Influences on Eyewitness Memory
● Natural degradation: memory naturally fades as the retention interval -amount of time
between viewing an event and being questioned about it- increases.
● Post-Event Information: Information learned after observing an event.
○ Has potential to alter your memory of a particular event.
○ Approx 88% of cases in the UK one year had multiple eyewitnesses who could
have potentially talked to one another (Skagerberg & Wright, 2008). Why could
this be a problem?
○ Post-Event Misinformation
■ Misinformation effect: when a person’s recall of an episodic memory
becomes less accurate as a result of post-event information
■ Loftus & Palmer (1974)
■ Loftus et al. (1978)
● Verbal Overshadowing: tendency of verbalisation to impair the recall of visual memories
○ Those who offered a verbal description prior to a lineup were 25% less accurate
than those in a control group (Schooler & Engstler-Schooler, 1990)
○ A mass replication attempt found a 16% decrease (Alogna et al., 2014)
● Unconscious Transference: when a witness identifies a suspect because they had seen
the innocent suspect before, but not as the perpetrator of the crime
○ Loftus (1976) & Brigham & Cairns (1988)
○ Possible explanation: Source confusion- when we misattribute the source origin
of a particular memory
Line-Up Presentation Methods
● Simultaneous Presentation: The more traditional line-up, in which all members are
shown to the witness at once.
● Sequential Presentation: An alternative procedure in which each member is shown
sequentially (one at a time)
○ Sequential presentations are associated with a 22% decrease in mistaken
identifications (Steblay et al., 2011). Why?
● Relative vs. Absolute Judgments
● Wells (1993)
Choosing Fillers for Line-Ups
● Match-to-Suspect Approach: When fillers (foils) are selected based on their similarity to
the physical appearance of the suspect
● Match-to-Description Approach: When fillers are selected based on their resemblance to
the physical description of the perpetrator given by the eyewitness
● Concerns for either approach?
The Influence of Feedback
● Post-Identification Feedback: When witness self-reports are distorted by feedback to the
witnesses that suggest that their identifications were accurate or mistaken
● Natural degradation: memory naturally fades as the retention interval -amount of time
between viewing an event and being questioned about it- increases.
● Post-Event Information: Information learned after observing an event.
○ Has potential to alter your memory of a particular event.
○ Approx 88% of cases in the UK one year had multiple eyewitnesses who could
have potentially talked to one another (Skagerberg & Wright, 2008). Why could
this be a problem?
○ Post-Event Misinformation
■ Misinformation effect: when a person’s recall of an episodic memory
becomes less accurate as a result of post-event information
■ Loftus & Palmer (1974)
■ Loftus et al. (1978)
● Verbal Overshadowing: tendency of verbalisation to impair the recall of visual memories
○ Those who offered a verbal description prior to a lineup were 25% less accurate
than those in a control group (Schooler & Engstler-Schooler, 1990)
○ A mass replication attempt found a 16% decrease (Alogna et al., 2014)
● Unconscious Transference: when a witness identifies a suspect because they had seen
the innocent suspect before, but not as the perpetrator of the crime
○ Loftus (1976) & Brigham & Cairns (1988)
○ Possible explanation: Source confusion- when we misattribute the source origin
of a particular memory
Line-Up Presentation Methods
● Simultaneous Presentation: The more traditional line-up, in which all members are
shown to the witness at once.
● Sequential Presentation: An alternative procedure in which each member is shown
sequentially (one at a time)
○ Sequential presentations are associated with a 22% decrease in mistaken
identifications (Steblay et al., 2011). Why?
● Relative vs. Absolute Judgments
● Wells (1993)
Choosing Fillers for Line-Ups
● Match-to-Suspect Approach: When fillers (foils) are selected based on their similarity to
the physical appearance of the suspect
● Match-to-Description Approach: When fillers are selected based on their resemblance to
the physical description of the perpetrator given by the eyewitness
● Concerns for either approach?
The Influence of Feedback
● Post-Identification Feedback: When witness self-reports are distorted by feedback to the
witnesses that suggest that their identifications were accurate or mistaken
