2.1.2 - the multi-store model of memory Flashcards
who developed the multi-store model of memory?
Atkinson and Shiffrin (1968)
what are the three parts of the memory?
sensory store (SS)
short-term memory (STM)
long-term memory (LTM)
what is the sensory store?
a very short-term store where information is kept before being encoded into the STMA
what is the short-term memory?
where information is kept whilst in current use - it has limited capacity and duration
what is the long-term memory?
where information we have previously encoded is kept, so it can be used in the future if needed
how is information transferred from the sensory store to the short-term memory?
a sensory experience enters the sensory store and is held briefly before it decays
attended (given attention to) information is transferred from the sensory store to the short-term memory
what is the role of the long-term memory in transferring information from the sensory store to short-term memory?
it makes sense of the information and assigns a verbal label eg. if we register the image of a horse in our SS, it can’t be stored as an auditory verbal STM until we have used our LTM to identify what the object represents
how is information transferred from the short-term to long-term memory?
information in the STM is held for around 30 seconds before decaying, unless it is rehearsed (consciously practiced and repeated)
information is transferred from the STM to LTM possibly due to rehearsal, but more durable memory traces can be achieved using mental operations like mnemonics
how does the sensory store encode information?
as 1 sensory register for each sensory modality (visual, auditory, haptic, olfactory, gustatory)
what is the duration of the sensory store?
around 50 milliseconds to a few seconds
what is the capacity of the sensory store?
3-4 items
how is information retrieved from the sensory store?
using scanning
how does the short-term memory encode information?
as acoustic (how information sounds) or verbal memory traces, due to the phonological similarity effect (similar sounding letters and words are acoustically confused in the STM making them more difficult to recall)
what is the duration of the short-term memory?
15-30 seconds - then decays completely unless maintained through rehearsal
what study demonstrates the duration of the short-term memory?
Peterson and Peterson (1959) - used interference task (counting backwards in 3s) to prevent rehearsal, pps had to remember trigram of 3 consonants for different time intervals, correct recall was likely after a few seconds but performance decreased significantly after 15-18 seconds
what is the capacity of the short-term memory?
5-9 items (using rehearsal, suggested by digit span experiments)
(Miller, 1956 - ‘the magical number seven, plus or minus two’)
how is information retrieved from the short-term memory?
largely based on a rapid sequential scan of stored information
rehearsal maintains information and builds memory trace into LTM
as more information is input into the store, information which is old or has a weaker memory trace is displaced and decays
how is information encoded in the long-term memory?
as semantic and temporal (but also acoustic and visual) - depends on rehearsal or a form of association between new and pre-existing knowledge stored there
what is the duration of the long-term memory?
potentially a lifetime, especially for faces and names
what study demonstrates the lengthy duration of the long-term memory?
Bahrick et al. (1975) - 400 pps aged 17-74 tested on names and faces of students in their high school yearbooks, identification was still 70-80% accurate 48 years after leaving school
what is the capacity of the long-term memory?
potentially limitless
what study demonstrates the potentially limitless capacity of the long-term store?
Brady et al. (2008) - showed pps 2500 objects over 5.5 hours and then showed them pairs of objects and asked them to identify which one they had seen, identification of original object was 92% when paired with different object and 88% when paired with similar object
how is information retrieved from the long-term memory?
using a semantic and temporal search - it was suggested that multiple copies of a memory were retained in the long-term store, and retrieving a partial copy of a memory trace can help us access a more complete copy through association
what study demonstrates information is retrieved using association from the long-term memory?
Atkinson and Shiffrin (1965) - graduate student initially couldn’t recall capital of Washington but when he recalled capital of Oregon he could recall capital of Washington because he had learned them together
what is the serial position effect?
demonstrated by Glanzer and Cunitz (1966) - recall of information at the beginning (primacy effect) and end (recency effect) of a list is higher than in the middle of the list
words at beginning have chance to be rehearsed and transferred to LTM, words at end of list displaced memory trace for middle words so they were left in STM
evidence for STM and LTM being separate structures - case studies of brain damaged patients?
Henry Molaison suffered anterograde amnesia after brain surgery for epilepsy which caused impairment to his LTM but his STM was mostly intact - affected differentially perhaps because in different regions of brain
Clive Wearing - LTM impairment after encephalitis but STM was unaffected, showing distinction between them
however, subjects and nature of these injuries are unique so may not be generalisable based on individual cases
evidence for STM and LTM being separate structures - Baddeley (1966)?
showed that two stores use different types of coding as people make different mistakes when recalling from them - lab experiment on sequential recall of 10 words which were acoustically or semantically related, found semantically related words were more difficult to recall from LTM than acoustically related ones
evidence for STM and LTM being separate structures - Glanzer and Cunitz (1966)?
showed that getting participants to do a displacement task eg. counting backwards in 3s after a serial-position task removed the recency effect but kept the primacy effect
therefore STM was affected but not LTM
evidence for STM and LTM being separate structures - Rundus (1971)?
showed that speeding up the reading of words in a serial-position task removed the primacy effect but not the recency effect
therefore LTM affected but not STM
weaknesses of multi-store model of memory - overly simplistic view of long-term memory?
Milner et al. (1968) taught HM to perform a task where he traced a shape while watching his hand in a mirror - he got better with practice but could never remember learning the skill
Kent Cochrane who had memory loss after a motorcycle accident could recall facts but not personal life events
suggests we have one long-term store for memory of practised skills and factual information, and another for autobiographical events (procedural and declarative memory)
weaknesses of multi-store model of memory - failure to address dynamic nature of short-term memory?
MSM assumed capacity of short-term store is unaffected by type of task we are performing
duel task experiments = compete for same cognitive resource as they are similar (two verbal or visual) or different cognitive resources because they are different (one verbal one visual)
they show that we perform poorly when dealing with similar tasks but better when dealing with different tasks
weaknesses of multi-store model of memory - emphasis on rehearsal when transferring information from short-term to long-term memory?
rehearsal is used to remember things, but it isn’t essential for permanent learning
we can remember information without consciously trying to learn it, and other strategies like imagery leave strong memory traces without using rehearsal
issues and debates - use of psychological knowledge in society?
rehearsal can reinforce learned information which can be used in education to help students learn effectively
Butler and Roediger (2007) - found significant evidence that short recall tests reinforced knowledge for long-term memory of lecture content given to participants
issues and debates - reductionism?
criticised for being too simplistic - proposes that memory has very different stores which underplays ways that different memory systems are connected
issues and debates - ethics?
case studies of brain-damaged patients are often anonymised using initials to protect patient identities and maintain their right to privacy
however, individuals in high-profile cases like Clive Wearing can’t be anonymised which can cause the issue of privacy being violated
issues and debates - understanding of how psychological knowledge has developed over time?
development of this memory model, while it has limitations, led to better and more precise theories of memory being proposed
supporting evidence - Rundus (1971)?
gave pps serial position recall tasks with some words in each list repeated one or more times - the more times a word was repeated, the more likely it was to be recalled
supports idea of rehearsal
contradictory evidence - Craik and Tulving (1975)?
asked pps questions about a series of words, some about the appearance and some about the meaning
in unexpected recall task, pps recognised more words where they had processed the meaning than the sound or appearance, even though all words were visible for the same amount of time and they weren’t deliberately learning them
suggests rehearsal isn’t essential for encoding information - way info is processed is also important
