memory Flashcards
multistore model
describes how information flows through the memory system - comprised of 3 stores, linked by processing
sensory register
- stimulus from environment passes into the SR
short term memory
- requires attention to pass into STM
long term memory
- requires maintenance rehearsal to pass into LTM
- retrieval is the process used to recall materials stored in LTM by tranferring it back to STM
MSM
ao3
✘ evidence suggests more than 1 type of STM
- KF, a px w amnesia was studied
- his STM for digits was poor when read out loud to him but much better when read himself
- suggests there must be different STM stores to process visual and auditory info
- which contradicts the MSM which states there is only 1 type of STM
- WMM is a better explanation for this
✘ oversimplifies LTM
- lots of research evidence suggesting there are different stores (semantic, episodic + procedural)
- MSM doesn’t reflect these different types of LTM + so is limited
sensory register
capacity: unknown but v large
duration: v limited (1-2 seconds)
coding: raw/unprocessed info (from all 5 senses)
STM
capacity: limited (7 +/- 2 chunks of info)
duration: limited (20 seconds)
coding: acoustic
LTM
capacity: unlimited
duration: lifetime
coding: semantic
capacity of STM
JACOBS
- used a digit span test
- students asked to repeat back a string of numbers/letters
- on average, ppts could recall 7.3 letters and 9.3 words
duration of STM
PETERSON & PETERSON
- students asked to recall 3-letter trigrams at different intervals (3, 6, 9, 12, 15 and 18 seconds)
- to prevent rehearsal, they had to count backwards in 3s from a specific number until asked to recall the letters
- 80% of trigrams recalled correctly after 3s
- 10% of trigrams recalled correctly after 18s
duration of LTM
BAHRICK:
- university graduates asked to match the names of former classmates w photographs from their high school yearbook
- 60% correct recall after 47 years
types of LTM
episodic:
- stores events from our lives
eg psychology lesson
- have to make conscious effort to recall them
semantic:
- stores our knowledge of the world
eg meaning of words
procedural:
- stores memories for actions + skills
eg driving a car
- recalled w/o awareness or effort
types of LTM
ao3
✔ research support - brain scan studies
- tulving et al had ppts perform various memory tasks while scanning their brains with a PET scanner
- episodic + semantic memories were in the prefrontal cortex
- semantic in the left side + episodic in the right
- this shows a physical reality in the brain that supports the existence of different types of LTM
✔ research support - case study evidence
- clinical studies of amnesia: HM & Clive Wearing
- showed both had difficulty recalling events that had happened to them in their pasts
- but their semantic memories were relatively unaffected
- so this suppots the view that there are different memory stores in LTM
- as one alone can be damaged but the others remain unaffected
✘ evidence based on case studies has low external validity
- unique + complex cases
- w serious lack of control over variables
- eg can’t control precise location of damage or personality variables
- low external validity
- difficult to generalise from these studies
working memory model
a model of STM, explaining how it’s organised + how it functions
- an improvement to the MSM
central executive
- attentional process which monitors incoming data
+ allocates slave systems to tasks - very limited storage capacity
✘ lack of clarity over CE making it unsatisfactory
- too simplistic + vague
- should be more clearly specified rather than just being ‘attention’
- some psychologists believe it may consist of different components
- if this is true it means the WMM hasn’t been fully explained
phonological loop
- temporarily retains auditory information
consists of
- phonological store - stores the words you hear
- articulatory process - allows maintenance rehearsal
✔ supporting evidence
- research has found that people find it more difficult to remember a list of long words rather than short words - this is the word length effect
- this is because there is limited space for rehearsal in the articulatory process
- the word length effect disappears when given an articulatory suppression task
- this is a strength of the model as it supports the function of the phonological loop
visuo-spatial sketchpad
- stores visual and spatial information when required
consists of:
- visual cache - stores visual data
- inner scribe - records arrangement of objects in visual field
✔ research to support VSS
- researchers have carried out dual task performance studies
- found that people have more difficulty doing 2 visual tasks simultaneously rather than doing a visual task and verbal task at the same time.
- this difference can be explained by the fact that both visual tasks compete for the same limited resources
- whereas when doing a verbal and visual task there is no competition.
- this provides evidence for the existence of the VSS
- MSM cant explain this
episodic buffer
- added in 2000
- temporary store for information
- facilitates communication between CE and LTM
- maintains sense of time sequencing
KF case study
✔ case study of patient KF
- injured in motorcycle accident + acquired brain damage
- poor STM ability for verbal information
- but could process visual information normally
- suggests that just his phonological loop was damaged but other areas of memory were intact
- supports existence of separate visual and acoustic store
- isn’t supported by the MSM
- however this evidence may be unreliable as it concerns a patient who had also suffered a traumatic experience
therefore findings cannot be generalised
forgetting
interference theory
- an explanation for forgetting
- occurs when 2 pieces of info are in conflict
- proactive interference: when an older memory disrupts a newer one
- retroactive interference: when a newer memory disrupts an older one
- worse when memories are similar
interference theory
baddeley & hitch
✔ research support
- investigated retroactive interference
- asked rugby players to recall the names of teams they had played against so far that season, some of which who had missed some games due to injuries
- accurate recall didn’t depend on how long ago the match took place but the no of matches played in the meantime
- concluded that this was the result of retroactive interference as the learning of new team names interfered w the memory of earlier ones
- shows that interference can apply to everyday situations
- high ecological validity
interference
ao3
✘ lack of control over extraneous/ppt variables
* not controlled (opposite of lab study)
* we don’t know what other events have occurred in each of the players’ lives that might effect their memory
* low internal validity
forgetting
retrieval failure
- an explanation for forgetting
- occurs due to absence of retrieval cues
- context-dependent forgetting: memory retrieval dependent on an external/environmental cue (eg the weather or a place)
- state-dependent forgetting: memeory retrieval dependent on an internal cue / state of mind (eg feeling upset or being drunk)
retrieval failure
godden & baddeley
✔ research support
* 18 scuba divers were split into 4 different conditions where they either learned words on land or underwater and then recalled them either on land or underwater
* words learned underwater were better recalled underwater + words learned on land were better recalled on land
* retrieval failure had occured when in a different environment, due to an absence of environmental cues
* demonstrates context-dependent forgetting
retrieval failure
ao3
✘ low ecological validity?
- differences in env/contexts would have to be v different for an effect to be seen
- underwater vs land - can’t apply this to real life situatuons
eyewitness testimony
leading questions
- response-bias explanation: suggests wording of the question has no real effect on ppts’ memories but influences how they decide to answer
- substitution explanation: suggests that the wording of a question actually changes the ppts’ memories of an incident
leading questions
loftus & palmer
- 45 american students made to watch clips of a car accident
- divided into 5 groups, each given a different verb in the critical question: “about how fast were the cars going when they hit each other?”
- different verbs being: hit, contacted, bumped, collided or smashed
- the verb “contacted” produced a mean estimate speed of 31.8mph
- the verb “smashed” produced a mean estimate speed of 40.5mph
- suggests EWT is affected by the wording of a question
eyewitness testimony
post-event discussion
- memory contamination: when witnesses discuss a crime + mix misinformation from other witnesses w their own memories
- memory conformity: when witnesses go along w each other to win social approval bcause they believe the other witnesses are right
post-event discussion
gabbert et al
- pairs of ppt made to watch a clip of the same crime but from different visual angles, giving some a clearer view of the crime than others
- both ppts discussed w each other what they had seen before being individually questioned
- 70% of the ppts mistakenly recalled aspects of the events they had not seen in the clip, but picked up in the PED
- in a control group, where there was no discussion, there were no errors
- ppts’ memories can be altered significantly by PEDs
leading qs & PEDs
ao3
✘ use of artificial materials
- ppts were watching clips of an accident, which is v different from witnessing a real life accident
- not true to real life - less stressful
- tells us little about the effect of leading questions/PEDs on EWT in real crimes and accidents
- lacks ecological validity
✘ demand characteristics
- ppts aware they’re being studied
- may work out aim of investigation
- in an attempt to be helpful, if they don’t know the answer to a question, they may just say whatever they think the researcher wants to hear
- means their answers may not actually reflect their true memories
- this challenges the validity of EWT research
eyewitness testimony
anxiety
johnson & scott (negative effect)
- ppts sat in waiting room were made to hear an argument in the next room + exposed to either:
- a man walking past holding a pen (low-anxiety)
- or the sound of breaking glass + a man walking past holding a paper-knife (high-anxiety)
- ppts then had to identify the man from 50 photos
- those in the low-anxiety condition, were correct 49% of the time
- those in the high-anxiety condition were correct 33% of the time
- tunnel theory of memory suggests witness’s attention is on the weapon (weapon focus) - source of anxiety
anxiety
johnson & scott
ao3
✘ may test surprise instead of anxiety
- ppts may focus on weapon because they’re surprised rather than because they’re scared
- similar research has been carried out, using unusual items instead, eg raw chicken
- EWT accuracy was found to be poorer for higher unusualness
- so weapon focus effect isn’t entirely due to anxiety
- thus doesn’t tell us specifically about the effects of anxiety on EWT
eyewitness testimony
anxiety
yuille & cutshaw (positive effect)
- conducted a study of a real-life shooting where 13 witnesses agreed to be interviewed 4-5 months after the shooting + were additionally asked to rate how stressed they felt at the time of the incident
- findings showed that those who reported highest levels of stress were most accurate
anxiety
yuille & cutshaw
ao3
✘ lack control of variables
- witnesses interviewed 4-5 months after the event
- many things happen to them in this time that can’t be controlled by the researchers
- eg PEDs
- these extraneous variables may be responsible for accuracy of recall, instead of anxiety
- low internal validity
yerkes-dodson law
- argue that the relationship between stress and accuracy is curvilinear rather than linear
- inverted U theory states accuracy will increase w stress but only to a certain point, after which it decreases dramatically
anxiety
ao3
✘ demand characteristics
- ppts aware they’re being studied
- may work out the aim of the investigation
- may answer according to what they believe will be most helpful to the researcher, instead of what’s true to their memory
- thus, research is not measuring the effect of anxiety on accuracy of EWT
- low internal validity
cognitive interview
- report everything
- context reinsatatemnt
- reverse order
- change perspective
report everything
- encouraged to include every detail, even if it seems irrelevant
- seemingly trivial details may be important or may trigger other memories
context reinstatement
- witness returns to og crime scene in their mind and imagines the environment + their emotions
- based on concept of context-dependent forgetting
- cues from the context may trigger recall
reverse order
- prevents the influence of schema/expectations
- also prevents dishonesty (harder to lie)
change perspective
- witness recalls incident from another person’s perspective
- prevents influence of schema/expectations on recall
enhanced cognitive interview
- fisher et al developed additional elements of CI
- includes focus on social dynamics of interaction (eg eye contact)
- includes reducing eyewitness’s anxiety, minimising distractions + asking open-ended qs
cognitive interview ao3
✔
✘ time consuming
- police reluctant to use CI because it takes much more time than standard police interview
- more time needed to establish rapport w witnesses to allow them to relax
- requires special training
- thus unlikely that proper version of CI is actually used, so full affects are not exhibited
