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The Emergence of Language (from Brain, Body, and Discourse)The Emergence of Language (from Brain, Body, and Discourse)

Brian MacWhinney- CMU

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The Special Gift Paradigm

1. Grammar Gene2. Speech is Special3. Modularity4. Critical Period*5. Poverty of the Stimulus*6. Sudden Evolution of Language*7. Centrality of Recursion*

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Genetic Locus?

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Cortical Module?

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Hard-wired modules?Hard-wired modules?Hard-wired modules?Hard-wired modules?

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Speech is Special?

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Sudden evolution?

• 7 MYA bipedalism• 4 MYA tools, opposing thumb• 3 MYA parietal expansion, TOM• 1.5 MYA general cortical expansion

• .3 MYA expanding pulmonic support• .1 MYA glottal control• 30,000 creativity explosion

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Expiration of the Special Gift

• Wild children are neurologically impaired

• Newport and Johnson show no point of sudden loss

• Recovery of language at 13 after hemispherectomy -- Vargha-Khadem

• L2 age effects not unique to language learning-- ballet, golf, even math

• Entrenchment account of L2

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Logical Problem?

• Mothers speak grammatically - Newport

• Degree-0 learnability - Lightfoot

• Competition provides the negative evidence - MacWhinney

• Error-free learning doesn’t occur - Pullum

• The Stimulus isn’t impoverished after all

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Stipulation and the Gift

• Rules have been the backbone of descriptive linguistics

• Rules can be stipulated• Children learn rules - Brown, Marcus, Pinker

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Big Mean Rules

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Big Mean Flowcharts

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Changing theories …

• Rules are softening• Evolution is stretching out• Modularity is getting plastic• Genome is becoming exaptive

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Kinder, gentler rules

• Pinker (1984) add -ed

• Aslin, Newport, Saffran (1999) golabu, pitaku

• Marcus’s (2000) baby rules S -> A + B +A

ga-ti-gaga-ti-gaga-na-gaga-na-gaga-gi-gaga-gi-gaga-la-gaga-la-gali-na-lili-na-lili-ti-lili-ti-lili-gi-lili-gi-lili-la-lili-la-lini-gi-nini-gi-nini-ti-nini-ti-nini-na-nini-na-nini-la-nini-la-nita-la-tata-la-tata-ti-tata-ti-tata-na-tata-na-tata-gi-tata-gi-ta

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But …

Core: X-bar, Merge,

recursion

Periphery

Lexicon, dialect, collocation, pragmatics, function, ….

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Emergentism

• Not: empiricism vs. nativism

• Instead: emergentism vs. stipulationism

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Emergence vs stipulationEmergence vs stipulation

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Emergent structure in Honeycombs

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Emergent Columns

Emergence of Oriented On-Off Neurons

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Emergent Computation

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Physical emergenceClosures inhibit voicing

Many languages lack /b/, few lack /p/

time 0 time 1 time 2

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Entrainment - Huygens

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Jaw entrains the glottis

Lip-smacking rhythms (Macneilage & Davis, 2001)

Thelen & Iverson, 1998 - jaw entrains glottis

Hippocampal timers (Buzsáki 2004)

Conversational synchrony (Wilson & Wilson 2005)

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Babbling entrains gesture

• Iverson, Thelen• Central role of rhythm• Babbling and gesture both arise from Broca’s area

• McNeill’s theory of growing points with gesture at the root of thought

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Dissipative Systems

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Catalysis

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Deformation

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Emergentist theory asks:

• How did a structure emerge?• Under what time-frame did it emerge?

• What dynamic processes are involved?

• How stable is the structure?• How does removal of supports alter the emergence?

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• Entrainment, physical and social• Adaptation, selection• Competition, strength• Hebbian learning, reinforcement• Topology, short connections• Self-organized criticality, catalysis

• Resonance• Deformation, induction, regulation

Mechanisms of Emergence

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Why now?

Without advanced methods, emergentist cognitive science was not possible

• We didn’t have CHILDES, TalkBank• Audio, video analysis was primitive - TalkBank

• 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.

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Sources of emergence

• Brain: Neural networks, short connections, area histology, spike propagation

• Body: Embodied cognition, the vocal apparatus

• Society: Discourse, roles, theory of mind

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Time-frames of EmergenceTime-frames of Emergence

1. Archaeogenetic2. Phylogenetic3. Embryological4. Developmental5. Online6. Diachronic

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The Emergence of Language

Lawrence Erlbaum Associates, 1999

Elman, J. et al (1996)

Rethinking Innateness

MIT Press

Books

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Examples

1. Morphological paradigms2. From lexicon to syntax3. Mutual exclusivity4. Perspective flow

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1. Neural Networks for Morphology

units

weights

learning rule

activations

connections

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Summing activation

x1 x2 x3

y1

z1 z2 z3

y2

.54

.22

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Neurons don’t send Morse code

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Memory molecules?

Worm Runners Digest

Training, grinding, feeding planaria

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The architecture

INPUT UNITS

OUTPUT UNITS

168 Left-justified 143 phonological 5 semantic

200 hidden20 gendernumber units

200 hidden7 units

der die das des dem den

17 case cues 11 phono

10 case units

•  •  •  •   •  •

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Networks work

• It worked -- it learned the input

• It generalized as in German and English

• It matched the developmental data

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With Limitations

The homophony problemringed -- rang -- wrung

The masquerading morpheme problem-chen-en in Nacken, Hafen vs -en in Wissen

The “underwent” problemMutter should guarantee die Grossmutter

The zero derivation problem

schlagen should predict der Schlag

The early “went” problem

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2. The answer

• Morphological learning must emerge from a lexical base

• Therefore, we first have to simulate the learning of the lexicon

Self-organizing lexical maps

Li, Farkas, MacWhinney - Neural network - computer simulation - L1 lexical learning - CHILDES input - no initial organization - short connections

Gradual Emergence

50, 150, 250, 500 words

DevLex Model

Bilingual self-organization

ENGLISH SEMANTICS

CHCHINESE SEMANTICS

CHINESE PHONOLOGY

ENGLISH PHONOLOGY

ASSOCIATIVE CONNECTIONS (Hebbian learning)

Self-organization

Self-organization

Word Form

Phonological

Word Meaning

Co-occurrence-based representation(derived from separate component exposed to

bilingual corpus)

Phonological Map

Semantic Map

ChineseSemantics

Chinese Phonology

Refining competition

Maps implement entrenchment

• Strong items dominate over weak.

• Late L2 items are parasitic on pre-existing L1 forms and maps

Module Entrenchment

Simultaneous Bilingualism

LX LYbalanced

dominatesL1 L2

Successive Bilingualism

Parasitism and Transfer

C

L2L1

turtle tortuga

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

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

5. Emergence from Resonance

• Graduated interval recall• Multimodal consolidation • Self-organized criticality

Graduated interval recall

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Neural Basis

Wittenburg et al. 2002

Optimization really helps

Chinese Resonance

Consolidation Circuits

Sound Meaning

Basal Ganglia

Hippo

campus

Dynamic

Scaffold

Consolidation

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.

• They are sensitive to: one-trial learning (amygdalal input) local episodic learning (hippocampal input) embodied learning (self-motion) statistical learning (basal ganglia, circuits) strategic resonant learning (frontal input)

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Example 4: Perspective and grammar

• Animal cognition is modular (bees)

• Perspective integrates across modules

• Language expresses perspective and changes in perspective

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Perspective

direct experience

deixis rolesplans

perspective perspectiveperspective perspective

language as a functional neural circuit

unified image

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The dorsal and the ventral paths

The dorsal and the ventral paths

enactive

depictive

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Mirror neurons -- Rizzolatti

Mirror neurons -- Rizzolatti

E grabs M grabs E with pliers M grabs

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Monkey grabbing in the dark

Monkey grabbing in the dark

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Perspective shift(MacWhinney y Pléh (1987)Perspective shift(MacWhinney y Pléh (1987)

# cambioSS: The dog that chased the cat bit the horse.

0

OS: The dog chased the cat that bit the horse. 1-

OO: The dog chased the cat the horse bit. 1+

SO: The dog the cat chased bit the horse. 2

SS > OS = OO > SOThe dog the cat the boy liked chased snarled. 4+

(dog -> cat -> boy -> cat -> dog)

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Ambiguity and perspective flow

• John saw the Grand Canyon flying to New York.• The women discussed the dogs on the beach. • Although John always runs, a mile seems like a

long distance to him.

• I ordered her pancakes.• Visiting relatives can be a nuisance.• The horse raced past the barn fell.

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Constructions that mark perspective shift

Passive AdverbalizationDouble Object BindingInverseDislocation

Obviative CleftingFictive agentTopicalización

Conflation PossessiveComparative EllipsisComplementation Coordination ….

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Other sample topics: the emergence of X from Y

• CV syllable from lip-smacking• Final devoicing from syllable structure

• Ergativity from subject omission

• Locatives from body parts• Superordinates from most frequent subordinates

• Use of Broca’s for ASL

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Getting it wrong

QuickTime™ and aMotion JPEG A decompressor

are needed to see this picture.

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Falsifiability of Emergentism?

• Core claim : all processes arise from dynamic interactions

• Core claim: Language arises from external pressures

• Conceptualization cannot be falsified, but specific implementations can.

• Specific implementations must be described mechanistically. This is really difficult.

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Summary

• Emergentism vs. Stipulationism• Emergence on five time-frames• Emergence from Brain, Body, and Society

• Four examples: morphology, syntax, ME, perspective

• Emergentist accounts can be wrong.• But emergentism cannot be falsified, it can only be implemented. This is really difficult.

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Elman, J. (1990). Finding structure in time. Cognitive Science, 14, 179-212.Elman, J. L. (1999). The emergence of language: A conspiracy theory. In B. MacWhinney (Ed.), The emergence of language (pp. 1-28). Mahwah, NJ: Lawrence Erlbaum Associates.Farkas, I., & Li, P. (2001). Modeling the development of lexicon with a growing self-organizing map. NIPS.Li, P., & MacWhinney, B. (1996). Cryptotype, overgeneralization, and competition: A connectionist model of the learning of English reversive prefixes. Connection Science, 8, 3-30.MacWhinney, B. (1977). Starting points. Language, 53, 152-168.MacWhinney, B. (1978). The acquisition of morphophonology. Monographs of the Society for Research in Child Development, 43, Whole no. 1, pp. 1-123.MacWhinney, B. (1993a). Connections and symbols: Closing the gap. Cognition, 49, 291-296.MacWhinney, B. (1993b). Is there a logical problem of language acquisition? In C. Smith (Ed.), Early Cognition and the Transition to Language. Austin, TX: University of Texas Press.MacWhinney, B. (1999). The emergence of language from embodiment. In B. MacWhinney (Ed.), The emergence of language (pp. 213-256). Mahwah, NJ: Lawrence Erlbaum.MacWhinney, B. (2000). Lexicalist connectionism. In P. Broeder & J. Murre (Eds.), Models of language acquisition: Inductive and deductive approaches (pp. 9-32). Cambridge, MA: MIT Press.MacWhinney, B., & Leinbach, J. (1991). Implementations are not conceptualizations: Revising the verb learning model. Cognition, 29, 121-157.MacWhinney, B. J., Leinbach, J., Taraban, R., & McDonald, J. L. (1989). Language learning: Cues or rules? Journal of Memory and Language, 28, 255-277.Miikkulainen, R. (1993). Subsymbolic natural language processing. Cambridge, MA: MIT Press.Miikkulainen, R., & Mayberry, M. R. (1999). Disambiguation and grammar as emergent soft constraints. In B. MacWhinney (Ed.), The emergence of language (pp. 153-176). Mahwah, NJ: Lawrence Erlbaum Associates.Rumelhart, D. E., & McClelland, J. L. (1986). On learning the past tense of English verbs. In J. L. McClelland & D. E. Rumelhart (Eds.), Parallel distributed processing: Explorations in the microstructure of cognition (pp. 216-271). Cambridge: MIT Press.