Memory Flashcards
define short term memory
The limited capacity memory story
- coding is mainly acousting
- capacity is 7 +-2 items
- duration is about 18 seconds
Define long term memory
The permanent memory store
- coding is mainly semantic
- unlimited capacity
- unlimited duration
Define coding
The format in which information is stored in the various memory stores
Define capacity
The amount of information that can be held in a memory store
Define duration
The length of time information can be held in memory
What research has been done into coding
Baddeley
- gave lists of words to four different groups of pps
- 1: acoustically similar
- 2: acoustically dissimilar
- 3: semantically similar
- 4: semantically dissimilar
- pps were shown the original words and asked to recall them in the correct order
- STM: worse at recalling acoustically similar words
- LTM: worse at recalling semantically similar words
What does semantic mean
Have similar meaning
What does acoustic mean
Similar sounding
What are examples of capacity
- digit span
- span of memory and chunking
What is the digit span research into capacity
Jacobs
- researcher reads out 4 digits
- pps recalls them out loud in the correct order
- the researcher adds 1 more digit until the pps can no longer recall them
- this was the individuals digit span
- the mean span of digits was 9.3
- mean span of letters was 7.3
What is the research into span of memory and chunking
Miller
- noticed things come in groups of 7s
- 7 days, 7 deadly sins, 7 notes
- Miller thought that the capacity of STM is about 7 +-2 items
- people can really 5 words as easily as 5 letters
- this is done by chunking
What is chunking
Grouping sets of digits or letters into units or chunking
What was the research done into duration
- duration of STM
- duration of LTM
What research was done into the duration of STM
Peterson + Peterson
- tester 24 in 8 trials
- in each trial the student was given a constant syllable
- also given a 3 digit number
- student then counted backwards from a number until told to stop
- counting backwards prevented mental rehearsal
- told to stop after varying periods of time
- recall worsened with more time between hearing and recall
- 3 seconds = 80% recall
- 18 seconds = 3% recall
What research was done into duration of LTM
- Bahrick
- studied 392 American participants between 17-74
- high school year books were obtained
- recall was tested in various ways
- 1: photo recognition test consisting of 50 photos
- 2: free recall
- within 15 years = 90% accuracy
- after 48 years = 70% accuracy
- free recall was less accurate
- 15 years = 60% accuracy
- 48 years = 30%
Evaluation points for research on coding
- separate memory stores
- artificial stimuli
PEEL for separate memory stores = coding
- strength
- Baddeley’s study identifies a clear difference between two memory stores
- later research showed that there are some exception to his findings
- STM being acoustically coded and LTM being semantically coded has remained constant
- led to the multi-store model
PEEL for artificial stimuli - research on coding
- limitation
- used artificial stimuli rather than meaningful material
- word lists had no personal meaning
- findings might not tell us much about coding in different kinds of memory tasks
- meaningful information may use semantic coding
- limited application
Evaluation for research on capacity
- a valid study
- not so many chunks
PEEL for a valid study - research on capacity
- strength
- study has been replicated
- old psychology research often lacked adequate controls
- some pps digit spans might have been underestimated
- distracted during testing
- Jacobs findings have been confirmed y others
- valid test of digit span in STM
PEEL for not so many chunks - research on capacity
- limitation
- Miller’s research may have overestimated STM capacity
- Cowan reviewed other research
- concluded that STM capacity is only about 4 +-1 chunks
- the lower end of Miller’s estimate is more appropriate
Evaluation points for research on duration
- meaningless stimuli in STM study
- high external validity
PEEL for meaningless stimuli in STM study - research on duration
- limitation
- stimulus material was artificial for Peterson + Peterson
- not completely irrelevant
- we do sometimes try to remember fairly meaningless material (phone numbers)
- recalling constant syllables doesn’t reflect most everyday memory activities
- lacked external validity
PEEL for high external validity - research on duration
- strength
- Bahrick’s study has high external validity
- the researchers investigated meaningful meteorites
- when the study was conducted with meaningless pictures recall rates were lower
- findings reflect a more real estimate of he duration of STM
What is the multi-store model
A representation of how memory worlds in terms of three stores
- sensory register
- short term memory
- long term memory
Also describes how information is transferred from one store to another, what makes some memories last and some disappear
What is the sensory register
- all stimuli from the environment pass through the sensory register
- comprises several registers: one from each sense
- coding for each is modality specific
- duration is very brief (<0.5 seconds)
- very high capacity
- information passes to the next component if it is payed attention to
What is modality specific
Depends on the sense
How is vidual information coded
Iconic memory
How is acoustic information coded
Echoic memory
What happens in the STM in the MSM
- information in codes mainly acoustically
- duration is about 18 seconds unless rehearsed
- limited capacity before forgetting occurs
- if information is rehearsed enough is passes to LTM
What is maintenance rehearsal
When we repeat material to ourselves over and over
What happens in the LTM of MSM
- potentially permanent memory store
- after information has been rehearsed for a prolonged time
- coded mostly semantically
- duration may be up to a lifetime
- MSM information must be transferred back to the STM via retrieval
Evaluation points for MSM
- research support
-COUNTERPOINT - more than one STM store
- elaborative rehearsal
PEEL for research support
- strength
- studies showing that STM and LTM are different
- Baddeley found that we tend to mix up word with similar meaning when using our STM
- mix up words with similar meaning when using our LTM
- further support from the studies of capacity and duration
- clearly show that STM and LTM are separate
COUNTERPOINT
- we form memories related to all sorts of useful things
- many studies that support MSM used none of these
- instead they used digits, letters and words
- MSM may not be a valid model of how memory works
PEEL for more than one STM store - MSM
- limitation
- evidence for more than one STM store
- Shallice + Warrington = studied KF
- KF had amnesia
- STM for digits was poor when read out loud to him
- recall was much better when reading the digits to himself
- there could even be another short term store for non verbal sounds
- MSM is wrong in claiming that there is just one STM store processing different information
PEEL for elaborative rehearsal - MSM
- limitation
- prolonged rehearsal is not needed for transfer to LTM
- the amount of rehearsal is what matters
- the more you rehearse the more likely it is to transfer to LTM
- called prolonged rehearsal
- the type of rehearsal is more important than the amount of
- elaborative rehearsal is needed for long term storage
- linking information with existing knowledge
- information can be transferred to LTM without prolonged rehearsal
- doesn’t fully explain how LTS is achieved
What is elaborative rehearsal
When you link information with existing knowledge