an EWT refers to an account given by people of an event they have witnessed
this includes identification of the perpetrators, details of the crime scene etc
what makes a memory a reconstructive process?
because memories are reconstructions based on schemas
what’s a schema?
they are units of knowledge that relate to everyday objects, situations or people
they enable us to predict events and make sense of unfamiliar circumstances
our recall of events is ‘matched’ with our schemas and understanding of the world, which if often based on what we have experienced in our particular culture so if new information doesn’t make sense, we unconsciously change it so it does match
this means that memories can be distorted in several ways so that they are not always accurate and reliable accounts
what did Wells report?
40 ‘death row’ cases in the US where the individuals were convicted as a result of an EWT have later been cleared using DNA evidence
what is an EWT affected by?
misleading information
anxiety
what are the two types of misleading information?
leading questions
post-event discussions
what’s a leading question?
a question phrased in such a way that it prompts a particular type of answer
what was the procedure of Loftus and Palmers study into leading questions?
they examined the effects of leading questions on an eyewitnesses recall of a car accident
the participants were asked on question; ‘How fast were the cars going when they ….. each other?’
the blank was filled in by either smashed, collided, bumped, hit and contacted within the groups
they were asked a week later ”did you see any broken glass?’
what were the findings of Loftus and Palmers study of leading questions?
when the verb ‘smashed‘ was used the mean estimate speed was 40.8mph compared to when ‘contacted’ was used with a mean speed estimate of 31.8mph
aswell as this, the participants who were told the word ‘smashed’ were much more likely to say yes to the question about the broken glass compared to the other conditions
what was the conclusion of Loftus and Palmers study into leading questions?
the verb used implied certain details about the incident such as faster or slower speed
what was the procedure of Loftus and Zannis into leading question?
participants were shown a brief clip of a car accident and were asked questions about what they had seen
half of the participants were asked: ‘did u see A broken headlight’ (open question)
half of the participants were asked: ‘did you see THE broken headlight‘ (leading question)
there was no broken headlight
what were the findings of Loftus and Zannis study into leading questions?
participants who received the open question: 7% said yes
participants who received the leading question: 17% said yes
what was the conclusion made by loftus and zannis study into leading questions?
using ‘the‘ in place of the ’a’ implanted the idea to the witness that there was is infact a broken headlight. this led participants to change their recall in relation to the implied response
what is a post event discussion?
a potential source of misleading information where witnesses discuss what they saw after an event. this can affect the accuracy of their accounts
what was the procedure of Gabberts study into post-event discussions?
her sample consisted of 60 students and 60 older adults
participants watched a video of a girl stealing money from a wallet but the participants were either tested individually (control group) or in pairs (co-witness group)
the participants in the co-witness group were told that they had watched the same video but they had seen different perspectives of the crime and only one had seen the girl steal
the participants in the co-witness group discussed the crime and completed a questionnaire of their recall of the crime
what were the findings of Gabberts study into post-event discussions?
71% of witnesses in the co-witness group recalled information that they had not seen
60% said that the girl was guilty, despite the fact they had not seen her commit a crime
what was the conclusion made of Gabberts study into post-event discussions?
the results highlight the issue of post-event discussion and the powerful effects this can have on the accuracy of EWT
what is anxiety?
a physiological arousal in the body which prevents us paying attention to important cues
what was the procedure of Johnson and Scotts study into anxiety?
participants were taken into a waiting room as they though they were going to take part in a lab experiment but they heard an argument in the next room
‘low anxiety condition’: a man entered the room with a pen and grease on his hand
’hight anxiety condition’: overheard the same argument but heard glass break and the man entered the room with a paper knife covered in ‘blood’
participants had to pick out the man from 50 photos
what was the findings of Johnson and Scotts study into anxiety?
low anxiety condition: 49% identified the man
high anxiety condition: 33% identified the man
the lower percentage in the high anxiety condition can be explained by the tunnel theory
what is the tunnel theory?
the tunnel theory of memory argues that a witnesses attention narrows to focus on the weapon because its a source of anxiety
what was the procedure of Loftus and Burns study into anxiety?
some participants were shown a violent film which included a boy being shot
others were shown a non-violent film
participants were later asked to recall the events of the film
what were the findings of Loftus and Burns study into anxiety?
participants had significantly impaired or reduced recall of the events leading up to the shooting compared to participants who watched the non-violent video
what was the procedure and findings of Fischers study into police interviews?
they studied police interview techniques and found that detectives often did not get the best information from witnesses because they:
bombarded people with questions
used closed ended questions
asked questions out of sync
interrupted witnesses
didnt allow witnesses to talk freely about experiences
what is the cognitive interview?
the cognitive interview is an interview technique designed to improve the detail ad accuracy of witness recall
what were the 4 components of the cognitive interview designed by Geiselman?
report everything
reinstate the context
reverse the order
change perspective
what does it mean by ‘report everything’ in the cognitive interview?
to ask the witness to report the maximum amount of information available even if it appears unimportant as this can trigger important memories
what does it mean by ‘reinstate the context’ in the cognitive interview?
try to return to both the environmental and emotional context of the scene as this is related to context-dependent forgetting
what does it mean by ‘reverse the order’ in a cognitive interview?
recount the scene in a different chronological order as this prevents witnesses reporting their expectations and prevents dishonesty
what does it mean by ‘change perspective‘ in the cognitive interview?
recount the scene from the point of view of another person involved as it prevents the witness from reporting expectations
what was the procedure of Geiselmans study into the cognitive interview?
they compared the number of correct items recalled by witnesses with a standard interview and a cognitive interview
what was the findings of Geiselmans study into the cognitive interview?
more correct details were elicited when using the cognitive interview
however, there was no difference in the number of errors made
what was the conclusion made of Geiselmans study into the cognitive interview?
the standard interview does not offer the use of retrieval cues to aid recall
what is the enhanced cognitive interview?
its a modified version of the standard cognitive interview made for children as it aims to build a trusting relationship between interviewer and witness
this can improve the quality of the communication and reduce witness anxiety and enhance recall