Section 2: Memory Flashcards
What is memory?
It is a mental process involving info being coded, retained and retrieved about the past.
It’s an aspect of cognitive psychology.
What is coding?
Refers to the format info is held/processed.
There are three forms of coding (acoustic, visual, and semantic)
What is storage and what’s capacity of a memory store?
The info held in memory.
Capacity is the amount of info held.
What’s duration in a memory store?
It’s how long a memory lasts.
What are the three types of memory?
The sensory register, STM and LTM.
They differ in duration, capacity and coding.
What’s the sensory register?
It’s a memory store that temporarily stores info from the 5 senses.
It constantly receives info from around us.
Unless we pay attention to the info, it disappears quickly (spontaneous decay)
- has limited capacity
- has very limited duration
- info coded depending on sense that picked it up (eg. tactile, auditory, visual)
Whats STM?
- has limited capacity
Miller (1956) found ppl remember about 7 items
As for STM’S capacity
Arguing that its capacity is 7+/-2 ‘miller’s magic number’
Suggested we use chunking to combine individual digits into larger meaningful units/groups
Eg, 20031987 chunked into 2003 and 1987
- has limited duration (up to 30s)
- Coding is usually acoustic
What’s LTM?
- has unlimited capacity
- has theoretically permanent duration
- coding is usually semantic (by meaning)
There are different types of LTM..
• Episodic memory
Stores info on events you’ve experienced.
Can contain info on a time, place, emotion and details of event.
These memories are declarative (can be consciously recalled)
• semantic memory
Stores facts and knowledge that can be consciously recalled
Like capital cities, word meanings
Not info on time/place learnt - just knowledge
• procedural memory
info on how to do things
Like walking, swimming, playing piano
Can’t be consciously recalled.
Why is info in STM coded mostly acoustically
We sometimes try keeping info active in our mind by repeating to ourselves.
Meaning it involves acoustic coding
Why is LTM generally semantic?
It’s more useful to code words in terms of meaning, rather than sound/appearance.
Coding in LTM can still be visual or acoustic.
Who created the msm and describe it.
By Atkinson and shiffrin in 1968
- proposed three separate memory stores
- vary in terms of coding and capacity and duration
- Environmental stimuli
- Sensory register
- Attention
- STM
- Maintenance rehearsal (back and forth between STM and LTM)
- LTM
- Retrieval (back through STM)
What was Peterson and Petersons’ study (1959)
•Aim
- to investigate duration in STM
•Method
- ppts shown meaningless trigrams (eg. CVM)
- asked to recall them after 3, 6, 9, 12, 15, or 18 secs
- during pause, counted backwards in threes from given numbers
—> a distractor/inference task prevents repeating letters internally
• Result
- after 3 secs ppts could recall 80% of trigrams
- after 18 secs only abt 10%
• Conclusion
- when rehearsal prevented, very little can stay in STM for longer than 18s
Peterson and Peterson’s study evaluation
+ variables tightly controlled
- laboratory experiment
- hence likely to be reliable; can be repeated as a standardised method
— lacks mundane realism / no application to reality
- nonsense trigrams are artificial tasks
- hence low ecological validity and cannot be generalised
— duration in STM may on stimulus type
- only one type of stimulus used
- cannot confirm if duration is longer with meaningful memories/incomplete
What was bahrick’ study
•Aim
- investigating duration in LTM and VLTMs (very long term memories)
•Method
- 392 ppl were asked to list names of ex classmates (free recall test)
- then shown photos and asked to recall names of ppl shown (photo recognition test)
- or given names to match with classmate photo (name-recognition)
•Result
- within 15 yrs of leaving school, ppts recognised 90% of names/faces
- 60% accurate free recall
- After 30 yrs free recall was 30% accuracy
- After 48 yrs name recognition was 80% and photo, 40%.
• conc
- evidence of VLTMs (very LTM) in real life setting
- recognition is better than free recall,
- so there’s huge store of info and not always easy to access all of it
Bahricks study evaluation (NEED ONE MORE?)
+ had high ecological validity
- because was a field experiment
- means can be generalised
— not very controlled
- because a ‘real life’ field study
- less reliable, as we don’t know why it was recalled well (eg. Looked at yearbook recently)
Jacob’s study
• Aim
- investigation capacity of STM
• Method
- ppts presented with string of letters or digits
- had to repeat them back in same order
- number of digits/letters increased till ppt failed to recall sequence right
•result
- digits recalled as mean span per ppt was 9.3
- and 7.3 for letters
- capacity increased with age during childhood
• Conclusion
- based on results range, he concluded STM has capacity of 5-9 items
- individual differences include STM capacity increasing with age
- possibly due to memory techniques (chunking)
Jacob’s study evaluation
— can’t be applied to real life (lacks ecological validity)
- due to artificial task
- means can’t be generalised
+ greater internal validity
- as tasks aren’t affected by existing memories
— incomplete
- as meaning info wasn’t tested
- whch could extend capacity in STM
What was baddeley’s study
•Aim
- to to investigate coding in STM and LTM
•
•method
- there were three conditions
Semantically similar words
Acoustically similar words
Unrelated words
And two subgroups in each condition (recalled immediately and 20mins later)
So 6 groups in total (had independent groups design))
People had to recall words in each condition/word list
•
• result
-ppts struggled to recall acoustically similar words
- when recalling word list immediately after (STM)
- AND struggled recalling semantically similar words from LTM
•
• conclusion
Patterns of confusion between similar words mean..
- LTM relies more on semantic coding
- STM on acoustic coding
Baddeley’s study evaluations
– lacks ecological validity
-as artificial tasks and ideas
- can’t be generalised
— also other types of LTM/coding not included
- hence study is incomplete
- can’t be generalised
+ independent groups design
- so no control over ppt variables
- meaning less internal validity
MSM evaluation
— lacks detail; oversimplified
- doesn’t mention diff types of LTM
- hence incomplete
+ supporting evidence (results and concs only)
- Jacob’s study supports stm capacity
- baddeley’s supports coding
- so is valid/ can be generalised
— has real life application (high ecological validity)
- eg. In a test
- shd be generalised
What is corkin’s case study
•aim
To investigate if LTM rlly is divided into diff types
•method
- to train a ppt (amnesiac HM) to repeatedly learn
how to carry out tracking a curvy line on a rotating disc
- even if he can’t physically remember his lessons learning it.
• result
- could remember how to do the task
- but not the events / experience learning it
• conc
- as he can make new procedural memories but not episodic
- it shows there are different types of LTM and they aren’t linked
Types of LTM evaluations
+ supporting evidence (corkin case study)
- shows LTM types exist and aren’t linked
- means that ideas of LTM types can be generalised
— challenges msm
- LTM is just one store
- no other types are mentioned whatsoever
— neuroimaging evidence
- different LTM types are shown to make diff areas of brain active
- hence LTM is in sections
What is the working memory model (baddeley’s and hitch 1974)
The model proposed STM isn’t a single store
But an active processor contains several different stores
..
The central executive, a key component, is described as attention.
It has a limited capacity and controls ‘slave’ systems
—> ALL have a limited capacity
• Phonological loop holds speech based info, eg. Trying to pronounce
- articulatory process (inner voice) rehearses info
- consists of phonological store (inner ear) to hear voice
The info loops round until it sounds right
• visuospatial sketchpad
- deals with temporary storage of visual / spatial info
• episodic buffer
- (added to model in 2000) briefly stores info
- from other subsystems and integrates it together
- along with info from LTM to make complete scenes or episodes
Like adding in maths 2+8 then 10 + 3.
diagram no.1
What experimental evidence did the working memory model come from
Baddeley and hitch based model off of studies using interference tasks
- when ppts were asked to performed two tasks at same time that use same system
- their performance will be affected
According to WWM, when both task involve using phonological loop
(Saying twinkle twinkle while silently reading) is very difficult
—> phonological loop has limited capacity so can’t cope with 2 tasks
- performance on one or both tasks will be affected
But two tasks in different systems..
Performance won’t be affected on either task
(Saying twinkle twinkle while tracking a moving object)
Evaluation of wmm
+ shallice and warrington did a case study of KF
- had impaired STM: can’t immediately recall words with verbal info, unless with visual info
- So had impaired auditory loop but intact visuospatial sketchpad
Good as can be explained by WMM not MSM
…
+ Gatyerole and baddeley reported on a laboratory study
One group had two tasks using visuospatial sketchpad and phonological loop (better perf)
Other had two tasks with only visuospatial sketchpad
Hence supports
…
+ model has less emphasis on rehearsal than msm
- rehearsal is one possible process in wmm
- explains why some memories enter ltm without rehearsal (other processes work)
…
— the wmm is simplistic/vague,
not explaining central executive (how choses where to send info)
What was the case study on LH/Farah et al?
LH was involved in a road accident.
He performed better on spatial tasks than ones involving visual imagery.
This suggests separate visual and spatial systems of the VSS
(Wch aren’t currently explained)
However, Logie divided visuospatial sketchpad, due to wmm being oversimplified
What was hunts study
•Aim
To investigate evidence for a limited central executive
•Procedure
A repeated measures design.
Ppts performed a psychomotor task (moving a lever between posts with thumb/finger)
And at the same time, an intelligence test with spatial patterns
•Results
As problems became more difficult on intelligence test
Performance on psychomotor task deteriorated
• conclusion
He interpreted deterioration in performance as evidence
that both tasks were using same component (VSS)
—> competing for same limited capacity available (of CE)
What actually is forgetting in STM
Experiments on memory assume that if u can’t retriev memories they’re forgotten and can’t be retrieved
- forgetting from STM is cos of availability problem
—> no longer available cos limited capacity or duration
—> info may have faded away (decay) or displaced/pushed out
What’s forgetting in LTM
Forgetting caused by decay (availability problem) or
- info is stored but hard to retrieve (accessibility problem)
- info is confused and there’s and interference problem (too similar)
What interference and the types of it
It’s the ability to remember a thing u learnt and can be affected by similar things learned before or after
• retroactive (new info makes harder to recall old)
• proactive (old interferes with ability to recall new)
Interference evaluation
+ supportive evidence (both high control)
Baddeley and hitch
Mcgeoch and mcdonald
+ real world application (might struggle to recall French vocab after learning German)
— interference effects more greater in artificial tasks and environments
— incomplete as doesn’t explain how or why interference happened
What was mcgoach and McDonald’s study
To investigate if interference is worse with similar memories
Three conditions
- list A (10 adjs) , 10 mins where they learned List B1 (synonyms of A)
- B2 (nonsense syllables)
- B3 (numbers)
- 12% Chance of full recall
- 26%
- 37%
So interference strongest the more similar the items are
Baddeley and hitch’s study
To investigate inference in an everyday setting
rugby players had to recal names of teams played against
- some players missed games; some played in all
- but time interval from start to end of season was same
—
If decay theory correct, then all players should recall a similar percentage of games played as time causes forgetting
If inference theory’s correct then those playing more games should forget propertianately more due to similar things mixed up
—> demonstrating interference in everyday
What is the retrieval failure theory
In this theory, forgetting is treated as retrieval failure (info still exists, just not accessible)
—> recalling info depends on getting the right cue
We have more retrieval chance of cue is appropriate
— cues can be internal (state cues = mood, emotion)
— or external (context cues = environment)
- we remember better in same context/state as we were in
- when we coded info originally (cue - dependent learning)
Mental reinstatement is imagining you’re in a cued environment
To enable recall of that info
What did golden and baddeley investigate (retrieval failure theory - external cues)
—> to see if environment cues affect recall
An independent groups, field experiment with deep sea divers
Who learned word lists on land or under water
Recall was tested in either same or different context
4 conditions
Result..
Different contexts showed more than a 30% decrease in recall
Compared to same context
What was Goodwin et als study (internal cues)
—> investigated if recall was better in the same state
Male volunteers had to remember word list either drunk (3x over driving limit) or sober
Then had to recall words 24hrs later
In either same or different state
4 conditions
Result..
- drunk or sober both times leads to better recall
- while different states in learning and recall = lowered performance
Evaluation of retrieval failure theory
+ research support (golden and badeely, Goodwin et al)
+ everyday life application (trying mental reinstatement)
— evidence studys’ tasks are artificial (lacking mundane realism)
— theory isn’t applicable to all types of memory, like no cues for procedural
What’s eye witness testimony and its factors
Ewt is the evidence provided by ppl who witnessed a particular event/crime
It relies on recall of memory
—> it includes eg criminal descriptions and crime scenes (time, date, location)
—> Witnesses are often innacurate in recalling events and ppl involved
Cognitive psychologists focus on working out what
factors affect accuracy of eyewitness testimony and
how accuracy can be improved in interviews
- affected by misleading info (leading questions)
- post event discussion
- witness age
What’s response bias explanation
Suggests the wording of the question has no real effect
On the ppts memories but just influences how the decide to answer
(lotus and palmer show this in the misleading info studies)
What was lotus and palmers study (including car crash one)
The aim was to investigate whether phrasing sentences in different ways affects recall in ewt
- method
45 students were shown 7 films of car crash accidents.
—> After each, ppts were given questionnaire, asking to describe the accident, and then answer specific questions about it
There was one critical question (how fast were cars going before they hit) - one group was given this
- the other four groups had smashed, collided, bumped, or contacted
This was a leading question as it suggested the answer a ppt may give
.
- result
Smashed (40mph mean speed)
Collided (39.3)
Bumped (38.1)
Hit (34)
Contacted (31.8)
What was loftus and palmer’s other study?
Has the same aim - to investigate how wording of questions cause response to differ
- method
The leading q may bias a ppts response / cause info to be altered before stored
To test, a new set of ppts (150) were divided into three groups, shown a film
Of a car crash lasting 1 minute and asked qs again abt speed
- ppts returned a week later when they were asked 10 qs abt the accident
- there were three conditions (week ago qs had hit, smashed or control- no speed implied)
- were asked did u see any broken glass
.
*result
Smashed = 16 said yes; 34 said no
Hit = 7 said yes
Control = 6 said yes
What’s evaluation of loftus and palmers studies
- an artificial experiment
Lacks mundane realism, as watching a video of a car crash
isn’t as emotionally arousing as reality, potentially affecting recall - experimental design (laboratory) leads to demand characteristics
Results are biased due to ppts expectations abt experiment’s purposes
As leading qs give clues (could have realised leading questions)
What’s post event discussion
Refers to a convo between two cowitnesses or an interviewer
And an eyewitness after a crime has taken place wch may contaminate a witnesses memory
—> two cowitnesses may discuss events, but their EWTs may become contaminated
—> combining (mis)info from other witnesses with own memories
Some studies have confederates feeding witnesses misinfo
Affecting recall
Conformity effect in post event discussions
Cowitnesses may reach an agreement of what actually happened
—> may go along with each other to win
- social approval/believe others are right, not themselves
This is memory conformity
Gabbert et al’s study
To investigate whether post event discussions can affect the memory recall of ppts
- method
Shown a video of a girl stealing money from wallet - one condition ppts were tested individually
- other condition was with a cowitness
In second condition were told they saw same videos; only one ppt saw girl steal money
Cowitnesses were told to discuss video then completed questionnaire
*result
71% ppts in second condition recalled info they didn’t see
—> 60% who didn’t see girl steal said she did
What’s repeat interviewing
Each time an eyewitness is interviewed there’s a chance
Interviewer’s comments will become incorporated into recall of these events
Also the case that the interview uses leading questions
And hence alter the individual”s memory for events
—> especially the case when children are being interviewed
What are effects of anxiety on EWT
anxiety has strong emotional and physical effects,
but isn’t clear if these effects make eyewitness recall better/worse
— a positive effect..
stress of witnessing a crime/accident makes anxiety through
Physiological arousal in body. The flight or fight response triggers,
Increasing alertness and improving memory as become more aware of surrounding cues
— anxiety has a negative effect on recall
Creating physiological arousal in body preventing paying attention
To important cues hence recall is worse.
- an approach to studying anxiety and ewt has been to look at
- effect of weapons (create anxiety) on accuracy of recall
.
Tunnel theory of memory argues a witness’ attention narrows
To focus on a weapon - a source of anxiety
Neglecting peripheral detail (criminal’s clothes)
Johnson and Scott’s study (negative effect)
To investigate how anxiety affects recall of peripheral details of a crime
*method
Led ppts to think they were participating in a lab study
—> whilst sitting in a waiting room ppts heard an argument in next room
— (low anxiety condition) a man then walked through waiting area carrying pen with grease on hands
— (hugh anxiety) same argument heard then broken glass sound. Same man walked out with paper knife with blood on
- result
Ppts were asked to pick the man from a set of 50 photos
49% could identify if he carried the pen
33% could identify if carrying knife
Yuille and cutshall (positive effect)
*method
Conducted study of a real life shooting in gun shop (Canada)
The shop owner shot a thief dead
—> 21 witnesses, 13 agreed to participate in the study
The interviews were held 4/5 months after and were compared with original police interviews made at the time
- accuracy was determined by number of details reported in each account
- witnesses were also asked to rate how stressed they felt (7 point scale)
- asked if they had emotional problems since event (insomnia)
- result
Witnesses were very accurate (little change after 5 months)
Some were less accurate - colour of items, age/height/weight estimates - ppts reporting most stress were most accurate
- 88% compared to less stress group)
How do we explain contradictory findings in effects of anxiety in EWT
deffenbacher (1983) applied to EWT the
Yerkes-Dodson inverted U hypothesis
—> lower anxiety levels produce lower levels of recall accuracy
- but memory becomes more accurate as the level of anxiety felt increases
However there comes a point where optimal anxiety levels are reached
The point of maximum accuracy
If an eyewitness experiences any more stress than this
Their recall suffers a drastic decline
What did fisher and gieselman argue about EWT on improving it and the techniques??
Standard interview involves interviewer asking specific/closed questions - multichoice answers. Questions are predetermined on written checklist.
Witnesses are discouraged from adding extra info.
Interview may ask leading questions to confirm witness’ beliefs abt crime
—> they contaminate a witness’ memory so later recalls inaccurate
EWT can improve (they argued) if police used better techniques
- such techniques shd be based on psychological insights on how memory works
- calling the techniques the CI (cognitive interview)
- four main techniques used
What are the four techniques in CI
- Report everything
- witnesses encouraged to say every detail, even if irrelevant/ not confident
May trigger further memories as a cue and may be important
Such memories could be pieced together from diff witnesses to make clearer picture - Context reinstatement
- Witness shd return to original crime scene in mind - imagine surroundings
Eg, weather, what they could see, emotions
Related to context-dependent forgetting, to make memories accessible
—> state and context cues are needed to access some memories - Reverse the order
- events shd be recalled in a diff order to original sequence
Eg. From final point to start, middle to start
Done to prevent ppl reporting expectations of how it mustve happened
Preventing dishonesty (hard to not tell truth in reverse) - Change pov
Witnesses should recall from other ppls povs
Eg. How it wdve appeared to other witnesses/criminal
Done to disrupt effect of expectations and schema on recall
—> schéma for a general setting (shop) generates expectations
—> schemas are recalled , not what actually happened
Gieselman et al study
*method
Ppts saw film of violent crime.
After 48hrs were interviewed with
- CI
- standard by LA police
- an interview with hypnosis
Facts accurately recalled and numbers of errors were recorded
- result
Mean number of correctly recalled facts - CI = 41.2
- hypnosis = 38
- standard = 29.4
No significant difference in number of incorrect responses found - conc
CI improves memory for events
A follow up study also showed ppts were less
likely to be misled by false info when CI was used
Evaluation of anxiety effects on ewt
— weapon focus is correlation; not cause and effect
- pickel (1998) said reduced accuracy of identification (due to weapon focus)
- may be due to surprise, not anxiety
To test, ppts watched a thief in hairsalon carrying
Scissors (high threat, low surprise)
Handgun (high threat and surprise)
Wallet (low threat and surprise)
Whole raw chicken (low threat, high surprise)
—> identification was least accurate in high surprise (not threat)
—- inverted U explanation is too simple
Anxiety is difficult to define and measure accurately
It has many elements - cognitive, behavioural, emotional and physical
—> inverted U explanation assumes only one is linked to poor performance
- physiological (physical) arousal
Evaluation of CIs
+ quantity vs quality
CI is designed to enhance quantity of correct recall
Without compromising quality
- ronkhen found 81% increase in correct info, but
61% increase of incorrect compared to standard interviews
+ enhanced CI
Fisher et al developed additional info CI
To focus on social social dynamics
- when to establish eye contact and how long (reduce anxiety)
- minimise distractions
- getting witness to talk slow
- open ended qs
—> Rohnken combined data from 50 studies
—> CI consistently provided more correct info than standard
— CI is time consuming
More time needed eg to allow witness to establish rapport/relax
—> CI requires specialist training so unlikely proper version used
—> explaining why police don’t use as much/arent impressed
+ Geiselman et al
What may the interviewer say in CI to tell witness to report everything
Some hold back info as they aren’t sure it’s important or you think I already know this info.
Please don’t leave anything out
What may the interviewer say for the witness to mention context reinstatement
Try think back to the day the event happened.
Think about the day - what you were doing, the weather, how you felt
Try get a picture of it in your mind
What may the interviewer say for the witness to reverse order of events
I would like you to try something wch may help you remember more.
I would like you to tell me what happened backwards
What was the very last thing happening, and what happened before that?
What may the interviewer say for the witness to change their pov
Try recall the incident from the pov of another person involved.
Think abt where they were and isolate all you remember about them, like in a spotlight.
What would they have seen?
Yuille and cutshall study evaluation
+ high ecological
field study based on real life event
Hence results can be generalised as nothing affecting behaviour
—> like demand characteristics
+ more ethical
Ppts volunteered to take part (ao3 volunteer sampling)
Also, anxiety wasn’t induced, so took advantage of this previous event
— unclear what contributed to accuracy of recall
Highest levels of stress were closest to the event
Hard to determine whether proximity or stress contributed to recall accuracy
—> So lacks control, confounding variables make hard to find conclusion
Johnson and Scott study evaluation
— ethical issues
Ppts may have felt distressed at sight if man with knife
Causing psychological harm and anxiety
But can be solved through debriefing
+ high ecological validity
Ppts weren’t aware this was staged
Causing reaction to be realistic
—> with no demand characteristics
— weapon focus is correlation; not cause and effect
- pickel (1998) said reduced accuracy of identification (due to weapon focus)
- may be due to surprise, not anxiety
To test, ppts watched a thief in hairsalon carrying
Scissors (high threat, low surprise)
Handgun (high threat and surprise)
Wallet (low threat and surprise)
Whole raw chicken (low threat, high surprise)
—> identification was least accurate in high surprise (not threat)
