Chapter 8Everyday Memory and Memory Errors

National University

College of Letters and Sciences

Steven Mendoza, Ph.D.,MSCP

Psychology Adjunct Professor

Introduction to Cognitive PsychologyVERITAS IN LUCEM EMEGERGIT

Some Questions to Consider

• What kinds of events from their lives are 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 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 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 A-photos.

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 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– 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 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 people make based on their experiences and knowledge

• Memory often includes information that is implied by or is consistent with the to-be-remembered 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 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