MULTI STORE MEMORY MODEL (MSM) Flashcards
Who created the MSM and what year?
Atkinson and Shiffrin (1968)
What does the MSM claim?
Memory is processed and retained in 3 distinct stores: The sensory register, The STM store + The LTM store
Sensory Register
- Entry, Capacity, Duration, Encoding, Transfer, Decay
- Information enters through our 5 senses
- Capacity = 3-5 items
- Duration = 0.5 seconds
- Encoding = modality specific
- Transferred to the STM when attention is paid
- Info can decay and will be forgotten if attention is not paid
STM Store
- Entry, Capacity, Duration, Encoding, Transfer, Decay
- Information enters this store from the SR when attention is paid
- Capacity = 5-9 items
- Duration = 18-30 seconds
- Encoding = acoustic
- Transferred to the LTM when info is rehearsed
- Old info can be displaced by new info causing it to decay
LTM Store
- Entry, Capacity, Duration, Encoding, maintenance, Decay
- Information enters this store from the STM when info is rehearsed
- Capacity = potentially unlimited
- Duration = potentially indefinite
- Encoding = mainly semantic
- Info in maintained by regular retrieval
- New info can interfere with old info which may cause it to decay over time
Who founded the sensory register? How?
SPERLING (1960) - Showed pps a visual array for 0.5 seconds and asked to recall the letters. When asked to recall a specific row pps recalled 75% in the cued row compared to 33% when asked to recall them all. (Fewer digit were easier to recall - low capacity)
Who founded STM? How?
3 people (Capacity, Duration, Encoding)
- MILLER (1957) - He tested pps recall and found that we remember in groups of 7s (capacity 5-9)
- PETERSON & PETERSON (1959) - Showed pps trigrams, then got them to recall them after interference tasks. He found their correct recalled answers dropped after 18-30 seconds (duration)
- BADDELEY (1966) - Acoustic encoding
Who founded LTM? How?
3 people (Duration, Encoding, Capacity)
- BAHRICH ET AL (1975) - Identification of names from high school remained accurate for up to 48 years (LTM stores info indefinitely)
- BADDELEY (1966) - Mainly semantic encoding
- BRADY ET AL (2008) - Pps shown 2500 objects over 5.5 hours. Later show each object paired with a very different unseen object, and pps were able to identify which one they had seen before (LTM has a huge capacity)
Strengths of the MSM
- EVIDENCE FROM CLIVE WEARING CASE STUDY - His STM was still intact, however he could not remember his past nor make new memories - he lived in moments (separate stores)
- SQUIRE ET AL BRAIN SCANS - memory tasks while conducting PET scans of pps. He found that the Hippocampus is more active during LTM tasks and the prefrontal cortex is more active during STM tasks
Weaknesses of the MSM
- EVIDENCE FROM CLIVE WEARING CASE STUDY - He could still play music just not remember learning it
- DeGroot (chess experts use information about the rules and experiences to aid recall from STM - high levels of interaction not accounted for)
HM Case Study
At 27 HM suffered severe anterograde amnesia (inability to form new long term memories) as a result of a very unethical brain surgery to treat his epilepsy. The surgery removed part of his brain called the hippocampus.
His STM was intact (30ish seconds) but he could not transfer that info into LTM and so had no new knowledge since before his operation. HM was studied extensively for over 50 years until he died at 82.
Clive Wearing Case Study
In 1985, he contracted a rare form of herpes virus that caused him brain damage, including the hippocampus and some tissue around it. Clive developed intrograde amnesia (inability to form new long term memories) and aspects of retrograde amnesia. Every 20 or so seconds, he had the perception of waking up in a coma - “restarting” his memory and consciousness. Clive’s STM is intact however he can not transfer that info LTM. Clive can still play music even though he can’t remember learning it
What is duration?
How long a memory will last
What is encoding?
How information is stored in the brain (formatting information in different ways)
What is capacity?
How many items of information the store can hold at once
