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Eyewitness TestimonyEyewitness Testimony
Reconstructive memoryReconstructive memory Schema driven errorsSchema driven errors
Effect of leading questionsEffect of leading questions Other factorsOther factors
Weapon focusWeapon focus Effects of anxiety/arousalEffects of anxiety/arousal Retrieval cuesRetrieval cues
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Reconstructive MemoryReconstructive Memory
Bartlett (1932)Bartlett (1932) Memory is not a direct record of what Memory is not a direct record of what
was witnessedwas witnessed What is encoded and how it is What is encoded and how it is
retrieved depends on:retrieved depends on: Information already stored in memoryInformation already stored in memory How this info is understood, structured How this info is understood, structured
and organisedand organised
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Reconstructive MemoryReconstructive Memory
SchemasSchemas Knowledge structures that relate to Knowledge structures that relate to
commonly encountered objects, commonly encountered objects, situations or peoplesituations or people
Enable us to predict events, make sense Enable us to predict events, make sense of unfamiliar circumstances, organise of unfamiliar circumstances, organise our own behaviourour own behaviour
Act as filters to perception & recallAct as filters to perception & recall
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Computer Information ProcessingComputer Information Processing
BANG!Can you wreck a
nice beach?
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Schema Driven ProcessingSchema Driven Processing
Yes. I can
recognise speech.
Can you wreck a
nice beach?
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Bartlett (1932)Bartlett (1932)
‘Pickaxe’
‘Turf cutter’
Input OutputSchema
Bartlett (1932)
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Bartlett (1932)Bartlett (1932)
War of the Ghosts War of the Ghosts When recalled by UK PPs:When recalled by UK PPs:
ShorterShorter Less detailedLess detailed Some details changed (e.g. seal hunting Some details changed (e.g. seal hunting
changed to fishing)changed to fishing) More ‘Western’ structureMore ‘Western’ structure
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EWT: Schema Driven ErrorsEWT: Schema Driven Errors
Witnesses to crimes filter information Witnesses to crimes filter information during acquisition & recallduring acquisition & recall Their schematic understanding may Their schematic understanding may
influence how info is both stored & influence how info is both stored & retrievedretrieved
Distortions may occur without the Distortions may occur without the witness realisingwitness realising
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EWT: Schema Driven ErrorsEWT: Schema Driven Errors
Past experiencesPast experiences Assumptions about Assumptions about
what usually what usually happenshappens
Stereotypes & Stereotypes & beliefs about crime beliefs about crime & criminals& criminals
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EWT: Leading QuestionsEWT: Leading Questions
Loftus (1970s onwards)Loftus (1970s onwards) Effect of leading questions on recallEffect of leading questions on recall
Leading questions introduce new Leading questions introduce new information information
Leading info may activate wrong Leading info may activate wrong schemas in witness’ mindschemas in witness’ mind
Consequently, witness may recall events Consequently, witness may recall events incorrectlyincorrectly
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EWT: Leading QuestionsEWT: Leading Questions
Loftus’ studies using film/video/slides Loftus’ studies using film/video/slides road accidentsroad accidents
‘‘How fast were cars going when they How fast were cars going when they hit…’ or ‘…when they smashed…’?hit…’ or ‘…when they smashed…’? ‘‘Smashed’ led to higher speed estimatesSmashed’ led to higher speed estimates
‘‘Did you see a/the broken headlight’?Did you see a/the broken headlight’? ‘‘The’ produced more affirmative The’ produced more affirmative
(incorrect) responses(incorrect) responses
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EWT: Leading QuestionsEWT: Leading Questions
Loftus’ research usually lab based:Loftus’ research usually lab based: Restricted samples (students)Restricted samples (students) Artificial stimuli (slides, videos, not real Artificial stimuli (slides, videos, not real
events)events) Potential for demand characteristics to Potential for demand characteristics to
influence responsesinfluence responses No legal/moral consequences for No legal/moral consequences for
inaccurate answersinaccurate answers
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EWT: Leading QuestionsEWT: Leading Questions
EWT most affected by leading Qs EWT most affected by leading Qs when:when: Witness believes questioner knows more Witness believes questioner knows more
than themthan them Witness does not realise they may be Witness does not realise they may be
misledmisled Leading information is peripheral, not Leading information is peripheral, not
centralcentral Leading information is not blatantly Leading information is not blatantly
incorrectincorrect
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EWT: Weapon FocusEWT: Weapon Focus
When a weapon is When a weapon is used to threaten a used to threaten a victim, their victim, their attention is likely attention is likely to focus on itto focus on it
Consequently, their Consequently, their recall of other recall of other information is likely information is likely to be poorto be poor
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EWT: Arousal EffectsEWT: Arousal Effects
Memory is most Memory is most effective at effective at moderate arousal moderate arousal levelslevels
If the witness was If the witness was in a state of in a state of extremely low or extremely low or high arousal then high arousal then recall may be poorrecall may be poorarousal
perf
orm
ance
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EWT: Retrieval CuesEWT: Retrieval Cues
Recall typically takes place in a Recall typically takes place in a different context to acquisitiondifferent context to acquisition Lack of retrieval cues (state and Lack of retrieval cues (state and
context) can inhibit recallcontext) can inhibit recall Reconstruction of the events (either Reconstruction of the events (either
imagination or simulation) can lead to imagination or simulation) can lead to enhanced recallenhanced recall
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