1. The cognitive area

2. The cognitive area KEY THEME: Memory
Loftus & Palmer – Eyewitness testimony
Grant et al. – context-dependent memory

3. Eye witness testimony Main piece of evidence in 20% of cases
75% of false convictions are due to inaccurate eye witness testimony

5. Background:
The inaccuracy of eye witness memory and the potential for memories to be distorted by the use of language has important practical applications and so is a focus of research.
In particular, the police and courts often rely on eye witness testimony in order to make decisions about what happened. And so, it is important it is as accurate as possible

6. What can influence the accuracy of ewt?
Misleading information
Has been found to be more able to create false memories the more believable, emotionally arousing and subtle it is

7. What can influence the accuracy of ewt?
A Leading questions
Questions that will increase the likelihood that an individuals schema’s will influence them to give a desired answer – “balloons at child's birthday party next to cake and clown?”
B Post-event discussion
PED concerns misleading information being added to a memory after the event has occurs – “the pedestrian didn’t look both ways before crossing the road”

8. LOFTUS AND PALMER (1974) Leading questions
Looked at:
Whether people reconstruct a memory
Whether the memory persists
Whether they can be ‘led’ into answering in a certain way

9. LOFTUS AND PALMER (1974) Leading questions
AIM:
Experiment 1: was to see whether using different verbs to describe a collision between two cars would affect estimates of the speed at which they were travelling when the crash took place

10. Experiment one - Leading questions
SAMPLE:
45 university students
No details of gender or age

11. Experiment one - Leading questions
Design:
Laboratory experiment
Independent measures design - shown 7 video clips of car crashes taken from Seattle Police Department

12. Experiment one - Leading questions
Procedure:
After each accident, participants wrote an account of what they recalled and answered the same questions
The key question being to estimate the speed of the vehicles in the car accident
There were five conditions – each condition varied through the verb used in the question

13. “About how fast were the cars going when they ________ each other?”
The key question;
“About how fast were the cars going when they ________ each other?”
Each group was given a different verb to fill in the blank. The verbs were ‘smashed, collided, bumped, hit or contacted’
The IV is….
The verb used
The DV is….
The speed reported

14. The words used actually changed ppts memory of the event!
RESULTS:
The verb used influenced the participants speed estimates
When the verb ‘smashed’ was used, the participants estimated the cars were travelling much faster than when the verb ‘contacted’ was used
What does this suggest with regards to our memory of events?
The words used actually changed ppts memory of the event!
Verb
Mean Speed Estimates
Smashed
40.8
Collided
39.3
Bumped
38.1
Hit
34.0
Contacted
31.8

15. Conclusions from experiment one
The use of misleading information in the form of leading questions affected the memory recall of the witnesses
This means that the questions the participants were asked changed the memory of the event
We don’t know whether the reported speed was due to a genuine change in the participant’s memory, or through demand characteristics (participants guessing the true nature of the experiment)

16. Experiment two post-event discussion
150 student participants were shown a short film that showed a multi-vehicle car accident
Laboratory experiment
The participants were split into three groups dependent on what question they would be asked
Group 1: “How fast were the cars going when they hit each other?”
Group 2: “How fast were the cars going when they smashed each other?”
Group 3: Not asked about the speed of the vehicles

17. One week later, all participants returned and were asked “Did you see any broken glass?”
There was no broken glass in the film

18. What do these results show??
Response
Smashed
Hit
Control
Yes 16 7 6 No 34 43 44
The results show that the verb used in the original question influenced whether the participants thought they had seen broken glass

19. Conclusions from experiment two
Misleading information in the form of post-event information can also affect memory recall of eyewitnesses
Video showing the influence of post-event information

20. Let’s evaluate… Where were the studies conducted?
Is this an ideal setting for an investigation looking at EWT?
Questionnaires were used to collect the data
Explain one strength of using a questionnaire in these studies
Explain one weakness of using a questionnaire in these studies

21. Let’s evaluate… How was memory measured? Are there any ethical issues?
Is this an ideal way to measure EWT? Is there a better way?
Are there any ethical issues?
What about those who have been in a real life crash before?

22. Let’s evaluate… Is it valid? Is it reliable?
Are there any issues with the sample?
How can this be used in real life?

23. Leading questions… false memories
Leading questions are powerful and change your memory of the event Can leading questions create a whole new false memory?

24. Can leading questions cause false memories?
Loftus & Pickrell (2003) wanted to investigate this…
120 students who had visited Disneyland as a child were divided into four groups
Group 1: Read a fake Disneyland advert featuring no cartoon characters
Group 2: Read the fake advert featuring no cartoon characters and were exposed to a cardboard figure of Bugs Bunny placed in the interview room

25. Can leading questions cause false memories?
Group 3 : Read the fake Disneyland advert featuring Bugs Bunny
Group 4: Read the fake Disneyland advert featuring Bugs Bunny and saw the cardboard figure of Bugs Bunny

26. Found: 30% of participants in group 3 and 40% of participants in group 4 remembered or knew they had met Bugs Bunny when they visited Disney Land
Has anyone here been to Disneyland and remembers meeting Bugs Bunny??
The participants had not met Bugs Bunny at Disneyland because Bugs Bunny is a Warner Brother and not a Disney character