380 likes | 530 Views
Cognitive Neuroscience. What is language?. Language and the Brain. Since the 19 th C great progress in our understanding of (a) brain and (b) language But little progress regarding the relationship between brain and language brain cognitive neuroscience language Why not?.
E N D
Cognitive Neuroscience What is language?
Language and the Brain • Since the 19th C great progress in our understanding of (a) brain and (b) language • But little progress regarding the relationship between brain and language brain cognitive neuroscience language Why not? • No animal model • The more “interesting” aspects are distant from stimulus and response
Why ask “what”? • A.D. 98-135: Celsus believed that the tongue, not the brain, was the source of speech disorders -> treatment: tongue massages and gargles • 1657: William Harvey was treated for his speech loss with a cut in the frenulum of the tongue (to loosen it); cupping, leeching, bleeding were accepted treatments for aphasia into the 19th C • The localization of function can only be as good as the theory of the function
Language as an Instinct “Language is not a cultural artifact that we learn the way we learn to tell time or how the federal government works. Instead, it is a distinct piece of the biological makeup of our brains” (Pinker, 1994). Chomsky argued that children are innately equipped with a plan common to the grammars of all languages—a Universal Grammar. “No one would take seriously the proposal that the human organism learns through experience to have arms rather than wings….human cognitive systems…prove to be no less marvelous and intricate…Why, then should we not study…language…as we study some complex bodily organ?” (Chomsky, 1975).
Language as an instinct: Arguments • Develops spontaneously, without instruction, without awareness of the underlying “rules” • Same developmental milestones across languages • Cannot be reduced to a general capacity to use symbols, need, intelligence, general characteristics of human information processing * Critical periods
Critical Periods In vision (but not chess) exposure during a critical period is crucial for normal development; similarly for language: (1) children not exposed to language before adolescence fail to acquire it later in life • adult/child differences in language acquisition Suggests a biological process with its own “clock”
Critical Periods: Creoles and Pidgins • Adult immigrants (without instruction) -> pidgins Pidgins: no consistent word order, no prefixes/suffixes, no tense marking, simple clauses only But: • Children of immigrants exposed only to pidgins -> creoles Creoles: bona fide languages, standardized word order, grammatical markers How can we explain this? -Innate language acquisition blueprint
Genetic Blueprint + Learning • Genetic blueprint: • Neural/cognitive machinery to organize/represent language stimuli in specific ways • The same across languages (Universal Grammar) • Learning: • The characteristics of the specific language in the environment are learned
Linguistics and Psycholinguistics Language knowledge: • phonology • morphology • syntax • semantics • orthography
Phonology • Our knowledge of the phonemes of the language and their legal combinations phoneme: smallest unit of language sound that serves to distinguish one word from another: pot/pod rot/lot pot/phot Some knowledge is language universal: all languages have CV syllables Some is language-specific: English: blin /*bnin Arabic: *blin/ bnin
Morphology • Our knowledge of the meaningful units of the language and how they can be legally combined in words morpheme: the smallest meaningful unit of language generalizations general+ize+tion+s *general+s+tion+ize
Syntax • Our knowledge of how words can be combined to express meaning the student praised the teacher the teacher praised the student *praised the student the teacher
Linguistics and Psycholinguistics Language knowledge: • phonology • morphology • syntax • semantics: knowledge of word meanings • orthography: knowledge of word spellings
Language Knowledge Examples to illustrate that our language knowledge is: • Detailed • Systematic • Abstract • Unconscious
Pluralization What’s the plural of: cab mop road rock How do you do this? • look up • rules
Pluralization Look up? • necessary for irregulars (child-child; foot-feet, mouse-mice) Why not look up everything? What’s the plural of: jat mun
Pluralization How might the rule be stated? {singular} + /s/ -> {plural} /k æ t/ + /s/ -> /k æ t s/ How well does it work? lock bat cap laugh log fad cab cave
Pluralization How about? banjo day cry sea due Or? jat/jad jaf/jav voe
Pluralization Revised rule: for singular ending in /t/, /p/, /f/, /k/: {singular} + /s/ -> plural for singular ending in /d/, /b/, /v/, /g/ or vowel: {singular} + /z/ -> plural
Pluralization Problems? • Doesn’t explain why there are two different plural sounds • Doesn’t explain the grouping of ending sounds with plural forms Note: only required for plurals (e.g., days/mace; sighs/mace; dens/dense)
Pluralization If we consider each phoneme as a set of features, the grouping becomes non-arbitrary Feature dimensions: -place of articulation (placement of tongue, lips, etc.) -manner of articulation (manner in which air is released) -voicing (+ or – movement of vocal folds)
Pluralization + voice-voice /b/ /p/ /g/ /k/ /d/ /d/ /v/ /f/ vowels, /n/, /m/, /l/ New rule: If final sound is + voice add /z/ (+voice) If final sound is – voice add /s/ (-voice)
Question Formation How do we generate questions from statements? the boy is crazy is the boy crazy? the girl can sing can the girl sing? Rule? Prepose the first auxiliary verb
Question Formation The boy who is smoking is crazy *Is the boy who smoking is crazy? The boy who is smoking is crazy Is the boy who is smoking crazy? New rule: Prepose the auxiliary following the subject noun phrase.
Question Formation Sentence Verb Phrase (subject) Noun Phrase is crazy Noun Verb Phrase who is smoking The boy
Sentence comprehension The spy saw the cop with the binoculars. Who had the binoculars? • the cop has binoculars • the spy has binoculars
Sentence Comprehension Where’s the difference? -not in the stimulus -rather, in the mental representation of the sentence’s structure:
Language Knowledge What is the nature of our language knowledge? • Detailed • Complex • Abstract • Systematic • Unconscious
PB video • Boy will fell • Crooked in the chair • Boy get k,k,..cooks to give a /g ou l/ • Water sink • Water is fall and water down to floors • Floors is wet there • Woman cleaning of…like plate….like washing
Language Knowledge What is the nature of our language knowledge? • Detailed • Complex • Abstract • Systematic • Unconscious
Language Knowledge Is our innate language capacity specific for spoken language? • American Sign Language (ASL) • not a translation of spoken English • basic units are spatial movements and contrasts • Syntax, morphology and “phonology” • (contrastive movement features)
ASL “phonology” has contrastive features: -configuration -place of articulation -movement Spoken phonology has contrastive features: -voicing -place of articulation -manner
Sign Language Critical Periods: • Deaf adults (i.e. neurologically normal) exposed to ASL only as adults -> ungrammatical ASL • Deaf children exposed to ungrammatical ASL -> grammatical ASL