Memory Eyewitness Testimony. Learning objectives Understand what is meant by eyewitness testimony...
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Transcript of Memory Eyewitness Testimony. Learning objectives Understand what is meant by eyewitness testimony...
Memory
Eyewitness Testimony
Learning objectives
Understand what is meant by eyewitness testimony (EWT)
Be aware of some of the factors that affect the accuracy of EWT.
Understand the impact of misleading information on EWT.
Describe the cognitive interview technique and understand its rationale.
Describe and evaluate evidence that underpins our understanding of EWT.
From The TimesMay 23, 2007
201 wrongful convictions are tip of the iceberg, says DNA charity Tim Reid in Washington A man who spent 19 years in jail for the murder of two children
will be exonerated formally in July, putting the number of inmates in America cleared by DNA evidence at more than 200.
Byron Halsey, who narrowly avoided the death penalty when he was convicted in 1988 of the sexual assault and murder of a girl, 7, and a boy, 8, had his conviction thrown out by a judge last week after DNA evidence pointed to another man as the killer.
Mr Halsey’s exoneration means that since the first American inmate was cleared by DNA evidence in 1989 another 200 have now been proven to be convicted wrongfully, according to the Innocence Project, a New York legal charity that pioneered the use of DNA analysis.
Affects of misleading information
Distortion after the event Due to post-event
information Loftus (1992) called this ‘misinformation
acceptance’ More so as time goes on
after the event Important implications
for questioning suspects.
Elizabeth Loftus
Used lab experiments
Using videos of road traffic incidents
Barbara Loftus
Followed by post-event informationIncluding leading questionsTest for memory of original eventFinding – false info after the event can
change the original memory
Classic study by Loftus (1975)
Participants were shown a film
Then divided into 2 groups
Group 1 was asked questions consistent with what they had seen
Procedure
How fast was the white sports car going when it passed the Stop sign.
How fast was the white sports car going when it passed the barn while travelling along the country road?
Findings
There had been a stop sign in the film but no barn.
17% in the experimental group (the group asked the leading questions) reported seeing a barn.
Only 3% in the control group (not asked leading questions) made this error.
Conclusion
Participants who are given misleading post-event information believed they had really seen the barn.
This information had been absorbed into their original memory.
Criticisms
Is it possible that participants are responding to demand characteristics?
This would mean participants hadn’t really had their memory changed.
To test this…
Loftus offered a money rewardFor correct recollection of details from a
film of an accident.One group saw a film involving a
pedestrian being knocked over after a car stopped at a Stop sign.
The other group saw the same incident except the car stopped at a Yield sign (American equivalent of Give Way).
Two days later Participants were given a set of questions
about the incident. One question was misleading. Participants who saw the Stop sign were
asked about a Yield sign. Participants who saw the Yield sign were
asked about a Stop sign. Loftus showed pairs of slides, one with a Yield
and one with a Stop.
Participants were divided as follows:1 offered no monetary rewardOffered $1 for each correct answerOffered $5 for each correct answer$25 offered for person in the group who
scored the most correct answersNEED FOR CORRECT ANSWERS
WAS EMPHASISED BY LOFTUS
Findings
In spite of financial incentives Over 70% made an error on the crucial
question in line with the misleading info they received.
This suggestsThat the original memory had been
altered as a result of the misleading post-event information.
Divide class into 2 groups:A and BGroup B should close their eyes when
Group A are doing the task and vice versa
Group B – write your answers down
Did you see a broken headlight in the clip you saw earlier?
How fast do you think the bike was going when it made contact with the car?
Group A – write your answers down
Did you see the broken headlight in the clip you saw earlier?
How fast do you think the bike was going when it smashed into the car?
findings
Are our findings the same as Loftus and Zanni (1975)?
They found17% of those with the leading question
reported seeing it7% of those asked about ‘a’ broken
headlight reported seeing it.
findings
The verbs, ‘smashed’, ‘bumped’, ‘collided’, or ‘contacted’
Had a significant effect on the estimates of speed.
A week later, those who had been given the word ‘smashed’ were more likely to report seeing broken glass even though there had been none.
Other factors affecting EWT
Information may not be registered in the first place.
In real life situations, accidents happen suddenly and people aren’t expecting something to happen.
Memories are reconstructed with preconceptions.
We fill in gaps with our own knowledge and experience of the world (schemas).
Schema for a bank robbery
Write a list of things that immediately comes to mind when thinking of a bank robbery.
Male Disguise Dark clothes Getaway car outside Driver in the car waiting According to Tuckey and Brewer (2003)
Interference with memory
Palace or museum
Lindsay et al. (2004)
Participants told about a
Burglary at a palace Or a school trip to a
palace
Interference when things are similar
When shown a video of a burglary at a museum who would make more errors on recall of details?
Those who had heard about palace burglary previously rather than a school trip.
Why?
Other factors that affect EWT
Anxiety
http://www.onlineclassroom.tv/psychology/catalogue/psychology_critical_issues/eyewitness_testimony