Memory Flashcards
Describe short-term memory (STM)
-acoustically coded
-limited capacity of approx 5-9 items
-duration of approx 18-30s
Describe long-term memory (LTM)
-semantically coded
-unlimited capacity, permanent store
-duration up to a lifetime
What is coding?
The format in which information is stored in various memory stores
Who did research on coding and when?
Baddeley 1966
Describe the procedure and findings of Baddeley’s research into coding
Gave different lists of words to 4 groups
1. acoustically similar
2. acoustically dissimilar
3. semantically similar
4. semantically dissimilar
Asked to recall the words in order
immediate recall (STM) was worse when acoustically similar- STM coded acoustically
after 20 minutes (LTM) recall was worse when semantically similar- LTM coded semantically
What is a strength and a weakness of Baddeley’s research into coding?
Identified clear difference between stores
-STM mostly acoustic
-LTM mostly semantic
-stood test of time
Helped understanding of memory leading to the MSM
Lacks mundane realism
-artificial stimuli with no personal meaning
-doesn’t say anything about memory in real life
-more meaningful STM may be coded semantically
Limited application
What is capacity?
The amount of information that can be held in a memory store
Who did research on capacity and when?
Jacobs 1887
Miller 1956
Describe the procedure and findings of Jacobs’ research into capacity
Researcher read out digits, adding one each time until the participant repeats it back in the incorrect order
Digit span for digits is 9.3 but 7.3 for letters as a mean
Describe Miller’s research into capacity
Found that things come in 7s (eg: days of the week, musical notes)
STM capacity is 7±2
Can also recall 5 words as easily as 5 letters via chunking
What is chunking?
Grouping sets of digits/letters into units/chunks
What is a strength and a weakness of research into capacity?
Jacobs’ research replicated
-although at time lacked adequate control over EVs and CVs
-so digit span may have been underestimated due to distraction
-but results confirmed by a controlled study by Bopp and Verhaeghen
Valid
Miller may have overestimated the STM capacity
-Cowan 2001 replicated concluding 4±1 chunks
Lower end of Miller’s estimation is more appropriate
What is duration?
The length of time information can be held in memory
Who did research on duration and when?
Peterson and Peterson 1959
Bahrick et al 1975
Describe the procedure and findings of Peterson and Peterson’s research into duration
24 students each in 8 trials with different retention intervals (3, 6, 9, 12, 15, 18)
In each trial they were given a consonantal trigram, and then had to count backwards from a 3-digit number to prevent mental rehearsal
After 3s, recall 80% accurate
But after 18s, recall 3% accurate
STM duration is 18s unless verbal rehersed
Describe the procedure and findings of Bahrick et al’s research into duration
392 Americans had their high school yearbooks obtained
Tested for photo recognition and free recall
Within 15y of graduation, photo recognition 90% accurate, but 70% after 48+y
Within 15y of graduation, free recall 60% accurate, but 30% after 48+y
Shows LTM may last up to a lifetime for some material
What is a strength and a weakness of research into duration?
Bahrick et al’s research has high external validity
-measures meaningful memories
-recall is lower for meaningless memories, shown by Shepard
Reflects more real estimate of LTM duration
Peterson and Peterson use artificial stimulus
-doesn’t reflect everyday memory activities with meaningful material
Lacks external validity
Who created the multi-store model of memory and when?
Atkinson and Shiffrin 1968
What is the multi-store model of memory?
3 unitary memory stores where information is transferred between them in a linear sequence to possibly become a memory
Describe the sequence of the multi-store model of memory?
Stimulus from environment –> sensory register –> STM —> LTM
What is on the arrow from the sensory register to the STM in the MSM?
Attention
What is on the arrow within the STM and to the LTM in the MSM?
STM- maintenance rehearsal
STM->LTM- prolonged rehearsal
What is on the arrow from the LSM to the STM in the MSM?
Retrieval
What is the arrow pointing downwards from the sensory register in the MSM?
Decay
What is the arrow pointing downwards from the STM in the MSM?
Response (remembering)
What is the sensory register (MSM)?
Where all stimuli from the environment goes
What is the coding of the sensory register (MSM)?
Modality specific
eg: iconic=visual echoic=auditory
What is the capacity of the sensory register (MSM)?
Very high
For example, one eye has over 100mil cells storing data
What is the duration of the sensory register (MSM)?
Very brief- less than half a second
Describe how information transfers between the STM and LTM in the MSM
Through maintenance rehearsal, material is repeated over and over, if if this is done for long enough (prolonged rehearsal) it passes to the LTM
To retrieve information, it’s transferred back to the STM
Describe the case of patient HM
His hippocampus was removed
He performed well on STM tasks
But remembered little personal/public events and his LTM never improved
Shows the stores are seperate
Describe the case of patient KF
He had amnesia
When read aloud, his digit span was poor
But when he read it himself, his recall was better
Shows separate STM stores for visual/auditory information
What is the strength of the multi-store model of memory?
A lot of research support
-HM shows that memory is made up of separate stores for different types of memory
-Baddeley showed STM mixed up when acoustic and LTM mixed up when semantic, shows they’re independent stores
The explanatory power of the MSM is increased
What are 2 weaknesses of the multi-store model of memory?
Oversimplifies memory, more than 1 STM store
-patient KF shows separate for visual/auditory
Unitary theory is questioned, reducing credibility
Other types of rehearsal needed to transfer information to the LTM
-Craik and Watson 1973 also found elaborative rehearsal, linking to existing knowledge needed to transfer
MSM can’t fully explain transfer to LTM, explanatory power reduced
Who created the working memory model and when?
Baddeley and Hitch 1974
What are the 4 components of the WMM?
Central executive
Visuo-spacial sketchpad
Phonological loop
Episodic buffer
In the WMM- the central executive…
1. What does it do?
2. What is its coding?
3. What is its capacity?
Monitors incoming data
Divides/focuses attention, allocating tasks to the 3 slave systems
Coding- can’t store information, but processes any modality
Capacity- very limited
In the WMM- the phonological loop…
1. What does it do?
2. What is its coding?
3. What is its capacity?
Processes auditory information (spoken/written) preserving the order
Made up of the phonological store (stores words heard) and the articulatory process (allows maintenance rehearsal)
Coding- acoustic
Capacity- 2 seconds
In the WMM- the visuo-spatial sketchpad…
1. What does it do?
2. What is its coding?
3. What is its capacity?
Processes visual and spacial information in the inner eye
Logie 1995 further divided to visual cache (visual info) and inner scribe (spacial info)
Coding- visual
Capacity- 3-4 objects
In the WMM- the episodic buffer…
1. What does it do?
2. What is its coding?
3. What is its capacity?
Added in 2000, temporary store for information processed by other stores
Maintains time sequencing
Links the WM to the LTM and wider cognitive processes
Coding: store for the central executive, modality free
Capacity- about 4 chunks
What are 2 strengths of the working-memory model?
Clinical evidence
-Patient KF, phonological loop damaged, visuo-spatial intact
Supports evidence of separate visual/acoustic stores
Dual-task performance supports
-Baddeley had participants do visual/verbal task at the same time with similar performance
-When both tasks the same, performance decreased due to competition, no competition in first task
Must be separate subsystems
What are 3 weaknesses of the working-memory model?
Clinical evidence…
-may have other cognitive impairments, KF in a motorbike accident caused trauma
Can’t generalise findings to other people
Dual-task performance…
-tasks lack mundane realism, high control in lab, not like real life
Can’t generalise findings to real-life situations
Lack of clarity over the nature of the central executive
-‘most important but least understood
-must be more than attention, may be subcomponents
WMM not fully explained, integrity decreased
Who created the theory about the 3 types of long-term memory and when?
Tulving 1985
What are the 3 types of LTM?
Episodic (like a diary)
Semantic (like a dictionary or an encyclopaedia)
Procedural
What is episodic memory?
LTM store for personal events from one’s own life
What is semantic memory?
LTM store for knowledge of the world including facts, words and concepts
What is procedural memory?
LTM store of how to do learnt motor skills
Give 4 features of episodic memory
- Time stamped (time and place)
- Consciously recalled/declarative
- Autobiographical
- Low resistance to forgetting/distorting
Give 4 features of semantic memory
- Not time stamped
- Consciously recalled/declarative
- Not autobiographical
- Moderate resistance to forgetting/distorting
Give 4 features of procedural memory
- Not time stamped
- Not consciously recalled/non-declarative
- Not autobiographical
- Resistance to forgetting/distorting
Give an example of episodic memory
First day of school
Give an example of semantic memory
Paris is the capital of France
Give an example of procedural memory
How to ride a bike
Describe the case of Clive Wearing
Had severe amnesia damaging hippocampus
Could still play piano brilliantly (procedural)
Knows that he has children and wife (semantic)
Can’t remember piano lesson or names of kids (episodic)
Give 2 strengths of the three types of LTM
Clinical evidence
-Clive Wearing and HM
-HM knew concept of dog, but couldn’t remember stroking dog
-Both had episodic damaged
Supports existence of different stores as just one can be damaged, increases credibility
Real world application in helping with memory problems
- Belleville et al 2006 made intervention
-episodic improved after training
Distinguishing between the different types can enable treatment
Give 2 weaknesses of the three types of LTM
Research has low population validity
-mostly on case studies of brain damage
-Clive Wearing had high intelligence and was professional, so not representative
Can’t generalise to others, explanatory power reduced
Conflicting neuroimaging evidence
-some say episodic on the right of prefrontal cortex
-others say right side for retrieval of episodic and left for encoding of episodic
Challenges the evidence to support as there is poor agreement
What is the interference theory as an explanation for forgetting?
Forgetting is due to information interfering with the retrieval of available information from the LTM
The memory can’t be accessed as 2 pieces of information disrupt each other, leading to forgetting/distortion of one/both memories
What are the 2 types of interference?
Proactive
Retroactive
What is proactive interference, and give an example
When an older memory disrupts the recall of a newer memory
A teacher forgets the names of their current class
What is retroactive interference, and give an example
When a newer memory disrupts the recall of an older memory
A teacher forgets the names of their previous students
Who did the study into similarity for interference, and when?
McGeoch and McDonald (1931)
Describe the procedure for McGeoch and McDonald’s similarity study
6 groups of participants had to learn 10 words until 100% accuracy, then learnt a new list
1. synonyms
2. antonyms
3. unrelated words
4. consonant syllables
5. 3-digit numbers
6. control group, no new list
Then, had to recall first list
Describe the findings and explanations for McGeoch and McDonald’s similarity study
Most similar material had the worst recall, so interference is strongest when the memories are similar
RI explanation- the new information overwrites previously similar memories due to their similarity
PI explanation- previously stored information makes new similar information harder to store
What are 2 strengths of the interference theory?
Lab studies support proactive and retroactive
-McGeoch and McDonald
-Keppel and Underwood, trigrams given to remember, earlier trigrams remembered as the earlier memory of the trigrams interfered with the later
Supports interference theory
Evidence of interference in real world
-Baddely and Hitch rugby players
-those playing most games had more interference and poorer recall of teams played
Interference can operate in the real world, increasing external validity
What are 2 weaknesses of the interference theory?
Lab studies used lack mundane realism
-artificial stimuli (don’t use memory in this way)
-short learning-recall time (usually much longer)
Interference can’t explain in the real world
Interference is temporary, can be overcome by cues
-Tulving + Psotka had list of words in categories
-recall was gradually worse (proactive interference), but category given and recall rose
Not said by the interference theory so explanation lacks validity
What is retrieval failure as an explanation for forgetting?
Forgetting occurs due to insufficient cues
The memory is available in the LTM, but not accessible
What is a cue?
A meaningful or indirect trigger allowing a memory to be accessed
Who developed the encoding specificity principle and when?
Tulving 1983
What does the encoding specificity principle (ECP) suggest?
A cue has to be present at encoding and retrieval to be helpful
Forgetting occurs when cues at encoding/retrieval are different/absent
What is an example of a meaningful cue?
Mnemonics
What are the 2 types of non-meaningful forgetting due to the absence of cues?
Context-dependent forgetting
State-dependent forgetting
What is context-dependent forgetting and the research that supports it?
Recall depends on an external cue (eg: place, weather)
Godden and Baddeley (1975)
What is state-dependent forgetting and the research that supports it?
Recall depends on an internal cue (eg: mood, drugs)
Carter and Cassidy (1998)
Describe the procedure and findings for Godden and Baddeley’s research into context-dependent forgetting
Had deep-seas divers learn + recall list in 4 different conditions:
1. Land + Land
2. Land + Underwater
3. Underwater + Land
4. Underwater + Underwater
Accurate recall was 40% lower in the 2 non matching conditions
Describe the procedure and findings for Carter and Cassidy’s research into state-dependent forgetting
Gave participants an antihistamine causing drowsiness, learnt a list of words in 4 different conditions
1. Drug + Drug
2. Drug + No drug
3. No drug + Drug
4. No drug + No drug
Non-matching conditions led to significantly worse memory performance
What are 2 strengths of retrieval failure?
Lots of research in lab and real life
-Godden and Baddeley + Carter and Cassidy
Validity is increased
Real-world application for use in cognitive interviews
-eyewitnesses mentally reinstate context
-more recall means more information is gathered
Helps police catch criminals, increases external validity
What are 3 weaknesses of retrieval failure?
Baddeley 1997 argued context effect not very strong
-have to be very different contexts for an effect to be seen
-usually environments not different enough to see effect
Doesn’t say much about everyday forgetting
Context effect related to the type of memory studied
-in 1980, Godden and Baddeley repeated with word recognition, not recall
-found no context-dependant effect, recall was the same in all conditions
Limited explanation only for recall
Encoding specificity principle can’t be tested
-it’s impossible to independently establish if cue is encoded
-reasoning on assumption, eg: if no recall on cue, it wasn’t encoded
Decreases validity as it’s unscientific
What is eyewitness testimony?
The ability of people to remember the details of events (eg: accidents, crimes) which they themselves have observed
What is misleading information?
Incorrect information given to an eyewitness, usually after an event, can take form of leading question or post-event discusssion
What is a leading question?
A question which suggests a certain answer because of the way it’s phrased
What is post-event discussion?
When eyewitnesses discuss experiences and memories, affecting the accuracy of recall
What are the 2 studies for misleading information?
Loftus and Palmer (1974)
Gabbert et al (2003)
Describe the procedure of Loftus and Palmer’s leading questions study
45 students watched clips of car accidents and were asked questions on it
The critical leading question was ‘How fast were the cars going when they ____ each other?’
5 groups had different verbs- contacted, hit, bumped, collided, smashed
Describe the findings and conclusion for Loftus and Palmer’s leading questions study
Mean estimated speed 31.8mph for contacted, but 40.5mph for smashed
Leading questions can bias the eyewitnesses recall of an event
Describe the procedure of Gabbert et al’s research into post-event discussion
Participants were paired and watched a video of the same crime from different angles
Each participant saw elements the other didn’t, eg: only one saw the title of a book carried by a woman
Both participants discussed, then individually completed a recall test
Describe the findings from Gabbert et al’s research into post-event discussion
71% of participants mistakenly recalled aspects of the event not seen in the video but picked up in discussion
In control, 0% mistakes
Explain the 2 explanations for how leading questions affect the accuracy of EWT
Substitution explanation- wording of the question can alter the memory, ‘smashed’ were more likely to report seeing glass than ‘hit’ when there was none
Response-bias explanation- wording has no effect on the memory but influences how participants decide to answer, ‘smashed’ encourages higher speed
Explain the 2 explanations for how post-event discussion affects the accuracy of EWT
Memory conformity- go along with others for social approval/believing others are right, actual memory unchanged
Memory contamination- EWT altered/distorted due to combining (mis)information from others with their own memories
What are 2 strengths of misleading information affecting the accuracy of EWT?
Use of lab study
-direct manipulation + high control
High internal validity so strong causal relationship established
Real-world application in criminal justice system
-police officers careful in phrasing questions
-also shows limitation + insufficient EWT
Improved legal system, reduces innocent convictions
What are 2 weaknesses of misleading information affecting the accuracy of EWT?
Lab study
- demand characteristics: use cues to fulfil expectations of researcher
- lacks mundane realism: less anxiety and responsability
- Yuille and Cutshall showed EWT more reliable in real life than lab
Misleading information may not affect memory in real life, findings not generalised, reduced external validity
Uses samples of students in Loftus and Palmer
-Warren et al found that children are more likely influenced by leading questions
-must have representative sample to conclude effect on EWT
Lacks population validity
What is anxiety?
A state of emotional (worried thoughts + tension) and physical (sweating _ increased heart rate) arousal
How can anxiety have a negative effect on recall?
Presence of weapon –> anxiety –> arousal –> weapon-focus –> not paying full attention
How can anxiety have a positive effect on recall?
arousal –> fight or flight –> increased alertness –> aware of cues –> better memory
What are the 2 studies looking into the effect of anxiety on eyewitness testimony?
Johnson and Scott (1976)
Yuille and Cutshall (1986)
Describe the procedure of Johnson and Scott’s study into the effect of anxiety on EWT
Participants in a waiting room for a ‘study’
Low anxiety condition heard a casual conversation and a man walked out with a pen and grease on his hands
High anxiety heard a heated argument and a man walked out with a bloody knife
Had to pick out the man from 50 photos
Describe the findings of Johnson and Scott’s study into the effect of anxiety on EWT
Low anxiety = 49% accuracy
High anxiety = 33% accuracy
Tunnel theory, attention narrows to weapon
Describe the procedure of Yuille and Cutshall’s study into the effect of anxiety on EWT
Was a real-life shooting in Canada where the shop owner shot the thief dead
13/21 witnesses took part in an interview 4-5 months later, compared with original police interview
Accuracy determined by the number of details recorded in each account
Had to rate stress on 7-point scale and state any emotional problems
Describe the findings of Yuille and Cutshall’s study into the effect of anxiety on EWT
Little change in volume/accuracy of recall
Higher stress increased accuracy- 88% compared to 75% with low anxiety
Anxiety has little effect on accuracy of EWT, but may enhance in real life
What law explains conflicting research into the effect of anxiety on EWT?
Yerkes-Dodson law (inverted U theory)
-memory more accurate until it is optimal, then recall drastically decreases
What is a strength of anxiety affecting EWT accuracy?
Studies (eg: Yuille and Cutshall) take place in real life
-no need to create an event, reduced demand characteristics
High ecological validity, findings can be generalised
What are 3 weaknesses of anxiety affecting EWT accuracy?
Studies may not be testing anxiety
-Pickel found recall was worse in high unusualness conditions (chicken + handgun), weapon-focus effect due to surprise not anxiety
-highest stress levels had closest proximity, hard to determine which
Doesn’t tell effects of anxiety on EWT
Research lacks internal validity
-lack of control over EVs and CVs (media accounts, interviews, post-event discussion)
-these factors may be responsible for the accuracy of recall
Credibility reduced
In all research, concept of anxiety difficult to operationalise
-many elements (cognitive, emotional, behavioural)
-anxiety classed differently as subjective
Reduces internal validity and explanatory power
Who created the cognitive interview and how?
Fisher and Geiselman (1992) using psychological insights into how memory works
What is the cognitive interview?
A method of interviewing eyewitnesses to retrieve more accurate memories in terms of both quality and quantity
What are the 4 stages of the cognitive interview?
- Report everything
- Reinstate the context
- Reverse the order
- Change perspective
What does ‘report everything’ involve in the cognitive interview?
Asking witnesses to state everything even if it seems irrelevant
-because info may be important or trigger important memories
eg: ‘I am interested in absolutely everything’
What does ‘reinstate the context’ involve in the cognitive interview?
Return to the crime scene in mind, imagining environment and emotions
-related to context-dependent forgetting
eg: ‘What could you hear at the time?’
What does ‘reverse the order’ involve in the cognitive interview?
Different order than original sequence
-prevents reporting expectations (schema) and dishonesty as harder to be untruthful if reversed
eg: ‘What is the most memorable event?’
What does ‘change perspective’ involve in the cognitive interview?
Report how it would appear from another perspective
-disrupts expectation (schema) of setting
eg: ‘Place yourself in the shoes of…’
Who created the enhanced cognitive interview, and what is it?
Fisher et al (1987)
Focuses on the social dynamics of the interaction
What are 5 examples of the enhanced cognitive interview?
- Knowing when to establish/relinquish eye contact
- Minimising distractions
- Reduce the eyewitness’ anxiety
- Getting witnesses to speak slowly
- Asking open-ended questions
What are 2 strengths of the cognitive interview?
Evidence that it works
-meta-anaylsis by Köhnken et al (1999)
-found cognitive interview gave average 41% increase in accurate information compared to standard interview
Effective strategy to recall available but not accessible memories
Flexible
-can overcome objections of police officers (who benefit most)
Changeability of what doesn’t work improves face validity
What are 3 weaknesses of the cognitive interview?
Köhnken et al also found an increase in incorrect information
-particularly in enhanced cognitive interview
-may sacrifice quality for quantity
Police officers should treat the EWT from cognitive interviews with caution
Hard to establish effectiveness
-not one procedure as ‘pick-and-mix’ of techniques
-not used in same way by all
Hard to compare effectiveness to other approaches
Police reluctant to use it as time-consuming
-more time for witnesses to relax
-special training for police officers
-unrealistic for police
May be better to focus on a few key elements
