topic 2: memory Flashcards
what is memory
its learning that has persisted over time, it’s our ability to store and retrieve information
how would you test the duration of short term memory
- give participants something to remember that has no meaning and can’t be remembered as a whole, eg. random trigram not a word or acronym
- distract them so that they can’t repeat it
- ask them to recall after different durations (5,15,15… 30 seconds etc.)
what was the study done on duration of STM
Peterson+Peterson
they investigated the duration of short term memory
laboratory experiment with a 24 psychology student sample
- had to recall meaningless three letter trigrams at different intervals
- had to count back in 3s or 4s from a specific number to prevent repetition
decided STM was 18-30 seconds
extrapolated their data to find that STM recall after 30 seconds would be 0
evaluate the Peterson & Peterson STM duration study
they investigated the duration of short term memory
+ standardised procedures made it repeatable
eg. use the same trigrams
– low ecological validity
we don’t usually count backwards in 3s to prevent repetition, so our STM isn’t actually used in the way that the study says it is
– low validity
the trigrams are meaningless, IRL we remember meaningful info.
participants could instead be told to write a shopping list then shop without it
– can’t generalise
psych students were used - good at remembering info + prior knowledge could cause demand characteristics
what study was done into STM capacity
the Jacobs study
participants were given lists of words/numbers
they had to immediately recall what was written in order after it was taken away
Jacobs gradually increased the length of the letters/digits until only on 50% of occasions could the participant recall correctly
he discovered number recall was easier than letters
people recalled an average of 9.3 numbers and 7.3 letters
he concluded that STM capacity was between 5 and 9 items
as age increases we appear to develop better recall strategies
evaluate the jacobs study on STM capacity
it was about the capacity of short term memory
– the research is old (1887), there may have been a lack of standardised scientific method
so extraneous variables may not have been controlled the room could be noisy/difficult word list
– repeated measures design increases chance of order effects
– low ecological validity
we usually remember things that are meaningful, not random letters or numbers; they have no incentive to remember these things
eg. remembering a number plate after a car crash
+ it provided useful knowledge surrounding capacity; eg. phone numbers and etc. are a length that can be remembered
+ a simple, standardised procedure that can be repeated
what can increase the capacity of STM
chunking; grouping together similar words/topics
define encoding
when information comes into our memory system from sensory input, it has to be changed into a form that the system can cope with in order to be stored
What study was done to explore encoding in STM and LTM
Baddeley
there were four groups; acoustically similar/acoustically dissimilar/semantically similar/semantically dissimilar
p’s were given a list with the og words in the wrong order and had to rearrange (either immediately/after 20 minutes)
DV was score on 10 word recall test
20% less of acoustically dissimilar were recalled than acoustically similar
so, STM must store acoustically since they got confused with similar sounding words
after 20 mins; list 4 recalled better than list 3, so LTM encodes semantically as they got confused with similar meanings
evaluate Baddeley’s study on LTM/STM encoding
+ repeatable; standardised procedures
4 conditions, 10 words, test 5 times, immediately + after 20 minutes
— ecological validity
meaningless words recalled, but in real life info has meaning and significance
+has been useful in day to day life
LTM encodes semantically, so it makes more sense to revise with mind maps vs reading out notes
describe the study on vLTM
Bahrick et al
almost 400 p’ between 17 and 74 were tested on memory of school friends
had to: free recall of classmates names
photo recognition test
name recognition test
photo matching test
year books were used to check for accuracy
p’s that had left school up to 34 yrs ago had a 90% accuracy on recognition tasks, for 48 years ago it was still 80%
evaluate Bahrick’s study on vLTM
+ repeatable if you have year books; so can be tested on different populations to find consistent results
+— ecological validity
mainly photograph recognition task - due to the meaningful stimuli
BUT matching photos and names has low ecological validity
— extraneous variables lower validity
may have seen classmates online/mentioned/in contact
+ protection from harm
researchers went to homes of elderly to interview incase they were distressed bc of not remembering names
what are the two models for memory
the multi store model of memory
the working memory model
what are elements of the multi store model of memory by Atkinson and Shiffrin, 1968 and how do they work together
information moves through the model in a linear manner and each store is viewed as separate and passive
what did HM and the star in the mirror task show
the task involved having to outline a star while looking at it in a mirror; a task that naturally requires practice
Henry had no recollection of previously completing the task but still improved each time
this was due to him being able to update his Procedural memory not his declarative memory
declaritive memory
a type of long-term memory that involves conscious recollection of particular facts and events.
procedural memory
cerebellum
Procedural memory is a part of the implicit long-term memory responsible for knowing how to do things.
what are some positives the multi-store model of memory
+ It’s supported by HM - it showed that LTM and STM are separate because it showed that the loops are different;couldnt form new LTM but could retrieve old LTM using STM
+ Peterson found STM duration to be 18-30 seconds vs Bahrick found LTM to be much longer - after 48yrs 80% of p’s still remembered their classmates
the durations are different so they must be separate, BUT they’re both lab research so have low ecological validity
+ MSM acknowledges qualitative differences between LTM and STM
bc it has separate stores for each
represents how eg. STM is encoded acoustically vs LTM is encoded semantically (supported by Baddeley and Miller)
what are some negatives of the multi store memory model
– it doesn’t consider the different LTM stores
it sees LTM as a single, unitary store, it doesn’t consider procedural, semantic and episodic LTM
also doesn’t represent how info can be transferred unconsciously to STM
– doesn’t consider the different aspects of STM as shown by KF
outline the sensory register
duration - short
capacity - very large
encoding - modality specific
we have no cognitive control over it
outline the STM store
duration - 18-30 seconds
capacity - 7 plus/minus 2, can be increased via chunking
encoding - acoustically
what does maintenance rehearsal do
it is when information is repeated continuously, the information will stay in STM
what is elaborative rehearsal
when the info is processed in a meaningful way that links it with info already in LTM to move it into LTM
outline the LTM store
duration - very long, may be unlimited, over 46 years (Bahrick et al.)
capacity - unlimited
encoding - semantically
outline the case of HM, Henry Molaison
he had severe epilepsy (around 10 seizures daily) due to a fall as a child
it was known that partially removing the hippocampus could decrease seizures, as medication wasn’t working, his dr wanted to remove the whole hippocampus
post surgery he seemed normal but he couldn’t remember meeting his new dr and reintroduced himself each time; he’d lost his STM (and had anterograde amnesia)and couldn’t form new declaritive memories
BUT, he could eat and communicate, his old memories were unaffected, he could do maintenance recall
outline the working memory model
describe the central executive (WMM)
limited capacity - 4 items
it can process info from any of the sensory systems
it allocates tasks to the sub-systems
components can only communicate with each other via the CE