Brain and Language

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Neurolinguistics – the study of the biological and neural

foundations of language.

- the study of the brain mechanisms and anatomical structures that underlie linguistic competence and performance.
Brain – consists of approximately 100 billion nerve cells
            - composed of cerebral hemispheres; one from the right

and left; joined the corpus callosum (network of more than

200 million fibers).

- most complex organ of the body, controlling motor and sensory activities and thought processes.
Cortex – surface of the brain; gray matter; decision making

organ of the body; receives the memories from all sensory

organs; initiates all voluntary and involuntary actions;

storehouse of memories.

Contralateral functions – the left hemisphere controls the right

side of the body and the tight hemisphere

controls the left side.

Localization – proposed by Franz Joseph Gall

-         different human cognitive abilities and behaviors are localized in specific parts of the brain.

-         Language is located at the frontal lobes of the brain and the most articulate and intelligent of his fellow students had protruding eyes.

Phrenology – organology; practice of determining personality
traits, intellectual capacities and other matters by examining the bumps on the skull.
Johann Spurzheim- Gall’s disciple introduced phrenology to America.
Aphasia – neurological term for any language disorder that
results from brain damaged caused by a disease or trauma.
Broca’s Area – French surgeon Paul Broca

-         language is localized to the left hemisphere of the brain. And more specifically to the front part of the left hemisphere.

Wernicke’s area – Carl Wernicke, a german neurologist
- described another vriety of aphasia that occurred in patients with lesions in areas of the left hemisphere temporal lobe.
Lateralization – localization of function to one hemisphere of

the brain.

Broca’s Aphasia – characterized by labored speech and certain

kinds of word finding difficulties, but it is primarily a disorder that affects a person’s ability to form sentences with the rules of syntax.

-         agramatic (it frequently lacks articles, prepositions, pronouns, auxiliary verbs, and other grammatical elements or function words)

-         have difficulty understanding complex sentences

-         impaired syntax and agrammatism

Wernicke’s Aphasia – produce fluent speech with good
intonation, and they may largely adhere to the rules of syntax; make numerous lexical errors and often producing jargon and nonsense words.
Jargon Aphasia – severe Wernicke’s Aphasia
                        - Speakers produce nonsense forms that make their

utterance uninterpretable.

Anomia – a form of aphasia in which the patint has word-finding

difficulties.

Dyslexia – reading disorder
Acquired dyslexics – before their brain lesions they were normal

readers

Developmental dyslexics- difficulty learning to read.
Japanese language – kana (sound system; each symbol
corresponds to a syllable) and kanji (ideographic; each symbol corresponds to a word)
Tip-of-the-tongue phenomenon (TOT) – severe anomia;

inability to find the word you wish to speak.

* Language difficulties suffered by aphasics are not caused by any general cognitive or intellectual impairment or loss of motor or sensory controls of the nerves and muscles of the speech organs or hearing apparatus. Aphasics can produce and hear sounds. Whatever loss they suffer has to do only with the language faculty (or specific parts of it).
Left hemisphere – lateralized for language; abstract system for

symbols and rules

Pliny the Elder – refers to an Athenian who “with a stroke a

stone fell presently to forget his letters only, and

could read no more; otherwise, his memory served

him well enough.”

Carl Linneus – published a case study of a man suffering from jargon aphasia.
Noninvasive brain recording technologies:

·        Computer tomography scan (CT Scan) and Magnetic Resonance Imaging (MRI) – can reveal lesions in the living brain shortly after the damage occurs

·        Positron Emission Tomography (PET) scans, Functional MRI scans and Single Photon Emission CT (SPECT) scans – provide images of the brain in action.

Magnetic Encephalography (MEG) – measures magnetic fields

in the living brain.

* Wernicke’s area is visibly distinctive in the left hemisphere of the fetus by the twenty-sixth gestational week. Infants as young as one week old show a greater electrical response in the left hemisphere to language and in the right hemisphere to music.
Brain’s Plasticity (flexibility)- the right hemisphere can take over many of the language functions that would normally reside in the left hemisphere.
Hemispherectomy – one hemisphere of the brain is surgically

removed; the procedure is used to treat

intractable case of epilepsy.

* Human brain is essentially designed to specialized for language in the left hemisphere but that the right hemisphere is involved in early language development.
* When the brain is surgically split, certain information from the left side of the body is received only by the right side o the brain and vice versa.
* In humans who have undergone split-brain operations, the two hemispheres appear to be independent, and messages sent to the brain result in different responses, depending on which side receives the message.
* The left hemisphere is superior for language, rhythmic perception, temporal-order judgments, and arithmetic calculations.
* Studies of human spli-brain patients have also shown that when the interhemispheric visual connections are severed, visual information from the right and the left visual becomes confined to the left and right hemispheres, respectively.
Dichotic listening- an experimental technique that uses auditory

signals to observe the behavior of the

individual hemispheres of the human brain.

Ipsilateral – same side
* The left hemisphere is not superior for processing all sounds, it is only better for those sounds that are linguistic.
Event-related brain potentials (ERP) – electrical signals

emitted from the brain in response to different

stimuli.

                                                            - the left hemisphere is

sensitive to grammatical structure even in the

absence of meaning.

Jabberwocky sentences – sentences that are grammatical but

contain nonsense words.

Specific Language Impairment (SLI) – only their linguistic
ability is affected, and not often only specific aspects of grammar are impaired.
                                                - children have problems with the use

of function words such as articles,

prepositions, and auxiliary

verbs, have difficulties with

inflectional suffixes on

nouns and verbs such as markers of

tense and agreement.

Savants – intellectually handicapped individuals who, despite

their disabilities in certain spheres, show

remarkable talents in others.

Turner Syndrome – have normal language and advanced

reading skills along with serious

nonlinguistic (visual and spatial) cognitive

deficits.

Williams syndrome – reveal a unique behavioral profile in
which certain linguistic functions seem to be relatively preserved in the face of visual and spatial cognitive deficits and moderate retardation.
Developmental dyslexia and SLI – have a genetic basis.
Klinefelter syndrome – show quite selective syntactic and

semantic deficits alongside intact

intelligence.

*Monozygotic (identical) twins are more likely to both suffer from SLI than dizygotic (fraternal) twins.
Critical-age hypothesis – assumes that language is biologically

based and that the ability to learn a

native language develops within a

fixed period, from birth to middle

childhood.

                                    - there is a window of opportunity between

birth and middle childhood for learning a

first language.

*Language acquisition, though an innate, neurologically based ability, must be triggered by input from the environment.
*The cases of Genie and other isolated children, as well as deaf late learners of ASL, show that children cannot fully acquire language unless they are exposed to it within the critical period – a biologically determined window of opportunity during which time the brain is prepared to develop language.
*The languages of our human ancestors of millions of years ago may have been syntactically and phonologically simpler than any language known to us today.
*The language faculty is modular (independent of other cognitive systems with which it interacts). Can be found in aphasia, SLI, savants and who learn past the critical period.