Psy1302 Psy1302 Psychology of Psychology of LanguageLanguage

Language Acquisition IILanguage Acquisition II

Lecture 18Lecture 18

Reading AssignmentReading Assignment

Fisher & Gleitman (2002)Fisher & Gleitman (2002) I. Outline of the task of language learningI. Outline of the task of language learning II. Where language learning beginsII. Where language learning begins

– Categorization of Speech SoundsCategorization of Speech Sounds– Segmentation of Spoken WordSegmentation of Spoken Word– Role of Sound in Syntactic AnalysisRole of Sound in Syntactic Analysis– Distributional Analysis and Discovery of SyntaxDistributional Analysis and Discovery of Syntax

II. MeaningsII. Meanings– Primitive Categories of ExperiencePrimitive Categories of Experience– Compositional MeaningCompositional Meaning– Interactions between linguistic and conceptual categoriesInteractions between linguistic and conceptual categories

IV. Forms to meaningIV. Forms to meaning– Mapping problemMapping problem– Concrete words firstConcrete words first– Old words make new words easier to learnOld words make new words easier to learn

V. Where learning endsV. Where learning ends

What does What does ““tokibu tokibu gikoba gikoba gopila gopila tipolutipolu”

mean anyway?mean anyway?

Mapping Form to Mapping Form to MeaningMeaning

To learn a language is, by definition, to acquire a set of pairings between sounds or more abstract linguistic structures and their meanings.

Fisher & Gleitman (2002)

Artist: Henry Gleitman

Elephant!

Learning by Learning by AssociationAssociation

John Locke, 1690 Book 3, IX, 9:

If we will observe how children learn languages we shall find that .... people ordinarily show them the thing....and then repeat to them the name

You learn the meaning of elephant because You learn the meaning of elephant because whenever you hear “elephant” you see an elephant. whenever you hear “elephant” you see an elephant.

Association is formedAssociation is formed Of course often you see other things as well...Of course often you see other things as well...

Learning by Learning by AssociationAssociation

Gavagai!

Unconstrained inductionUnconstrained induction(or the radical indeterminacy of (or the radical indeterminacy of translation)translation)

Quine, 1960Quine, 1960

What could What could “gavagai” mean?“gavagai” mean?

Rabbit?Mammal?

Ears?

Brown?Fluffy?

Carrot eater?

ScurryingHopping

Thumping

Stay!

What a cutie!

Meal!Rabbit only until eaten!

That’s not a dog!

Chinchila rabbit?

Animal?

vegetarian?

Long ears?

Look!

Unconstrained inductionUnconstrained induction

RABBIT!

RABBIT

EAR and PAW

RABBIT

+ FLOOR

Sometimes I wonder

too!

Learning by Learning by AssociationAssociationPROBLEMSPROBLEMS1. Relying on Association could be 1. Relying on Association could be

slowslow– Have to rule out many alternate Have to rule out many alternate

hypotheseshypotheses– Yet, children sometimes learn words Yet, children sometimes learn words

in a single trial.in a single trial.

“Give me the chromium tray, not the blue tray.”Fast Mapping Carey & Bartlett

Learning by Learning by AssociationAssociationPROBLEMSPROBLEMS2. Some meanings cannot be 2. Some meanings cannot be

disentangled from situationsdisentangled from situations

GIVING RECEIVING

VERBS

PREPOSITIONS

ABOVE

BELOW

Learning by Learning by AssociationAssociationPROBLEMSPROBLEMS3. How do we learn words that do 3. How do we learn words that do

not refer to concrete objects?not refer to concrete objects?– ““nap”, “hour”nap”, “hour”– mental states: e.g. “think”mental states: e.g. “think”

Learning by Learning by AssociationAssociationPROBLEMSPROBLEMS4. We do not always see object or 4. We do not always see object or

action at the same time as we action at the same time as we hear the word.hear the word.

– “– “Where’s your mother?”Where’s your mother?”

– “– “Eat your peas”Eat your peas”

– – OPENING action occurs only 1/3 of OPENING action occurs only 1/3 of the times that “open” saidthe times that “open” said

Learning by Learning by AssociationAssociationPROBLEMSPROBLEMS5. Does not necessarily explain 5. Does not necessarily explain

how we learn to generalize word how we learn to generalize word to new instancesto new instances

– An object can be categorized at many levelsAn object can be categorized at many levels– And in many ways (by shape, size, texture, And in many ways (by shape, size, texture,

function)function)

ChairsChairs

http://en.wikipedia.org/wiki/List_of_chairs

Child sees only a few exemplars of dog....how does she learn to extend the word to all these different types of dogs?

Given all the above problems with Given all the above problems with the the learning by associationlearning by association account…account…

How do children ever learn the How do children ever learn the mappings between form and mappings between form and meanings?meanings?

Successful comprehension of any Successful comprehension of any intended linguistic expression cannot intended linguistic expression cannot be achieved without some be achieved without some commonality of thought.commonality of thought.

Language LearningLanguage Learning

Language learning is possible because Language learning is possible because babies can organize categories in babies can organize categories in much the same ways as their adult much the same ways as their adult caretakers do.caretakers do.

Language LearningLanguage Learning

Child sees only a few exemplars of dog....how does she learn to extend the word to all these different types of dogs?

Dogs

Shmogs

Word LearningWord Learning Children develop reasonable biases in how Children develop reasonable biases in how

to interpret meanings of novel wordsto interpret meanings of novel words– Development of these biases may be influenced Development of these biases may be influenced

by naming practices of the target language by naming practices of the target language being learned being learned

They draw on various sources of They draw on various sources of information in learning word meaningsinformation in learning word meanings

– Social cuesSocial cues– Linguistic cuesLinguistic cues

State of the learner’s linguistic knowledge State of the learner’s linguistic knowledge will dictate sources of information recruitedwill dictate sources of information recruited

Word Learning BiasesWord Learning Biases

Mutual ExclusivityMutual Exclusivity Assume that every object has just Assume that every object has just

one name (E. Markman)one name (E. Markman) Less limited: assume that there Less limited: assume that there

are no synonyms (E. Clark)are no synonyms (E. Clark)

Mutual Exclusivity in Mutual Exclusivity in ActionAction Experimenter “Look here’s a dax”Experimenter “Look here’s a dax”

Mutual Exclusivity in Mutual Exclusivity in ActionAction Child ....that’s a telephone Child ....that’s a telephone

it can’t be a daxit can’t be a dax

Mutual Exclusivity in Mutual Exclusivity in ActionAction Child ....so that other thing must Child ....so that other thing must

be a dax!be a dax!

18 months-olds can do this…

Social PerspectiveSocial Perspective

Word learning occurs in a social contextWord learning occurs in a social context Child is NOT attempting to map a word to Child is NOT attempting to map a word to

something in the worldsomething in the world Child is attempting to discover another Child is attempting to discover another

person’s intention to referperson’s intention to refer– Referent = the thing/event/action in the world that Referent = the thing/event/action in the world that

an instance of the word refers toan instance of the word refers to– Meaning = the concept that is paired with a wordMeaning = the concept that is paired with a word

Word learning is an attempt at mind reading!Word learning is an attempt at mind reading!

Joint ReferenceJoint Reference

Joint Reference: when speaker and Joint Reference: when speaker and listener both interpret a phrase as listener both interpret a phrase as referring to the same thingreferring to the same thing

Achieved through joint attention Achieved through joint attention based onbased on– Prior linguistic contextPrior linguistic context– Shared goals or world knowledgeShared goals or world knowledge– Visual attention to physical contextVisual attention to physical context

Baldwin (1991)Baldwin (1991)Social Cue - Joint Social Cue - Joint ReferenceReference

1

2

1

2

Follow-In:Mom looks at same thing.

Disjoint:Mom looks at different thing.

Mom then says: “Oh, look at the toma! See that toma? Wow, that’s a toma!” Child then asked to identify “toma”.

18 months-olds succeed at tracking where mom is looking and using that to determine what is the “toma.”

Children make use of the linguistic context in which words appear

Verb vs. nouns

Mass nouns (e.g. sand)

Count nouns (e.g., dog)

Linguistic ContextLinguistic Context

$#>@)(!&%

He’s sebbing!

Brown, 1957

Using Linguistic Using Linguistic ContextContext

Look, a seb!

Using Linguistic Using Linguistic ContextContext

Brown, 1957

Using Linguistic Using Linguistic ContextContext

Look, some seb!

Brown, 1957

State of the learner’s State of the learner’s linguistic knowledge and linguistic knowledge and information recruitedinformation recruited• • Initially, child has impoverished information Initially, child has impoverished information

about linguistic context and the structure about linguistic context and the structure of the worldof the world– Don’t understand many wordsDon’t understand many words– Don’t understand much about syntaxDon’t understand much about syntax

Shared physical context must be keyShared physical context must be key Speakers attention can be inferred through:Speakers attention can be inferred through:

– eye gazeeye gaze– body orientationbody orientation– gesturesgestures

Vocabulary growthVocabulary growth

By the age of 3 years, children have been By the age of 3 years, children have been learning about 8 new words a daylearning about 8 new words a day

AgeAge Language DevelopmentLanguage Development

1-2 months1-2 months Cooing (oh, ah)Cooing (oh, ah)

6 months6 months Babbling (ba)Babbling (ba)

8 months8 months Reduplicated Babbling (bababababa)Reduplicated Babbling (bababababa)

10 months10 months Variegated Babbling (badago)Variegated Babbling (badago)

1 year1 year First words (mummy)First words (mummy)

Repeating sound sequencesRepeating sound sequences

1-1.5 years1-1.5 years One word stage (3-50 words) One word stage (3-50 words)

2 years2 years Two-word or Telegraphic stageTwo-word or Telegraphic stage

2-2.5 years2-2.5 years Word SpurtWord Spurt

3 years3 years Intelligible to strangersIntelligible to strangers

Receptive vocabulary: 1200-2000 Receptive vocabulary: 1200-2000 wordswords

4 years4 years Speak grammaticallySpeak grammatically

6 years6 years Receptive vocabulary: 14,000 wordsReceptive vocabulary: 14,000 words

Some Milestones in Language Development

What caused the rapid What caused the rapid vocabulary vocabulary development?development? Conceptual Development?Conceptual Development? Changes in Representations of Changes in Representations of

the Input?the Input?– What kinds of words are easily What kinds of words are easily

learned through observation?learned through observation?– What kinds of words rely on What kinds of words rely on

knowledge of words and syntax for knowledge of words and syntax for learning?learning?

Vocabulary Vocabulary CompositionComposition

Common Nouns

Predicates

Close Class

Perc

en

t of

Tota

l V

ocab

ula

ry 60

50

40

30

20

10

0

# of Words in Vocabulary

from Bates, E., Dale, P. S., & Thal, D. (1995).

Experiment: Limits of Experiment: Limits of ObservationObservation Question: Which words are easier Question: Which words are easier

to learn from observation? to learn from observation? To answer question: Gleitman & To answer question: Gleitman &

colleagues asked adult speakers colleagues asked adult speakers who are “cognitively mature” to who are “cognitively mature” to view SCENES of what mothers are view SCENES of what mothers are saying to their children and see saying to their children and see which words they could learn.which words they could learn.

Experiment with English SpeakersSnedeker, Gleitman, and Brent (1999)

Stimuli preparation1. Videotape English speaking mothers playing with their 18-24 month old children

2. Transcribe video tape for mothers’ 24 most frequent nouns and 24 most frequent verbs.

3. For each of the most frequent word, randomly select 6 uses of the word.

4. Edit each instance for 40 second clips. Audio was removed and a beep is sounded at instant word uttered.

Final Guess

On to Next Mystery Word

watch clip #6

watch clip #5

watch clip #4

watch clip #3

watch clip #2

watch clip #1

Subject’s Task: Identify the “mystery word” represented by the beep.

Guess word.

Guess word again.

Guess word again.

Guess word again.

Guess word again.

Guess word again.

Percent Correct Identification in English

Snedeker, Gleitman, and Brent (1999)

0%

5%

10%

15%

20%

25%

30%

35%

EnglishPer

cen

tag

e o

f C

orr

ect

Iden

tifi

cati

on

Noun Verb

Why nouns differ from Why nouns differ from verbs in ease of verbs in ease of acquisitionacquisition Nouns typically name objects and Nouns typically name objects and

Verbs typically name eventsVerbs typically name events Objects persist, events typically do notObjects persist, events typically do not Object concepts and event concepts Object concepts and event concepts

are organized differentlyare organized differently– Hierarchies for objectsHierarchies for objects– Dimensions for eventsDimensions for events– Leads to multiple salient categorizations Leads to multiple salient categorizations

for all event WITHIN a language (fewer for for all event WITHIN a language (fewer for object)object)

Dividing words up into Concreteness Categories English Experiment -- Snedeker, Gleitman, and Brent (1999)

* BLOC = Basic Level Object Category

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

24 Nouns vs. 24 Verbs 12 BLOCs vs. 12 Non-BLOCs

(Nouns)

13 Observables vs. 11 Unobservable

(Verbs)

Per

cen

tag

e o

f C

orr

ect

Iden

tifi

cati

on

NounVerb

24 Nouns

24 Verbs

*BLOCNon-BLOC

e.g. dog

e.g. thing

ObservableUnobservable

e.g. throw

e.g. think

Proposal for Proposal for Vocabulary Vocabulary DevelopmentDevelopment1. Scenes:1. Scenes:

– Child relies on situational context Child relies on situational context alonealone

– Can learn only very concrete words: Can learn only very concrete words: object labelsobject labels

Proposal for Proposal for Vocabulary Vocabulary DevelopmentDevelopment2. Nouns:2. Nouns:

– Object labels Object labels richer richer representation of linguistic contextrepresentation of linguistic context

– – Utterance = set of known nounsUtterance = set of known nouns– Child can learn concrete relational Child can learn concrete relational

words spatial prepositions many words spatial prepositions many verbsverbs

Hear 3 nouns (man, apple, you)….man…..GORP…apple….youVs.Hear 2 nouns (man, apple)….man…..GORP…apple

How knowing some How knowing some words will help words will help learning…learning…

Proposal for Proposal for Vocabulary Vocabulary DevelopmentDevelopment3. Syntactic Frames:3. Syntactic Frames: Learning relational words allows Learning relational words allows

the child learn the basic grammar the child learn the basic grammar of her languageof her language

Utterance is represented as a Utterance is represented as a syntactic structure + known wordssyntactic structure + known words

This representation allows the child This representation allows the child to learn more abstract wordsto learn more abstract words

Examples of words Examples of words learnedlearned by 12 months (scenes):by 12 months (scenes):

– mommy, bottle, telephone, cup, himommy, bottle, telephone, cup, hi by 20 months (nouns):by 20 months (nouns):

– go, sit, hug, hand, big, upgo, sit, hug, hand, big, up 30+ months (frames):30+ months (frames):

– by, around, listen, think, other,by, around, listen, think, other,

Snedeker & Gleitman (2002)Snedeker & Gleitman (2002)

Targets Targets – Videotaped interactions of 4 mother-child pairsVideotaped interactions of 4 mother-child pairs– 24 most common 24 most common verbsverbs chosen as targets chosen as targets– for each target 6 instances randomly selectedfor each target 6 instances randomly selected

Ss participated in one of 7 Information Ss participated in one of 7 Information ConditionsConditions– ScenesScenes– NounsNouns– FramesFrames– Scenes + NounsScenes + Nouns– Scenes + FramesScenes + Frames– Nouns + FramesNouns + Frames– Scenes + Nouns + FramesScenes + Nouns + Frames

Scenes ConditionScenes Condition

Final Guess

On to Next Mystery Verb

Etc….

Task: Subjects guess mystery verb from watching 6 instances of word use in video clips. The video clips are silent except beeps replace the moments the mystery word were uttered.

Example: “play”

beep

beep

Guess Word.

Guess Word Again.

Nouns ConditionNouns Condition

On to Next Mystery Verb

Example: “play”

Task: Subjects shown the nouns co-occurring with the mystery verb in 6 sentences, the same sentences as those in the video clips with the beeps.

Guess Word.

Guess Word Again.

Guess Word Again.

Guess Word Again.

Guess Word Again.

Final Guess

1. elephant, piano

2. mommy

3. I, it, you

4. it, you

5. drums

6. music, you

1. Can kax SIRN the bussit?

2. Noggle SIRN?

3. Can po SIRN while lo nirp nu?

4. Lo are gonna SIRN nu?

5. SIRN the neps.

6. Lo SIRN tuggy wilm.

Frames ConditionFrames Condition

On to Next Mystery Verb

Example: “play”

Task: Subjects guess the mystery verb from the 6 sentence frames. The sentence frames are constructed by replacing words in the 6 utterances with nonsense words.

Guess Word.

Guess Word Again.

Guess Word Again.

Guess Word Again.

Guess Word Again.

Final Guess

Correct Identification Correct Identification Varies with Information Varies with Information ConditionCondition

Nouns Scenes

Frames

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

% C

orr

ect

on

Fin

al

Tri

al

p < .05

Correct Identification Correct Identification Varies with Information Varies with Information ConditionCondition

Scenes

Scenes+Nouns

Full Info

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

% C

orr

ect

on

Fin

al

Tri

al

p < .05

p < .05

Correct Identification Correct Identification Varies with Information Varies with Information ConditionCondition

Nouns Scenes

Scenes+

Nouns

Frames

Scenes+

Frames

Nouns+

Frames

Full Info

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

% C

orr

ect

on

Fin

al

Tri

al

p < .05

p < .05

p < .05

Word LearningWord Learning

Children develop reasonable biases in how Children develop reasonable biases in how to interpret meanings of novel wordsto interpret meanings of novel words

– Development of these biases may be influenced Development of these biases may be influenced by naming practices of the target language by naming practices of the target language being learned being learned

They draw on various sources of They draw on various sources of information in learning word meaningsinformation in learning word meanings

– Social cuesSocial cues– Linguistic cuesLinguistic cues

State of the learner’s linguistic knowledge State of the learner’s linguistic knowledge will dictate sources of information recruitedwill dictate sources of information recruited