowledge)
(+) Research evidence for coding, capacity, duration etc
(-) Most supporting research uses artificial tasks e.g. trigrams, no.s, word recall etc, so poor external validity.
(-) Oversimplifies STM: patient KF had difficulties immediately recalling digits read out to him but had much better memory when he could read them aloud himself
(-) Oversimplifies LTM: Tulving used PET scans to show that there are diff types of LTM which each use diff areas of the brain; not just one store like the MSM says.
