Transcript Emergentist Approaches to Language
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
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Emergentism
• Not: empiricism vs. nativism • Instead: emergentism vs. stipulationism Emergentism 16
Emergence vs stipulation
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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
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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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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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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
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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 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
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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.
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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.
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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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MacWhinney, B. (1978). The acquisition of morphophonology. , 179-212.
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Farkas, I., & Li, P. (2001). Modeling the development of lexicon with a growing self-organizing map. , 3-30.
NIPS
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Li, P., & MacWhinney, B. (1996). Cryptotype, overgeneralization, and competition: A connectionist model of the
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, Whole no. 1, pp. 1-123.
MacWhinney, B. (1993a). Connections and symbols: Closing the gap.
Early Cognition and the Transition to Language The emergence of language Cognition, 29
, 121-157.
Journal of Memory and Language, 28
Miikkulainen, R. (1993). In B. MacWhinney (Ed.), , 255-277.
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