Stages of Memory
- Preparation/ Attention Stage: See features or individual
- Encoding Stage: Take note of certain features
- Short-term Memory: Less detail from original encoding
- Long-term memory: similar information but not all able to be retrieved
- Retrieval Stage: Able to recall aspects of memory
What factors can affect how much is encoded in an eyewitness
Inattention and Unexpectedness
- Did they expect something to happen
How can memories change in recall
- Order of events may change
- may embellish certain details
- Fill in gaps that were forgotten
What differences in interviewing techniques can affect the retrieval stage of memory
- Wording of questions
- Another witness recalling memories that you then believe as your own
- Time elapsed since witnessing crime
Types of retrieval
- Recall Memory: Reporting details of a witnessed event (free recall or questions)
- Recognition Memory: Reporting whether what is currently being viewed/heard is the same as the previously seen person/item of interest (is this something you have seen or heard before)
Eyewitness Research: Independent Variables
ESTIMATOR VARIABLES: Present at the time of the crime
- Cannot be changed in field, can be controlled in lab studies
- Eg: Age of witness, lighting, presence of a weapon, intoxication
SYSTEM VARIABLES: Can be manipulated to increase or decrease eyewitness accuracy
- Can be changed, under the control of the justice system to change
- Ex: Structure of interview, type of lineup procedure
Eyewitness Research: Dependent Variables
OPEN-ENDED RECALL AND/OR DIRECT QUESTION RECALL
- Recall of crime/event or Recall of perpetrator
- Can be verbal or written
- Analyzed by amount of info, type of info and accuracy of info
RECOGNITION OF PERPETRATOR
Issues with current Interview Techniques
- Officers commonly interrupt witnesses (switches line of thinking)
- Officers ask short, specific questions (Focuses on one piece instead of full picture, easier to remember whole picture)
- Asks questions in a random order (lack of temporality impacts ability to recall)
- Contamination of co-witnesses can occur
- Ask leading or suggestive questions
Memory Conformity
What one witness reports influences what the other witness reports
Loftus & Palmer: Car accident study
- Participants watched a video of a car accident
- Asked “How fast were the cars going when they _____ each other” filling in the blank with smashed, bumped, collided, contacted
- Faster speeds were reported when smashed was used
- Slower speeds reported when bumped or contacted was used
- Brought back to ask if glass was broken and those who had the word smashed were more likely to say yes
Loftus: Demonstrators disrupting class
- 3 minute video of 8 demonstrators disrupting a class
- Half of the participants were asked “was the leader of the 12 demonstrators male”
- other half: “was the leader of the 4 demonstrators male”
- One week later: “how many demonstrators were there?”
- First half: average 8.85, second half: avg 6.4
What is the Misinformation Effect
Witness presented with inaccurate information after an event will incorporate that misinformation into subsequent recall
What are the hypothesis for the misinformation effect
- Misinformation Acceptance Hypothesis: Witnesses guess at the answer they think the experimenter wants
- Source Misattribution Hypothesis: Accurate and inaccurate memories both recall - however, witnesses do not remember where each came form
- Memory Impairment Hypothesis: Original memory is replaced or altered, original memory is no longer accessible
Standard Cognitive Interview
- Only conducted on witnesses, they must be willing
REINSTATING THE CONTEXT - Put back in situation, what senses are present
REPORTING EVERYTHING - Free recall from beginning to end
- Can add questions if in temporal order and context
REVERSING ORDER - End-beginning
- Allows catching of additional details
CHANGING PERSPECITVE - What might someone else in the room have witnessed
Enhanced Cognitive Interview
Same steps with focus on;
- Rapport Building
- Supportive interviewer behaviour ( don’t interrupt, accept pauses, express attention)
- Transfer of control (let witness lead conversation)
- Focused Retrieval (open-ended questions)
- Witness-Compatibility Questioning (match thinking of witness, same subject)
Why is the enhanced cognitive interview not always used?
Takes time and a specific space
- Ideal but not necessary
What have studies found on describing perpetrators?
- Hair and clothing are most common descriptors
- In staged crimes (know its going to happen) avg 7.35 descriptors
- In real crimes (physiological arousal causes decrease in attention) avg 3.94
- Writing out worse than verbal description
What type of descriptors are accurate vs inaccurate?
Gender and race most accurate
ACCURATE
- Hair color
- Hair length
- Age
- Height
- Complexion
- Type of top
INACCURATE
- Weight
- Eye color
- Color of Footwear
Featural vs configural recognition
- Featural for object
- Configural for faces
Line ups
- Provide evidence that the suspect is the perpetrator
- Made up of foils and suspect
- If suspect is selected it provides evidence against person
- Default values: sex, race, maybe hair color
Similarity-to-suspect strategy
Matches lineup members to suspect’s appearance
- Hair color, eye color, height, weight
- Too similar makes it hard to pick out
Match-to-description Strategy
Distractors have features that were described in initial description
Fair Lineup
Suspect does not stand out from distractors
Assessing Lineup Accuracy
- Correct identification: identify target when present
- False Rejection: Identify no target when target is present
- Foil identification: Identify a foil
- Correct rejection: Identify no target when perpetrator isn’t present
- False Identification: identify target when perpetrator isn’t present
