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what have we learned from past two lessons?
Forgetting Schemas How schema’s can influence our memory Specifically so in EWT
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Last lesson we watched a video which showed witnessing an event and recalling what we saw is not as easy as we thought
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Starter: let’s try again!
What are issues with this study?? Can YOU spot the murderer? Part 2 What does this show? The difficulty of being an eyewitness
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Lesson 3: ewt
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Lesson aims To be able to outline the factors which affect eye witness testimony
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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
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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”
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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
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Experiment one - Leading questions
45 university students were each shown 7 video clips of car crashes in a laboratory experiment 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
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“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
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The words used actually changed ppts memory of the event!
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? Verb Mean Speed Estimates Smashed 40.8 Collided 39.3 Bumped 38.1 Hit 34.0 Contacted 31.8 The words used actually changed ppts memory of the event!
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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)
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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
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One week later, all participants returned and were asked “Did you see any broken glass?”
There was no broken glass in the film
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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
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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
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Let’s evaluate… Where were the studies conducted?
Using whiteboards, write your answer on the board and when told to, reveal to the class 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
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Leading questions… false memories
Leading questions are powerful and change your memory of the event Can leading questions create a whole new false memory?
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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
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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
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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
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Another study… Clifasefi & colleagues 2013
Provided participants a document that claimed to be a personalised food and drink profile The participants believed this was put together by a powerful computer software based on participants earlier responses to questionnaire
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For one group, their profiles included false information that they had once, under the age of 16, drank so much alcohol they were sick – the ppts read their ‘profile’ Later the participants completed a memory test with leading question asking if they had become sick from too much alcohol Researchers found significant number of participants recalled being sick due to too much alcohol before they were 16 even though this did not occur and was in fact a false memory
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What did this study not take into consideration which may influence the results?
The participants may have got drunk and were sick under the age of 16 but may have not wished to report it in their questionnaire
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