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Modern Classic TheoryDog
visual
features
letters
sounds
meanings
Knowledgeabout dogs
Dog Memories
Chase
word dog
Saw“Lassie”On TV
GotBit
In May FIDOmydog
Cats
4-legs animal pet barks
shallow
deep
D O G
“d” “o” “g”
ActivationOf
shallowestlevels
Sensory memory
Temporaryactivationof mediumand deep
Levels(limited
Capacity)
Short-term store
transferto LTS
(add newStructure) Saw on
ListTuesday
Oct 8
What is long-term store?
GeneralKnowledge
Memory forevents inyour life
Skills
Episodic Memory•I remember the time when I forgot the classroom combination
•I remember the time when I fell off my tricycle
Semantic MemoryI know that 8 is a number.
I know that Walt Disney created Mickey Mouse.
Procedural MemoryI know how to play tennis
I know how to speak
Semantic and episodic memory together arecalled Declarative or Propositional Memory.
They store meaning.
Forgetting from LTS
Decay theory
Memories fade with time
Interference Theory
Memories are lost as a direct result ofother learning
New learning interferes with old learning
Same issue as in extinction
decay vs. inhibition
Minami & Dallenbach (1946
Cockroach Experiment
Shock
Trained until learn to avoid shock
NormalActivity
SensoryDeprivation
In Box
NormalActivity
Memory is lost due to interference
Jenkins & Dallenbach (1924) (humans)
%correct recall
afterSleep(60%)
(10%) awake
Savingsin
relearning
1 2 3 8interval (hours)
100%
1 2 3 8 (hours)
100%
Similarity Principle
The more similar any two events are,
the more their memories interfere with
each other
Example
B C P T V E C (hard)
Y B S K X O P (easy)
Studies of Interference
… Event Event Event Event Event Event …..
your life
attemptto
recall
PI = proactive interference
RI = retroactive interference
PI
PI
RI
RI
Similarity in paired-associate learning
The retroactive interference (RI) paradigm
Experimental Group Control Group
List 1 List 1DAX-quickly same itemsZIL-happyYOV-trouble
learn until perfect
List 2DAX-soldierZIL-traffic restYOV-heavy
Test for DAX-? DAX-?List 1 ZIL-? ZIL?
YOV-? YOV-?
control group is better
RI experiment shows that new learning interferes
with old learning
Does old learning interfere with new learning?
YES,
Proactive Interference (PI) Experiment
Experiment Group
Learn List 1
Learn List 2
Recall List 2
ControlGroup
Rest
Learn List 2
Recall List 2
Control group does better
Release from P.I. (Wickens)
•Proactive interference increases from trial1 to 3
•But if items on 4th trial are very different, recall is better
•Shows that similarity causes interference
%correct
| | | |1 2 3 4
Trials
changecategory
don’tchangecategory
Which changes give the biggest release from PI?
Hi-release
animals - furniture
numbers - letters
“good” words - “bad” words
Lo-release
2-syllable — 3-syllable
ink color
A change in meaning produces biggest release
What release from PI experiments tell us
•similar things interfere in memory
•the similarity that matters in recall fromLTS is semantic
Therefore, words are stored in LTS interms of their meaning
Do we ever really forget?
Once in LTS, does it stay?
Loftus & Loftus (1980)
Which do you believe?
(1) Everything we learn is permanently in themind, although sometimes particular details are not accessible. With hypnosis or other techniques, inaccessibledetails could be recovered.
(2) Some details that we learn may be permanently lost from memory. Such details couldnever be recovered because they are nolonger there.
Are these reasons forbelieving memory
is permanent?
•Penfield’s brain stimulation experiments
•hypnosis
•spontaneous recovery of memories
•psychoanalysis
From Loftus & Loftus (1980)
STOP
STOP
Loftus’s Experiment
Subjects view aseries of slides
A or B?
StopSign
YieldSign
Phase 2Subjects asked 20 questions
“Did you see a tree?”
“What color was the car?”
“Did another car come up behind the red car whenit went through the yield sign?”(misleading question)
Phase 3Forced choice recognition test
Results of Stop-Yield Experiment
If you got misleading question, 80% picked thewrong slide
If you did not get the misleading question(control group), subjects picked thecorrect slide
Loftus’s Interpretation
old memory (stop sign) is replaced bythe new information (yield sign)
OLD MEMORY IS GONE
BUT…..
This experiment does not prove the old memory is gone, only that it was not retrieved.
Is Old Memory Really Gone?
Other experiments by Loftus
Subjects told afterward that they may have beenfooled; 90% still thought it was a yield sign
Offered $25 if they got it rightStill got it wrong
Hypnosis (Putnam, 1979)made subjects worse
McCloskey & Zaragoza’s Criticism
You don’t forget the stop sign, you fail to retrieve it
When you fail to retrieve it you must guess on thetest
AND subjects are biased to guess “yield” becausethey remember the question
STOP “yieldsign”
McCloskey & Zaragoza’s Experiment
Phase 1Slides - petty theft of money
man reaches in tool box under ahammer to steal money
Phase 2
Misled Group
Read transcriptof event that
mentions“screwdriver”
Control Group
Transcriptmentions
“hammer”
Phase 3Half of the subjects in control and misled
group are tested on the original Loftus procedure
Was it a hammer or a screwdriver?
The misled group chooses hammer 38%
The control group chooses hammer 72%
The other half of the subjects are tested on a modified procedure
Was it a hammer or a wrench?
misled group “hammer” 72%control group “hammer” 75%
Original memory of “hammer” is NOT destroyed in misled condition
Colorof grass=
Meaning
Semantics is the study of meaning.
Problem:What is the mental representation of themeaning of a sentence?
“Grass is green”
MethodsLinguisticsArtificial IntelligenceExperimental Psychology
Meaning of a sentence = a set of propositions
Proposition = “a basic idea”
a unit of meaning just large enough to betrue or false
Propositions
ROSES ARE REDMY DOG HAS FLEASGRASS IS PURPLE
Not propositions
DOGSPURPLE
A proposition isn’t a sentence;It’s a thought
“The book is red”“The book’s color is red”“Das buch ist rot” (German)
Complex sentences express more than oneproposition
“The big brown dog is hungry”
1. DOG1 is BIG2. DOG1 is BROWN3. DOG1 is HUNGRY
“Jane and Bill are students”
expressthe sameproposition
Formal Treatment
Proposition = Abstract unit of meaning thatexpresses a relation amongconcepts
concepts
“John”“dogs’“Fido”
“justice”
(nouns ornoun phrases)
Relations(verbs or verb-
like words or phrases)
“gives”“likes”
“is next to”
IS NEXT TO (JOHN, BILL)
LIKES (JOHN, BILL)
JOHN BILL
ConceptsRelation
likes
Semantic Memory
(General KnowledgeBasic Facts
“Generic” Memory)
contains propositions
FLAT
TABLE CHAIR
BACK
is has
concepts
relation
Semantic Memory
Network of Propositions
Furniture
Sitting
Back4 legs
TableChair
Flat
used
for
is
has has hasis
is
Cognitive Economy Question
FOUND IN (CHAIRS, BUILDINGS)
FOUND IN (TABLES, BUILDINGS)
FOUND IN (FURNITURE, BUILDINGS)
How are these propositions represented insemantic memory?
Buildings
found in
found in
found in
One possibility: Non-economical Storage
Store everything separately
FOUND IN (TABLE, BUILDINGS)FOUND IN (CHAIR, BUILDINGS)FOUND IN (FURNITURE, BUILDINGS)
Buildingsfound in
Other possibility: Economical StorageStore only what is necessary. If you can infer something from what is already stored,don’t store it.
STORE: FOUND IN (FURNITURE, BUILDINGS)
DON’T FOUND IN (TABLE, BUILDINGS)STORE FOUND IN (CHAIR, BUILDINGS)
Economical Storage - only what’s necessary
Non-economical Storage - store everything
Collins & Quillian (p. 417)
animal
bird
skin
feathers
fly
canary
yellow
ostrich
sing
has
is
has
can
can’tis
is
is
can
SUPPORTS
Each link adds .08 seconds
“Canaries haveskin”RT = 1.46 sec
“Canaries canfly”RT = 1.38 sec
“Canaries are yellow”RT = 1.30 sec
Conrad’s Experiment
“A shark has teeth”
“A shark has gills”
But results showed
“A shark has teeth” is faster
ConcludeCognitive economy does not occur for
frequently associated properties
have
is
have
is
animal
fish
shark
teeth
gills
Should beharder
haveteeth
Semantic Memory
Knowledge of facts
iscanary bird
Episodic Memory
Personal events
“I remember going bowlinglast October”
Are episodic and semantic memoriespart of the same memory system. Or are theyseparate kinds of memory:
Our intuitions suggest that they are different.
The relation betweenepisodic and semantic memories
Events in your life
Memory for
the specificevent
(episodic memory)
Memory forthe facts that
you learnfrom events
(semantic memory)
Semantic memories are strong(often used)
Many episodic memories are hard to retrieve(not often used, much more interference)
Source amnesia (Thorn, 1960)We can forget the event, but rememberthe facts
Semantic Part
Episodic Part
I learned
Amethyst Yellowsturns
(while hypnotized May 10)
Source amnesia in hypnosis(Thorn, 1960)
•subjects hypnotized
•given general test of semantic memory, e.g., “An amethyst is a blue or purplegem. What color does it turn whenheated?”
•subject told “yellow”
subject awakened
Asked same question.Gets it right, but doesn’t know the source
forgot episodic (event)
remembered semantic (general knowledge)
2ndgrade
teacher
GeorgeWashington
FirstPresident
was
said(Jan 10 in school)
OlderSister
GeorgeWashington
FirstPresident
said
(May 3 at home)
I
GeorgeWashington
FirstPresident
read
(June 10 at home)
Semantic and episodic memory are in the
same memory system.
But we often forget episodic memories
because they have more inteference and are used
less often.
ThirstyWindowsCircularGenerationTriumphDiluteScorpionPerfumeMortalGothicSpicesBridal
N
O
S
R
L
1. Mor 2. Wea 3. Tri 4. Col 5. Gra 6. Sco 7. Bri 8. Tan 9. Dil10. Sca11. Gar12. Spi13. Win14. Per15. Tra16. Cir17. Mar18. Par19. Gen20. Dis21. Thi22. Ban23. Sal24. Got
1. Mortal S 2. Weapon N 3. Triumph S 4. Colorful N 5. Gradually N 6. Scorpion S 7. Bridal S 8. Tangent N 9. Dilute S10. Scanner N11. Garlic N12. Spices S13. Windows S14. Perfume S15. Trailer N16. Circular S17. Marble N18. Parent N19. Generation S20. Disown N21. Thirsty S22. Banker N23. Salary N24. Gothic S
Implicit Memory
Changes in performance on a task due toa study episode even though you are nottrying to remember the items
examplesStem completion S C OFragment completion S _ O _ _ I _ N
Explicit Memory
Your ability to intentionally rememberitems from a study episode
examplesRecallRecognition
Read these sentences
THE GIRL BROKE THE WINDOW.
Test reading a week later
THE GIRL BROKE THE WINDOW.
Result:Backward sentences are read faster ifthey were backwards the first time
implicit or explicit?
Ask subjects to judge whether each sentence ispresented the same way as before
implicit or explicit?
Processing Dissociations
Some variables affect explicit, but not implicitmemory, or vice versa
ExampleLevel of processing affects explicit,but not implicit memory
Graf & Mandler (1984)
Study words
Rate “liking” count “enclosures” (deep) (shallow)
Test
Stem completion Cued recall (implicit) (explicit)
Processing level Deep processinghas no effect leads to better
memory
Roediger & Blaxton (1987)
Modality (visual vs. auditory words)
Implicit memory is reduced if the modality is changed from study to test
STUDY TEST fragment completion
hear “morbid”OR
see MORBID M _ R _ _ D
Fragment completion is worse when you hear theword
Explicit memory (e.g., recall) is not affected bymodality of the words
Other Dissociations
Weldon & Roediger (1987)
Study words & pictures
DOG PENCIL CAR
TEST
fragment completion free recallimplicit explicit
P _ _ C _ _
fragment completion pictures areis better only for recalled betterstudied words than words
Results are opposite for implicit and explicit
Implicit memory (stem completion)
Changes in performance on a task due toa study episode
•not affected by level of processing
•is reduced when modality of the word changes
•does not occur when studied episode involves
pictures
Explicit memory (recall, recognition)
Intentionally remembering items from astudy episode
•strongly affected by level of processing
•not reduced when modality changes
•is better when the studied episode is pictures
instead of words
Why do implicit and explicit memory test actdifferently?
The tests reflect memory for different information
letters
wordmeaning
MORBID
MORBID
M O R B I D
means
explicit memoryadd new event to LTS
implicit memorystrengthen
existingconnections
Psych 248
Event
Nov 6
in on