College_Language.ppt

8/10/2019 College_Language.ppt

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The major transitions

(JMS & ES, 1995)

**

*

*

* These transitions are regarded to be difficult


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Why is language so interesting?

Because everybody knows that only we talk

although other animals may understand a

number of words

Language makes long-term cumulative

cultural evolution possible

A novel type of inheritance system with

showing unlimited hereditary potential


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Understanding language

evolution is difficult


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Three interwoven processes

Note the different time-scales involved Cultural transmission: language transmits itself as

well as other things

A novel inheritance system


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Language is not Weismannian

germgerm germ

soma soma

germDNA

protein

DNA

protein

germNeural

representation

sentence sentence

Neural

representation
http://vlp.mpiwg-berlin.mpg.de/vlpimages/images/img7153.jpg


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Design features of language

Compositionality (meaning dependent on how

parts are combined) Recursion (phrases within phrases)

Symbolicism (versusicons and indices)

Cultural transmission (rather than genetic) SYMBOLIC REFERENCE and SYNTAX


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A simple experiment (Hauser &

Fitch) Finite state grammar

(AB)nis recognizable

by tamarins Phrase structure

grammar AnBnis

NOT.

Humans recognize

both


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Our evolutionary relatives

What has happened on our linage in the past few

million years so that our genes allow for the

development of a brain that can sustain syntax?


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Words are symbols, Saussurean

signs

TREE

Object

Concept

Symbol
http://images.google.com/imgres?imgurl=personales.ciudad.com.ar/Derrida/saussure1.jpg&imgrefurl=http://personales.ciudad.com.ar/Derrida/saussure_1.htm&h=242&w=200&sz=11&tbnid=gkgMcAyrMZwJ:&tbnh=104&tbnw=86&start=8&prev=/images%3Fq%3DFerdinand%2Bde%2BSaussure%2BAND%2Bphoto%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sa%3DN


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Word representation is

distributed

and is related to the somatosensory handling of thedesignated object


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Principles and parameters

Principle: a universal property of human

language, assumed to be innate.

Parameter: a two (or more) valued choice

determining a general property

distinguishing one type of language from

another.


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Syntactic processes and

information Colourless green ideas sleep furiously

Structurebuilding (phrases, etc.)

Checking agreement(e.g. in German nounphrases must be marked for case)

Mapping thematic roles(John loves Mary,

Mary loves John)

Complexity(the dog was chased by the cat)

SYNTAX IS NOT WORD ORDER!!!
http://images.google.com/imgres?imgurl=www.pressmaterial.se/ordfront/forfattare/images/noam-chomsky.jpg&imgrefurl=http://www.pressmaterial.se/ordfront/forfattare/index.shtml&h=500&w=360&sz=39&tbnid=vmysLPllTj4J:&tbnh=126&tbnw=91&start=4&prev=/images%3Fq%3DChomsky%26hl%3Den%26lr%3D%26ie%3DUTF-8


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The D- and S-structures

The sentence is:Mary

was chosen


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The traditional view

Brocas area: the seat

of syntax

Wenickes area: theseat of semantics

(fluent aphasia)

Double dissociation

Unfortunately (?) not

quite true
http://images.google.com/imgres?imgurl=www.psychology.psych.ndsu.nodak.edu/mccourt/website/htdocs/HomePage/Psy486/Historical%2520origins%2520of%2520neuropsychology/broca.JPG&imgrefurl=http://www.psychology.psych.ndsu.nodak.edu/mccourt/website/htdocs/HomePage/Psy486/Historical%2520origins%2520of%2520neuropsychology/historical_origins_of_neuropsych.htm&h=637&w=537&sz=78&tbnid=Rp9bS1LyM18J:&tbnh=134&tbnw=113&start=2&prev=/images%3Fq%3DBroca%2Bphoto%26hl%3Den%26lr%3D%26ie%3DUTF-8http://images.google.com/imgres?imgurl=www.psychology.psych.ndsu.nodak.edu/mccourt/website/htdocs/HomePage/Psy486/Historical%2520origins%2520of%2520neuropsychology/wernicke.JPG&imgrefurl=http://www.psychology.psych.ndsu.nodak.edu/mccourt/website/htdocs/HomePage/Psy486/Historical%2520origins%2520of%2520neuropsychology/historical_origins_of_neuropsych.htm&h=304&w=205&sz=29&tbnid=nnnbbILzDFkJ:&tbnh=111&tbnw=75&start=1&prev=/images%3Fq%3DWernicke%2Bphoto%26hl%3Den%26lr%3D%26ie%3DUTF-8


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New data on Broca

One can have syntactic deficit with intact Broca

Affected Broca does not always produce problems

in morphosyntax

Some Broca aphasics have problems withsemantics as well

Broca lesion neither necessary nor sufficient for

syntactic deficit

BUT may be essential for COMPLEX sentences

(a problem with working memory?)


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Neuroimaging studies of syntactic

processing By comparing syntactically complex to

simple sentences

By comparing sentences to lists of unrelatedwords

By comparing sentences containing non-

real words to normal ones Comparing sentences with syntacticviolation to those without


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Semantic and syntactic violations

Syntactic violation versus

Correct sentences

Semantic violation

Other violation

Semantic violation versus

Correct sentences

Syntactic violation


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Where is syntax in the brain?

In many areas These include some parts of the RIGHT

hemisphere

None of these areas is exclusively dedicatedto syntax

Broca: semantics phonology, memory,music perception

INCONSISTENT WITH A STRICTLYANATOMICAL MODULAR VIEW


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Resolution (Kaan & Swaab, 2002)?

Maybe there is a dissociation at the cellular

level between these functions, below

resolution

Maybe the combinationof these areas forms

a unique network

Different parts of the network are recruited

to different syntactical tasks

MAYBE, BUT WHY NOT IN APES?


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An even more radical resolution:

The Language AmoeBa (LAB)

hypothesis

Szathmry, E. (2001) Origin of the human

language faculty: the language amoebahypothesis. In (J. Trabant & S. Ward, Eds.):

New Essays on the Origin of Language.

Berlin/New York: Mouton/de Gruyter, pp.41-51.


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Recuerdos de mi vida (Cajal, 1917,

pp. 345350)At that time, the generally accepted idea that the

differences between the brain of [non-human]mammals (cat, dog, monkey, etc.) and that ofman are only quantitative, seemed to me unlikelyand even a little offensive to human dignity. . .

but do not articulate language, the capability ofabstraction, the ability to create concepts, and,finally, the art of inventing ingeniousinstruments. . .

seem to indicate (even admitting fundamentalstructural correspondences with the animals) theexistence of original resources, of somethingqualitatively new which justifies the

psychological nobility ofHomo sapiens?. . . .
http://images.google.com/imgres?imgurl=www.ucm.es/info/hcontemp/leoc/images/imagmadcult/cajal.jpg&imgrefurl=http://www.ucm.es/info/hcontemp/leoc/ciencia%2520en%2520madrid.htm&h=305&w=257&sz=19&tbnid=bt_yrV0LtnoJ:&tbnh=111&tbnw=94&start=5&prev=/images%3Fq%3DCajal%26hl%3Den%26lr%3D%26ie%3DUTF-8


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Species-specific differences in

cortical microstructures do exist


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Differences in the primary visual

cortex among primates (Preuss et al)

In monkeys: the

honeycomb

Modifications in

evolution


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The difference in gene expression

patterns Despite our close

genetic relationship to

chimps The epigenetic

difference in the

brains seems

enormous

Th l i h


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The evolutionary approach

genes

development

behaviour

selection

learning

environment

Impact of evolution on the developmental

genetics of the brain!


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Crucial facts for LABLocalisationof language is not fully geneticallydetermined: even large injuries can be tolerated before a

critical period.

Language localisation to certain brain areas is a highlyplastic process, both in its development and its endresult.

It does seem that a surprisingly large part of the braincan sustain language:there are (traditionallyrecognised) areas that seem to be most commonlyassociated with language, but by no means are theyexclusive, either at the individual or the populationlevel, during either normal or impaired ontogenesis.

Whereas a large part of the human brain can sustainlanguage, no such region exists in apes.


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Crucial theses of LAB

The language amoeba is the neuronal activity

patternthat essentially contributes to processing oflinguistic information, especially syntax. It is adynamical manifestation of Chomskys languageorgan, as it were

An appropriate and rather widespread connectivitypatternof the immaturehuman brain renders it apotential habitat for the emerging language amoeba.

This condition does not require too many altered

(probably regulatory) genes, but there are great risksinvolved, which make this major transitiondifficult indeed.


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Variation and selection in neural

development Changeuxs version

There is vastoverproduction ofsynapses

Transient redundancy isselectively eliminatedaccording to functionalneeds

The statistics and thepruning rules for thenetwork architecture areunder genetic control


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The structure of the visual system

Partial crossing at the chiasm allows for

stereoscopic vision


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Development of the columns of

ocular dominance

The initial overlap

decreases with time

Visual input is

NECESSARY for

columnar development


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Genes and visual input make up

for normal vision Synapses are pruned

during development

A blindfolded eyedoes not send sensoryinformation to thecortex

Its column shrinks tonegligible size

Reversiblewithin theCRITICAL PERIOD


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TheFOXP2gene is mutant in a

family with SLI SLI: specific language impairment

In the KE family the mutation is a single

autosomal dominant allele Another individual has one copy deleted

TWO intact copies must be there in

humans! The mutation affects morphosyntax:

Yesterday I went to the church


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Possible regulatory modes of the

FOXP2gene


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Interpreting the nature of SLI-

related conditions Sometimes SLI affects

specifically grammar

Sometimes if affects other

linguistic functions

Sometimes several other

functions are affected

Outcome must depend on

the region of expression of

the (genetic) disturbance

in the developing brain


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Nucleotide substitutions in the

FOXP2gene

Bars are nucleotide substitutions

Grey bars indicate amino acid changes

Likely to have been recent target of selection

C l ti f th l d


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Coevolution of the language and

the brain

An old idea (Wilson):increased brain size leadsto more complex

behaviour Which in turn, due to

increased environmentalcomplexity, selects forincreased brain size

Another crucialcomponent: geneticassimilation

Rapoport scheme applied to

language


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One method of finding out (within

ECAgents)

Simulated dynamics of interacting agents

Agents have a nervous system

It is under partial genetic control

Selection is based on learning performance

for symbolic and syntactical tasks

If successful, look and reverse engineer the

emerging architectures


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Between linguistic input and

output


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Transmission dynamics in

simulated agents

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College_Language.ppt

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