collaborative commentary - macwhinney 1 the sudden evolution of language? -- pillar #6 brian...

Collaborative Commentary - MacWhinney1

The Sudden Evolution of Language? -- Pillar #6

Brian MacWhinney Psychology

Carnegie Mellon


The Seven Pillars of UG

1. Grammar Gene2. Speech is Special3. Language Organ and Modularity4. Critical Periods5. Poverty of the Stimulus6. Sudden Evolution of Language7. Recursion - LND


Data Sources

1. Direct Evidence• Genetics• Fossils, reconstructions, comparative physiology• Settlement patterns, habitat range• Tools, artifacts, art• Climactic changes - glaciation, eruptions

2. Indirect Evidence Human ontogeny, language acquisition Neurology Linguistics -- function, gesture, phonology, recursion Evolutionary Psychology All of the above across other primates and other

species


Core Issues

• Saltation vs. Coevolution• Developing an account that is consistent with the

observed data• Recent focus by Hauser, Chomsky, Fitch on

recursion as the core of language• Can we use this account to predict new findings

and results in: Comparative behavior Comparative neurology Fossils, tools, settlement, genetics Evolutionary Neural Networks Evolutionary Psychology


Lessons from Child Language

Language learning involves linking a series of abilities Audition Segmentation Imitation Articulation, Timing Attention Lexicon Combination Recursion ….


Lessons from Functional PsychoLinguistics

• Language is grounded on cognition in Direct perception Space/Time/Aspect deixis Causal Roles Social Roles

• Each level is organized by perspective• Incremental processing starts from

embodied core -- McNeill• Compilation relies on item-based patterns

and recursion


Lessons from Evolutionary Theory

• Adaptations must lead to individual reproductive advantage

• Group advantages are secondary• Advantages can be linked to

disadvantages (sickle cell, autism)• Populations are dynamic• Changes are gradual and emergent -

but this is still debated


Skill Network

• Each attainment builds on previous ones.• Each relies on abilities that are found in a

more limited form in our primate cousins.• Each ability can in turn be decomposed

into subcomponents.• Given this, simple saltation is impossible.• However, some key changes could foster

productive co-evolution of the network.• What forces could support continued

progress?


Continued Support

• The shift to bipedalism continued across three million years.

• The role of the freed hands changed over time, but was a continuing drive.

• Social forces exerted continual pressure.

• Social forces combined with the role of the hands.


A Grounded Social Climber

• As a bipedal, man is like the kangaroo.• Unlike the kangaroo, hominids were

climbers who used their hands.• The hands were then used to control

tools, but …• Forced into face to face contact, the

hands could also contribute to social interaction.


Proto-Mimesis

• Bipedalism opens up face-to-face contact

• The hands operate in the contact area

• This produces proto-mimesis (Zlatev) with pointing and teaching

• Vocalization locks in attention


Partial Differences

• Some ape lexical learning, but incomplete

• Some ape planning abilities (Goodall straws), but incomplete

• Some ape intersubjectivity, but incomplete

• Some ape pointing, but incomplete


Sharper Changes

• Cortical control of vocalization• Duality of patterning - Recursion?• Brain expansion• Physical changes

Articulation - teeth, mouth Phonation - vocal cords, bent vocal tract Thumb Posture, parturition, neotony


Problems with Saltationism

• Only deals with the last 100,000 years, not the last 6 million years

• Ignores 300% increase in brain size• Ignores many morphological changes• Ignores homo erectus expansion.• Fails to deal with gesture• Fails to deal with skill network• Etc…


Five Periods

• Bipedalism 7-4 MYA• Social Cohesion 4-2 MYA• Mimesis 2-.2 MYA• Phonology 300,000 - 50,000• Creativity 50,000 - now


Cognitive Attainments

• Bipedalism Basic imagery, tool use, spatial recursion

• Social Cohesion Cortical control of vocal-auditory channel

• Mimesis Gestural item-based pattern, prosody

• Phonology Phonemic system, phonological loop

• Creativity Item-based, perspective


1. Bipedalism

• Coppens East Side Story 10-7 MYA• Jungle -> savannah (lakes?)

Handedness and affordances for arboreal Deixis for terrestrial

• Tool use and locomotion (primary)• Communication (secondary)• Groups needed for protection against

predators


Neuronal Support

• Parietal reorganization at 4MYA- Holloway Body image projection Navigation and deixis Spatial images support recursion Facial recognition (supramarginal)

• Tools, navigation, social cohesion


2. Social Cohesion

• Expansion at 4MYA, contraction at 3.5MYA• Habilis/ergaster vs. australopithecus• Competition was won by the most

cohesive and planful groups Good social partners Sexual arms race Dominance vs. external aggression Role of dialect marking Dunbar, Power, Worden social accounts


Cortical Control of Vocalization

• Primate system links Arousal (amygdala, brainstem) Motivation (basal ganglion) Memory (limbic, hippocampus)

• The primate external striatum was absorbed by the neocortex, giving cortical control

• Control is now from the supplementary motor and anterior cingulate


3. Mimesis

• Parallel evolution The gestural channel contained the content The vocal channel contained the social glue

• Disorganized nature of mimetic processes• Inefficient gestalt encoding• Mechanisms:

Imitation Pointing Joint attention (Intersubjectivity) Perspective-taking


Monkey See, Monkey Do

• Whiten 2003 Patteson 1978


Early Gestalts

• Mimetic patterns do not separate verbs and nouns

• Me-hand-grab-axe-up-swing-down-cut-chips-sound

• This can be imitated as a Gestalt, but Gestalt storage is expensive

• I chop wood.


Satisfied Preconditions

• Hands were free• Hands were controlled by complex plans• Spatial maps had evolved for self and group• The visual system could generate and store

images• Visual images encoded hierarchically and

open to recursion• Vocalization and eye-gaze controlled

attention in face-to-face interaction


Neuronal Support

• Tripling in brain size (some allometric)• Earlier growth was in specific areas

Parietal Cortical control of vocal channel

• New pressures Need for full simulation of the body for mimesis Storage of mimetic sequences Processing of mimetic operators Teaching of mimetic sequences by mothers Perspective-switching


How successful?

• Expansion to all of Eurasia• At the expense of other hominids• Big, unorganized brain• No vocal systematization• Climate changes of the Pleistocene

led to new pressures


4. Phonology

• Phonological patterning MacNeilage and vocal gesture Gupta and MacWhinney and the phonological

loop

• Making efficient use of lexical storage• Capitalizes on evolution in TOM and

perspective


Vocal Adaptations

• Lower larynx and hence larger (and distinct) pharynx

• Longer local cords (at least in adult males)• Aerodynamical streamlined conus elasticus

(underside of vocal cords• Expanded neuronal control of intercostals at

300,000

These adaptations produce loud, efficient, and low-pitched vocalizations (but not necessarily speech itself).


Facial Musculature


Ears, Teeth


Vocal Cords


Source-Filter Theory


Bent Vocal Tract


Possible Vowels


Neanderthal and Cro-Magnon


Neuronal Support

• Broca’s for lip-smacking becomes Broca’s for CV syllabic framework

• Phonological loop involving superior temporal stores lexical items

• Lexical items have access to all of the brain, but not dynamically


Reuse of earlier mechanisms

• Phonological store allows vocal rehearsal

• Hippocampus stores the episodic basis of lexical meanings

• DLPFC stores plans for tools use and mimesis

• Integrated frontal function constructs group relations: kinship, reciprocals, hierarchy


5. Phoenix

• Narrowing of evolutionary window at 70,000

• Computed through females, but males must be similar

• Perhaps due to Toba Batak, perhaps to a pandemic

• Survivors were an interesting subset of the earlier population

• Phoenix from the Ashes


Creativity Explosion

• Artifacts at 50,000 - carved bone, amulets

• Cave paintings at 30,000• Burial at 30,000• Opposition to Neanderthal• Mithen theory of demodularization


Suspects

• Perspective• Recursion• Priesthood


Perspective Hypothesis

directexperience

space/timedeixis

socialplans

perspective perspectiveperspective

language as a functional neural circuit

unified embodied image

perspective


Evolution and Perspective

• The five periods do not match the four cognitive levels

• But each level was constructed as a part of this process

• Each was progressively refined over time

• The phonetic revolution underlies the grammar, but the grammar maps to cognition, not phonology


But…

• TOM is developed in chimps• Perspective was important during

mimesis• Imitation was present• Imagery was present• Mirror neurons are in monkeys


Recursion

• Next talk: What Chomsky means by recursion reduces to item-based patterns

• Item-based patterns require Items Slots Features Clustering


Patterns from Combinations

• cookie = “would you please open the cupboard

door and bring me down a cookie”

• want ##### cookie• want # cookie• want cookie• Nim Chimpsky, Washoe, Sara, Lana


Item-based Patterns

• my + X Position Meaning relation Possible fillers My little dolly

• Where + X Where the wheel goes? Where goes the wheel?


Sockets are action-based

Throw____give__ __

--- breaks

__kick __ __ running


Feature-based patterns

• big + X, nice + X ….• Adj + X• Adj + N• But what about?

Actor + Action Subject + Verb Topic + Comment


Patterns to Creativity

• Item-based patterns provided full recursion

• Recursion linked dynamically to perspectival systems

• Articulate language users became priests

• Priests constructed the afterworld and myth


Syntax and Perspective

• Tim saw the Grand Canyon flying to New York.

• Jessie stole a picture of *her/herself.• Jessie stole me a picture of her/*herself.• The adults in the picture are facing away

from us, with the children hidden behind them.

• Did the bicyclist appear to fall?• Tim couldn’t find Mary’s beloved cat.


Social Perspectives

I claim that reason is a self-developing capacity. Kant disagrees with me on this point. He says it’s innate, but I answer that that’s begging the question, to which he counters, in Critique of Pure Reason, that only innate ideas have power. But I say to that, what about neuronal group selection? And he gives no answer.


Conclusions

• Language evolution was gradual, relying on coevolution of language, thought and gesture.

• We can distinguish five major periods.• Recursion was important in recent

changes, but relied on earlier spatial patterns

• Most recent changes involves coordination of recursion and lexicon with perspective

collaborative commentary - macwhinney 1 the sudden evolution of language? -- pillar #6 brian...

Documents

recursion slide

recursion lnd slide

core of language

language organ

sudden evolution of

social forces

social interaction

freed hands