memory Flashcards
capacity of stm
limited
7 +/- 2 pieces of info
evaluation of capacity of stm studies
miller 1956:
- looks at wide range of research reliable
- didnt conduct his own research so couldnt see if he got the same results
- theory of stm supported by research
- cowan 2001 found that stm has 4 chunks, not 7 like miller suggested
jacobs:
- digit span test
- read out 4 digits, then recall them
- conducted his own experiments
- own data = mostly reliable
- limited data (women of certain age group)
- conducted experiment on letters aswell = 2 sets of data
duration of stm study procedure + evaluation
peterson and peterson:
- 24 psychology students
- experimenter read out triagram to ptp, then was told to count back in 3s or 4s
- result : as delay between hearing triagram increased, ability to recall decreases.
- conclusion: duration of approximately 18 seconds.
- nonsense triagrams lacks mundane realism
- students tend to be more intelligent than the general public
how is info coded in stm
acoustically
coding in stm study
baddeley 1966:
- 4 groups, list of words acoustically/semantically, similar/dissimilar
- asked to recall in correct order
- when asked to recall immediately, they tended to do worse with acoustically similar words
- artificial stimuli lacks mundane realism
capacity of ltm
unlimited
duration of ltm study procedure + evaluation
bahrick et al:
- 400 ptps, 17-74
- free recall, photo recognition, name recognition
- tested with 15 years = 90% accurate visual + verbal recognition
- after 48 years, recall declined to 80% name recall, 70% face recall
- free recall less good
- recognition better than recall which means we need prompts to remember stuff
- not lab exp = ecological validity
- ptps may have rehearsed beforehand
- high external validity
how is info coded in ltm
semantically
coding in ltm study and evaluation
baddeley 1966:
- 4 groups, list of words acoustically/semantically, similar/dissimilar
- asked to recall in correct order
- when asked to recall words 20 mins later, they did worse with semantically similar words
- controlled environment
- poor hearing tested by Baddeley, everyone given a hearing test
- artificial stimuli lacks mundane realism
what is the msm
presents how memory is stored, transferred between stores, retrieved, forgotten etc
msm description
3 stores: sensory register, ltm, stm
- sensory register = haptic, echoic, iconic. large capacity, duration of less than half a second. info will only pass to stm if we pay attention
- ltm = unlimited capacity, duration of 47 years.
- stm = 7 +/- 2 pieces of info capacity, duration of approximately 18 seconds
study to support msm
- HM supports idea that stm and ltm are seperate stores. 1996: had epilepsy and went under surgery to remove hippocampus and temporal lobes. alleviated epilepsy, left him with ltm problems, was unable to form new memories. couldn’t transfer new information into ltm. could remember people he had known long ago but forgot new people.
study against msm
shallice and warrington:
- kf, motorbiike accident
- could still add memories to ltm even though stm was damaged
- msm cant explain this
- kf had poor stm recall for auditory stimuli, increasing accurate recall for visual stimuli
- kf able to differentiate and recall both verbal & non verbal sounds, suggest there’s diff types of stm
general evaluation of msm
- oversimplified: not enough info
- studies to support lack mundane realism e.g digit and letters instead of a shopping list. msm may not be a valid model of how memory works irl
- prolonged rehearsal isnt needed to transfer to ltm, the more you rehearse, more likely to transfer to ltm (prolonged rehearsal). craik and watkins (1973) found that the type of rehearsal is more important than the amount. elaborative rehearsal is needed for lt store to age. suggests that msm doesnt fully explain ltm
- acknowledges qualitative differences between stm and ltm, shows them as seperate stores. stm = acoustically, ltm = semantically
- msm portrays accurate view on differences between ltm and stm. baddeley found that we mix up acoustically similar words in stm and semantically similar in ltm. shows they are diff
wmm description
- suggest stm is made up of central executive, phonological loop, visuospacial sketchpad and episodic buffer
- ce: overall control, responsible for lots of tasks
- pl: ‘inner voice’ limited capacity, deals with auditory info
- vss: used when planning a spatial task
- eb: limited capacity, integrates info from other areas
evidence to support wmm
- shallice and warrington: kf, supports wmm cause findings show that kf had poor stm recall for auditory stimuli, increased recall for visual stimuli, suggests components of memory which processes auditory and visual stimuli are seperate
evaluation of study to support wmm
- unclear whether kf had other cognitive impairments which may have affected his performance on memory tasks e.g injury caused by motorcycle accident. trauma may have affected his cognitive performance. challenges evidence from clinical studies of people with brain injuries that may have affected many different systems
general evaluation of wmm
- studies of dual task performance support separate existance of vss. baddeley et al’s ptps carried out a visual and verbal tasks at the same time. performance on each was similar to when they carried out the tasks seperately. when tasks were both visual and verbal, performance declined on both drastically cause both visual tasks compete for the same subsystem (vss) whereas there is no competition when performing a visual verbal task together. shows a seperate subsystem that process visual input.
- central executive not exactly defined. process is vague, ce may be made up of sub components
- lack of explanation draws doubt about accuracy. ce needs to be more clearly specified than just being simply ‘attention’ e.g psychologist believe the ce may consist of seperate sub components, ce = unsatisfactory component
3 types of ltm
procedural
semantic
episodic
procedural ltm
- for performance of certain actions
- unconscious recall
research for procedural ltm
hm and corkin:
- hm taught new motor skill
- gradually improved as days went on
- tested days later, did well but no recollection of doing task before
episodic ltm
- personal memories, includes details of event, context etc
- have to make effort to recall