Transcript Ling 21: LANGUAGE & THE BRAIN Neurolinguistics: The study of how language is represented and processed in the brain.

Ling 21:
LANGUAGE & THE BRAIN
Neurolinguistics: The study of
how language is represented
and processed in the brain
ROAD MAP
Now that we’ve:
Defined critical thinking
Identified traits of a
critical thinker
Identified some of the
barriers to critical thinking
and
Defined and analyzed
arguments in terms of
their component parts, . . .
ROAD MAP
We will turn our
attention briefly to
some things that
we know about
language in the
brain, in particular:
The structure of
the brain
Aphasia
Signed languages
Language in the Brain
• Have you ever
– Observed children learning learn their first language?
– Studied American Sign Language?
– Known anyone who has suffered a stroke?
• How are humans and other animals similar?
• How do we communicate differently from other
animals?
• How do researchers investigate how the brain is
organized and how it works?
Language in the brain
THE HUMAN BRAIN
• The brain is composed of neurons, nerve cells
that are the basic information processing units
of the nervous system.
• The cerebral cortex is the gray wrinkled mass
that sits over the rest of the brain and accounts
for language representation and processing.
• The longitudinal fissure separates the left and
right hemispheres of the brain.
• The corpus callosum is the bundle of nerve
fibers that connects the two hemispheres.
FUNCTIONS of the BRAIN HEMISPHERES
• In terms of muscle movement, each hemisphere is
responsible for half of the body – contralateral
responsibilities.
– Right hemisphere -> left side of body
– Left hemisphere -> right side of the body
• In terms of higher cognitive functions, the
hemispheres are lateralized –
– Left hemisphere -> analytic tasks
• Math, Language
– Right hemisphere -> recognition of complex
patterns
• Faces, Melodies
LATERALIZATION
• Specialization of brain functions in either left or
right hemisphere of the brain
• Said to occur around puberty
• More pronounced with right-handed people than
left-handed people
– RH people exhibit language difficulties with
damage to the right hemisphere
– LH people show language representation in both
hemispheres
• Said to contribute to differences between children
and adults with respect to second language learning
INVESTIGATING THE BRAIN
• Autopsy studies –
– Broca’s area: lower rear of left frontal lobe
• Images of the living brain
– Computerized axial tomography (CAT scan)
– Positron emission tomography (PET)
• What does PET do?
• How does it do that?
• Describe the experiment – what the subject was asked
to do (three tasks) and what it showed
– Functional magnetic resonance imaging (fMRI)
INVESTIGATING THE BRAIN
(continued)
• Learning from hemispheric connections and
disconnections
– Dichotic listening studies show that we process
language better through right ear
– Split brain studies – ‘key’ experiment
APHASIA
A language deficit caused by damage to the brain,
often be a stroke or an accident
• Nonfluent (motor) aphasia – front of left cortex
– results in either slow effortful speech or complete
speechlessness
– Broca’s aphasia –
• Speech is very halting
• Function words are omitted (it, is, to, a, etc.)
• Pronunciation is simplified (spoon > poon, etc.)
• Inflectional endings are omitted (running > run,
etc.)
– Broca’ aphasics are aware of their language deficit
APHASIA
• Fluent (sensory) aphasia – rear of left cortex
– No difficulty producing language
– Great difficulty selecting, organizing and
monitoring language
– Wernicke’s aphasia
• Generally unaware of their deficit
• Patient rarely makes any sense
YouTube - Wernicke's and Broca's Aphasia
LANGUAGE as FORM & CONTENT
• Non-fluent aphasia – Form is compromised
but the content of language remains
relatively intact.
• Fluent aphasia – Characterized by a rapid
flow of form with little content.
• Working with aphasics
• Exercise: O’Grady, p. 534-535, questions 1,
2, 4, 5, 6 & 7.
VISUAL LANGUAGE
• Deafness is not a language
impairment.
• Language vs. speech
–Language = an abstract cognitive
system
–Speech = an action using the vocalauditory mode
• Deafness requires a language in a
different (i.e., non-vocal) mode
VISUAL LANGUAGES
• Sign languages differ from one culture to
another.
• They are NOT mutually intelligible.
SIGNED LANGUAGES vs. PANTOMIME
• Pantomime = iconic
• Signed languages = abstract
• Three levels of iconicity for signs
– Transparent: Understood by untrained
observers – eat, food
– Translucent: Easy to recognize when they are
explained – wonder (OSU LF, p. 405)
– Opaque: Have no recognizable relationship to
their referent – onion (OSU LF, p. 405)
SIGNED LANGUAGE
vs. MANUAL CODES
• Manual code: An artificially contrived system
for representing a natural language (e.g.,
Manually Coded English)
– Has no syntax or structure of its own
– Created by hearing people for the deaf
• Signed language: a natural language not based
on the spoken language used around it
– Has a distinct structure and syntax
– Is created by deaf people
ASL vs. PSE vs. SEE
• What’s the difference?
– Signed Exact English: “What is your name?”
– Pidgin Signed English: “What you name?”
– American Sign Language: “You name what?”
• From a deaf person on Ask Yahoo: If you're taking a class or using books,
the books will mostly be ASL. (Some will be SEE - Signing Exact English - but
I would avoid those like the plague.) As you use the signs, you will naturally
be using PSE - using ASL signs in English order - to communicate. As you
learn more about the linguistics of the language you can switch to more
ASL.… The signs would be similar, but the order would be different.
In terms of communication between PSE and ASL, I'm Deaf and I don't have
a problem with understanding PSE or using it myself with people who don't
always "get" ASL, but I've had a lot of English training. Some native ASL
users will have trouble understanding you if you're using PSE, but most are
used to it from hearing people, so you won't have a lot of difficulty.
AMERICAN SIGN LANGUAGE
• Used by the deaf in the U.S. and Canada
• Dates to 1815 – Thomas Hopkins Gallaudet
• Influenced by
– French Sign Language (SLF)
– Deaf signs in use at the time
– Written and spoken English
• Not mutually intelligible with British,
Chinese, or Russian Sign Language
DICTIONARY OF ASL
• Sign structure consists of 3 formational
elements (Parameters)
• The shape of the hand used in the sign (which
fingers are used, whether fingers are extended or bent,
the general configuration of the hand; E.G., ‘apple’ vs.
‘candy’)
• The place of articulation of the sign in space or
on the signer’s body (temple, ear, chest, e.g.,
‘apple’ vs. ‘onion’)
• The particular movement associated with the
sign (repeated circular motion, slow elliptical motion,
e.g., ‘think’ vs. ‘wonder’)
PHONEMES, CHEREMES
• Alone they are meaningless (like letters)
• Together they form different words when combined in
different ways (like tan & pan)
• If I make the same movement at the same point of
articulation, but change the hand shape, the sign has a
different meaning (apple & candy, p. 405)
• If I make the same movement with the same
handshape at a different point of articulation, the sign
has a different meaning (apple & onion, p. 405)
• Think and wonder have the same handshape and point
of articulation, but differ in movement (p. 405).
PROSODY
In spoken languages, intonation affects
sentence meaning. Rising intonation often
indicates a yes-no question.
John fed the cat.
John fed the cat?
In signed languages, facial expressions have the
same function.
A yes-no question is accompanied by a
raised brow.
PRONOUNS
The signer first signs the person or object being
discussed, then points or gazes to a point in
space in front of his or her body.
When the signer wants to refer again in the
conversation to the person or object, the
signer points to that location.
This is the equivalent of the spoken he/she/it,
him/her/it, etc.
STRESS & COMPOUNDING
• In spoken English, the stress pattern of a compound
word distinguishes it from a mere combination of its
components.
– BLACK BIRD vs. BLACKbird
• In ASL, the equivalent to vocal stress is duration; the
second element in a compound is always stressed – the
first is signed quicker.
– BLUE SPOT vs. blueSPOT
ASL SOCIOLINGUISTICS
• Dialect differences exist,
– due to geographic isolation
– ‘accents’ as well as vocabulary differences
• Borrowing from English exists, due to
– Bilingualism
– Large specialized vocabulary of English
– Linguistic oppression against the deaf
– Struggle between pro-English & pro-ASL factions
among the deaf
SL NEUROLINGUISTICS
Deaf people who suffer damage to the left hemisphere of
their brains will, like hearing people, suffer from
aphasia- they may have slow awkward signing (Broca’s
aphasia) or may produce ‘sign salad’ (Wernicke’s
aphasia)
Damage to the right hemisphere frequently results in the
loss of some spatial functioning. Patients asked to draw
a clock, for example, may draw only a semicircle,
neglecting the left side.
Deaf people who suffer damage to the right hemisphere
of their brains will not lose their ability to sign.
Conclusion: Sign language is controlled by the same
regions of the brain that control spoken language, not
by the visuo-spatial centers.
American Sign Language
Pair Work
• In your first essay, you are asked to describe
your strengths and weaknesses as a critical
thinker, providing specific exam[ples to
illustrate. In pairs, describe to your partner the
situation you are planning to write about.