Chapter 8
Everyday Memory and Memory Errors
Some Questions to Consider
• What kinds of events from their lives are
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•
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people most likely to remember?
Is there something special about memory for
extraordinary events like the 9/11 terrorist
attacks?
What properties of the memory system make
it both highly functional and also prone to
error?
Why is eyewitness testimony often cited as
the cause of wrongful convictions?
Autobiographical Memory (AM)
• Recollected events that belong to a person’s
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•
past
Mental time travel
Multidimensional
– Spatial, emotional, and sensory
components
Autobiographical Memory
• Sensory component
• Greenberg and Rubin (2003)
– Patients who cannot recognize objects also
experience loss of autobiographical
memory
– Visual experience plays a role in forming
and retrieving AM
Autobiographical Memory
• Cabeza and coworkers (2004)
– Comparing brain activation caused by
autobiographical memory and laboratory
memory
– Participants viewed
• Photographs they took (A-photos)
• Photographs taken by someone else
Autobiographical Memory
• Both types of photos activated brain
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•
structures associated with
– Episodic memory
– Processing scenes
A-photos also activated brain structures
associated with
– Processing info about the self
– Memory for visual space
– Mental time travel memory
Very rich memories
Caption: (a) fMRI response of an area in the parietal cortex showing areas activated by
both the A-photos and the L-photos during the memory test. The graph on the right
indicates that activation was the same for A-photos and L-photos. (b) Areas in the
parahippocampal gyrus that were activated by the A-photos and the L-photos. The
graph indicates that in this area of the brain, activation was greater for the Aphotos.
Memory Over the Lifespan
• What events are remembered well?
– Significant events in a person’s life
– Highly emotional events
– Transition points
Reminiscence Bump
• Participants over the age of 40 asked to recall
•
events in their lives
Memory is high for recent events and for
events that occurred in adolescence and
early adulthood (between 10 and 30 years of
age)
Caption: Percentage of memories from different ages, recalled by a 55-year-old,
showing the reminiscence bump. (Reprinted from Journal of Memory and Language,
39, R.W. Schrauf & D.C. Rubin, “Bilingual Autobiographical Memory in Older Adult
Immigrants: A Test of Cognitive Explanations of the Reminiscence Bump and the
Linguistic Encoding of Memories,” pp. 437-457, Fig. 1, Copyright © 1998 with
permission from Elsevier.
Reminiscence Bump
• Hypotheses about the reminiscence bump
Caption: Explanations for the reminiscence bump
Reminiscence Bump
• Self-image hypothesis
– Memory is enhanced for events that occur
as a person’s self-image or life identity is
being formed
– People assume identities during
adolescence and young adulthood
• Many transitions occur between ages 10 and 30
Reminiscence Bump
• Cognitive hypothesis
– Encoding is better during periods of rapid
change that are followed by stability
– Evidence from those who emigrated to the
US after young adulthood indicates
reminiscence bump is shifted
Caption: The reminiscence bump for people who emigrated at age 34 to 35 is shifted
toward older ages, compared to the bump for people who emigrated between the ages
of 20 to 24. (Reprinted from Journal of Memory and Language, 39, R.W. Schrauf &
D.C. Rubin, “Bilingual Autobiographical Memory in Older Adult Immigrants: A Test of
Cognitive Explanations of the Reminiscence Bump and the Linguistic Encoding of
Memories,” pp. 437-457, Fig. 2, Copyright © 1998 with permission from Elsevier.
Reminiscence Bump
• Cultural life-script hypothesis
• Each person has
•
– A personal life story
– An understanding of culturally expected
events
Personal events are easier to recall when
they fit the cultural life script
Memory for Emotional Stimuli
• Emotional events remembered more easily
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and vividly
Emotion improves memory, becomes greater
with time (may enhance consolidation)
Brain activity: amygdala
Flashbulb Memories
• Memory for circumstances surrounding
shocking, highly charged important events
– 9/11/01
– Kennedy assassination
– Challenger explosion
• Where you were, and what you were doing?
Flashbulb Memories
• Highly emotional
• Vivid
• Very detailed
Flashbulb Memories
• Repeated recall
– Initial description: baseline
– Later reports compared to baseline
Flashbulb Memories
• Results suggest that these memories can be
inaccurate or lacking in detail
• Even though participants report that they are
very confident and that the memories seem
very vivid
Caption: Results of Talarico and Rubin’s (2003) flashbulb memory experiment. (a) The decrease in
the number of details remembered was similar for memories of 9/11 and for memories of an
everyday event. (b) Participants’ belief that their memory was accurate remained high for 9/11, but
decreased for memories of the everyday event. (Extracted from “Consistency and Key properties of
Flashbulb and Everyday Memories,” by J.M. Talarico & D.C. Rubin, Psychological Science, 14, 5,
Fig. 1. Copyright © 2003 with permission from the American Psychological Society.
Flashbulb Memories
• Davidson and coworkers (2006)
– Memories for 9/11/01 more resistant to
fading than memory for other events
around that time
• Cues helped 9/11/01 memories more
Flashbulb Memories
• Narrative rehearsal hypothesis
– Repeated viewing/hearing of event
• TV, talking with others
• Could introduce errors in own memory
The Constructive Nature of Memory
• What actually happens + person’s
knowledge, experiences, and expectations
The Constructive Nature of Memory
• Bartlett’s “war of the ghosts” experiment
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– Had participants attempt to remember a
story from a different culture
– Repeated reproduction
Results
– Over time, reproduction became shorter,
contained omissions and inaccuracies
– Changed to make the story more
consistent with their own culture
Source Monitoring
• Source memory: process of determining
origins of our memories
• Source monitoring error: misidentifying
source of memory
– Also called “source misattributions”
Caption: Design of Jacoby et al.’s (1989) “becoming famous
overnight” experiment.
Source Monitoring
• Jacoby et al. (1989)
• After 24 hours, some non-famous names
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were misidentified as famous
Explanation: some non-famous names were
familiar, and the participants misattributed the
source of the familiarity
– Failed to identify the source as the list that
had been read the previous day
Making Inferences
• Memory can be influenced by inferences that
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people make based on their experiences and
knowledge
Memory often includes information that is
implied by or is consistent with the to-beremembered information but was not
explicitly stated
– Pragmatic inferences: based on knowledge
gained through experience
Caption: Design and results of Bransford and Johnson’s (1973)
experiment that tested people’s memory for the wording of action
statements. More errors were made by participants in the
experimental group because they identified more sentences as being
originally presented, even though they were not.
Schemas and Scripts
• Schema: knowledge about what is involved in
a particular experience
– Post office, ball game, classroom
• Script: conception of sequence of actions that
occur during a particular experience
– Going to a restaurant; to the dentist
Schemas and Scripts
• Schemas and scripts influence memory
– Memory can include information not
actually experienced but inferred because
it is expected and consistent with the
schema
– Office waiting room: books not present but
mentioned in memory task
– The constructive nature of memory can
lead to errors or “false memories”
Construction of Memories
• Advantages
– Allows us to “fill in the blanks”
– Cognition is creative
• Understand language
• Solve problems
• Make decisions
Construction of Memories
• Disadvantages
– Sometimes we make errors
– Sometimes we misattribute the source of
information
• Was it actually presented, or did we infer
it?
Power of Suggestion
• Misinformation effect: misleading information
presented after a person witnesses an event
can change how that person describes the
event later
– Misleading postevent information (MPI)
Power of Suggestion
• Loftus and coworkers (1975)
– See slides of traffic accident with stop sign
– Introduce MPI: yield sign
– Participants remember what they heard
(yield sign) not what they saw (stop sign)
Power of Suggestion
• Loftus and Palmer (1974)
– Hear “smashed” or “hit” in description of
car accident
– Those hearing “smashed” said the cars
were going much faster than those who
heard “hit”
Power of Suggestion
• Hypotheses about the misinformation effect
Caption: Explanations for the misinformation effect
Power of Suggestion
• Memory-trace replacement hypothesis
– MPI impairs or replaces memories that
were formed during original event
Power of Suggestion
• Retroactive interference
– More recent learning interferes with
memory for something in the past
– Original memory trace is not replaced
Power of Suggestion
• Source monitoring error
– Failure to distinguish the source of the
information
– MPI is misattributed to the original source
Power of Suggestion
• Lindsey (1990)
– Heard a story; two days later again with
some details changed
– Told to ignore changes
– Same voice for both stories created source
monitoring errors
– Changing voice (male to female) did not
create as many errors
False Memories
• Hyman and coworkers (1995)
– Participants’ parents gave descriptions of
childhood experiences
– Participant had conversation about
experiences with experimenter;
experimenter added new events
– When discussing it later, participant
“remembered” the new events as actually
happening
Errors in Eyewitness Testimony
• Testimony by an eyewitness to a crime about
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what he or she saw during the crime
One of the most convincing types of evidence
to a jury
– Assume that people see and remember
accurately
But, like other memory, eyewitness testimony
can be inaccurate
– Mistaken identity
– Constructive nature of memory
Errors in Eyewitness Testimony
• Wells & Bradfield (1998)
– Participants view security videotape with
gunman in view for 8 seconds
– Everyone identified someone as the
gunman from photographs afterwards
– The actual gunman’s picture was not
presented
Errors in Eyewitness Testimony
• Errors due to attention and arousal
– Low: attend to irrelevant information
– High: focus too narrowly
– Moderate: best for being aware of relevant
information
Caption: Results of Stanny and Johnson’s (2000) weapons-focus
experiment. Presence of a weapon that was fired is associated with a
decrease in memory about the perpetrator, the victim, and the
weapon.
Errors in Eyewitness Testimony
• Errors due to familiarity
– Source monitoring
Caption: (a) Design of Ross et al.’s (1994) experiment on the effect of
familiarity on eyewitness testimony. (b) When the actual robber was not in the
photospread, the male teacher was erroneously identified as the robber 60
percent of the time. (c) When the actual robber was in the photospread, the
male teacher was erroneously identified less than 20 percent of the time.
Errors in Eyewitness Testimony
• Errors due to suggestion
– Suggestive questioning
• Misinformation effect
– Confirming feedback
Caption: Design and results of Wells and Bradfield’s (1998) “Good,
you identified the suspect” experiment. The type of feedback from the
experimenter influenced the participants’ confidence in their
identification, with confirming feedback resulting in the highest
confidence.
Errors in Eyewitness Testimony
• Confidence in one’s memories may be
increased by postevent questioning
• May make memories easier to retrieve
What Is Being Done?
• Inform witness perpetrator might not be in
lineup
• Use “fillers” in lineup similar to suspect
• Use sequential presentation (not
simultaneous)
• Improve interviewing techniques
– Cognitive interview