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