memory and cognition
DESCRIPTION
Memory and Cognition. PSY 324 Topic 7: Everyday Memory & Memory Errors Dr. Ellen Campana Arizona State University. Intro to Everyday Memory. So far we’ve talked about a lot of different types of long-termmemory, but many of the studies have been about memory for lists of words - PowerPoint PPT PresentationTRANSCRIPT
Memory and Memory and CognitionCognition
PSY 324PSY 324
Topic 7: Everyday Memory & Memory Topic 7: Everyday Memory & Memory ErrorsErrors
Dr. Ellen CampanaDr. Ellen Campana
Arizona State UniversityArizona State University
Intro to Everyday Intro to Everyday MemoryMemory
So far we’ve talked about a lot of So far we’ve talked about a lot of different types of long-termmemory, different types of long-termmemory, but many of the studies have been but many of the studies have been about memory for lists of wordsabout memory for lists of words
In this chapter we’ll be talking more In this chapter we’ll be talking more about how long-term memory about how long-term memory functions in everyday lifefunctions in everyday life Autobiographical memoryAutobiographical memory Flashbulb memoryFlashbulb memory Memory as a constructive processMemory as a constructive process
Source memorySource memory
Autobiographical Autobiographical MemoryMemory
Autobiographical Autobiographical MemoryMemory
Autobiographical memoryAutobiographical memory = recollection = recollection of events that belong to a person’s pastof events that belong to a person’s past Mostly episodic memoryMostly episodic memory
Field perspectiveField perspective – as if – as if experiencingexperiencing the event the event Common for recent eventsCommon for recent events
Observer perspectiveObserver perspective – as if – as if seeingseeing the event (seeing the event (seeing self)self)
Common for more remote memoriesCommon for more remote memories
Also includes semantic memories related to the Also includes semantic memories related to the self self
Where you were born, what your first word was, etc.Where you were born, what your first word was, etc. Much more complex than memory of word Much more complex than memory of word
lists!lists!
Autobiographical Autobiographical MemoryMemory
Autobiographical memory is Autobiographical memory is multidimensionalmultidimensional Spatial, emotional, sensory, etc.Spatial, emotional, sensory, etc.
Visual information plays a large roleVisual information plays a large role Greenberg & Rubin (2003) – neurophysiological Greenberg & Rubin (2003) – neurophysiological
evidence (visual cortex damage)evidence (visual cortex damage) Can’t recognize objects => Autobiographical memory Can’t recognize objects => Autobiographical memory
impaired, even non-visual aspectsimpaired, even non-visual aspects
Autobiographical memory is much richer than Autobiographical memory is much richer than laboratory memorylaboratory memory Cabeza & Coworkers (2004) – brain imaging studyCabeza & Coworkers (2004) – brain imaging study
Richness of Richness of Autobiographical Mem.Autobiographical Mem.
Cabeza & Coworkers (2004)Cabeza & Coworkers (2004) Gave participants cameras to take pics Gave participants cameras to take pics
of 40 specific campus locationsof 40 specific campus locations A-photos:A-photos: photos individuals took photos individuals took
themselvesthemselves L-photos:L-photos: lab photos (taken by another lab photos (taken by another
student)student)
Richness of Richness of Autobiographical Mem.Autobiographical Mem.
Cabeza & Coworkers (2004)Cabeza & Coworkers (2004) Gave participants cameras to take pics of Gave participants cameras to take pics of
40 specific campus locations40 specific campus locations A-photos:A-photos: photos individuals took themselves photos individuals took themselves L-photos:L-photos: lab photos (taken by another student) lab photos (taken by another student)
Phase 1: exposed to A-photos & L-photosPhase 1: exposed to A-photos & L-photos Not in the scannerNot in the scanner
Phase 2: shown A-photos & L-photos (some Phase 2: shown A-photos & L-photos (some new, some from before)… had to say which new, some from before)… had to say which was whichwas which
This part was in the scannerThis part was in the scanner
Richness of Richness of Autobiographical Mem.Autobiographical Mem.
Cabeza & Coworkers (2004): FindingsCabeza & Coworkers (2004): Findings A-photos & L-photos activated many of A-photos & L-photos activated many of
the same structuresthe same structures Medial Temporal Lobe: episodic memoryMedial Temporal Lobe: episodic memory Parietal Cortex: scene processingParietal Cortex: scene processing
A-photos activated many additional areasA-photos activated many additional areas Regions that process memory for selfRegions that process memory for self Regions that process memory for visual spaceRegions that process memory for visual space Regions associated with experience of mental Regions associated with experience of mental
time traveltime travel HippocampusHippocampus
Richness of Richness of Autobiographical Mem.Autobiographical Mem.
Why talk about that imaging study?Why talk about that imaging study? Demonstrates that autobiographical Demonstrates that autobiographical
memory is richer than lab memorymemory is richer than lab memory Even though participants were viewing the Even though participants were viewing the
same location for A-photos and L-photos, A-same location for A-photos and L-photos, A-photos activated more areas than L-photos.photos activated more areas than L-photos.
Activation thought to be related to memories Activation thought to be related to memories of the experience of taking the pictureof the experience of taking the picture
If even simple, relatively unimportant If even simple, relatively unimportant memories have rich representations, memories have rich representations, what makes some “stand out” in our what makes some “stand out” in our minds more than others?minds more than others?
Memory Over the Memory Over the LifespanLifespan
Memory over the Memory over the LifespanLifespan
What memories tend to “stand out”?What memories tend to “stand out”? Personal milestonesPersonal milestones Highly emotional eventsHighly emotional events Events that become big parts of a person’s Events that become big parts of a person’s
lifelife Major transition pointsMajor transition points
Juniors & seniors recalled more events from Juniors & seniors recalled more events from Sept of freshman year than any other monthSept of freshman year than any other month
Alumni recalled both September of freshman Alumni recalled both September of freshman year and end of senior year events more than year and end of senior year events more than other timesother times
Memory over the Memory over the LifespanLifespan
Memory is different for different Memory is different for different times in lifetimes in life Memory between ages 10 and 30 Memory between ages 10 and 30
“stands out”“stands out” This effect is called the This effect is called the reminiscence reminiscence
bumpbump See figure 8.3 to see what this looks See figure 8.3 to see what this looks
like on the graphlike on the graph
Memory over the Memory over the LifetimeLifetime
Why the Why the reminiscence bumpreminiscence bump?? Life-narrative hypothesisLife-narrative hypothesis
People tend to assume their life identities People tend to assume their life identities between 10-30between 10-30
Many important “firsts” between 10 and 30Many important “firsts” between 10 and 30 Cognitive hypothesisCognitive hypothesis
Encoding is better for periods of rapid Encoding is better for periods of rapid change, followed by stability (10-30=change, change, followed by stability (10-30=change, stability after that)stability after that)
Evidence: bump is shifted for late vs. early Evidence: bump is shifted for late vs. early immigrants immigrants
Memory over the Memory over the LifetimeLifetime
Why the Why the reminiscence bumpreminiscence bump?? Life-narrative hypothesisLife-narrative hypothesis
People tend to assume their life identities between 10-People tend to assume their life identities between 10-3030
Many important “firsts” between 10 and 30Many important “firsts” between 10 and 30 Cognitive hypothesisCognitive hypothesis
Encoding is better for periods of rapid change, Encoding is better for periods of rapid change, followed by stability (10-30=change, stability after followed by stability (10-30=change, stability after that)that)
Evidence: bump is shifted for late vs. early immigrants Evidence: bump is shifted for late vs. early immigrants Cultural script hypothesisCultural script hypothesis
Cultural expectations shape recall (typical events, Cultural expectations shape recall (typical events, times)times)
Memories Across the Memories Across the LifespanLifespan
All three hypotheses probably contribute All three hypotheses probably contribute to the occurrence of the reminisence to the occurrence of the reminisence bumpbump
These also interact with the other factors These also interact with the other factors that make certain memories “stand out”that make certain memories “stand out” Milestones, transitions, events that are part Milestones, transitions, events that are part
of our major “life story”of our major “life story” Highly emotional eventsHighly emotional events
Next: Next: flashbulb memoriesflashbulb memories (emotional (emotional events)events)
Flashbulb MemoryFlashbulb Memory Flashbulb memoriesFlashbulb memories are episodic are episodic
memories about the memories about the context in which context in which you found outyou found out about highly emotional about highly emotional eventsevents Often culturally-relevant events (JFK, Often culturally-relevant events (JFK,
challenger, 911)challenger, 911) Remembered for a long time, in vivid detailRemembered for a long time, in vivid detail
Why called “flashbulb”? Brown and Why called “flashbulb”? Brown and Kulik used this analogy in a paper about Kulik used this analogy in a paper about JFK’s assassinationJFK’s assassination Their paper looked at memory after many Their paper looked at memory after many
years…years… … … but were these memories accurate?but were these memories accurate?
Flashbulb MemoryFlashbulb Memory
To test accuracy of flashbulb memories, To test accuracy of flashbulb memories, researchers use a method called researchers use a method called repeated recallrepeated recall Right after an event, people write about it Right after an event, people write about it
((baselinebaseline)) Later they are asked to write about it againLater they are asked to write about it again Researchers compare writings for each Researchers compare writings for each
personperson Neisser & Harsch (1992) – repeated Neisser & Harsch (1992) – repeated
recall for the challenger explosionrecall for the challenger explosion
Neisser & Harsch (1992)Neisser & Harsch (1992)
Quote from day after event: Quote from day after event:
I was in my religion class and some people I was in my religion class and some people walked in and started talking about [it]. I walked in and started talking about [it]. I didn’t know any details except that it had didn’t know any details except that it had
exploded and the schoolteacher’s exploded and the schoolteacher’s students had all been watching, which I students had all been watching, which I thought was so sad. Then after class I thought was so sad. Then after class I went to my room and watched the TV went to my room and watched the TV program talking about it, and I got all program talking about it, and I got all
the details from that.the details from that.
Neisser & Harsch (1992)Neisser & Harsch (1992)
Same person, quote from 2 ½ years later:Same person, quote from 2 ½ years later:
When I first heard about the explosion I When I first heard about the explosion I was sitting in my freshman dorm room was sitting in my freshman dorm room with my roommate, and we were with my roommate, and we were watching TV. It came on a news flash, watching TV. It came on a news flash, and we were both totally shocked. I was and we were both totally shocked. I was really upset, and I went upstairs to talk really upset, and I went upstairs to talk to a friend of mine, and then I called my to a friend of mine, and then I called my parents.parents.
Schmolke and coworkers Schmolke and coworkers (2000)(2000)
O.J. Simpson trialO.J. Simpson trial Response at 3 days: I was in the commuter Response at 3 days: I was in the commuter
lounge at college and saw it on TV. As 10:00 lounge at college and saw it on TV. As 10:00 approached, more and more people came into approached, more and more people came into the room…the room…
Response at 32 months (same person): I first Response at 32 months (same person): I first heard it while I was watching TV at home in my heard it while I was watching TV at home in my living room. My sister and father were with me…living room. My sister and father were with me…
Conclusion: “it seems unlikely that so-called Conclusion: “it seems unlikely that so-called flashbulb memories differ from ordinary flashbulb memories differ from ordinary episodic memories in any fundamental episodic memories in any fundamental way.”way.”
Are Flashbulb Memories Are Flashbulb Memories Special?Special?
Talarico and Rubin (2003) – 911 eventTalarico and Rubin (2003) – 911 event Some evidence that they are Some evidence that they are not specialnot special
Accuracy and number of details decreased similarly Accuracy and number of details decreased similarly for flashbulb and everyday episodic memoriesfor flashbulb and everyday episodic memories
Some evidence that they are Some evidence that they are specialspecial Participants’ Participants’ beliefs that memories were accuratebeliefs that memories were accurate
stayed high for flashbulb, but dropped for everyday stayed high for flashbulb, but dropped for everyday episodic memoriesepisodic memories
Participants’ ratings of Participants’ ratings of vividnessvividness and and how well they how well they could “relive” eventscould “relive” events stayed high for flashbulb, but stayed high for flashbulb, but dropped for everyday episodic memoriesdropped for everyday episodic memories
Are Flashbulb Memories Are Flashbulb Memories Special?Special?
Davidson and Coworkers (2006) – Davidson and Coworkers (2006) – also 911also 911 Found flashbulb memories Found flashbulb memories more more
resistant to fadingresistant to fading congruence scores high for flashbulb, but congruence scores high for flashbulb, but
dropped for everyday eventsdropped for everyday events All participants remembered 911, but only All participants remembered 911, but only
65% were able to recall what the other 65% were able to recall what the other memory wasmemory was
Are Flashbulb Memories Are Flashbulb Memories Special?Special?
Davidson and Coworkers (2006) – also 911Davidson and Coworkers (2006) – also 911 Found flashbulb memories Found flashbulb memories more resistant to more resistant to
fadingfading congruence scores high for flashbulb, but dropped congruence scores high for flashbulb, but dropped
for everyday eventsfor everyday events All participants remembered 911, but only 65% were All participants remembered 911, but only 65% were
able to recall what the other memory wasable to recall what the other memory was Why? Why?
Flashbulb memories about emotional events Flashbulb memories about emotional events (amygdala)(amygdala)
Added rehearsal: Added rehearsal: narrative rehearsal hypothesisnarrative rehearsal hypothesis
Are Flashbulb Memories Are Flashbulb Memories Special?Special?
What’s the point? Are they or aren’t they?What’s the point? Are they or aren’t they? Two studies found conflicting resultsTwo studies found conflicting results
Differed with respect to cues Differed with respect to cues Talarico & Rubins – participants created their own… Talarico & Rubins – participants created their own…
therefore remembered everyday memories better therefore remembered everyday memories better (Mantyla from last time)(Mantyla from last time)
Robinson and Coworkers – participants used given cuesRobinson and Coworkers – participants used given cues
Still an open debateStill an open debate About memory in general, this tells us…About memory in general, this tells us…
Emotional context of event can influence Emotional context of event can influence memorymemory
Knowledge (even if it comes later) can affect Knowledge (even if it comes later) can affect the original memorythe original memory
The Constructive The Constructive Nature of Nature of MemoryMemory
The Constructive Nature of The Constructive Nature of MemoryMemory
People reporting memories unknowinglyPeople reporting memories unknowingly Omit detailsOmit details Distort or change things that actually Distort or change things that actually
happenedhappened Report things that never actually happenedReport things that never actually happened
Constructive approach to memory Constructive approach to memory What people report as memories are What people report as memories are
constructed by the person based on what constructed by the person based on what happened plus additional factors happened plus additional factors ((knowledge, experience, expectationsknowledge, experience, expectations))
““War of the Ghosts”War of the Ghosts”Bartlett (1932)Bartlett (1932)
Description of myth from an unfamiliar Description of myth from an unfamiliar cultureculture
Repeated productionRepeated production – participants came – participants came back a number of times to tell the same storyback a number of times to tell the same story Similar to Similar to repeated recallrepeated recall for flashbulb for flashbulb
memoriesmemories Participants made more errors over timeParticipants made more errors over time
Errors reflected something about the processErrors reflected something about the process Story changed to be consistent with participants’ Story changed to be consistent with participants’
cultureculture Confusing details left outConfusing details left out Details changed (canoe -> boat)Details changed (canoe -> boat)
Educated GuessesEducated Guesses
Bahrick and Coworkers (1996)Bahrick and Coworkers (1996) Recall your own high school gradesRecall your own high school grades
A recall = 89%A recall = 89% D recall = 29%D recall = 29%
Why these types of errors?Why these types of errors? People tend to remember positive events morePeople tend to remember positive events more Memory is constructiveMemory is constructive
If they were A/B students, they make a prediction If they were A/B students, they make a prediction that a specific grade was that a specific grade was most likelymost likely an A, and an A, and remember it that wayremember it that way
How does constructive memory work?How does constructive memory work?
Source MonitoringSource Monitoring
Source monitoringSource monitoring (and errors) is part of (and errors) is part of the explanation for how constructive the explanation for how constructive memory worksmemory works Source memorySource memory is the memory for is the memory for how you how you
acquiredacquired a certain memory a certain memory Did I hear that on the news or did someone tell me?Did I hear that on the news or did someone tell me?
Source monitoring errorsSource monitoring errors / / source source misattributionsmisattributions are when you remember the are when you remember the fact, but think it came from the wrong sourcefact, but think it came from the wrong source
Memories disconnected from source over Memories disconnected from source over timetime
Source Monitoring Source Monitoring ErrorsErrors
Jacoby and Coworkers (1989) – becoming Jacoby and Coworkers (1989) – becoming famous overnightfamous overnight Acquistion: read a list of names (all made up, Acquistion: read a list of names (all made up,
and people were told this just after reading)and people were told this just after reading) Immediate test: identify famous names from Immediate test: identify famous names from
list list Non-famous, new namesNon-famous, new names Names from prior listNames from prior list Famous namesFamous names
Delayed test: same as immediate, 1 day laterDelayed test: same as immediate, 1 day later
Source Monitoring Source Monitoring ErrorsErrors
Jacoby and Coworkers (1989) – Jacoby and Coworkers (1989) – becoming famous overnightbecoming famous overnight Results: made-up names from the list that Results: made-up names from the list that
people saw in the acquisition stage were people saw in the acquisition stage were more likely to be rated as famous (in more likely to be rated as famous (in participants’ memory these fictitious people participants’ memory these fictitious people “became famous overnight”)“became famous overnight”)
Explanation: Made-up names more familiar Explanation: Made-up names more familiar than new names during delayed test, but than new names during delayed test, but participants didn’t remember participants didn’t remember whywhy they they seemed so familiar (seemed so familiar (sourcesource), so they ), so they attributed familiarity to famousnessattributed familiarity to famousness
Constructive MemoryConstructive Memory
Source misattributionSource misattribution involves involves participants making participants making inferencesinferences about the source, and using those to about the source, and using those to construct / reconstruct memoryconstruct / reconstruct memory Flashbulb memory studiesFlashbulb memory studies Bartlett’s war of the ghosts experimentBartlett’s war of the ghosts experiment Bahrick & coworkers’ high school Bahrick & coworkers’ high school
grades experimentgrades experiment Jacoby & coworkers’ becoming famous Jacoby & coworkers’ becoming famous
overnight overnight
Memory and InferenceMemory and Inference
So memory as a So memory as a constructive constructive processprocess What we remember is constructed based What we remember is constructed based
on events, percepts, experience and on events, percepts, experience and knowledgeknowledge
The process of memory construction The process of memory construction involves involves making inferencesmaking inferences
This is a normal consequence of a largely This is a normal consequence of a largely adaptive memory– in other words “it’s a adaptive memory– in other words “it’s a good thing.”good thing.”
Brewer (1977) / Brewer (1977) / McDermott & Chan (2006)McDermott & Chan (2006)
The children’s snowman vanished when The children’s snowman vanished when the temperature reached 80.the temperature reached 80.
The flimsy shelf weakened under the The flimsy shelf weakened under the weight of the books.weight of the books.
The absent-minded professor didn’t The absent-minded professor didn’t have his car keys.have his car keys.
The karate champion hit the cinder The karate champion hit the cinder block. block.
The new baby stayed awake all night.The new baby stayed awake all night.
…… …… people who read these sentence people who read these sentence often inaccurate remembered the often inaccurate remembered the sentences as… sentences as…
Brewer (1977) / Brewer (1977) / McDermott & Chan (2006)McDermott & Chan (2006)
The children’s snowman vanished when The children’s snowman vanished when the temperature reached 80.the temperature reached 80.
The flimsy shelf weakened under the The flimsy shelf weakened under the weight of the books.weight of the books.
The absent-minded professor didn’t The absent-minded professor didn’t have his car keys.have his car keys.
The karate champion hit the cinder The karate champion hit the cinder block. block.
The new baby stayed awake all night.The new baby stayed awake all night.
melted
lost
collapsed
broke
cried
Pragmatic InferencePragmatic Inference
Changes in wording we just saw are Changes in wording we just saw are examples of examples of pragmatic inferencepragmatic inference We use our experience to fill in the details We use our experience to fill in the details
without even realizing we are doing itwithout even realizing we are doing it Two more in the book you should know aboutTwo more in the book you should know about
Bransford & Johnson (1973) – hammer exampleBransford & Johnson (1973) – hammer example Arkes & Freedman (1984) – baseball exampleArkes & Freedman (1984) – baseball example
Inference uses knowledge and Inference uses knowledge and experience, which are represented by experience, which are represented by schemasschemas and and scriptsscripts
SchemasSchemas SchemasSchemas are representations of what is are representations of what is
usually or prototypically involved in an usually or prototypically involved in an experienceexperience A kids’ birthday party, a movie, oktoberfest, A kids’ birthday party, a movie, oktoberfest,
holidaysholidays Even if a movie theater is out of popcorn when Even if a movie theater is out of popcorn when
you go, you may later infer there was popcorn you go, you may later infer there was popcorn therethere
Brewer & Treyens (1981) - office studyBrewer & Treyens (1981) - office study This type of representation is what causes This type of representation is what causes
us to substitute “cried” for “stayed up all us to substitute “cried” for “stayed up all night” in the sentences we heard earliernight” in the sentences we heard earlier
ScriptsScripts are representations of the are representations of the sequence of actions that usually occur sequence of actions that usually occur during an experienceduring an experience Restaurant, class, sports, evening out, Restaurant, class, sports, evening out,
holidaysholidays Even if you may not have gone trick-or-Even if you may not have gone trick-or-
treating one Halloween, you may treating one Halloween, you may remember doing so laterremember doing so later
Bower and Coworkers (1979) – dentist Bower and Coworkers (1979) – dentist office studyoffice study
ScriptsScripts
Bower and Coworkers Bower and Coworkers (1979)(1979)
The DentistThe DentistBill had a bad toothache. It seemed like Bill had a bad toothache. It seemed like
forever before he finally arrived at the forever before he finally arrived at the dentist office. Bill looked around at the dentist office. Bill looked around at the
various dental posters on the wall. various dental posters on the wall. Finally the dental hygienist checked and Finally the dental hygienist checked and x-rayed his teeth. He wondered what the x-rayed his teeth. He wondered what the dentist was doing. The dentist said that dentist was doing. The dentist said that Bill had a lot of cavities. As soon as he’d Bill had a lot of cavities. As soon as he’d made another appointment, he left the made another appointment, he left the
dentist’s office.dentist’s office.
Bower and Coworkers Bower and Coworkers (1979)(1979)
Study included many stories like “the Study included many stories like “the dentist”dentist”
After a delay, participants were given After a delay, participants were given titles and asked to write what they titles and asked to write what they remembered about the storiesremembered about the stories ““Bill checked in with the dentist’s Bill checked in with the dentist’s
receptionist” ….receptionist” …. …….Common even though it wasn’t really there.Common even though it wasn’t really there
People filled in details based on their own People filled in details based on their own script for going to the dentistscript for going to the dentist
Construction: Plusses & Construction: Plusses & MinusesMinuses
Inferences in memory are much like gestalt Inferences in memory are much like gestalt laws in perception – they are also laws in perception – they are also heuristicsheuristics HeuristicsHeuristics – provide a “best guess” which is fast, – provide a “best guess” which is fast,
efficient and easy to store, but sometimes efficient and easy to store, but sometimes inaccurateinaccurate Hammer example – how inefficient it would be to have Hammer example – how inefficient it would be to have
to make all these details clear every time!to make all these details clear every time! AlgorithmsAlgorithms – opposite of heuristics, provide an – opposite of heuristics, provide an
accurate answer but take time, capacity, etc.accurate answer but take time, capacity, etc. In the case of memory, require infinite storageIn the case of memory, require infinite storage S in the book was said to have this (it wasn’t all good!)S in the book was said to have this (it wasn’t all good!)
Like gestalt laws, in practical terms Like gestalt laws, in practical terms our inferences are very often right our inferences are very often right
Sometimes our memories can be Sometimes our memories can be manipulated by suggestions by othersmanipulated by suggestions by others Memories createdMemories created Memories changedMemories changed
Ramifications for law and the court Ramifications for law and the court systemsystem
Construction: Plusses & Construction: Plusses & MinusesMinuses
Memory and Memory and SuggestionSuggestion
The Power of SuggestionThe Power of Suggestion
People are suggestiblePeople are suggestible Advertisements, political arguments Advertisements, political arguments
affect our attitudes, beliefs, and behaviorsaffect our attitudes, beliefs, and behaviors Information presented by others can also Information presented by others can also
influence our memory for past eventsinfluence our memory for past events Misinformation EffectMisinformation Effect – misleading – misleading
information presented after a person information presented after a person witnesses an event can change how witnesses an event can change how the person describes the event laterthe person describes the event later Misleading information in this situation is Misleading information in this situation is
called called misleading postevent misleading postevent information (MPI)information (MPI)
Method: Presenting MPIMethod: Presenting MPI Step 1: Information to be remembered is Step 1: Information to be remembered is
presented presented Could be a list of words, film, slideshow, etc.Could be a list of words, film, slideshow, etc.
Step 2: MPI is presented to some Step 2: MPI is presented to some participants and not othersparticipants and not others MPI is presented in a natural way so MPI is presented in a natural way so
participants do not know they are being misledparticipants do not know they are being misled Step 3: All participants report on their Step 3: All participants report on their
memory of the information presented in memory of the information presented in step 1step 1 Reports compared for the two groups of Reports compared for the two groups of
participantsparticipants
Loftus & Coworkers Loftus & Coworkers (1978)(1978)
Step 1: slide show of accidentStep 1: slide show of accident Car stops at a stop sign, then turns corner and hits Car stops at a stop sign, then turns corner and hits
pedestrianpedestrian Step 2: participants answer questions Step 2: participants answer questions
MPI group: “did another car pass the red Datsun MPI group: “did another car pass the red Datsun while it was stopped at the while it was stopped at the yield signyield sign?”?”
Control:“did another car pass the red Datsun while it Control:“did another car pass the red Datsun while it was stopped at the was stopped at the stop signstop sign?”?”
Step 3: participants see pictures, say which are Step 3: participants see pictures, say which are oldold Critical picture: car parked at a yield sign (new Critical picture: car parked at a yield sign (new
picture)picture) MPI group more likely to say yes (which was an error)MPI group more likely to say yes (which was an error)
Loftus & Coworkers Loftus & Coworkers (1978)(1978)
Study demonstrates that Study demonstrates that misleading misleading postevent information (MPI)postevent information (MPI) can can affect details of what people affect details of what people remember seeingremember seeing
Another similar study looks at how Another similar study looks at how MPI can affect the conclusions people MPI can affect the conclusions people draw about other aspects of the draw about other aspects of the situationsituation Also replicates the finding from Loftus & Also replicates the finding from Loftus &
Coworkers (1978)Coworkers (1978)
Loftus and Palmer Loftus and Palmer (1974)(1974)
Participants watched a video of a car crashParticipants watched a video of a car crash Participants answered questions about the Participants answered questions about the
filmfilm MPI group: How fast were the cars going when MPI group: How fast were the cars going when
they they smashedsmashed into each other? into each other? Control: How fast were the cars going when Control: How fast were the cars going when
they they hithit each other? each other? Answers comparedAnswers compared
MPI group (smashed) answered 41 mph, on MPI group (smashed) answered 41 mph, on avg.avg.
Control group (hit) answered 34 mph, on avg.Control group (hit) answered 34 mph, on avg.
Loftus (1993, 1998)Loftus (1993, 1998)
Participants from Loftus & Palmer Participants from Loftus & Palmer invited back one year laterinvited back one year later Question: Did you see any broken glass? (no Question: Did you see any broken glass? (no
= right)= right) ResultsResults
MPI group (smashed) answered yes 32%MPI group (smashed) answered yes 32% Control group (hit) answered yes 14%Control group (hit) answered yes 14%
More evidence that MPI affects memory More evidence that MPI affects memory for details (even details that are for details (even details that are inferred)inferred) How does this happen???How does this happen???
What Causes the What Causes the Misinformation Effect?Misinformation Effect?
Memory-trace replacement hypothesisMemory-trace replacement hypothesis (Loftus)(Loftus) MPI replaces memories for the original eventMPI replaces memories for the original event Process of Process of consolidationconsolidation is a possible is a possible
mechanismmechanism Retroactive interference hypothesisRetroactive interference hypothesis
Recent information interferes with (but Recent information interferes with (but doesn’t replace) previously learned doesn’t replace) previously learned informationinformation
Source monitoring error hypothsisSource monitoring error hypothsis Both memories are stored, but during recall Both memories are stored, but during recall
we forget which came from which sourcewe forget which came from which source
Evidence: Source Evidence: Source Monitoring Error Monitoring Error
Lindsay (1990)Lindsay (1990) Day 1: People saw slides, narrated by female Day 1: People saw slides, narrated by female
voicevoice Day 2: People heard story (no slides) with a few Day 2: People heard story (no slides) with a few
details changed (brand names, etc.) details changed (brand names, etc.) All MPI, no control groupAll MPI, no control group Some participants heard a male voice tell the story, Some participants heard a male voice tell the story,
while others heard a female voice tell the storywhile others heard a female voice tell the story Data: answers to questions about details that Data: answers to questions about details that
were changed for the story and details that were were changed for the story and details that were notnot
Why are voices important? Voice can be a Why are voices important? Voice can be a cue to source, which may make it easier to cue to source, which may make it easier to rememberremember
Lindsay (1990)Lindsay (1990)
% “suggested” responses(wrong)
Female
Voice
Male Voice
Misled detailsControl details
Source Monitoring Source Monitoring ErrorsErrors
False memories for early events also False memories for early events also related to source monitoringrelated to source monitoring
Hyman, Jr. and Coworkers (1995)Hyman, Jr. and Coworkers (1995) Got stories from parents of college studentsGot stories from parents of college students Asked students about these events (and fake Asked students about these events (and fake
ones)ones) With repeated recall, false memories were With repeated recall, false memories were
inducedinduced How is this a source monitoring error?How is this a source monitoring error?
Familiarity caused people to believe it Familiarity caused people to believe it happened, and then they happily filled in details happened, and then they happily filled in details via inferencevia inference
More on False Memories for More on False Memories for Early EventsEarly Events
Lindsay and Coworkers (2004) – Slime Lindsay and Coworkers (2004) – Slime studystudy False memory effect stronger with a False memory effect stronger with a
picture picture DuBreuil and Coworkers (1998) – DuBreuil and Coworkers (1998) –
MobilesMobiles False memories can come out during False memories can come out during
hypnosishypnosis People are very confident that these are People are very confident that these are
realreal
Eyewitness Eyewitness TestimonyTestimony
Memory and LawMemory and Law
Eyewitness testimonyEyewitness testimony – when someone – when someone who was present at a crime reports who was present at a crime reports about what he or she sawabout what he or she saw Most convincing types of evidence for a juryMost convincing types of evidence for a jury Witness confident-> evidence even more Witness confident-> evidence even more
convincingconvincing Accuracy & Confidence correlation is 0.29Accuracy & Confidence correlation is 0.29
Errors have of eyewitness testimony Errors have of eyewitness testimony have resulted in the conviction of have resulted in the conviction of innocent peopleinnocent people
Memory and LawMemory and Law
David Webb, Charles Clark, Lenell David Webb, Charles Clark, Lenell Gertner all went to jail (later released Gertner all went to jail (later released when testimony was discovered to be when testimony was discovered to be inaccurate)inaccurate)
40 cases of exoneration based on DNA 40 cases of exoneration based on DNA evidence that became available after evidence that became available after convictionconviction 36 involved erroneous eyewitness testimony36 involved erroneous eyewitness testimony
8.5 average years in prison8.5 average years in prison 5 death sentences5 death sentences
Perceptual ErrorsPerceptual Errors Eyewitness testimony can be affected by Eyewitness testimony can be affected by
both perception and memory – we’ll start both perception and memory – we’ll start with perceptionwith perception
Two studies presented videos of crimes Two studies presented videos of crimes to participants and then gave them to participants and then gave them photos, asked them to identify the photos, asked them to identify the perpetratorperpetrator 100% / 61% picked someone from the 100% / 61% picked someone from the
photos, even though the correct person photos, even though the correct person wasn’t in the photoswasn’t in the photos
In actual crime scenes, many causes… In actual crime scenes, many causes…
Crime ScenesCrime Scenes
Errors associated with AttentionErrors associated with Attention Easterbrook (1959) – as arousal Easterbrook (1959) – as arousal
increases, attention narrowsincreases, attention narrows crime scenes arousal is high, relevant details crime scenes arousal is high, relevant details
can be missedcan be missed Weapons focusWeapons focus – presence of a weapon – presence of a weapon
narrows attention narrows attention Worse if weapon is fired (Stanny and Worse if weapon is fired (Stanny and
Johnson, 2000)Johnson, 2000) Decreases memory for victim, perpetrator AND Decreases memory for victim, perpetrator AND
weaponweapon
Crime ScenesCrime Scenes
Errors due to familiarityErrors due to familiarity Crime scenes involve perpetrator, Crime scenes involve perpetrator,
victim, and innocent bystandersvictim, and innocent bystanders Bystanders can be incorrectly identified Bystanders can be incorrectly identified
as perpetrators based on familiarityas perpetrators based on familiarity Memory researcher Donald ThompsonMemory researcher Donald Thompson Sailor example Sailor example
Confirmed in lab studies Confirmed in lab studies
Crime ScenesCrime Scenes
Errors due to suggestionErrors due to suggestion ““did you see the white car?” – later may did you see the white car?” – later may
have a false memory of a white carhave a false memory of a white car ““which one of these men did it?” – implies which one of these men did it?” – implies
that the person is in the lineupthat the person is in the lineup Witness selects one, then becomes confident Witness selects one, then becomes confident
over timeover time ““that one???” “OK” – confirmation of the that one???” “OK” – confirmation of the
witness’s choice (which will inflate witness’s choice (which will inflate confidence in the choice)confidence in the choice)
Wells and Bradfield (1998) confirmed in the labWells and Bradfield (1998) confirmed in the lab
Crime ScenesCrime Scenes
Increasing confidence due to Increasing confidence due to postevent questioningpostevent questioning Shaw (1996) – participants were more Shaw (1996) – participants were more
confident in false memories of items confident in false memories of items from an apartment if they had been from an apartment if they had been asked questions about themasked questions about them Answering questions about an object makes Answering questions about an object makes
it easier to retrieve memories about it laterit easier to retrieve memories about it later People mistake People mistake ease of retrievalease of retrieval for for
accuracyaccuracy
What can be done?What can be done? First, recognize the problem and First, recognize the problem and
communicate it to jurors communicate it to jurors Make some procedural changesMake some procedural changes
Inform witnesses that perp may not be in the Inform witnesses that perp may not be in the lineuplineup
In lineups, use “fillers” that are similar to the In lineups, use “fillers” that are similar to the suspectsuspect
When presenting a lineup use sequential When presenting a lineup use sequential rather than simultaneous presentationrather than simultaneous presentation
Improve interviewing techniquesImprove interviewing techniques Cognitive interviewCognitive interview (25-60% more information (25-60% more information
than police interview)than police interview)