Lecture 10 30 Nov., 2005 Language Acquisition Helena Gao 1 2 Required readings: Tomasello, M. (2003). Constructing A Language. A Uage-Based Thoery of Language Acquisition. Harvard University Press. Chapter two: Origins of Language. pp. 8-42 Lee, T. H. (2002). Two types of logical structure in child language. Journal of Cognitive Science 3: 155-182. Pinker, S. (1994). The Language Instinct. New York: Morrow. Chapter 1: An instinct to acquire an art. pp. 15-24. Recommended readings: Pinker, S. (1995). Language acquisition. In L. R. Gleitman, M. Liberman, and D. N. Osherson (eds.), An invitation to cognitive science. 2nd Ed. Volume 1: Language. Cambridge, MA: MIT Press. Chapter 5: Why the child holded the baby rabbits: A case study in language acquisition. pp. 107-133. Gould, J. L., & Marler, P. (1987). Learning by Instinct. Reprinted as Chapter 7 in Wang, W. S.-Y. (ed.), (1991), The Emergence of Language: Development and Evolution; Readings from Scientific American Magazine, pp. 88-103. New York, NY: W.H. Freeman. Moskowitz, B. A. (1978). The Acquisition of Language. Reprinted as Chapter 10 in Wang, W. S.-Y. (ed.), (1991), The Emergence of Language: Development and Evolution; Readings from Scientific American Magazine, pp. 131-149. New York, NY: W.H. Freeman. 3 Language acquisition theories Two types of perspectives centered around “nurture” and “nature” distinction or on “empiricism” and “nativism”. Empiricism: all knowledge comes from experience, ultimately from our interaction with the environment through our reasoning or senses. Nativism: at least some knowledge is not acquired through interaction with the environment, but is genetically transmitted and innate. neither nurturists (environmentalists) disagree thoroughly with the nativist ideas nor do nativists with the nurturist ideas. 4 Usage Based Accounts – Theory of Language Acquisition Supported by recent research characterize children’s language in terms of cognitive and communicative processes involved children’s early language based on specific linguistic items and expressions they comprehend and produce Three processes involved: Imitative learning Finding patterns in language Combining linguistic constructions creatively 5 Tomasello’s View (2003) The human uses of symbols is primary, with the most likely evolutionary scenario being that the human species evolved skills enabling the use of linguistic symbols phylogenetically (p. 9) The human adaptation for symbolic communication emerges in human ontogeny quite predictably across cultures at around 1 year of age. It emerges in the context of a whole suite of new social-cognitive skills, the most important for language acquisition being the establishment of joint attentional frames, the understanding communicative intentions, and a particular type of cultural learning known as role reversal imitation. (p. 19) 6 Early skills of Intention-reading (1) The joint attentional frame (2) Understanding communicative intentions Joint attentional frames are defined intentionally, that is, they gain their identity and coherence from the child’s and the adult’s understandings of “what we are doing” in terms of the goal-directed activities in which we are engaged. (p. 22) Children understand adult communicative intentions, including those expressed in linguistic utterances, most readily inside the common ground established by joint attentional frames. (p. 24) (3) Cultural learning in the form of role reversal imitation Children who understand that other persons have intentional relations to the world, similar to their own, may attend especially carefully to the behavioral means that these persons have devised for meeting their goals, and so may imitate their intentional actions. (p. 26) 7 The development of grammar Behavioural theory Language acquired through learning (e.g., operant conditioning, imitation) Parents and teachers model grammatically correct language and provide feedback Evidence? 8 Theories of grammar development 1. Behavioural theory Evidence more contrary than supportive. Brown and Hanlon (1970) 3 findings Ungrammatical sentences rarely corrected Sentence corrected only if they are untrue Child:“Doggie bited daddy” Mother: “Yes, that’s right” Child (sees a car):“Dere’s a truck” Mother: “No, that’s a car” Ungrammatical requests as likely to be fulfilled as ungrammatical requests 9 Theories of grammar development 1. Behavioural theory Evidence more contrary than supportive. Imitation? Adults don’t use telegraphic speech Adults don’t over-regularize verbs 10 Theories of grammar development Nativist/linguistic perspective Acquisition of grammar too complex, too rapid to be the result of learning Poverty of the stimulus Chomsky: Language Acquisition Device Genetically-specified grammatical processor Recent evolutionary adaptation Evidence? 11 Theories of grammar development Cross-linguistic Languages of the world conform to a Universal Grammar (Chomsky) Genetic Grammatical impairments run in families (Pinker) Comparative Our closest evolutionary ancestors (Chimps) cannot learn grammar Dissociations Language and general intelligence dissociate in Williams Syndrome Developmental Grammar acquired effortlessly and systematically 12 Imitation - Research findings In early infancy there is some face-to-face dyadic mimicking of behaviors (Meltzoff & Moor, 1977) Meltzoff (1995) found 18-month-olds appeared to understand what the adult intended to do and performed the action instead of just mimicking the adult’s actual behavior. Aktar & Tomasello (1998a) investigated infants’ imitation of accidental actions vs. intentional actions. They found that 16month-olds mainly produced the adult’s intentional actions (there) but not the accidental ones (Woops!) 13 Meltzoff, A. N. & Moore, M.K (1977). Imitation of facial and manual gestures by human neonates. Science, 198. 75-78 2- to 3-day-old infants imitating (a) tongue protrusion, (b) mouth opening, and lip protrusion demonstrated by adult experimenters. gestures by human neonates. 14 Early Skills of Pattern-Finding Human infants are experts from early in development in finding visual patterns (Haith & Benson, 1997) Synthesized speech exposed to 8-month-olds (Saffran, Aslin, & Newport, 1996). Infants prefered to listen to the origial ones heard. Marcus et al. (1999) found that 7-month-olds preferred the speech stream containing the same tri-syllabic nonsense “words” that have the same pattern (e.g., bapopo) as they originally heard (e.g., wididi, delili) Gomez & Gerken (1999) found very similar results with 12month-olds. These results indicate that prelinguistic infants are able to find patterns in auditory stimuli of an abstract nature. (Tomasello, 2003: 30) 15 Universal pattern of language development complex grammar 2 word This suggests that language is acquired as a result of highly specialized biologically programmed mechanisms operating on the linguistic input. 1 word babble 6-10 mo 12 mo The same pattern is observed in every culture 18 mo 36 mo 16 Language Development: Stages and Rule Systems Brown’s (1973) Stages Mean Length of Utterance is a good index of child’s language maturity. Stages indicate growth of language complexity. Stage 1 - 12 to 26 months of Stage 2 - 27 to 30 months of Stage 3 - 31 to 34 months of Stage 4 - 35 to 40 months of Stage 5 - 41 to 46 months of age = MLU 1.00 to 2.00 age = MLU 2.00 to 2.50 age = MLU 2.50 to 3.00 age = MLU 3.00 to 3.75 age = MLU 3.75 to 4.50 17 Sensitive periods: Isolated children Genie was an isolated child… as an infant she was locked away and not spoken to. She was discovered by the authorities when aged 13. Though she acquired words, she never acquired correct grammar: 18 Isolated children (cont.) By contrast, Isabelle and her mute, brain-damaged mother escaped from the imprisonment of her grandfather when she was aged 6½. Within eighteen months, her language was not significantly behind the level expected at her age: 19 Language Exposure and Language Use Cameron-Faulkner, Lieven, and Tomasello (2003) examined 12 English-speaking mothers’ speech during samples of their linguistic interactions with their 2- to 3-year-old children 20 The overall findings: Children heard an estimated 5000 to 7000 utterances per day Between one-quarter and one-third of these were questions. More than 20% of these were not full adult sentences, but rather some kind of fragment (most often a noun phrase or prepositional phrase) About one-quarter of these were imperatives and utterances structured by the copula Only about 15% of these had the canonical English SVO form (i.e., transitive utterances of various kinds) supposedly characteristic of the English language; and over 80% of the SVOs had a pronoun subject. 21 The specific words and phrases with which mothers initiated utterances: Are you ..., I'll ..., It's ..., Can you ...., Here’s ...., Let's ..., Look at ..., What did ..., etc. 22 More than half of all maternal utterances began with one of 52 highly frequent item-based frames i.e., frames used more than an estimated 40 times per day for more than half the children. Mostly consisting of 2 words or morphemes. 23 More than 65% of all of the mothers’ utterances began with one of just 156 item-based frames. Approximately 45% of all maternal utterances began with one of just 17 lexemes: What (8.6%), That (5.3%), It (4.2%), You (3.1%), Are/Aren't (3.0%), Do/Does/Did/Don't (2.9%), I (2.9%), Is (2.3%), Shall (2.1%), A (1.7%), Can/Can't (1.7%), Where (1.6%), There (1.5%), Who (1.4%), Come (1.0%), Look (1.0%), and Let's (1.0%). Children used many of these same item-based frames in their speech, in some cases at a rate that correlated highly with their own mother's frequency of use. 24 Cameron-Faulkner, Lieven, & Tomasello (2003) What’s What’re What do What did What has What about What shall What can What does What hppnd What were What kind of .18 .09 .05 .04 .03 .03 .02 .02 .02 .01 .01 .01 Where’s Where’re Where shall .05 .02 .01 Who’s Who did .08 .01 Which one .02 Why don’t .01 How many .01 31 frames => 80% of Wh Qs 13 frames => 65% of Wh Qs 25 Early Gestures Human infants produce three main types of gestures: Reutilizations Deictic gestures Symbolic gestures Gestures run the gamut from non-symbolic to symbolic – and emerge along with the first linguistic skills – is strong evidence that children’s ability to communicate symbolically is not tied specially to language but rather emanates from a more fundamental set of social-cognitive skills (Tomasello & Camaiono, 1997) 26 Early Holophrases An important issue for later language development is what parts of adult expressions children choose for their initial holophrases. The answer presumably lies in the specific language they are learning and the kinds of discourse in which they participate with adults, including the perceptual salience of particular words and phrases in adults’ speech (Slobin, 1985) 27 Early Holophrases – language specific In English, most beginning language learners acquire a number of so-called relational words such as more, gone, up, down, on and off, presumably because adults use these words in salient ways to talk about salient event s (Blom, Tinker, and Margulis, 1993; McCune, 1992) Many of these words are verb particles in adult English and so the child at some point must learn to talk about the same events with phrasal verbs such as pick up, get down, put on, and take off. In Korean and Mandarin Chinese, in contrast, children learn fully adult verbs from the onset f language development because these verbs are most salient in adult speech to them (parallel to an English verb like remove for clothing: Choi & Gonpnik, 1996: Gopnik & Choi, 1995; Tardif, 1996) 28 Thomas Lee’s data (2002) Mandarin-speaking children’s Sensitivity to quantifier type and thematic roles in their understanding of inverse scope for sentences. Suggestion Young children (about 4yeasrs of age) are sensitive to constraints of the conceptual-intentional system on quantifier scope interpretation 29 Phonological development Systematic age-related changes in the ability to perceive and produce the elementary sounds of language. 30 Phonological development Categorical phoneme perception at 1 month Vowel discrimination at 2 months Loss of the ability to discriminate non-native phonemes by the end of the 1st year 31 Phonological development 6-8 weeks cooing (vowel-like sounds with consonant produced by closure of the back of the mouth (e.g., “g” or “k”) Later, comes to include consonants produced by closure of the front of the mouth (e.g., “m” or “b”) 32 Phonological development 3 to 6 months Emergence of babbling, the production of consonant-vowel combinations like “da” and “ba” Reduplicated babbling Repetition of C-V combinations 9 to 10 months More complex combinations 33 Phonological development Interesting babbling facts Cross-linguistic consistency in the timing of the onset of cooing and babbling, although some cross-linguistic differences in the sounds produced Deaf infants babble in the first months of life 34 Learning words Evidence of word-comprehension @ 6 months (Tincoff & Juszyck, 1999) . By 6, children understand over 5,000 different words. 20 new words a week for 5 years!!! 35 Learning words Words learning begins during mother-infant interaction. Best when child focussed on object, and mother labels it. Association formed. How does child know what the word refers to? 36 Learning words What are the words that infants first learn? Nelson (1973) First words name objects (65%), or actions (14%). Do infants’ first words have the same meaning they do for adults? 37 Learning words No: Often different from adult meanings. Overextensions. Meaning of a word overgeneralized. "Dog" for any animal with 4 legs. Underextensions. Meaning of a word too constrained. Car refers only to child’s father’s car. 38 Learning words Most frequently used words? Goplink (1982) Longitudinal, home-observation study. Before 24 months, children most frequently use words that provide commentary on their ongoing activity. "Gone", "there", "oh dear", "down". 39 Early word comprehension 7-8 months olds. Typical early understood words: mummy, daddy, clock, drink, teddy (Harris, et al., 1995) Acquire 5 to 10 words a day from about 15th month through the 6th year of life (Gleitman and Cleitman, 1992) Vocabulary spurt: total number of words grow fairly steadily until 12 months of age, when there will typically be a sharp increase in vocabulary Average number of words understood by boys and firls bet. 8 and 16 months 40 of age (Fenson et al. 1994. p. 74) The development of grammar Telegraphic Speech Examples (Brown, 1973) (1) Agent-action: "Tommy hit" (2) Action-object: "Give cookie" (3) Possessor-possession: "My car" (4) Questions: “Where daddy?” 41 The development of grammar 1. Telegraphic Speech Is telegraphic speech grammatical? Braine, 1976 Pivot grammar [Pivot word + open word] “e.g., More ________” Bloom, 1990 No wild grammars (e.g., “Big he”) Gross violations rare (e.g., “Daddy eat” vs “Eat daddy”) 42 The development of grammar 2. Inflectional morphology Rules governing the use of morphemes like inflections (e.g., -s, -ed that alter the, -ing) syntactical function of specific words E.g., Past tense Acquired in a regular sequence Not all past tenses formed through use of the [stem +“ed”] rule (E.g., Run/Ran) How do children learn the exceptions? 43 The development of grammar 3. Irregular past-tense Rules governing the use of morphemes like inflections (e.g., -s, -ed that alter the, -ing) syntactical function of specific words Developmental U-shaped curve 44 The development of grammar 100 Proportion correct 3. Irregular past-tense Developmental U-shaped curve 90 Developmental U-shaped curve 80 70 60 50 40 30 1 2 3 4 Time 5 6 45 The development of grammar 3. Irregular past-tense Developmental U-shaped curve Irregular form learned first. “Ran” Then over-regularization occurs. “Runned” Finally, irregular forms reappear. “Ran” Why does this occur? 46 The development of grammar 3. Irregular past-tense Competing mechanisms Irregulars first learned through association. Then, children learn the past-tense rule. Over-applied. Must re-learn the exceptions. 47 Theories of Cognitive and Language Development: Piaget, Vygotsky and Bruner Comparisons and Contrasts 48 Outline Brief review of Piaget’s theory The role of culture - implications for Piaget’s theory The theory of Vygotsky The theory of Bruner 49 Summary of Piaget Stage theory of development - older children think qualitatively differently to younger children 4 stages: Stage 1: Sensorimoter Period (0-2 years) Stage 2: Pre-operational stage (2-7 years) Stage 3: Concrete Operational Stage (7-11 years) Stage 4: Formal Operational Stage (11+ years) Development is the combined result of: maturation of the brain and nervous system experiences that help children adapt to new environments adaption: an organism’s ability to fit in with it’s environment. 50 Alternative to Piaget 1: Lev Vygotsky 1896 - 1934 Work remained little known because it was banned by Stalin after Vygotsky’s death Collapse of the Soviet Union meant: greater dialogue between the West and Russia Vygotsky’s work translated into English 51 Vygotsky’s Theory: The role of culture/social interaction Sociocultural environment ALL IMPORTANT for cognitive development Different contexts create different forms of development Cognitive processes (language, thought, reasoning) develop THROUGH social interaction Development is a product of CULTURE Vygotsky emphasised the role of: social interaction instruction 52 Central idea Zone of Proximal Development (ZPD): the difference between the level of actual development and potential development 53 Example from Seifert, Hoffnung & Hoffnung Parent: Here are four books for you and the same for your brother Child: The same? (He investigates his brother’s pile of books.) No, he has more (spoken with annoyance). Parent: No, really, they’re the same. Take another look. Child: He does have more. Parent:Try laying his out in a row. Then lay yours out too. Then compare Child:(Does as suggested) One two three four . One two three four. The same! (He looks satisfied) 54 Summary of the role of social interaction 1. Confirm existing knowledge 2. Add new information Instruction most effective when: it builds on previous knowledge and skills (e.g. counting) it provides a ‘sensible’ challenge - there’s no point pushing children beyond their potential 55 Vygotsky’s theory: The role of language Piaget’s view: language is just another representational system. Underdeveloped until 6 to 7 years of age Vygotsky’s view: language is social and communicative. Essential for cognitive development. Why did Vygotsky think this? Private speech - children talk to themselves 56 Vygotsky suggested: adults give instructions to children (social speech) children start to use parent’s instructions to direct their own behaviour (private speech) private speech becomes internalised as thought processes (silent statements) Children use this ‘internalised’ speech to plan and organise behaviour => cognitive development 57 Summary of Vygotsky Culture and social interaction very important in cognitive development Social interaction with knowledgeable others moves development forward - ZPD Language is central to cognitive development: social speech => private speech => thought 58 Alternative to Piaget 2: Jerome Bruner Very influenced by Piaget’s and Vygotsky’s work Responsible for introducing Vygotsky’s work to the non-Soviet world 59 Bruner’s Theory: Similarities with Piaget Socio-Cognitive Stage Theory: Enactive Mode Iconic Mode Symbolic Mode Abstract thinking develops out of concrete thinking 60 Bruner’s Theory: Similarities with Vygotsky Interpersonal communication necessary for development - socio -cognitive theory Development relies on active intervention of expert others: SCAFFOLDING Contingency Rule (Wood, 1980) 61 Bruner’s Theory: The role of language Language is important: without language, thought is limited language forms the basis of understanding: prelinguistic thought - games and rituals rituals gradually replaced as adult adds information rituals replaced by linguistic modes of communication 62 Summary of Bruner Socio-cognitive stage theory Based on interaction with adults Relies on adults developing reciprocal behaviour with the child 63 Overall Conclusion Piaget underestimated the importance of culture and social interaction Vygotsky: social interaction and language necessary for cognitive development Bruner: Stage theory but emphasised role of social interaction and language 64 Akhtar (1999) & Abbot-Smith et al. (2001) Weird Word Order English-speaking children hear utterances with “weird word order” (familiar and unfamiliar verbs) “The cow the horse is meeking/pushing” (SOV) They are encouraged to use these same verbs with new characters engaging in these same actions 65 AKHTAR (1999) & ABBOT-SMITH et al. (2001) Percentage of mean number of utterances which were mismatches, as a function of condition and age group 100 90 80 70 60 Ungrammatical Familiar Verb Ungrammatical Novel Grammatical Novel 50 40 30 20 10 0 2;4 (AbbotSmith et al) 2;8 (Akhtar) 3;6 (AbbotSmith et al) 3;9 (AbbotSmith et al) 4;4 (Akhtar) 66 Golinkoff et al. 1987 * * “look! cookie monster’s tickling big bird” “look! big bird’s tickling cookie monster” see also Naigles (1990), Fisher (2000) 67 Childers & Tomasello (2001) Developmental Psychology Children at 2:6 hear several hundred transitive utterances over 4 days/sessions • Either familiar or unfamiliar English verbs • With either nouns only in slots or nouns & pronouns (consistent) Test is traditional nonce verb learning • child hears nonce verb as intransitive or passive and must produce in transitive 68 Number of children in each condition (out of 10) who produced at least one productive utterance with at least one nonce verb during testing 9 8 7 6 5 4 3 2 1 0 Nouns Pronouns Familiar Unfamiliar Verb Verb Control 20% = same as in previous studies 69 Diessel & Tomasello, Cognitive Linguistics (2001) Development of Matrix Clauses Age Sarah >2;11 Adam I think [2;11] (2) 3;0-3;11 I think [3;1] (26) (Do) you think [3;7] (2) I think (7) Do you think [3;3] (4) Does he think [3;3] (3) You don’t think [3;5] (1) What do you think [3;5] (1) I don’t think [3;8] (2) 4;0-5;0 I think (42) I think (99) Do you think (3) Do you think (5) I thought [4;1] (7) I don’t think (2) I’m thinking [4;2] (1) Why do you think (2) They think [4;3] (1) What do you think (1) What do you think [4;4] (1) One think [4;6] (1) I don’t think [4;8] (2) Paul think [4;10] (1) I’ll think [4;10] (1) 70