eyewitness memory lecture 1

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Devlin report, 1973
(How important is eyewitness testimony?)
Examined all identification parades in England and Wales
850 people prosecuted after being picked from a line-up by a witness
41% prosecuted based on eyewitness evidence alone
74% of these resulted in convictions
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Loftus crime scenario, 1974
(How important is eyewitness testimony?)
Man enters store, demands money, shoots and kills owner and owners daughter, gunman flees to nearby apartment
Circumstantial evidence: 18% voted to convict
Witness: 70% voted to convict
Discredited witness: 68% voted to convict
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Conclusion of Loftus crime scenario, 1974
(How important is eyewitness testimony?)
Jurors take eyewitness testimony seriously

They weight it more heavily than other forms of evidence
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Centre for wrongful convictions (Warden, 2001)
(Is eyewitness testimony reliable?)
86 people in the US sentenced to death but later legally exonerated (DNA evidence)

54% eyewitness testimony played role in conviction
38% eyewitness testimony was the only evidence
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Rattner 1988
(Is eyewitness testimony reliable?)
The main error contributing to wrongful convictions is eyewitness misidentification (52.3%), followed by perjury by witness (11%) and negligence by criminal justice officials (9.9%)
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Wright & McDaid 1996
(Is eyewitness testimony reliable?)
A survey of London identification parades found in 20% of cases, an innocent person was convicted as the culprit
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Turnbull guidelines 1977
(Is eyewitness testimony reliable?)
In cases of disputed eyewitness evidence, judge should instruct jury:
a witness may be wrong, confidence in witness may be based on the quality of observation
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Memory vs past
Memory is a reconstruction of the past, stored memory is fragmentary and ambiguous, experiencing the past requires putting the fragments together and filling in the gaps
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Memory vs past 2
To do this, we rely on inference and guesswork, background knowledge, information in the environment and errors can occur at any of these points
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Why do we study memory errors?
To understand the reliability of eyewitness testimony and improve techniques for questioning witnesses and suspects
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Misinformation effect
When our memory for past events is altered after exposure to misleading information

Loftus, miller, burns, 1978
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Misinformation effect procedure

Loftus, miller, burns, 1978
Ps saw a car at a stop sign and were questioned afterwards with either accurate or inaccurate questions which was followed by a forced choice recognition test
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Misinformation effect results
Accurate question = 75% correct
Misleading question = 41% correct
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Post-event information (PEI) distorts memory for the original event
1. PEI replaces or blocks access to original
2. original memory not remembered but PEI information remembered
3. both original & PEI remembered (demand characteristic)
4. both original memory & PEI remembered (source confusion)
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Testing possibility 1
McCloskey & Zaragoza, 1985
Control exp=hammer slides and no narrative
Misled exp=hammer slides and spanner narrative
Misled= 37% correct
Control=72% correct
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Testing possibility 1 modified
Same experiment but with hammer and screwdriver
Misled=72% correct
Control=75% correct
The misleading narrative did not erase original memory
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Loftus and Palmer, 1974
(Misinformation effect)
Ps watched a film of a RTC and were asked "how fast were the cars going when they ___ each other?"
Smashed=40.8mph, bumped=38.1mph, hit=34.0mph, contacted=31.8mph
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Loftus students at a train station
(How "real" are false memories?)
2 women left a bag unattended and a man took something from it. women questioned witnesses about a "stolen tape recorder"
Over half said they saw the tape recorder and most described it in detail
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Loftus et al, 1989
(How "real" are false memories?)
When biased by misleading questions, people make false memory judgements quickly and with high confidence
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Sutherland & Hayne, 2001
(How "real" are false memories?)
Mary lost and given white teddy bear
Post-event questioning involved accurate, misleading and neutral questions
Misleading questions had a greater effect on memory for peripheral facts
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Kassin & Kiechel, 1996
(False confessions)
Experiment whereby pressing ALT key crashes experiment
Compliance= NW-65%, W-100%
Internalisation= NW-12%, W-65%
confabulation= NW-0%, W-35%
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Other cards in this set

Card 2

Front

Loftus crime scenario, 1974
(How important is eyewitness testimony?)

Back

Man enters store, demands money, shoots and kills owner and owners daughter, gunman flees to nearby apartment
Circumstantial evidence: 18% voted to convict
Witness: 70% voted to convict
Discredited witness: 68% voted to convict

Card 3

Front

Conclusion of Loftus crime scenario, 1974
(How important is eyewitness testimony?)

Back

Preview of the front of card 3

Card 4

Front

Centre for wrongful convictions (Warden, 2001)
(Is eyewitness testimony reliable?)

Back

Preview of the front of card 4

Card 5

Front

Rattner 1988
(Is eyewitness testimony reliable?)

Back

Preview of the front of card 5
View more cards

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