A Unified Model for L1 and L2 Brian MacWhinney HKIEd, Carnegie Mellon Unified Model Thanks to ... • • • • • • • • • • • • • • Elizabeth Bates Csaba Pléh Julia Evans Ping Li Yoshinori Sasaki Reinhold Kliegl Vera Kempe Elena Pizzuto Roman Taraban Yuki Yoshimura Chris Jones Yvan Rose Nora Presson Yanhui Zhang • NIMH (25 years) Michèle Kail Klaus Köpcke Natasha Tokowicz Igor Farkas Richard Wong Jeff Sokolov Janet McDonald Stan Smith Patricia Brooks Melita Kovacevic Jared Leinbach Kees De Bot Yanping Dong Sue-mei Wu Kerry Kilborn Maryellen MacDonald Ovid Tzeng Arturo Hernandez Antonella Devescovi Beverly Wulfeck Hasan Taman Dan Slobin Zhou Jing Joe Stemberger Christophe Parisse Phil Pavlik Anat Prior NSF (10 years) MacArthur (3 years) Unified Model Economic Assumptions • Competence in English is crucial for success in the global economy. • But most of the population of the world does not speak English as L1. So English is L2. Other L2s have parallel roles. • It is not enough to restrict L2 competence to the elite, since work is becoming increasingly based on language skills. • Different social and economic configurations will require differing levels of L2 competence. Unified Model Position 1: Early Immersion • There is a Critical Period for language learning. • There is a learning/acquisition dichotomy. Late bilinguals can never achieve full L2 competence. • Therefore, we must start immersion L2 programs at the pre-primary level. • And spend billions of dollars in exposure, but not really teaching. Unified Model Position 2: Focus on community • There is a Critical Period and a learning/acquisition dichotomy. • However, immersion will not work and can conflict with other goals in early childhood education. • Pre-college education should be in the native language. • Full bilingualism is only possible if the community becomes bilingual. Unified Model Position 3: Focus on quality • There is no critical period for second language learning, although there are important age effects. • Critical period effects are due to entrenchment and competition. • What is important is not the timing of learning, but the quality of exposure. • We may still need billions of dollars, but in teaching, not just exposure. • Languages can be learnt and taught. There is no real learning/acquisition dichotomy. Unified Model The Positions • Position 1 -- UG: Chomsky, Lenneberg, Krashen, Long, Hurford, Pinker, Newport, Meisel • Position 2 -- Sociolinguistics: Fishman, Swain, Ervin-Tripp, Gumperz • Position 3 -- Emergentism: Bates, Ellis, Bialystok, Snow, MacWhinney, Ringbom Unified Model 7 Pillars of UG 1. Critical Period -- today’s focus 2. Grammar Gene 3. Speech is Special 4. Modularity 5. Poverty of the Stimulus 6. Sudden Evolution of Language 7. Centrality of Recursion Unified Model 7 pillars of emergentism 1. 2. 3. 4. 5. 6. 7. L1-L2 competition and entrenchment Gradual evolution Modules are made not born Polygenic emergent genome Speech relies on mammalian abilities Learning on input Emergence of recursion Unified Model Which will stand? Unified Model Entrenchment vs. Critical Periods • • • • • • • Critical Periods are linked to infancy. Observed drop is not precipitous. Lateralization is not linked to CP. Language is not a unitary ability. Golf, ballet are also age-related. No mechanism has been discovered. UG-related syntactic patterns are not strongly fossilized - Birdsong Unified Model Critical Periods • Bee dance, cricket song • Does the ability need a trigger? • When does it start and end? Unified Model 12 L1 CP≠ L2 CP L’enfant Sauvage by François Truffaut Truffaut as Dr. Jean Itard Unified Model 13 How many CPs? • • • • • • • • 6 mos -- deaf children 2 -- Early bilingual impacts 5 -- Output phonology Flege 8 -- Korean adoptees, literacy, orthography 13 -- Hemispherectomies, synaptic pruning 15 -- Shift in learning, growth of strategies 20 -- Beginning of decline 40 -- Social difficulties Unified Model 14 Where is the critical drop? • Newport & Johnson Unified Model Hakuta actual 15 A real CP - Hubel & Weisel PERCENT L EFT VISUAL CORTEX CELLS RESPONDING TO CLOSED RIGHT EYE (Norm al > 5 0%) Age at e ye c losu re (d ays ) Du ratio n (d ays) 0 3 6 9 21 27 30 31 65 90 120 480 10 23 30 60 120 180 Ad u lt 84 32 0 0 26 14 19 12 10 59 15 53 70 Unified Model 16 What we know • Critical periods are basic to embryology. • Critical periods for binocular vision in cats; periods for exposure to song in birds; precocial bird attachment; • Animals have many instincts; but is language an instinct? • Kuhl and Werker: brain locks in on early sounds • Bosch, Juszyck: Auditory system builds early contrasts • Rosenzweig rats in rich environments get bigger brains. Unified Model 17 A bridge too far • • • • • • No evidence for early brain effects Mozart for babies Linda Acredolo and Baby Signs Mobiles, language while you sleep Suzuki method There is nothing wrong with early L2 learning, but no evidence that it is indispensable • Early bilingualism ≠ Early L2 learning Unified Model 18 CP for holding pens? Unified Model Chopsticks? Unified Model Multiple language abilities • Bulgarian grad student who wrote at the top of the class, but had a noticeable accent. • Hungarian diplomat with perfect English, but nothing to say. • Japanese grad student with perfect interaction and comprehension, but impossible definite articles and slow test-taking. • Fossilization for specific German nouns vs. fossilization for some past tenses. Unified Model How can we decide? • Neurological evidence for a Critical Period • Immigrant studies Proof of success in native acquisition for age of arrival well past the Critical Period. Proof of failure after some early age of arrival. • L2 Classroom studies Big correlational analyses (questionable method) Randomized clinical trials (if we could get funding) Microgenetic method studies (my current preference) experiments -- can we teach r/l? online methods TalkBank video methods Unified Model Mechanisms of UG • Genes • Modules • Principles, Parameters, Rules Unified Model Mechanisms of Emergence • • • • • • • Entrainment, physical and social Adaptation, selection Competition, strength, reinforcement Maps, topology, short connections Self-organized criticality Resonance Homeostasis, homeorhesis, feedback Unified Model Why the shift to emergentism? • Without advanced methods, emergentist cognitive science was not possible • We didn’t have CHILDES, TalkBank • Audio, video analysis was primitive • We couldn’t simulate - PDP, SOM, ART • We couldn’t image the brain - ERP, fMRI • We couldn’t study learning in vivo - PSLC. • With these advances, emergentism is becoming the default stance. Unified Model Unified Competition Model maps transfer chunking buffers resonance competition codes mental models Unified Model L1 and L2 • The learning goals are the same. • The available mental processes are the same. • However, the specific challenges are different. Unified Model 27 L1 Learning Challenges • • • • Segmenting out words Organizing phonological gestures Bootstrapping syntax Conversational sequencing Unified Model 28 L2 Challenges • Maximizing positive transfer • Avoiding negative transfer • Overcoming age effects Using resonance to overcome entrenchment Proceduralizing declarative structures Ullman/Paradis Unified Model 29 Component Theories 1. Competition 2. 3. 4. 5. 6. 7. 8. interactive activation, Bayes Maps SOM, entrenchment Transfer A relation between maps Chunking chunking theory, fluency Buffers processing load, CAPS Resonance memory theory, Pimsleur, coding Mental model perspective, embodiment Codes sociolinguistics, identification Unified Model 1. Cue Competition • Whodunit? The tiger pushes the bear. The bear the tiger pushes. Pushes the tiger the bear. The dogs the eraser push. The dogs the eraser pushes. The cat push the dogs. Il gatto spingono i cani. Unified Model Cues vary across languages • English: The pig loves the farmer SV > VO > Agreement • German: Das Schwein liebt den Bauer. Den Bauer liebt das Schwein Case > Agreement > Animacy>Word Order • Spanish: El cerdo quiere al campesino. Al campesino le quiere el cerdo. "Case" > Agreement > Clitic > Animacy > Word Order Unified Model Cues Device Example Word Order the dog chases the cat Function words der - die - das Affixes was tak-en Clitics nous, le, ba Constructions the more -- the merrier Unified Model Central Claim •Cue validity predicts cue strength •(Bayesian statistics) [p(function)|form] - comprehension [p(form)|function] - production Cue validity measured in corpora Cue strength measured in experiments Unified Model Cues Compete The bear the tigers chases. “Tigers”-as-Agent preverbal position competes “Bear”-as-Agent SV agreement Unified Model Initial Position L1/L2 Competition I often go ... / Je vais souvent ... V + Adv Adv + V competes speaking English: speaking French: ADV 1st Unified Model ADV 2nd Heavy Adv Strength measured in experiments Unified Model English Children Unified Model Hungarian Children Unified Model Italian Children Unified Model English L1, Dutch L2 Dissertations by Janet McDonald and Kerry Kilborn Unified Model Dutch L1, English L2 Unified Model Findings - 22 studies • Validity predicts Strength. • Children and L2 learners pick up frequent cues first, then they settle on reliable cues. • For timed tasks, strong fast cues dominate. • L2 learners attempt transfer, but then learn cues, as in L1. They gradually reach L1 levels of cue strength. Unified Model 2. Maps • • Maps are central to the processing theory. They control transfer, entrenchment, and embodied encoding. Maps are emergent: - Neural systems: Jacobs & Jordan 1992 - Children: Karmiloff-Smith 1997 - Robots: Nolfi 1996, Tani 2002 Unified Model Self-organizing lexical maps Li, Farkas, MacWhinney - Neural network - computer simulation - L1 lexical learning - CHILDES input - no initial organization - short connections Unified Model Gradual Emergence 50, 150, 250, 500 words Unified Model Refining competition Unified Model Bilingual self-organization Word Form Phonological Map Phonological ENGLISH PHONOLOGY Self-organization CHINESE PHONOLOGY Chinese Phonology ASSOCIATIVE CONNECTIONS (Hebbian learning) Word Meaning Co-occurrence-based representation (derived from separate component exposed to bilingual corpus) Self-organization CHCHINESE SEMANTICS Chinese Semantics ENGLISH SEMANTICS Semantic Map Unified Model Maps implement entrenchment • Strong items dominate over weak. • Late L2 items are parasitic on pre-existing L1 forms and maps Unified Model Module Entrenchment Simultaneous Bilingualism LX LY balanced Successive Bilingualism L1 L2 dominates Unified Model 3. Transfer • Mapability Item-based (want X) patterns will not transfer Grammatical semantics can be a difficult map Phonology, semantics, pragmatics all map and transfer • Markedness Unmarked pattern-based will: Adv + V Marked pattern-based is weak: Adv + V + S Semantic/phonological prototypes transfer • Filtering Japanese r/l second formant transitions. English learners of tones. Unified Model Examples • • • • taco -> t’aco wenn (if) -> when tell me a story -> say me a story install a new version -> install new version Unified Model The Culprits • • • • • • Entrenchment Transfer (crosstalk) Learning your own errors Strategy blockage Social culprits Aging Unified Model Social Culprits • Overcommitment too much email, too many committees • Declining L2 contact environment • Avoidance of L2 input • Allegiance to L1 Unified Model Aging • • • • • • Loss of Auditory Acuity - age effects Loss of Motor Control - Parkinsonism Cell death -- both cortical and white matter Declining transmission speed Declining hippocampal storage Trauma Unified Model Fighting back 1. 2. 3. 4. Undoing transfer Unblocking social barriers Unblocking strategy barriers Increasing differentiation and resonance Unified Model Overcoming Parasitism C L1 turtle C L2 L1 tortuga turtle Unified Model L2 tortuga ERP evidence of transfer - P600 • The cat likes to eat. vs The cat likes to eating. P z P600 5 V Plausible (eat) Implausible (eating) 200 400 600 800 Osterhout & Nicol (1999) Unified Model L1 supports L2 Su abuela cocina/*cocinando muy bien. Her aunt cooks/*cooking very well. Unified Model L1 (English) blocks attention El/los libros son muy interestantes. The/the books are very interesting. Unified Model L2 cares, L1 oblivious Ellos fueron a una/*un fiesta. They went to a/a party. Unified Model Behavioral Data Unified Model 4. Chunking •Task: Repeat 坐公共汽車去 •Learn: gōnggòngqìchē “bus” 公共汽車 Syllables plus tone encodings fill working memory Chunk: gōnggòng is linked to “public” Chunk: qìchē is linked to “motor car” Supportive links to characters Compound is a weak chunk, weak tone sequence Embed weak chunk in “sit ___ go” frame 坐 (公共汽車) 去 Unified Model Translation Disfluency • Do you want to take a bus to Nanjing next week? • Nǐ xiǎng xià ge xīngqī zuò gōnggòngqìchē qù Nánjīng ma? • Chinese requires temporal before verb. • About to say: Nǐ xiǎng zuò • • • • Pause …. Insert “xià ge xīngqī” Continue Result: Non-fluency Unified Model Chunks mesh into slots • • • sit + (vehicle slot) + go (adverb slot) + V (topic slot) + comment • Fluent plan emerges from coordination of individual item-based patterns Unified Model PSLC studies of Fluency • • Online Dictation -- French, Chinese Yuki Yoshimura’s CMU dissertation on Fluency in Japanese L2 - sentence repetition after reading and listening. Unified Model Repetition and WM Comparison between read -aloud and production time Complexity = complex Comparison between read -aloud and production time Complexity = simple 16 read-aloud production 16 14 Length of utterance (sec) Length of utterance (sec) 14 12 12 10 10 8 6 4 2 0 read-aloud production 4 6 8 10 8 6 4 2 0 Sentence Length 4 6 8 Sentence Length Unified Model 10 Omissions Error Analysis by type complexity = complex 1 Number of errors in production omis s ion 0.8 retrace 0.6 grammatic al e rror 0.4 s ubs titution 0.2 addition 0 4 6 8 Sentence Length Unified Model 10 Adding Novel Words Effect of novel words Listening group x Reading group 16000 Listening Length of utterance (ms) Reading 14000 12000 10000 8000 6000 zero 1 2 Number of novel words in each sentence Unified Model Friederici • German Natives show for semantic violations: N400 for syntactic violations: ELAN & P600 • L2 Russian natives - 5 years in Germany for semantic violations: N400 for syntactic violations: no ELAN, but P600 • Brocanto and mini-Nihongo Learners: ELAN and P600 • fMRI Conclusion: L1 and L2 use same areas, but L2 relies more on Broca’s Unified Model 5. Buffers • Competition occurs in buffers • Incrementalism, role-slot filling • This is developed in MacWhinney (1987) Kempen & Hoenkamp (1987) Levelt (1990) O’Grady (2006) Unified Model 71 6. Resonance • Graduated interval recall • Multimodal consolidation • Self-organized criticality Unified Model Graduated interval recall •Pimsleur 67 Unified Model Neural Basis Wittenburg et al. 2002 Unified Model Consolidation Circuits Dynamic Meaning Sound Consolidation Hippo campus Basal Ganglia Scaffold Unified Model Chinese Resonance Unified Model Consolidation and Time • Bones, muscles, cell walls, mitochondria, and immune system becomes stronger after periods of use and breakage. • These systems respond to pressures across time frames. (slow muscles, fast muscles) • Neurons work the same way. Unified Model Math Models: Pavlik 2006 t=time from practice d=decay rate n=number of presentations m=memory activation a=base decay rate c=scales effect of activation on decay u=maximal study benefit v=rise to asymptote speed Unified Model Four Pools • Pool 1 – item is strong, then wait • Pool 2 – item is weak enough to make practice efficient but strong enough to make drilling more efficient • Pool 3 – item is weak and retrieval will fail, so study practice is more efficient • Pool 4 – unpracticed items • Algorithm selects items in this order: 2, 3, 4, 1 • Learned items are removed from pools Unified Model Optimization really helps Unified Model 7. Mental models • • • • We build up mental models through perspective-taking. Comprehensible input -- L2 speaker can construct a coherent mental model. L2 conversation-based teaching has to make sure the mental model is on track. Frames, scaffolds, can support this. Unified Model 8. Codes • Code-switching • L2 is a code choice • Codes involve perspective taking in mental models • Role of video in learning, identification Unified Model 82 The Unified Model • • • • • • • Competition is central. Both L1 and L2 are emergent. Item-based constructions compete in L1 and L2 learning. Transfer arises from entrenchment in maps. Fluency develops through chunk meshing. Resonance and spacing produce robust learning. Conversation supports perspective switching and model construction. Unified Model Conclusions • • • • The Unified Model integrates our understanding of first and second language acquisition. Language learning relies on emergentist processes. Language can be taught and learned. Age-related effects arise from entrenchment and social commitment, not UG. Unified Model Links • http://psyling.psy.cmu.edu/papers • http://psyling.psy.cmu.edu/talks Unified Model 85 Aphasics - Word Order Unified Model Aphasics - Agreement Unified Model
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