Memory Flashcards
What is coding
The way in which information is changed and stored in memory
Who researched the different types of coding
Baddeley (1966)
How is STM coded
Acoustically
How is LTM coded
Semantically
What was Baddeley’s experiment (1966) in coding
Gave participants word lists of acoustically similar words, like cat, cab, can.
Also gave semantically similar words, like great, large, big.
What is the capacity of STM
7 +- 2
What is duration of STM
15-30 seconds
Who found the capacity of STM
Miller (1956)
Who found duration of STM
Peterson and Peterson (1959)
What is the duration of LTM
Potentially unlimited
What is the capacity of LTM
Potentially unlimited
Who carried out a study into the duration of LTM
Bahrick et al
What was Bahrick et als study
392 Americans between 17 and 74
1) Recognition test:
50 photos from high school yearbooks; 90% accurate recall after 15 years, 70% accuracy after 48 years.
2) Free recall test:
Participants list names of their graduating class; 60% recall after 15 years, 30% recall after 48 years.
What is a strength of Baddeley’s coding theory
Showed there were two memory stores, leading to the development of the multi-store model of memory in later years.
What is a limitation of Baddeley’s coding theory
Used artificial stimuli
Words had no personal meaning to participants, so tells us little about coding for everyday tasks.
This suggests it lacks ecological validity, and so is difficult to generalise to and apply to the wider population.
What is a limitation of Miller’s research
May overestimate STM capacity
Cowan (2001) reviewed other research and concluded capacity of STM was about 4+-1.
This means the lower end of Miller’s estimate (5) may have been more accurate.
What is a limitation of Peterson and Peterson research
Meaningless stimuli
Recall of consonant syllables doesn’t reflect meaningful everyday memory tasks, meaning the study lacks external validity.
What is a strength of Bahrick et als research
High external validity
Everyday meaningful memories (people’s faces and names) were studied.
When lab studies were conducted with meaningless pictures to be remembered, recall rates were lower.
This means Bahrick et als findings reflect a more “real-life” estimate of duration of LTM.
Draw the multi store model of memory
Who developed the multi store model of memory
Atkinson and Shiffrin
What is the sensory register and what is its coding duration and capacity (CDC)
All stimuli from environment goes here, e.g someone talking.
Coding - depends on stimuli, can be coded any way,
Duration - very brief, around a second
Capacity - very high. Over one million cells in one eye storing data goes to sensory register.
How is information transferred from SR to STM
Information passes further into memory only if attention is paid to it
What is STM and explain its CDC
A limited and temporary store
Coding - acoustic
Duration - 15 - 30 seconds
Capacity - 7 +- 2
How is information transferred from STM to LTM
Maintenance rehearsal
When we repeat (rehearse) material back to ourselves.
What is LTM and explain its CDC
A permanent memory store
Coding - mostly semantic
Duration - potentially unlimited
Capacity - potentially unlimited
How do we retrieve information from LTM
Has to be transferred back to the LTM through a process called retrieval.
What is a research support of MSM
Baddeley (1966)
Found we tend to mix up similar sounding words when using our STM (implying it is acoustically coded)
Found we mix up semantically similar words when using our LTMS.
This shows that these memory stores are separate and independent.
What is a limitation of MSM
Evidence suggesting more than one STM store
Shallice and Warrington 1970
KF had amnesia. STM recall for digits was poor when he heard them but much better when he read them.
Therefore MSM is wrong to claim there is just one STM store
What are the types of LTM stores
Episodic
Semantic
Procedural
What is episodic memory
Remembers events and experiences, e.g a recent visit to the doctors.
What is semantic memory
Stores our knowledge
Like a combination of dictionary and encyclopaedia, e.g how to apply to university, the taste of an apple, the meaning of words.
What is procedural memory
Stores memories for actions or skills, like driving a car or cycling.
Can be recalled without awareness or effort.
What is a case study strength of differing types of LTM
Clinical amnesia studies
Study of HM/ Clive Wearing
Difficulty recalling events in their past (episodic memory) but did not have semantic memories effected - HM did not need to have what a dog is explained to him.
Procedural memory also intact - Clive Wearing still played the piano after amnesia.
What is a strength of different types of LTM (not a case study)
RWA
Helps those with memory problems
Memory loss in old age is often specific to episodic memory.
Belleville et al (2006) created an intervention for older people targeting episodic memory, which improved their memory when compared to control group.
What is a limitation of different LTM stores
Conflicting findings
Buckner and Peterson (1996) reviewed research findings and concluded that semantic memory is in left prefrontal cortex.
However Tulving et al (1994) found semantic memory associated with the right prefrontal cortex.
This challenges neurophysiological support for types of memory.
Draw the working memory model
Who theorised the working memory model
Baddeley and Hitch (1974)
What is the central executive
Allocates information to subsystems
Supervisory role
What is the central executives capacity
Very limited to none
How is central executive coded
Flexible; takes in all data
What is the phonological loop made up of
Phonological store
Articulatory process
What is the phonological loop
Deals with all auditory information
What is the phonological store
Stores the words you hear (inner ear)
What is the articulatory process
Allows maintenance rehearsal (repeating sounds to keep them in working memory)
AKA the inner voice
How is phonological loop coded
Acoustically
What is the capacity of the phonological loop
About two seconds worth of what you can say
What is the visuo-spatial sketchpad
Stores visual and/or spatial information when required, e.g remembering how many windows your house has
What is the Visio-spatial sketchpad divided into
Visual cache
Inner scribe
What is the visual cache
Stores visual data
What is the inner scribe
Records arrangement of objects in visual field
How is visuo spatial sketchpad coded
Visually
What is visuo spatial sketchpads capacity
Three to four objects
What is the episodic buffer
A temporary store for information
Integrates visual, spatial and verbal information from other stores
Maintains sense of time sequencing; recording events that are happening
Links to LTM.
How is episodic buffer coded
Flexibly; encompasses all information
What is episodic buffer capacity
About four “chunks”
What is a strength of working memory model
Shallice and Warrington (1970)
Studied KF who had a brain injury
STM for auditory information was poor, but could process visual information normally, suggesting phonological loop was damaged while VSS was intact.
Supports theory of seperate stores
What is a limitation of working memory model
Lack of clarity over central executive
Baddeley (2003) said that the CE was most important but least understood component of his model.
Believed there must be more to the CE than just ‘attention’, like separate subcomponents.
What is a validity issue with WMM
Dual task studies support the model (using one store for two tasks simultaneously causes worse results)
However, these studies were done in controlled lab settings, and are unlike everyday tasks, e.g recalling random letter sequences.
This means there is little ecological validity
What is interference
When two pieces of information disrupt each other
What are the two types of interference
Proactive interference - old interferes with new
Retroactive interference - new interferes with old
What is proactive interference (with example)
When an older memory disrupts a new memory.
For example, a teacher learns many new names in the past year and so cant remember names of her new class
What is retroactive interference (with example)
When a newer memory disrupts an older one
For example, when a teacher learns many new names this year and so cant remember the names of her past class
What are the two types of interference and describe them
Proactive interference (PI) - previous information makes new info more difficult to store
Retroactive interference (RI) - new information overwrites previous memories which are similar
Who did the research into effects of similarity
McGeoch and McDonald (1931)
What was McGeoch and McDonalds study’s procedure
Participants asked to learn a list of words to 100% accuracy (i.e could recall perfectly)
Once learned, were given new material that varied in similarity to old
e.g, group 1 had synonyms, 2 had antonyms, 3 had unrelated words, etc
What were McGeoch and McDonalds study’s results
Performance depended on nature of second list.
Most similar material (the synonyms) had worst recall.
What is a strength of interference to explain forgetting
Baddeley and Hitch (1977)
Asked rugby players to recall number of teams they played against across the season
Players did not play equal games due to injuries
Those who played most had worst recall (most interference)
Suggests that interference operates in everyday situations increasing validity
What is a limitation of interference
Ecological validity
Lab studies tightly controlled variables to measure results, which is unlike real life.
What is retrieval failure
An explanation for forgetting in which forgetting information is due to the absence of correct retrieval cues or triggers.
Information is in LTM but is not accessible.
How are cues formed
When a memory is stored, we also store information about the situation, which are known as retrieval cues.
When we return to this situation, these retrieval cues can trigger our memory to be retrieved.
What are the two types of retrieval cue
External/context cues - environmental, like smell or taste.
Internal/state cues - how we feel, e.g physical, emotional, a certain mood, drunk
What did Gordon and Baddeley (1975) study in relation to retrieval cues
Context depending forgetting
What was the procedure for the context based forgetting study
Deep sea divers given word lists to learn and were later asked to recall them.
There were four conditions:
1: learn on land - recall on land
2: learn on land - recall underwater
3: learn underwater - recall on land
4: learn underwater - recall underwater
What were the results of the context based forgetting study
Accurate recall 40% lower in conditions 2 and 3 (mismatched contexts) than in 1 and 4 (matched contexts)
Shows retrieval failure was due to absence of encoded context clues
What is a strength of retrieval failure as an explanation for forgetting
Range of supporting evidence
Godden and Baddeleys study. Carter and Cassaday (drugs study).
Eysenck and Keane (2010) argued that retrieval failure may be the main reason for forgetting in LTM.
What did Loftus and Palmer study (1974)
Leading questions and their effect on eyewitness testimony (EWT)
What was the procedure of Loftus and Palmers (1974) study
45 participants (students) shown a clip of car accidents and then answered questions about speed.
Critical question was “About how fast were the cars going when they hit each other”.
There were five groups of participants and each were given a different verb in the critical question: hit, contacted, bumped, collided or smashed.
What were the findings of Loftus and Palmers (1974) study
Verb ‘contacted’ produced a mean estimated speed of 31.8mph.
Verb ‘smashed’ produced mean estimated speed of 40.5mph.
The leading question (verb choice) biased eyewitness recollections of events.
What are the two explanations for why leading questions affect EWT
Response-bias
Substitution explanation
What is response bias
Wording of question doesn’t effect eyewitness memory of an event, but influences the answer given.
What is substitution explanation
Wording of a question does affect eyewitness memory, interfering with original memory and distorting its accuracy.
What did Gabbert et al (2003) study
Post event discussion
What was Gabbert et al’s (2003) procedure
Paired participants to watch a video of the same crime, but filmed so each participant could see elements in the event that the other could not.
Both participants discussed what they had seen on the video before completing a test of recall.
What were the results of Gabbert et al’s study
71% of participants wrongly recalled aspects of the event that they could not have seen on the video, but had heard in the discussion
In the control group, which had no discussion, there were no subsequent errors.
This is evidence of memory conformity affecting EWT
Why does post event discussion affect EWT
Memory contamination
Memory conformity
What is memory contamination
When co witnesses discuss a crime, they mix (mis)information from other witnesses into their own memories
What is memory conformity
Witnesses go along with each other to win social approval, or because they believe the other witnesses are right
What is a strength of misleading information affecting EWT
RWA
Loftus and Palmers study lead to police changing interview techniques to be more careful in avoiding leading questions.
Psychologists now sometimes called to the stand to explain limitations of EWT to juries, which should reduce false convictions and improve the justice system.
What is a limitation of misleading information affecting EWT
Evidence against memory conformity
Skagerberg and Wright’s (2008) study had participants discuss a scene of a mugging clip.
In one, mugger had dark brown hair, in the other, light brown.
Participants recalled a ‘blend’ of the two clips, with one stating the hair was ‘medium brown’.
What is weapon focus
Witnesses attention is drawn to the weapon in a crime more than other details of the event, as the weapon causes anxiety
Who studied the negative effects of anxiety on EWT
Johnson and Scott (1976)
What was Johnson and Scotts procedure for their study
Participants sat in waiting room believing they were about to go to a lab study
Two conditions; low and high anxiety crime acted in front of them
Participants later asked to pick the man from a line up of 50 photographs
Explain the two conditions in Johnson and Scotts study
High anxiety condition - heated argument heard, accompanied by sound of breaking glass. Man then walked through the waiting room holding a bloody knife
Low anxiety condition - participants heard a casual conversation and then saw a man walk through waiting room carrying a pen with grease on his hands.
What were the findings in Johnson and Scotts study
49% of participants in low anxiety condition were able to identify the man.
33% of high anxiety participants were able to identify the man.
Shows weapon focus on the knife had a detrimental effect on the witnesses ability to identify the man.
Who did a study on whether anxiety has a positive effect on EWT
Yuille and Cutshall (1986)
What was the procedure of Yuille and Cutshalls study
In an actual crime, gun store owner shot a thief dead. 21 witnesses, 13 agreed to participate in study.
Interviewed Ps 4-5 months after the incident. Information recalled was compared to police interviews taken at time of shooting.
Witnesses also rated how stressed they felt at time of incident.
What did Yuille and Cutshall find
Witnesses were very accurate in what they recalled, and there was little change after 5 months. Some details less accurate like height and weight.
Participants who recorded highest level of stress were most accurate, with about 88%, compared to 75% for the less stressed group.
Suggests anxiety does not reduce accuracy of EWT and may even enhance it.
How can the contradictory studies of anxiety’s effects on EWT be explained
Inverted U-Theory
What is the inverted U-Theory
Yerkes and Dodson (1908)
Argue relationship between performance and arousal/stress is an inverted U.
Deffenbacher (1983) reviewed 21 studies on EWT with contradictory findings and found that the Yerkes-Dodson effect could explain how both high and low levels of anxiety produce low recall, while optimum levels produce very good recall.
What is a limitation of Johnson and Scott’s study
Anxiety may not be relevant to weapon focus
Participants may have focused on weapon not from anxiety but from surprise.
Pickel (1998) found accuracy in identifying the “criminal” was poorest when object held was unexpected, e.g a raw chicken or a gun in a hairdressers (both unusual)
Suggests weapon focus is due to unusualness rather than anxiety, so tells us nothing about effects of anxiety.
What is a strength for Johnson and Scott’s findings
Valentine and Mesout (2009)
Used heart rates to divide visitors to Londons Labyrinth into high and low anxiety groups.
High anxiety participants were less accurate than low anxiety participants in identifying a target person.
Supports claim that anxiety negatively affects EWT
What is a strength of Yuille and Cutshalls study
Christianson and Hubinette (1993)
Interviewed witnesses to bank robberies.
Some were direct victims (high anxiety), others were bystanders (less anxiety).
More than 75% accurate recall across all witnesses. Direct victims were most accurate.
Suggest anxiety does not affect EWT and may even enhance it.
Who created the cognitive interview
Fisher and Geiselman (1992)
What are the 4 stages of the cognitive interview
1) Report everything - witnesses told to include every detail of event, even if seems irrelevant. Can trigger other memories.
2) Reinstate the context - witness returns to crime scene in their mind and imagines the environment and how they felt (external retrieval cues)
3) Reverse the order - Events recalled in a different order, e.g end back to the beginning. Prevents witnesses basing their descriptions on expectations of how the event must have happened rather than actual events. Also prevents dishonesty
4) Change perspective - Witness recalls how event must have looked from someone else’s perspective. Prevents influence of schema on recall.
What is a research support for cognitive interview
Meta analysis by Kohnken et al (1999)
Combined data from 55 studies comparing CI with the standard police interview.
CI produced average of 41% more correct information than standard interview. Only four studies showed no difference.
Suggests that CI is effective in helping witnesses recall information that is available but not accessible.
What is a negative of Kohnken et al’s study
Also found increases of inaccurate information.
Therefore, police officers need to be very careful about how they treat eyewitness evidence from CI.
What are 2 limitations of CI
Time consuming to train officers to use CI, and takes a long time to establish rapport with witnesses.
Suggests CI is not realistic to be used widely by police forces.
Some elements more useful than others
Milne and Bull (2002) found each individual technique of CI alone produced better information than standard interview.
However, when combining ‘report everything’ and ‘reinstate the context’, recall was better than any other technique alone or combined, which casts doubt on overall credibility of CI.
