Flashcards in Cognitive - Eyewitness Testimony Deck (43):
What 5 factors effect Eyewitness testimony?
-Age of witness
-Use of Cognitive Interview
What is weapon focus?
Concentration of a crime witness's attention on a weapon and the resultant reduction in ability to remember other details of the crime
Name a study into weapon focus
State the procedure of Loftus' study into weapon focus
Volunteers waited in a waiting room. In one condition they hear low-volume discussion before a man leaves the near room holding a pen. Second condition they hear a high-volume hostile argument before a man leaves with a blood-stained knife. The participants were showed 50 photos to identify the man
State the results of Loftus' study into weapon focus
Pen: 49% identified the correct man
Knife: 33% identified the correct man
What were the conclusions made from Loftus' study into weapon focus?
Concentrating on a weapon distracts attention away from appearance of the perpetrator (weapon focus effect)
Anxiety / stress induced by the sight of a weapon narrows the focus of attention
This improves the recall of central details of a scene but diminishes accurate recall of peripheral details
Name and explain a piece of supporting evidence for Loftus' study into weapon focus
Loftus & Messot
Participants presented with a series of slides showing an event in a fast-food restaurant. Half saw cutomer give cashier a cheque, other half saw him point a gun at him. Eye movements recorded.
Found more eye fixations of weapon than on cheque and fixations on weapon for longer duration. Memory in weapon condition poorer than memory in cheque condition.
Name and explain a piece of supporting evidence for Loftus' study into weapon focus, involving a violent film
Loftus & Burns
2 conditions: violent or non-violent film.
Found in violent condition less accurate information about the crime.
Evaluate Loftus' research into weapon focus
-Supporting evidence (Loftus & Burns, Loftus & Messot)
-Low ecological validity (lab experiment)
-Ethical issues (deceiving participants)
-Contradictory later evidence (e.g Yuille & Cutshall)
Name 2 field studies into the effect of anxiety on the accuracy of EWT
-Yuille and Cutshall
-Christian and Hubinette
Explain the procedure and results of Yuille and Cutshall
Interviewed 13 witnesses from a real-life shooting involving the owner of a shop and an armed thief. The shop owner was wounded but recovered an the thief was shot dead. Some witnesses were close proximity, others were far.
Found that witnesses closest to the event provided the most detail, and those most distressed at the time provided most accurate detail 5 months later (anxiety enhanced the accuracy of EWT)
Explain the procedure and results of Christian and Hubinette
Questioned 110 witnesses (some victims of incidents, some just bystanders).
The victims were more accurate in recall than the bystanders.
This was a genuine incident as opposed to a staged one (more ecological validity) and opposes Loftus' study
What are schemas?
Packages of knowledge that we acquire through experience. They help us to build up a picture of our world and enable us to make predictions about our day to day lives. Established by Cohen.
What are the 5 ways Cohen suggested that schemas effect your memory?
- Selection (ignoring information that doesn't fit current schemas)
- Abstraction (remembering the overall gist without exact details)
- Interpretation (providing existing knowledge to help us understand existing knowledge)
- Normalisation (memories distorted to fit with our existing information
- Retrieval (help us to fill gaps in memory to make a best guess)
Name a study into schemas
Brewer and Treyens
State the procedure of Brewer and Treyens
Got participants to wait one at a time in a room for 35 seconds. The room looked like an office and contained 61 items. Most objects were ones you would expect to be in an office, others such as a skull, a brick and a pair of pliers, were not. Later they were asked to recall the items in the office.
State the findings of Brewer and Treyens
Most likely to recall typical office objects
Most mistakes came from substitution (e.g 'pens' that would be in the schema for office but weren't actually there).
Also the 'schema plus tag' effect (e.g the skull)
What is the 'schema plus tag' theory?
Having a schema for a situation but 'tagging' information that wouldn't be expected there
Evaluate the concept of schemas
It is a rather vague concept and schema theory offers no explanation as to how the schemas are acquired in the first place
Summarise schemas in relation to EWT
We are only able to take in so much information at the scene of a crime or incident. At a later date when we are asked to provide greater detail then we rely on past experience (schemas) to fill in the gaps. We use expectations to reconstruct our memory.
How much do children remember in comparison to adults?
-Children are generally inferior to adults when it comes to providing a complete account of past events (amount of information they can recall or recognise increases with age)
-Due to inferior encoding, storage and retrieval ability and lack of prior knowledge)
How accurate is a child's memory in comparison to an adult's?
-Geiselman and Padilla found children aged 7-12 were less accurate than adults in a filmed robbery report.
-Other researches failed to find such differences
Name a study into how age effects the quantity of information individuals are able to recall after 5 months
Flin et al
State the procedure of Flin et al's study
Staged an incident and questioned children and adults about it a day later and again five months later.
What were the findings from Flin et al's study?
Both groups (young and old) performed equally well the following day but after five months the children’s group had forgotten significantly more, suggesting the EWT of children becomes less reliable over time
Evaluate Flin et al's study
-Good ecological validity (children asked to recall after 5 months in court)
-Bad ecological validity (they were told to concentrate, not like in reality)
Name and explain a study into how age effects source recognition
Poole and Lindsay
State the procedure for Poole and Lindsay's study
Got children of varying ages (three to eight) to watch a science demonstration following which they listened to a story which contained some of the science material but also some new information. They were later questioned on where they got the information from; the story or the demonstration.
What were the findings from Poole and Lindsay's study?
The younger age group were less able to distinguish the source of the information (either from the story or the demonstration) but the older children were more able to do this.
Poole an Lindsay concluded that young children are poor at ‘source recognition’ they are unlikely to make for good eye witnesses.
Evaluate Poole and Lindsay's study
-It was a field experiment, so no demand characteristics
-Difficult to eliminate extraneous variables
What did Ceci and Bruck conclude as the 4 main factors affecting children's EWT?
-Interviewer bias (e.g leading questions)
-Repeated questions (more likely to change answer when question is repeated)
-Stereotype induction (say negative things because of the context of being asked the questions)
-Encouragement to 'think really hard' (may form new memories that didn't happen)
How does children's encoding affect their EWT?
Lack of appropriate schema makes it difficult to encode accurately.
Could be beneficial; adults could rely on schema to remould their memory incorrectly
How does children's storage affect their EWT?
Time between encoding and retrieval effects accuracy. Children's EWT is likely to suffer more than adults' as the storage interval increases
How does children's retrieval affect their EWT?
More susceptible to misleading information / leading questions, which effects the accuracy of their retrieval
Name a study into misleading questions being a factor affecting the accuracy of EWT
Loftus & Zanni
State the procedure of Loftus & Zanni's study
Involved a short film, and participants were divided into 2 groups and asked a series of questions; one group asked 'open' questions and one group asked 'misleading' questions about a broken headlight. (There wasn't a broken headlight)
State the results of Loftus & Zanni's study
17% who were asked the misleading question answered saying they saw a broken headlight
7% who were asked the open question saw it
Concluded the wording of the question had a significant effect on participants' memory of the event (misleading questions distorted the memory)
Evaluate Loftus & Zanni's study
-Potentially just demand characteristics (participants trying to please the interviewer through their implications)
-Realistic material increasing ecological validity
-Artificial situation, low ecological validity (but was the same across both groups so can't explain the difference in results)
-Deceived the participants (no fully informed consent)
Name a study into how misinformation can effect EWT
State the procedure of Loftus' study into misinformation
Participants shown a film showing the events leading up to a car crash and were then asked 10 questions about the film. The experimental group had the question 'How fast was the car travelling when it drove past the barn' (misinformation about the barn) and the control group 'How fast was the car travelling on the country road'.
One week later the participants were asked 'did you see a barn?' (open question to both groups)
What were the results from Loftus' study into misinformation?
Only 3% of the control group said they had seen a barn
17% of the experimental group saw it
Misleading information had an effect on participants' memory
Name and explain a study into Old people and the weapon focus
Showed a film of a confrontation in a shop, one with a knife and one without a knife.
80% of them failed to recall a knife in the attacker's hand.
Only 20% of younger adults failed to recall the knife.
This might mean that elderly people are less susceptible to the weapon focus, which might mean that their recall of other peripheral details is better