ENG 227 Chapter Main Points Chapter 1, Spring 2012

Part I: The Nature of Human Language/ Introduction: Brain and Language  Neurolinguists study abnormal or damaged brains in relation to language.  The human brain is asymmetrical both structurally and functionally.  Asymmetries are clear in language-related areas.  Recent scientific studies uphold the idea of localization of language, and other cognitive functions, in specific parts of the brain.  Aphasia cases point to lateralization of language functions, as well as modularity: o Broca’s area (left/frontal lobe): damage implies poor syntax/grammar (agrammatic aphasia) o Wernicke’s area (left/temporal lobe): damage implies semantic incoherence o Content words and function words are processed in different parts of the brain or through different neural mechanisms.  Many aphasics suffer from anomia – inability to find the words they want to say.  Deaf aphasics suffer in terms of sign language production, meaning the brain is lateralized for language in general (symbols and related rules), not just for speech and hearing.  A reported historical case of aphasia involves forgetting how to read in one language as opposed to another.  Many historical cases include paralysis of the right side of the body along with aphasia.  Some language comprehension (of intonation, jokes, and metaphors) is attributable to the right side of the brain.  Brain imaging points to specific brain areas for naming people, animals, and tools.  Despite lateralization, there is plasticity (flexibility) in young developing brains. Children with left hemispherectomy suffer initial aphasia but later transfer their language skills to the right side of the brain, ending up seemingly normal.  The right brain plays a great role in language development in the first two years of life. Young children with right brain lesions show language delays, and those with right hemispherectomy by age two do not develop language.  Experiments on split brain patients also show left brain language dominance.  Other experimental evidence of brain organization: contralateral stimuli are processed better than ipsilateral (same side) stimuli; non- linguistic sounds are processed better by the right brain.  Some children without brain lesions may have difficulties/slowness in acquiring language. This is called specific language impairment (SLI), in which different language components – phonology, syntax and lexicon – may be selectively affected.  Linguistic savants illustrate dissociation between the language faculties and other cognitive faculties. Some of these savants may have very low nonverbal IQs.  The genetic basis of language is illustrated through cases of SLI and developmental dyslexia.  The critical age hypothesis states that language is biologically based. First language acquisition must take place by mid childhood for the grammar faculties to develop. Well known cases of feral children (Victor, Amala & Kamala, and Genie) indicate that vocabulary can be picked up later, but not grammar.  Many bird species also have a critical period for learning bird song, but many seem to have a basic genetically ingrained song pattern ready from birth.  The details of both bird song and human language are picked up through experience by a certain age.  Language development in the species: a quantitative (gradual/Darwinian) or a qualitative leap from other primates?  Language lateralization is not unique to the human brain.