CHILD LANGUAGE ACQUISITION

Group 5 07305037 Shitanshu Verma

07305086 Rajeshwar G07305905 Girija Limaye07305913 Apoorv Sharma

MOTIVATION

QUESTIONS

When does a child starts listening ?If child is left alone with a deaf mother will it learn ?

oAkbar’s experimentIf we try to make a chimp available to all the inputs

will it learn ?oObvious no, but what makes humans unique

You must have observedoFor a child a dog is any four legged animaloFor a child a city is just the home he knows in the

cityoChild never misplaces

Do you know:oChildren don’t like when we talk to them in

mothereseoChildren understand more phones than adults

IF WE UNDERSTAND THE PROCESSFields it will benefit

o Psycholinguisticso Neural Networkso Psychologyo Statistics

Get insight into brains of humans Compare with other animalsUnderstand the mental representation

Why a seminar in NLP course?o teach the machines the same way

TILL NOW IT IS UNEXPLAINED

IN THIS PRESENTATION

Broad coverage of various aspects of child language acquisition studieso Observationso Theories

Scope and Roadmapo Fundamentalso Human’s special affinity to languageo Stages of child language acquisitiono Theories explaining CLA

We would not talk (much) abouto Specific theories explaining individual stages

Eg. Motor Theory Account

Basics and Biological Human Adaptation

LANGUAGE

Languageo Grammar o Vocabularyo Recursive

Animals communicateo Have soundso Special meanings to soundso Unique to humans

Seems it is innate to humanso Seems !

CHILD LANGUAGE ?

INNATENESS – BIOLOGICAL DEVELOPMENT

The infant's vocal tract resembles that of a chimpanzee!

o Indistinct oral and pharyngeal cavitieso The soft palate (velum) reaches the epiglottis

This facilitates breathing through the nose while suckling

o By three months the larynx descends into the pharynxo Allows greater range of speech sounds o Increases the risk of choking

BRAIN – DEVELOPMENT AND SUPPORT TO LANGUAGE

Linguistic capability requireo Minimum levels of brain sizeo Long-distance connectionso Extra synapseo These are developed highly during first few years

in childreno Infant body is very plastic

Left hemisphere surrounding the Sylvian fissure, that appears to be designed for language

High cognitive capabilitieso Sound and speech : Use broad pitch and rhythm

efficiently

STAGES OF CHILD LANGUAGE ACQUISITION Observing a child grow

WAY WE CAN STUDY

Various aspects and wayso Perception developmento Speech development

o Focus on phonological developmento Focus on meaning understanding developmento Focus on grammar developmento Individual studies on them

We will be doing a mixture of these

PRE-BABBLING(VERY YOUNG)

Pre-equipped to head phonetic contrastso even for languages not spoken around them

later become insensitiveo At 10 to 12 monthso Seem to be discovering phonemes

Infants can distinguish between /p/ and /b/ at three or four months

BABBLING(4-6 MONTHS)

Using indiscriminate utterance of speech sounds

Utterances may be other than native language

Very few consonant clusters Repeated syllables are common

PERCEIVING PHONEMIC DISTINCTIONS

Differences between the sounds of different languages

Both Hindi and English: /ba/ vs. /da/o 6-8 month-old babies and adults could discriminate

Hindi, not English, easy /Ta/ vs. /ta/o 6-8 month-old babies could discriminate.o Adults could not initially but could after 25 trials of training.

Hindi, not English, /th/ vs. /dh/o 6-8 month-old babies could discriminate.o Adults could not, and never learned

Babies can discriminate the sounds of all the world’s languages and adults cannot

Perceptive Development

They show high cognitive abilities

Children can discriminate betweenHuman speech from other sounds and prefer to

listen to it

Their mother’s voice and other adult women’s voice

Infant directed speech from Adult directed speech

Mother Tongue from Other language

RECOGNIZING AND REMEMBERING WORDS

6 to 7.5 monthsolearn to identify familiar words in context

7.5 monthsoEnglish-learners can identify words with strong-weak stress patterns

10.5 monthso Can identify words with weak-strong patterns

Common words are remembered more

Recognizing and Remembering Words

Nouns before verbsContent verbs before auxiliary verbsMeanings are over generalize or under

generalizedo City name

oonly the house they visit in cityo Dog

oAny four legged animalThe ends of words learned more quicklyo -nana for banana. o true even in language where the stress in

always on the first syllable.

HOLOPHRASTIC (1 YEAR)

Utter their first word as early as nine monthso Mamao dada  (these words resemble babbling)

Often the words are simplifiedo "du" for ducko "ba" for bottle 

First words of children are common throughout the planeto food, body parts, water, toys, mama, etco then routine words used in social interaction

yes, no, want, bye-bye, hi

TWO-WORD STAGE(18 MONTHS-2 YEARS)

Sentences are of limited meaningo ownership-- Daddy's shoeso describing events-- Me fallo labelling-- That dogo vocational relations-- toy in box

Children design pivot grammarso Prefer certain words - pivotal (axis) wordso Use different words with the pivots to create

phrases

LEARNING THAT ELEMENTS ARE ORDERED

InfantsoRarely scramble the order of words.oHear more to their mother tongueoElder babies could find distance dependency

The boy, who I like, is here todayoSensitive to the statistical properties of what they hear

Develops before and during infancy

DOES THIS MEAN THAT BABIES ‘KNOW’ GRAMMAR ‘INNATELY’?

Younger babies could not do this, though some experiments found that they could do a related but much simpler task at 7 months

Babies are sensitive to the statistical properties of what they hear and these sensitivities are developing before and during infancy.

FURTHER DEVELOPMENT(AFTER 18 MONTHS)

Begins to form longer utterancesLack grammatical correctness but the

meaning is conveyed Some examples

o dirty hand wash ito car sleeping bed = the car was now parked in

the garageInflection is learnt by the age of 3 Look for phrases to built upon the rules of the

languageThe sentences become more lengthy and

grammatically complex afterwards

EXPLAINING CHILD LANGUAGE ACQUISITION

Theories on Child Language Acquisition

THEORY – CLASSIFICATION

On basis of principleso Nature

brain has innate propensity for CLAo Nurture

CLA is general cognitive abilityno specific biological evolution

o None is fully in opposition to otheroWhich is dominant factor

THEORY – UNIVERSALLY ACCEPTED FACTS

The basic ability to acquire language is innate to the childo Needs external trigger

Akbar’s experimentIntelligence is not related with L1ANo specific structural property of language

has yet been proven to be innate

THEORY – OPEN ISSUES

None explains all the observationsIs it modularity of brain?Is it native to brain?

note difference between nativism and modularity

L1 competency is better than L2 competencyL2 acquisition at different extent

Some Popular Theories

CognitiveImitation and positive reinforcementInnatenessand others like Motherese

COGNITIVE THEORY

Nurtureo No special part of brain promotes LA

Introduced by Piaget

Language acquired attributed too general intellectual development

Processo acquires concepts

o concept -> word mappingnatural cognitive development

COGNITIVE THEORY

Suggestso simpler ideas learnt earlier

o irrespective of grammatical complexity

Explainso order of certain aspects of LA

Does not explaino Why languages emerge?

Cognitively found in animals, but they don't acquire language

o Studies: Despite abnormal mental development, children speak fluently

Inputs to Child Language Acquisition

Positive Evidenceoinformation available for correct grammatical structures

Negative Evidenceoinformation available for incorrect grammatical structures

Mothereseomodified language used by parents

ProsodyoMelody, timing and stress

ContextoLearns only with help of contextoNever learn from radio or television

IMITATION AND POSITIVE REINFORCEMENT

By imitating adults and repeating what they hear

Limitations:o Based on observations

Unanswered:o Mistakes: indicate application of rules, not just

imitation (intelligent mistakes)o Feedback

Governed by Truth value rather than syntax

POVERTY OF THE STIMULUS

Claimo Grammar is unlearn able given the linguistic data

available to children.Premises

o Limited input signals receivedo The degenerate nature:

frequent incorrect usage, utterances of partial sentences

o Patterns that cannot be learned using positive evidence alone.

Conclusiono Child must have some form of innate linguistic

capacity.

INNATENESS

Innate capabilities of language learningo Language Acquisition Device

assumed to have Syntactic structures

o They only learn wordsExplains intelligent mistakes (with LAD)Limitations

o Only focus is on grammaro Syntactic structures: Language dependent,

Innate??o Explaining LAD?

LANGUAGE ACQUISITION DEVICE

Supposed to be an Organ of brainIntractable complexity of language

acquisitionAssumed Components

o technique for representing input signalso a way of representing structural information

about themo some initial delimitation of the class of possible

language structure hypotheseso a method for determining meaning of

hypotheses for each sentence

LANGUAGE ACQUISITION DEVICE

Stepso Input signals --> structural informationo Checks the compatibility of input with the

hypothesiso Checks the compatibility using knowledge

of implications for each hypothesiso One hypothesis or ‘grammar’ is selected

as being compatible with the input signals.o This grammar provides the device with a

method of interpreting sentences

Conclusion

Humans do have a better biological evolved body for language

Certain traits such as sound processing are innate to infants

Children learn language remarkably fast Interesting patterns are present in child

language acquisition process Various theories have been proposed

None explains all Nature vs Nurture is the prime issue

References

www.wikipedia.org Language Acquisition, Steve Pinker, Draft

version pandora.cii.wwu.edu Language Acquisition, Elena Lieven, School of

Psychological Sciences,University of Manchester

Language Acquisition, Michel Frank