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Eyewitness Testimony Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading questions Other factors Other factors Weapon focus Weapon focus Effects of anxiety/arousal Effects of anxiety/arousal Retrieval cues Retrieval cues www.psychlotron.or g.uk

Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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Page 1: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 2: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 3: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 4: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

Computer Information ProcessingComputer Information Processing

BANG!Can you wreck a

nice beach?

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Page 5: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

Schema Driven ProcessingSchema Driven Processing

Yes. I can

recognise speech.

Can you wreck a

nice beach?

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Page 6: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

Bartlett (1932)Bartlett (1932)

‘Pickaxe’

‘Turf cutter’

Input OutputSchema

Bartlett (1932)

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Page 7: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 8: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 9: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 10: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 11: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 12: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 13: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 14: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 15: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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Page 16: Eyewitness Testimony Reconstructive memory Reconstructive memory Schema driven errors Schema driven errors Effect of leading questions Effect of leading

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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