Transcript Document

7 – False Memory
False memories are surprisingly common.
● Laboratory Studies
● Eyewitness Memory
● Memories of Abuse
False Recall Experiment
Ss heard list of words related to missing critical word (e.g., sleep)
Later, Ss tried to recall words and gave confidence rating for each response (1-5).
Many Ss falsely recalled critical word, often with high confidence
(Deese, 1959; Roediger & McDermott, 1995)
Would this procedure produce false memories if Ss knew hypothesis in advance?
Demo
Again, I will quickly read a list of words related to the same topic.
Please close your eyes and listen carefully.
Lunch
butter
food
eat
sandwich
cheese
flour
jelly
dough
crust
loaf
toast
slice
Recognition Test
For each word,
Butter
Meal
Food
Eat
Mustard
Pepper
Sandwich
Cheese
Flour
Jelly
Bread
Dough
Lettuce
Crust
Loaf
Toast
Pepper
Slice
Raise your hand if word was on list
yes
no
yes
yes
no
no
yes
yes
yes
yes
no
yes
no
yes
yes
yes
still no
yes
Raise 1 – 5 fingers, depending on confidence.
1 = unsure
5 = certain
blank
Demo. Circle your answer.
1. Which city is farther west?
Reno
Los Angeles
2. Which city is farther north?
Milan (Italy) Toronto (Canada)
3. What portion of India lies south of the equator?
none
1/3
2/3
all
4. What portion of Africa lies south of the equator?
none
1/3
2/3
all
5. What portion of South America lies east of Tampa? none
1/3
2/3
all
Odd # questions were easy fillers.
Even # questions were critical items.
1. Which city is farther west?
Reno
Los Angeles
2. Which city is farther north?
Milan 45°N
Milan (Italy)
Toronto 43°N
Toronto (Canada)
3. What portion of India lies south of the equator?
None
4. What portion of Africa lies south of the equator?
1/3
5. What portion of South America lies east of Tampa?
North America  Northwest
South America  Southeast
All
Study
Ss answered geography questions.
Which is farther north, Rome or NYC?
Answer: Rome
Why? In Ss’ mental map, North America and Europe are equally north.
Experiment
Ss studied ambiguous picture with a verbal label.
eyeglasses
OR
barbell
When tested, Ss’ drawings skewed toward verbal label.
Thus, verbal label distorted memory.
(Carmichael, Hogan, & Walters, 1932)
blank
Experiment
Each S was first told to wait (alone) in a professor’s office before study began.
Later, an E led S to another room.
S given surprise test: “Recall items in the office.”
Most Ss recalled “books” but office had none.
Thus, prior knowledge created false memory.
(Brewer & Treyens, 1981)
Misinformation
Experiment
Study Phase: Ss saw slide show in which red car stops at a stop sign (right slide below).
Questionnaire Phase: Ss answer many questions. Question 17 was:
Did another car pass the red Datsun while it was stopped at the _____?
or
stop sign
(truth group)
yield sign
(misinformation group)
Test: “Which of these two slides did you see during the Study phase?”
Percent Correct
truth
(Loftus et al., 1978)
misinformation
75%
41%
Experiment
S saw doctored photo of S in a hot air balloon as a child.
Later, about ½ of the Ss recalled details from their “memory” of balloon ride.
Photo added credibility to misinformation.
(Garry & Gerrie, 2005)
Misinformation can produce impossible memory.
Experiment
Ss evaluated fake Disneyland ad featuring Bugs Bunny (who is not a Disney character).
Later, many Ss recalled meeting Bugs Bunny while visiting Disneyland.
(Braun et al., 2002; Braun-LaTour et al., 2004)
Misinformation can produce false memory of trauma.
Experiment
E recruited sibling pairs for study about “personality traits of siblings” (a lie).
Older sibling became confederate.
Older sib told younger sib 16 stories about young sib’s childhood.
15 stories were true, 1 was false (lost in shopping mall)
Later, younger S recalled details about false memory.
When told that 1 story was false, most younger sibs could not identify it.
(Loftus & Coan, 1994)
Jim tells E the following story while his 14-year-old brother Chris listens:
Jim:
“It was 1981 or 1982. I remember that Chris was five. We had gone shopping at
the University City shopping mall in Spokane. After some panic, we found Chris
being led down the mall by a tall, oldish man (I think he was wearing a flannel shirt).
Chris was crying and holding the man’s hand. The man explained that he had just
found Chris walking around crying his eyes out just a few moments before and was
trying to help him find his parents.”
Chris is later asked to recall every story on numerous days.
Here are excerpts from his “memory” of being lost in the shopping mall
Day 2: “That day I was so scared that I would never see my family again. I knew that I
was in trouble.”
Day 3: “I remember my mom telling me never to do that again.”
Day 4: I also remember the old man’s flannel shirt.”
Day 14: I was with you guys for a second and I think I went over to look at the toy
store, the Kay-Bee toy and, uh, we got lost and I was looking around and I thought,
“Uh-oh. I’m in trouble now.” You know. And then I … I thought I was never going to
see my family again. I was really scared you know. And then this old man, I think he
was wearing a blue flannel, came up to me … he was kind of old. He was kind of bald
on top … he had like a ring of gray hair … and he had glasses.”
Face Memory Demo
You’ll see several faces, one at a time.
Just look at each face.
Study Face
Study Face
Study Face
Study Face
Study Face
Get ready for Test phase
You’ll see 15 faces.
Your page is numbered 1 - 15.
For each test face, write “yes” if test face was one of the study faces.
Twist:
Add confidence rating
1 = guess
5 = certain
Test 1
Test 2
Test 3
Test 4
Test 5
Test 6
Test 7
Test 8
Test 9
Test 10
Test 11
Test 12
Test 13
Test 14
Test 15
Face Memory Demo
H=
1
2
FA =
target (1)
target (2)
Were 9, 10, and 13 harder than other foils?
5
Each was a repeat foil
6
7
target (3)
8
9
10
11 target (4)
12
13
14 target (5)
15
/ 10 =
H – FA =
3
4
/5=
9=3
10 = 5
13 = 1
False Eyewitness Identification
False IDs are sometimes caused by misinformation.
Example
Witness describes Culprit X.
Witness shown mug book photo of Y, who resembles X.
Witness says, “Maybe, but I don’t think so.”
Later, police ask Witness to look at photos again.
Witness says, “Yeah, Y is the guy.” (Source memory error.)
Y goes to prison.
Demo
Photo of man who robbed store and killed guard
Answer: He’s not there!
Can you spot the culprit?
1
2
4
Source:
Gary Wells
3
5
How to reduce frequency of false IDs during lineup:
Remind witness that culprit might not be there.
Everyone present should be “blind.”
Lineups should be sequential, not simultaneous.
(Wells et al., 2000)
Statistical claims about False IDs (students not responsible for this slide)
Mistaken eyewitness is greatest cause of false convictions
(Huff et al., 1986)
False eyewitness IDs cause 2000 wrongful convictions / year
(Loftus & Ketcham, 1991)
Eyewitness is only major evidence in 80,000 cases / year.
(Goldstein et al., 1989)
Between 1989 and 2007, DNA evidence exonerated 197 men.
Average time in prison for these men: 12 years.
In 75% of these cases, conviction based at least partly on eyewitness ID.
False Memories of Abuse
Misinformation can lead people to falsely recall memories of abuse.
Example
Investigator repeatedly asks child if parent/teacher/babysitter did X.
Ultimately, child falsely recalls X.
Evidence suggests that a large portion of these memories are false.
1. Countless experiments have shown how easily false memories can be planted.
2. Many of the convicted abusers were exonerated for forensic reasons.
Dale Akiki
Day care volunteer.
One parent accused Akiki of inappropriate behavior.
Investigators repeatedly questioned the 3- and 4-year-old kids.
Ultimately, many kids recalled being raped or sodomized.
Akiki spent 30 months in jail waiting for a trial.
After a 7-month trial, he was acquitted of all charges.
Later, videotapes of interrogations surfaced.
Videotapes showed kids being badgered by investigators.
Many of the kids’ accusations were absurd.
One kid recalled Akiki killing a giraffe in class.
(Robinson, 1996)
McMartin Preschool
In 1983, student’s mother tells police that her son was sodomized by teacher.
That teacher was the accuser’s estranged husband.
Claims: satanic abuse, sodomy, and sexual encounters with animals
Then every school kid was asked if these events had happened.
By 1984, officials claimed that 360 kids had been abused.
Interview videotapes revealed the kids’ accusations were prompted.
In some cases, kids were told to “pretend.”
Some kids reported orgies at car washes and airports.
In 1984, 7 teachers charged with 321 counts of child abuse involving 48 kids.
After years of trial and retrials (while some were in prison), all were acquitted.
When Jean Piaget was age two, he was nearly kidnapped.
Piaget’s nanny foiled the attempt.
The story made the newspaper.
Piaget’s parents rewarded the nanny with a watch.
When Piaget was older, he could recall the event.
"I was sitting in my pram, which my [nanny] was pushing in the Champs Elysees,
when a man tried to kidnap me. I was held in by the strap fastened round me while
my [nanny] bravely tried to stand between me and the thief. She received various
scratches and I can still see vaguely those on her face. Then a crowd gathered, a
policeman with a cloak and a white baton came up, and the man took to his heels. I
can still see the whole scene, and can even place it near the tube station.”
Piaget (1951, 1962)
"When I was about 15, my parents received a letter from my former [nanny] saying
that she had been converted…. She wanted to confess her past faults, and in
particular to return the watch she had been given on this occasion. She had made up
the whole story, faking the scratches. I, therefore, must have heard, as a child, the
account of this story, which my parents believed, and projected it into my memory."
Piaget (1951, 1962)
Repressed Memory
Example
Therapist repeatedly asks depressed client whether she was abused as a child.
Ultimately, client recalls abuse.
Claim: Memory of abuse was repressed and later recovered.
Evidence suggests that many recovered memories are false.
1. Dozens of experiments have shown how easily false memories can be planted.
2. Studies of victims of verified trauma (e.g., war) reveal no repression.
In fact, many of these victims cannot forget (e.g., PTSD).
3. Repression is not as adaptive as it might seem.
Forgetting trauma  more likely to repeat it  less likely to survive
George Franklin
In 1989, he was convicted of murdering daughter’s 8-year-old friend in 1969.
Sole evidence was his adult daughter’s “recovered” memory
He spent seven years in prison before winning appeal.
He later won malpractice claim against daughter’s therapist.
The Rutherfords
A counselor helped woman remember that her father had
regularly raped her
twice impregnated her
forced her to abort the fetuses
The father had to resign from his post as a clergyman.
Later, a medical exam revealed that his daughter was a virgin.
Daughter received a $1-million settlement in 1996.
Loftus (1997)
From The Courage to Heal
Bass & Davis, 1988
You may think that you don’t have memories, but often as you begin to talk about what
you do remember, there emerges a constellation of feelings, reactions, and
recollections that add up to substantial information. To say, “I was abused,” you don’t
need the kind of recall that would stand up in a court of law. Often the knowledge that
you were abused starts with a tiny feeling, an intuition ... Assume your feelings are
valid. So far, no one we’ve talked to thought she might have been abused, and then
later discovered that she hadn’t been. The progression always goes the other way,
from suspicion to confirmation. If you think you were abused and your life shows the
symptoms, then you were (p. 22).
From
The Sexual Healing Journey: A Guide for Survivors of Sexual Abuse
Wendy Maltz
“Spend time imagining that you were sexually abused, without worrying about
accuracy, proving anything, or having your ideas make sense.”
False Memory at USF
E-mail from USF administrators to USF Psychology Department
Feb 4, 2004
“Please be aware that there was an incident in the parking lot behind PCD this
morning, during which a woman was confronted by a man with a knife. I understand
that she is okay, although there were some marks left on her neck, and the attacker
was not apprehended.”
Follow-Up E-mail – The next day
“… After questioning by the University Police, it was ascertained that the woman had
possibly had an attack in her past. The UP therefore determined it was a “flashback”
episode, no crime had occurred, and no report was filed. As to the previous
information about witnesses, marks on the woman’s neck, description of the
attacker, these were all initially provided to the department by a faculty member in
CSD [Communication Sciences and Disorders]. ”
John Mack, MD
Harvard Med School (died in 2004)
Mack helped many patients “recover memories” of alien abductions.
He believed their accounts.
Mack: “They floated through a wall or out a car, carried up on this beam of light into a
craft and there subjected to a number of now familiar procedures which involve the
beings staring at them; involves probing of their body, their body orifices; and a
complex process whereby they sense in the case of men, sperm removed; in the
women, eggs removed; some sort of hybrid offspring created which they're brought
back to see in later abductions.”
Elizabeth Loftus
Claim
Very emotional events are not forgotten –flashbulb memory
(Kulik & Brown, 1977)
Examples
JFK assassination
Challenger crash
9-11 attacks
Are memories of emotional events really immune to forgetting?
How can this claim be tested?
Experiment
Ss surveyed 1 day after 1986 Challenger crash
(How did you hear? Who was with you?)
When tested 1 year later, much forgetting occurred.
Conclusion
Emotional events are forgotten less often than non-emotional events.
But the difference is one of degree.
Thus, “flashbulb memories” are not special.
Rebuttal: Perhaps Ss were not emotionally invested.
(Neisser & Harsch, 1992)
Experiment
Ss asked to recall when they heard the verdict in famous murder trial (OJ Simpson)
Initial Test (3 days later) included
fact questions
Where were you? Who told you? What were you doing? etc.
emotion rating (1-5)
How strong or intense was your emotional reaction?
Final Test (15 or 32 months later, by random assignment)
Same fact questions as Initial Test
For each question, Ss gave confidence rating (1 – 5)
1 = low confidence, 5 = high confidence
(continued)
Some of the Findings
Final test responses included many errors, including “major distortions.”
Forgetting worse after longer test delay.
Example
15 months
Ss with “major distortions” 11%
32 months
43%
Ss had strong confidence in memories that were false.
Example
61% of “major distortions” received confidence rating of 4 or 5
Ss who reported more emotion forget nearly as much as other Ss.
(Schmolk et al., 2000)
The End
Demo
In a moment, I will quickly read a list of words related to the same topic.
Please close your eyes and listen carefully.
School Supplies
notebook
pen
scissors
folder
stapler
eraser
binder
pencil
tape
ruler
glue
protractor
Next Step
In the margin of your page, write as many words as you can remember.
Order does NOT matter.
Next Step
Next to each word, write your confidence that the word was on list.
1 = not sure
5 = certain
Answer Key:
School Supplies
notebook
pen
scissors
folder
stapler
eraser
binder
paper
pencil
tape
ruler
glue
protractor
Experiment
In therapy, some patients recover memories of alien abduction.
These patients and controls participated in experiment.
First, “alien abductees” described their abduction; E recorded each story.
E also makes recordings of stories that did not involve abduction.
Later, all Ss listen to all recordings.
For “abductees,” but not controls, GSR was higher for “abduction” scripts
Conclusions
Abductees apparently believe they were abducted.
Presence of emotional response does not mean that response is true.
(McNally et al., 2004)