Transcript No Slide Title

Amnesia from Brain Damage
Concussion
Shock
Lesions
Drugs
Alcohol (Korsakoff’s syndrome)
Back
Symptoms
Retrograde Amnesia (RA)
Anterograde Amnesia (AA)
You usually have both
Retrograde
Loss of memory for events prior to the
damage
Loss is greatest for time right before
damage
Is RA a retrieval or storage deficit?
You can recover from RA
Therefore, it is a retrieval deficit
RA in rats (Winocur’s experiment)
(only forget things for a few days before damage)
Phase 1
rats learn to associate a reward with
a particular smell
Phase 2
Control Group
No lesion
to hippocampus
Experimental Group
Hippocampus is
lesioned either 1,7, or
14 days after learning
control
memory
for
phase
1
experimental
|
14
|
7
days since learning
|
1
RA in people (Butlers & Cermak (1986))
Patient P.Z.
University professor who developed amnesia in
1982 (had written autobiography three years
before)
Recall of facts from book
90 –
RA

50 –

|
|
before
1930 1940

|
1950

|
1960

|
|
1970
1980
Anterograde Amnesia
Loss of memory for events after damage
Does AA affect STS or LTS?
Immediate Free Recall
Baddeley & Warrington
normals
amnesics
serial position
Maintenance in STS is not affected
Problem is with LTS
Is AA due to failure to transfer to LTS or
failure to retrieve from LTS?
If you can recover from AA, you still can
never retrieve the events that happened while
you had AA
Therefore, AA is a failure to transfer to
LTS
Not all LTS is affected in amnesia
Lost
performance in explicit memory tasks
(recall, recognition)
learning new vocabulary
learning new facts (semantic memory)
Not Lost
•implicit memory (e.g., stem completion)
•ability to learn new skills
Milner (1965)
Trace star
using
mirror
mirror
Amnesics learned as fast as normals
Cohen’s Tower of Hanoi Experiment
Normals and amnesics must learn how to
solve problem
Result
Normals and amnesics learn task at
the same speed
Amnesics don’t remember having done
the task
Amnesics have normal ability to learn new skills
A Theory of Amnesia
Procedural/Declarative Theory
(Cohen)
Amnesia is a disorder of declarative memory
(episodic and semantic memory)
Procedural memory is normal
skill learning
o.k.
implicit meaning
o.k.
What does the hippocampus do?
It allows us to combine different kinds of
knowledge to make new memories.
If the hippocampus is gone, what happens?
Can’t form new memories for events
(can’t combine parts of events)
Can’t store new propositions
(can’t learn new facts)
(can’t remember what you read)
Why do you lose recent old memories (RA)
as well as the ability to form new memories
(AA)?
It takes time (weeks, months) to completely
lay down a new memory. You need the
hippocampus to hold onto recent memories
before they are completely formed.
What can you do without a hippocampus?
Your STS is o.k. (activation of existing parts of
network)
You can strengthen existing connections in LTS
(explains some kinds of implicit memory)
(and why procedural memory is o.k.)
Hypnosis & Memory
1. Can difficult-to-retrieve memories be
reached through hypnosis?
2. What is the nature of post-hypnotic amnesia.
Post-hypnotic Amnesia
•loss of memory for events during hypnosis
•caused by suggestion from hypnotist
Why is it important?
 causes

of forgetting
semantic/episodic memory
Evans & Kihlstrom
subjects hypnotized and given 12 tests
heading nodding
eyes close
hand lowering
arm immobilization
finger lock
arm rigidity
hands moving together
communication inhibition
fly hallucination
eye catalepsy
post hypnotic suggestion to touch ankle
post hypnotic amnesia suggestion
subject is awakened
20 -
Perfect
Amnesia

15 -

Distribution of
number of
items recalled


10 -

5-

|
0
|
1




|
2
|
3
|
4
|
5
|
6
|
7
|
8
|

|

|

|
9 10 11 12
Subjects with perfect amnesia either think
hypnosis was brief or recognize that there’s a
gap in their memory.
“Try to recall as many tests as you can”
9–
8–
7–
6–
5–
4–
3–
2–
1–
Hi
Medium
Lo
Hypnotizability of Subjects
Hi subjects had vague recall
“something about a fly”
Lo subjects had specific recall
“You tried to get me to think there was
a fly”
“Try to recall as many tests as you can”
“Now you can remember everything”
9–
8–
7–
6–
5–
4–
3–
2–
1–
Recall is
equal after
amnesia is
lifted
Hi
Medium
Lo
Hypnotizability of Subjects
Retrieval
Failure
Hi subjects had vague recall
“something about a fly”
Lo subjects had specific recall
“You tried to get me to think there was
a fly”
Are the memories completely blocked before
amnesia suggestion is lifted?
Hull (1933)
Subjects experiencing post-hypnotic
amnesia show savings in re-learning
Group 1
Learn
List A
TOLD
TO
FORGET
Relearn
list A
Group 2
Rest
TOLD
TO
FORGET
Learn
list A
Group 1 does much better
Graham & Patton (1968)
Blocked items still cause RI
Learn B
2. Learn list A
Rest
3. Learn list A
Learn B
TOLD TO FORGET
1. Learn list A
Test A 54%
Test A 87%
Test A 46%
Groups 1 and 2 Hypnotized
Group 1 shows as much RI as Group 3
Williamson, Johnson & Erikson (1965)
Subject hypnotized
(high hypnotizable)
Learned list
many, pencil, work . . .
Awakened
Test recall (could recall almost none)
Fragment completion
m_n_
OLD
p e_ _ i _
OLD
t_n_
NEW
.
.
.
Solved fragments much more often for old
words
Relation between Recall and Recognition
Phase 1
Recall
Recognition
Search
for
Memories
Phase 2
Decide if
they are
the ones
you want
Decide if
items are
the ones
you want
Hypnotic amnesia occurs in recall, but not
really in recognition.
Therefore, it affects the search phase of retrieval
Hypnotic Enhancement
Alien abduction??
Recall of former lives??
Police work
L.A.P.D. Study
70 volunteer witnesses hypnotized
77% of cases got “useful” information
from hypnosis
BUT NO CONTROL GROUP
People vs. Shipley (1982)
Supreme court decision
Hypnosis does not contribute to
accurate testimony
Hypnosis leads to more false recall
Shaul (1978)
hypnotized subjects showed more
correct recall, but also more
false recall
Hypnosis leads to unjustified confidence
Putnam (1979)
stop-sign yield-sign experiment
hypnotized subjects were not more
accurate at choosing the correct
sign. But they were more confident
Details of an Example Study
Rudman (1984)
Does hypnosis aid recognition memory?
PHASE 1
(1) Subject enters room
(2) Confederate enters room, apologizes and
leaves
(3) Subject hypnotized and tested for
susceptibility
(4) Subject “awakened” and told they may be
asked back
PHASE 2
24 highly hypnotizable subjects called
back 1 month later to the same room
3 groups
8
Hypnotized
8
Simulators
8
Not hypnotized
Subjects told to “visualize” the last time in room.
Five photographs of people forced choice
recognition and rate confidence
Results
Hypnotized
Simulators
Not Hypnotized
Number correct (out of 8)
6
5
6
No difference in recognition
Hypnotized
Simulators
Not Hypnotized
Number who were confident
(out of 8)
8
4
1
Hypnotized subjects were more confident
Criterion Shift Hypothesis
Hypnosis does not change the accuracy
of memory search processes. But it does make
the subject more willing to call something a
memory.
 False
Recall

False Alarms in Recognition

Higher Confidence
How criterion shift might work
Study List:
DOG
TREE
CUP . . .
ON LIST
DOG
chase
CAT
TREE
weaker link
CUP
has
over
LEAVES
SAUCER
How criterion shift might work
Study List:
DOG
TREE
CUP . . .
ON LIST
DOG
DOG
chase
CAT
CAT
weaker link
TREE
CUP
CUP
has
LEAVES
LEAVES
over
SAUCER
Memory search works by spreading activation
Recall everything more activated than some
criterion, e.g., 10 units of activation
How criterion shift might work
Study List:
DOG
TREE
CUP . . .
ON LIST
weaker link
RECALL
“dog”
“tree”
DOG
DOG
chase
CAT
CAT
TREE
CUP
CUP
has
LEAVES
LEAVES
over
SAUCER
Memory search works by spreading activation
Recall everything more activated than some
criterion, e.g., 10 units of activation
How criterion shift might work
Study List:
Hypnotized
Shift criterion
down to 5
DOG
TREE
CUP . . .
ON LIST
weaker link
RECALL
“dog”
“tree”
“cup”
“cat”
“leaves”
DOG
DOG
chase
CAT
CAT
TREE
has
LEAVES
LEAVES
CUP
CUP
over
SAUCER
More words are recalled because more words are
activated above the lower criterion. “cat” and
“leaves” are falsely recalled
Does music aid performance on cognitive tasks?
The Mozart Effect
Rauscher, Shaw & Ky (1993)
Listen
to 10
minutes
of Mozart
Listen to 10
minutes of
repetitive
music
10
minutes
of
Silence
Test on spatial abilities
e.g., jig-saw puzzles
mental rotation
Result: You’re better after the Mozart
Interpretation
Brain regions for musical processing are
shared with regions for spatial processing.
(Music “warms up” these regions.)
Is the Mozart Effect For Real?
Nantais and Schellenberg (1999)
Exp 1
score
on
test
Mozart
12.8
Exp 2
Mozart
13.0
Subjects who
preferred Mozart
Subjects who
preferred story
Silence
11.9 significant
difference
Interesting
Story
12.9
Mozart
14.6
Story
13.2
11.6
12.7
no
difference
Conclude: There’s nothing special about Mozart or any
music for enhancing spatial tasks.
•Doing anything interesting right before the test helps
performance, compared to being bored.
Repression
“The essence of repression lies in simply rejecting
and keeping something out of consciousness.”
—Freud
Does this happen?
Of course.
Everyday Repression
(1) turn away from unpleasant things
poor encoding
Peters (1988)
poorer recognition of nurse who gives
inoculation than for a neutral helper
(2) Don’t think about unpleasant things
fewer rehearsals, poor memory
Meltzer (1950)
Students forgot more of the
unpleasant memories that occurred
over the holidays
Real “Freudian” Repression
•painful information is kept out of consciousness
without the person being aware that they are
rejecting it
•can lead to mental illness
Two Kinds of Repression
Perceptual Defense
Sensory
Memory
STS
Memory Defense
STS
LTS
Perceptual Defense
15 msec
TABOO WORD
Taboo words must be flashed for a longer
duration before subjects report the word.
Conclusion
Indeterminant
Subjects may be less likely to report seeing
a taboo word.
Is a Taboo Word Effect Perceptual?
(Zajonc (1962)
Group 1
TABOOdog
CONTROL
Group 2
see
say
whore TABOOwhore dog
cat
where CONTROL
TABOO needs
longer exposure
see
say
where
cat
no difference
Effect is due to the reluctance to say
TABOO words
Memory Defense
Psychogenic Amnesia
Loss of memory from “psychological” causes.
Loss for specific situation, or temporary loss of
identity
Specific Situation
Case of Madame D. (Janet).
Told of husband’s death (as a joke). Became
unable to remember event.
(gradually memory returned)
Loss of Identity (who you are)
Fugue State
Sometimes you “flee” current circumstances
Only detailed study of psychogenic amnesia
P.N. studied by Schacter, Wang, Tulving &
Freeman (1982)
Episode occurs after grandfather’s funeral
•lasted 4 days
•lost most episodic memories
•retained semantic memories
•loss was retrograde more than anterograde
Organic
Psychogenic
•more A.A.
•lose episodic &
semantic
•brain damage
•more R.A.
•lose episodic &
personal identity
•traumatic events
Dissociative Identity Disorder
(Multiple Personalities)
Personalities may not remember events
experienced by other personalities
(interpersonality amnesia)
Eich, Macaulay, Lowenstein & Dihle
(1997)’s experiment
Phase 1
“Frank” is replaced by “Jim”
“Jim” reads 20 words
“Jim” does test of picture fragment completion
What is this?
Phase 2
“Jim” is replaced by “Henry”
(“Henry” is told “Jim” heard words. “Henry
could not recall ANY of them NO FREE RECALL)
“Henry” does cued recall for words that “Jim”
saw. Cue is first three letters.
“Henry” gets 20 new words
“Henry” does picture
fragment completion
5 pictures were done by “Jim”
5 pictures were new
Picture Fragment Completion
improvement from
seeing picture before
–2.0
–1.0
Jim
Jim
Jim
Henry
Henry
Jim
There is implicit memory (picture fragment
completion) across different personalities
Phase 3
“Jim” comes back
•“Jim” could not free recall any of “Henry’s”
words
•cued recall for “Henry’s” words
•cued recall for his own words
(from Phase 1)
•picture fragment completion
5 new pictures
5 “Jim” had seen
5 “Henry” had seen
Results
Cued Recall
50 –
40 –
30 –
20 –
10 –
study
test
“Jim”
“Jim”
“Jim”
“Henry”
“Henry”
“Jim”
Very poor explicit memory across different
personalities
Why is interpersonality amnesia
found in recall only?
Explicit, episodic memory
SelfConcept
1
SelfConcept
2
episodic
memories
Semantic Memory
Procedural Memory
(perceptual skills)
picture identification