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

Brian MacWhinney- CMU EmergentismE 1

The Special Gift Paradigm

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Grammar Gene Speech is Special Modularity Critical Period* Poverty of the Stimulus* Sudden Evolution of Language* Centrality of Recursion* Emergentism 2

Genetic Locus?

Emergentism 3

Cortical Module?

Emergentism 4

Hard-wired modules?

Emergentism 5

Speech is Special?

Emergentism 6

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 Emergentism 7

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 Emergentism 8

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 Emergentism 9

Stipulation and the Gift

• • • Rules have been the backbone of descriptive linguistics Rules can be stipulated Children learn rules - Brown, Marcus, Pinker Emergentism 10

Big Mean Rules

Emergentism 11

Big Mean Flowcharts

Emergentism 12

Changing theories …

• • • • Rules are softening Evolution is stretching out Modularity is getting plastic Genome is becoming exaptive Emergentism 13

Kinder, gentler rules

• • • Pinker (1984)  add -ed Aslin, Newport, Saffran (1999)  golabu, pitaku Marcus’s (2000) baby rules  S -> A + B +A

ga-ti-ga ga-na-ga ga-gi-ga ga-la-ga li-na-li li-ti-li li-gi-li li-la-li ni-gi-ni ni-ti-ni ni-na-ni ni-la-ni ta-la-ta ta-ti-ta ta-na-ta ta-gi-ta

Emergentism 14

But …

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

Core: X-bar, Merge, recursion

Periphery

Emergentism 15

Emergentism

• Not:  empiricism vs. nativism • Instead:  emergentism vs. stipulationism Emergentism 16

Emergence vs stipulation

Emergentism 17

Emergent structure in Honeycombs

Emergentism 18

Emergent Columns

Emergence of Oriented On-Off Neurons Emergentism 19

Emergent Computation

Emergentism 20

Physical emergence Closures inhibit voicing

Many languages lack /b/, few lack /p/ time 0 time 1 time 2 Emergentism 21

Entrainment - Huygens

Emergentism 22

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) Emergentism 23

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 Emergentism 24

Dissipative Systems

Emergentism 25

Catalysis

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Deformation

Emergentism 27

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?

Emergentism 28

Mechanisms of Emergence

• • • • • • • • Entrainment, physical and social Adaptation, selection Competition, strength Hebbian learning, reinforcement Topology, short connections Self-organized criticality, catalysis Resonance Deformation, induction, regulation Emergentism 29

Why now?

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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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Emergentism 30

Sources of emergence

• Brain: Neural networks, short connections, area histology, spike propagation • Body: Embodied cognition, the vocal apparatus • Society: Discourse, roles, theory of mind Emergentism 31

Time-frames of Emergence

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Archaeogenetic Phylogenetic Embryological Developmental Online Diachronic Emergentism 32

The Emergence of Language Lawrence Erlbaum Associates, 1999 Elman, J. et al (1996) Rethinking Innateness MIT Press Books Emergentism 33

Examples

1. Morphological paradigms 2. From lexicon to syntax 3. Mutual exclusivity 4. Perspective flow Emergentism 34

1. Neural Networks for Morphology

units connections activations weights learning rule Emergentism 35

Summing activation

z1 z2 z3 y 1 .54

x1 .22

x2 y 2 x3 Emergentism 36

Neurons don’t send Morse code

Emergentism 37

Memory molecules?

Worm Runners Digest Training, grinding, feeding planaria Emergentism 38

The architecture

OUTPUT UNITS der die das des dem den •  •  •  •   •  • INPUT UNITS 10 case units number units Emergentism 17 case cues 11 phono 39

Networks work

• • It worked -- it learned the input It generalized as in German and English • It matched the developmental data Emergentism 40

With Limitations

The homophony problem ringed -- rang -- wrung The masquerading morpheme problem -chen -en

in

Nacken, Hafen vs -en in Wissen The “underwent” problem Mutter

should guarantee

die Grossmutter The zero derivation problem schlagen

should predict

der Schlag The early

“

went” problem

Emergentism 41

2. The answer

• Morphological learning must emerge from a lexical base • Therefore, we first have to simulate the learning of the lexicon Emergentism 42

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

Word Form

Phonological Self-organization

Word Meaning

Co-occurrence-based representation (derived from separate component exposed to bilingual corpus) Self-organization Phonological Map

ENGLISH PHONOLOGY CHINESE PHONOLOGY

Chinese Phonology ASSOCIATIVE CONNECTIONS (Hebbian learning) Chinese Semantics

ENGLISH SEMANTICS

Semantic Map

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 LY balanced L1 Successive Bilingualism L2 dominates

Parasitism and Transfer

C L1 turtle L2 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

Pimsleur 67

Neural Basis

Wittenburg et al. 2002

Optimization really helps

Chinese Resonance

Consolidation Circuits

Dynamic Sound Meaning Consolidation Hippo campus Scaffold Basal Ganglia

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)

Example 4: Perspective and grammar

• • • Animal cognition is modular (bees) Perspective integrates across modules Language expresses perspective and changes in perspective 60 Emergentism

Perspective

unified image language as a functional neural circuit perspective direct experience perspective deixis EmergentismE perspective plans perspective roles 61

The dorsal and the ventral paths

enactive depictive Emergentism 62

Mirror neurons -- Rizzolatti

E grabs M grabs E with pliers M grabs Emergentism 63

Monkey grabbing in the dark

Emergentism 64

SS: OS: OO: SO:

Perspective shift

(MacWhinney y Pléh (1987)

The dog that chased the cat bit the horse.

# cambio 0 1 The dog chased the cat that bit the horse.

The dog chased the cat the horse bit.

The dog the cat chased bit the horse.

SS > OS = OO > SO The dog the cat the boy liked chased snarled.

(dog -> cat -> boy -> cat -> dog) 1+ 2 4+ Emergentism 65

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.

Emergentism 66

Constructions that mark perspective

Passive

shift

Adverbalization Double Object Inverse Obviative Fictive agent Conflation Comparative Complementation Binding Dislocation Clefting Topicalización Possessive Ellipsis 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 Emergentism 68

Getting it wrong

QuickTime™ and a Motion JPEG A decompressor are needed to see this picture.

Emergentism 69

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.

Emergentism 71

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