10 Eyewitness Memory Flashcards
What is the misinformation effect?
Exposure to incorrect information about an event after it has occurred often causes people to incorporate this misinformation into their memories
Discuss differences between physical and eyewitness evidence
Physical evidence (e.g. Hairs, fibre, DNA etc)
- Protocols for collecting, preserving and interpreting physical evidence are dictated largely by forensic scientists
- Protocols have a scientific foundation, grounded in what experts suggest are optimal ways to avoid contamination
- Physical evidence is often ‘circumstantial’
Eyewitness evidence
-Typically collected by non-specialists in human memory
-Protocols for collecting, preserving and interpreting eyewitness evidence has not incorporated scientific psychological research to the extent that it could
Often directly links a suspect to a crime
How do we know eyewitness evidence is unreliable?
- DNA exoneration case studies
- Eyewitness research
- Encoding: What happens at the scene of the crime
- Storage: before we recall, retain the event memory and the person description for a period of time
- Retrieval: often include system variables
According to eye witness research, errors can occur at different stages so what errors occur at the Encoding stage?
We can’t change what happens at the scene of the crime but it is important that we understand how different features of the crime and the witness will affect how reliable and accurate the witness will be
-different factors can influence the accuracy of memory and these are called estimator variables (cannot be changed)
According to eye witness research, errors can occur at different stages so what errors occur at the Storage stage?
The more duration in the storage phase, the more we’re likely to forget or encounter incorrect information through different sources
According to eye witness research, errors can occur at different stages so what errors occur at the Retrieval stage?
- System variables are the variables we have control over and we have control over how we question witnesses about crimes and how we conduct identification parades
- Different procedures and different questions can influence how accurate the witness is likely to be
What is an important thing to remember when questioning eyewitnesses after a specific event has just happened?
Try to question witnesses quickly after the event happens for most accurate results and a lot of bad stuff can happen if delayed for too long
Why is it important to question witnesses after the event as soon as possible?
The longer the delay the more possible sources they will encounter the more likely they will encounter misinformation about the event and the more susceptible they are to the information as their memory trace faces
What are three ways to encounter post-event information?
- Leading questions about the event (smashed/hit car)
- Hearing about the event from the media (white van, snipers in blue car)
- Hearing about the event from other witnesses
Describe research that demonstrates how leading questions about the event can lead to misinformation?
Participants showed film of traffic accident
Asked how fast they were going when the cars smashed/hit each other
One week alter, participants in the smashed condition were more than twice as likely to recall broken glass, when there was none
*The difference in one word changed people’s memory reports on what happens
Describe research that demonstrates how hearing about an event through the media can lead to misinformation?
Participants shown pictures of shoplifting incident
Then read brief summary of the crime, which including some incorrect details
Participants incorporated the incorrect details from the summary into their memories
What are the two types of co-witness information and what did the eyewitness survey reveal?
Direct transfer: witnesses discussing the event with one another
Indirect transfer: third party tells you about the information that another witness has said
Eyewitness Survey
- majority of witness’ report discussing event with a co-witness
- Main reason: providing information
- more witnesses reported they had been encouraged by the police to discuss event with co-witnesses
What does the research on comparing ways to encounter misinformation reveal about type of information effects?
Study investigated the impact of different methods of encountering post-event information
- Leading questions - Media report - Indirect co-witness information - Co-witness discussion with confederate - Control
No effect of post-event information method on memory accuracy for control items
For accurate information, direct and indirect co-witness conditions more accurate
For misleading information direct and indirect co-witness conditions less accurate
Why is it important to study the co-witness discussion?
- Research has consistently shown that participants report misinformation that was previously stated by a co-witness during discussion
- Warnings not effective: only report what you remember from the video not what you heard from another person
This phenomenon has become known
- Social contagion of memory - Memory conformity
No effect of co-witness discussion on identification decision
What is the legal perspective on co-witnesses?
A witness’s assertions of relevant facts should be based upon his or her own experiences” and not those of another
