CHILD LANGUAGE ACQUISITION

1. CHILD LANGUAGE ACQUISITION Group 5 07305037 Shitanshu Verma 07305086 Rajeshwar G 07305905 Girija Limaye 07305913 Apoorv Sharma

2. MOTIVATION

3. QUESTIONS • When does a child starts listening ? • If child is left alone with a deaf mother will it learn ? • Akbar’s experiment • If we try to make a chimp available to all the inputs will it learn ? • Obvious no, but what makes humans unique • You must have observed • For a child a dog is any four legged animal • For a child a city is just the home he knows in the city • Child never misplaces • Do you know: • Children don’t like when we talk to them in motherese • Children understand more phones than adults

4. IF WE UNDERSTAND THE PROCESS • Fields it will benefit • Psycholinguistics • Neural Networks • Psychology • Statistics • Get insight into brains of humans • Compare with other animals • Understand the mental representation • Why a seminar in NLP course? • teach the machines the same way TILL NOW IT IS UNEXPLAINED

5. IN THIS PRESENTATION • Broad coverage of various aspects of child language acquisition studies • Observations • Theories • Scope and Roadmap • Fundamentals • Human’s special affinity to language • Stages of child language acquisition • Theories explaining CLA • We would not talk (much) about • Specific theories explaining individual stages • Eg. Motor Theory Account

6. Basics and Biological Human Adaptation

7. LANGUAGE • Language • Grammar • Vocabulary • Recursive • Animals communicate • Have sounds • Special meanings to sounds • Unique to humans • Seems it is innate to humans • Seems !

8. CHILD LANGUAGE ?

9. INNATENESS – BIOLOGICAL DEVELOPMENT • The infant's vocal tract resembles that of a chimpanzee! • Indistinct oral and pharyngeal cavities • The soft palate (velum) reaches the epiglottis • This facilitates breathing through the nose while suckling • By three months the larynx descends into the pharynx • Allows greater range of speech sounds • Increases the risk of choking

10. BRAIN – DEVELOPMENT AND SUPPORT TO LANGUAGE • Linguistic capability require • Minimum levels of brain size • Long-distance connections • Extra synapse • These are developed highly during first few years in children • Infant body is very plastic • Left hemisphere surrounding the Sylvian fissure, that appears to be designed for language • High cognitive capabilities • Sound and speech : Use broad pitch and rhythm efficiently

11. STAGES OF CHILD LANGUAGE ACQUISITION Observing a child grow 

12. WAY WE CAN STUDY • Various aspects and ways • Perception development • Speech development • Focus on phonological development • Focus on meaning understanding development • Focus on grammar development • Individual studies on them • We will be doing a mixture of these

13. PRE-BABBLING(VERY YOUNG)‏ • Pre-equipped to head phonetic contrasts • even for languages not spoken around them • later become insensitive • At 10 to 12 months • Seem to be discovering phonemes • Infants can distinguish between /p/ and /b/ at three or four months

14. 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

15. PERCEIVING PHONEMIC DISTINCTIONS Differences between the sounds of different languages • Both Hindi and English: /ba/ vs. /da/ • 6-8 month-old babies and adults could discriminate • Hindi, not English, easy /Ta/ vs. /ta/ • 6-8 month-old babies could discriminate. • Adults could not initially but could after 25 trials of training. • Hindi, not English, /th/vs. /dh/ • 6-8 month-old babies could discriminate. • Adults could not, and never learned • Babies can discriminate the sounds of all the world’s languages and adults cannot

16. Perceptive Development • They show high cognitive abilities • Children can discriminate between • Human 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

17. RECOGNIZING AND REMEMBERING WORDS • 6 to 7.5 months • learn to identify familiar words in context • 7.5 months • English-learners can identify words with strong-weak stress patterns • 10.5 months • Can identify words with weak-strong patterns • Common words are remembered more

18. Recognizing and Remembering Words • Nouns before verbs • Content verbs before auxiliary verbs • Meanings are over generalize or under generalized • City name • only the house they visit in city • Dog • Any four legged animal • The ends of words learned more quickly • -nana for banana.  • true even in language where the stress in always on the first syllable.

19. HOLOPHRASTIC (1 YEAR)‏ • Utter their first word as early as nine months • Mama • dada  (these words resemble babbling)‏ • Often the words are simplified • "du" for duck • "ba" for bottle  • First words of children are common throughout the planet • food, body parts, water, toys, mama, etc • then routine words used in social interaction • yes, no, want, bye-bye, hi

20. TWO-WORD STAGE(18 MONTHS-2 YEARS) • Sentences are of limited meaning • ownership-- Daddy's shoes • describing events-- Me fall • labelling-- That dog • vocational relations-- toy in box • Children design pivot grammars • Prefer certain words - pivotal (axis) words • Use different words with the pivots to create phrases

21. LEARNING THAT ELEMENTS ARE ORDERED • Infants • Rarely scramble the order of words. • Hear more to their mother tongue • Elder babies could find distance dependency • The boy, who I like, is here today • Sensitive to the statistical properties of what they hear • Develops before and during infancy

22. 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.

23. FURTHER DEVELOPMENT(AFTER 18 MONTHS) • Begins to form longer utterances • Lack grammatical correctness but the meaning is conveyed • Some examples • dirty hand wash it • car sleeping bed = the car was now parked in the garage • Inflection is learnt by the age of 3 • Look for phrases to built upon the rules of the language • The sentences become more lengthy and grammatically complex afterwards

24. EXPLAINING CHILD LANGUAGE ACQUISITION Theories on Child Language Acquisition

25. THEORY – CLASSIFICATION • On basis of principles • Nature • brain has innate propensity for CLA • Nurture • CLA is general cognitive ability • no specific biological evolution • None is fully in opposition to other • Which is dominant factor

26. THEORY – UNIVERSALLY ACCEPTED FACTS • The basic ability to acquire language is innate to the child • Needs external trigger • Akbar’s experiment • Intelligence is not related with L1A • No specific structural property of language has yet been proven to be innate

27. THEORY – OPEN ISSUES • None explains all the observations • Is it modularity of brain? • Is it native to brain? • note difference between nativism and modularity • L1 competency is better than L2 competency • L2 acquisition at different extent

28. Some Popular Theories • Cognitive • Imitation and positive reinforcement • Innateness • and others like Motherese

29. COGNITIVE THEORY • Nurture • No special part of brain promotes LA • Introduced by Piaget • Language acquired attributed to • general intellectual development • Process • acquires concepts • concept -> word mapping • natural cognitive development

30. COGNITIVE THEORY • Suggests • simpler ideas learnt earlier • irrespective of grammatical complexity • Explains • order of certain aspects of LA • Does not explain • Why languages emerge? • Cognitively found in animals, but they don't acquire language • Studies: Despite abnormal mental development, children speak fluently

31. Inputs to Child Language Acquisition • Positive Evidence • information available for correct grammatical structures • Negative Evidence • information available for incorrect grammatical structures • Motherese • modified language used by parents • Prosody • Melody, timing and stress • Context • Learns only with help of context • Never learn from radio or television

32. IMITATION AND POSITIVE REINFORCEMENT • By imitating adults and repeating what they hear • Limitations: • Based on observations • Unanswered: • Mistakes: indicate application of rules, not just imitation (intelligent mistakes)‏ • Feedback • Governed by Truth value rather than syntax

33. POVERTY OF THE STIMULUS • Claim • Grammar is unlearn able given the linguistic data available to children. • Premises • Limited input signals received • The degenerate nature: • frequent incorrect usage, utterances of partial sentences • Patterns that cannot be learned using positive evidence alone. • Conclusion • Child must have some form of innate linguistic capacity.

34. INNATENESS • Innate capabilities of language learning • Language Acquisition Device • assumed to have Syntactic structures • They only learn words • Explains intelligent mistakes (with LAD) • Limitations • Only focus is on grammar • Syntactic structures: Language dependent, Innate?? • Explaining LAD?

35. LANGUAGE ACQUISITION DEVICE • Supposed to be an Organ of brain • Intractable complexity of language acquisition • Assumed Components • technique for representing input signals • a way of representing structural information about them • some initial delimitation of the class of possible language structure hypotheses • a method for determining meaning of hypotheses for each sentence

36. LANGUAGE ACQUISITION DEVICE • Steps • Input signals --> structural information • Checks the compatibility of input with the hypothesis • Checks the compatibility using knowledge of implications for each hypothesis • One hypothesis or ‘grammar’ is selected as being compatible with the input signals. • This grammar provides the device with a method of interpreting sentences

37. 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

38. 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