PSY 3173 Lecture Notes - Lecture 4: Eyewitness Testimony, Eyewitness Memory, Cognitive Interview
28 Apr 2018
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January 25, 2017
Eyewitness Testimony
Learning Objectives
Independent and dependent variables in eyewitness research
The misinformation effect
Cognitive interview
Lineup procedures and how they can be biased
Expert testimony on eyewitness issues
Recommendations for collecting eyewitness evidence
The Role of Memory
Eyewitness testimony relies on: encoding, storing, and recalling information
Storing memories requires several steps including attention, encoding, short-term memory, long-term memory
Not all memories pass successfully through these stages and problems may occur at each stage
-Can make memories unreliable and incorrect
The Stages of Memory
Encoding
Storage
Retrieval
Types of Eyewitness memory
Eyewitnesses perform two types of memory retrieval
-Recall memory: reporting details of a previously witnessed event/person
-Recognition memory: determining whether what is currently being viewed/hear is the same as the perviously
witnessed item/person
Studying Eyewitness Issues
Archival data: police reports, trial transcripts
Naturalistic observation: observations in the field
Laboratory simulations: ex. university students participating in studies
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January 25, 2017
Types of Eyewitness Independent Variables
Estimator variables: present at the time of the crime and cannot be changed
-Not under the control of the criminal justice system
-Ex. age of witness, distance between witness and event, time of day that the event occurred
System variables: can be manipulated to increase (or decrease) eyewitness accuracy
-Under control of the criminal justice system
-Can be manipulated after the crime has occurred
-Ex. lineup procedure, gender of officer speaking to the witness, type of interview, location of interview
Types of Eyewitness Dependent Variables
Recall of the event
Recall of the perpetrator
Recognition of the perpetrator
Interviewing Witnesses
Open ended recall/free narrative: witnesses are asked to recount what they witnessed without being prompted
-More likely to contain the truth
Direct question recall: witnesses are asked specific questions about the event/perpetrator
-Risk planting false memories or influencing memories
-Risk interrupting the witness during free recall - can make them lose their train of thought and forget details
Police officers may impeded the interview process by:
-Interrupting witnesses during free recall
-Asking short specific questions which may not get at critical information
-Asking questions not relevant to what the witness is currently describing
Witness Contamination
Witnesses can be “contaminated” by information they may become aware of from other witnesses
-Ex. If they directly communicate with each other or learn of what others reported
Known as memory conformity: witnesses may conform to agree with everyone else
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Document Summary
Lineup procedures and how they can be biased. Eyewitness testimony relies on: encoding, storing, and recalling information. Storing memories requires several steps including attention, encoding, short-term memory, long-term memory. Not all memories pass successfully through these stages and problems may occur at each stage. Recall memory: reporting details of a previously witnessed event/person. Recognition memory: determining whether what is currently being viewed/hear is the same as the perviously witnessed item/person. Laboratory simulations: ex. university students participating in studies. Estimator variables: present at the time of the crime and cannot be changed. Not under the control of the criminal justice system. Ex. age of witness, distance between witness and event, time of day that the event occurred. System variables: can be manipulated to increase (or decrease) eyewitness accuracy. Under control of the criminal justice system. Can be manipulated after the crime has occurred. Ex. lineup procedure, gender of of cer speaking to the witness, type of interview, location of interview.
