Memory: topic 2 ‘multi store model of memory’ Flashcards
What is a model of memory?
- a model of memory is a basic idea of how the memory system operates and the various parts that make up the memory system / how the parts work together
Who created the multi-store model of memory?
- Atkinson and Shiffrin 1968
What is the MSM claimed to be made up of?
- claims that memory is made up of three stores linked my processing
What 3 are the components in the MSM?
- sensory register, short term memory and long term memory
What is the sensory register?
- where information is held at each of the 5 senses: sight, smell, touch, taste and sound
What is the sensory register constantly doing?
- receiving and coding modality-specific information, but most of this receives no attention
What is the capacity and duration of the sensory register?
- very large capacity
- very limited duration, so incoming data remains here for a very brief period
How is data encoded and transferred into the STM from the SR?
- when the persons attention is focused on the SR
- codes through acoustic coding (based on how the information sounds)
How are STM’s lost and why?
- through displacement
- STM can only hold about 7+/- 2 items so if this is overloaded, old info may be pushed out or decayed
What is the capacity of STM?
- 7+/-2 items
What is the duration of STM?
- 18-30 seconds
How do short term memories fade?
- memories will fade if maintenance rehearsal does not take place
How is information transferred from STM to LTM?
- if info is rehearsed and understood (elaborative rehearsal) then it will be transferred to the LTM store
How is LTM coded?
- semantically (based on meaning)
What is the capacity of LTM?
- LTM can hold an unlimited amount of info and can hold it for up to a lifetime
What happens when info needs to be recalled from LTM?
- info is retrieved from LTM into STM
How are long term memories forgotten?
- retrieval failure or interference
strength of the MSM - evidence supports that the memory is made up of different stores (case study)
- case studies shows there are separate stores for STM and LTM
- KF who suffered brain damage in a motorcycle accident
- his STM was damaged in verbal stm (only had a digit span of 2 digits) but mostly unaffected for visual stm
- LTM remained completely intact
- supports the model as it supports the view that memory does have separate stores otherwise damage to the memory would have damaged all KF’s memory equally
limitation of MSM suggests the STM store is not unitary (case study)
- MSM argues that there is only type of STM but research shows this might be false
- evidence from KF because his STM was damaged for verbal stm (digit span of 2 digits) but mostly unaffected for visual stm
- this is a problem because it goes against the view that STM is one unitary store otherwise damage to KF’s STM would have affected all of his stm equally
- therefore MSM is insufficient to fully explain STM on its own
support for idea of separate STM and LTM stores from Murdock’s research
- Murdock’s serial position research found that no matter how many words a person is shown and then asked to recall, items at the beginning if the list have a greater recall than those in the middle (called the primary effect) and the words at the end have a greater recall than those in the middle too (recency effect)
- this supports the MSM as recalling more words at the beginning of the list (primary effect) supports the idea that rehearsed information passes into LTM (maintenance rehearsal). recalling more words at the end of the list (recency effect) supports the idea that there is a separate STM as they have not had time to decay unlike words in the middle which were poorly recalled as they had little time for rehearsal and may have also been displaced by later words in the list
limitation of MSM suggests LTM is also not unitary - case study
- MSM argues there is only one type of LTM research suggests otherwise
- Clive Wearing - brain damage - caused extensive brain damage - lost episodic memory (eg no memory of his wedding) but still had use of procedural memory (eg could still play piano)
- goes against view that LTM is one unitary store otherwise all damage to LTM would be affected equally
- therefore MSM is insufficient to fully explain LTM on its own
support for features of the sensory register Sperling
- ppts shown letter chart for 50 milliseconds and asked to recall as many letters as possible
- only remember 3 letters
- when high, medium or low time was played immediately after the chart to indicate top, middle or bottom row of letters, ppts could recall 3 letters from any row
- supports idea that the SR has very large capacity and short duration as ppts clearly had no problem holding memory of entire image (large capacity) which fades in the time it takes to report back the items (duration or milliseconds)
