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Brain and Language
Islamic Azad University-NajafabadIsfahan
Saeedeh Shafiee2016
Outline
Brain’s anatomy
Aphasia
Brain lateralization
Split Brains
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LEFT HEMISPHERE OF HUMAN BRAIN (Heny 639)
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LEFT HEMISPHERE(Fromkin Rodman Hyams)
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Figure 16-1
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CORPUS CALLOSUM
With the corpus callosum intact, the two halves of the body have
no secrets from one another. With it sectioned (as in severe
epilepsy), the two halves become two different conscious
mental spheres, each with its own experience base and control
system for behavioral operations…. Unbelievably as this may
seem, this is the flavor of a long series of experimental studies
first carried out in the cat and monkey.”
(Fromkin Rodman Hyams)
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Cerebral Lateralization of Function
Major differences between the function of the left and right cerebral hemispheres
The two Cerebral hemispheres communicate through the corpus callosum
Split-brain patients – what happens when the connections are severed?
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Cerebral Lateralization of Function
Aphasia
deficit in language comprehension or production due to brain damage –usually on the left
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Aphasia
Broca’s area – production– Damage > expressive aphasia, agrammatic
– Normal comprehension, speech is meaningful – but awkward
Wernicke’s area – comprehension– Damage > receptive aphasia
– Poor comprehension, speech sounds normal – but has no meaning – ‘word salad’
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BROCA’S APHASIA
“Cookie jar…fall
over…chair…water…empty…ov…ov…[Exami
ner: “overflow?”] Yeah.”
(Heny 637)
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People with Broca’s aphasia sometimes substitute synonyms of
the words they mean: freedom for liberty, parrot for canary,
overseas for abroad, long for large, small for short, long for tall.
Or they may substitute the word in its wrong grammatical
category: decision for decide, concealment for conceal, portrait
for portray, bath for bathe, dliscussion for discuss, and memory
for remember.
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BROCA’S APHASIA IS LIKE
TELEGRAPHIC SPEECH
Compare the Following:
Broca’s Aphasia
Children’s Language
Tarzan’s Language
The Lone Ranger’s friend Tonto’s Language
Genie’s Language
The Language of a Telegram
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WERNICKE’S APHASIA
Well, this is…mother is away here workingout
o’here to get her better, but when she’s
working, the two boys looking in the other
part. One their small tile into her time here.
She’s working another time because she’s
getting, too.”
(Heny 638)
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People with Wernicke’s aphasia might use sentences like these collected by Harry Whitaker:
There is under a horse a new sidesaddle.
In girls we see many happy days.
I’ll challenge a new bike.
I surprise no new glamour.
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Dyslexia
Dyslexia – reading difficulties
Developmental dyslexia – apparent when
learning to read
Acquired dyslexia – due to brain damage
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Copyright © 2006 by Allyn
and Bacon
SLIPS OF THE TONGUE, EAR, PEN,
AND HAND
In 1973, Victoria Fromkin edited an important book entitled Speech Errors as Linguistic Evidence.
In 1980, she edited another important book entitled Errors in Linguistic Performance: Slips of the Tongue, Ear, Pen, and Hand.
Fromkin shows how slips of the tongue, ear, pen and hand (in signing) give important insights into the way the human mind works.
TOT: “Tip of the Tongue” Phenomenon: Sometimes when we are searching for a word in our brain, we come up with a near miss. The wrong word sounds like, scans like, or has a similar meaning to the right word:
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SIGMUND FREUD
Sigmund Freud said that slips of the tongue often are evidence
of people’s subconscious desires, as when the President of
the Lower House of Parliament opened a meeting by saying:
“Gentlemen, I take notice that a full quorum of members is
present and herewith declare the meeting closed.”
(Nilsen & Nilsen 8)
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Brain Lateralization and Plasticity
Evidence for plasticity and lateralization
• Hemispherectomy
• Split-Brains
• Dichotic listening
• Event-related bran potentials
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The Split Brain
Corpus callosum– Transfers learned information from one hemisphere
to the other
– When cut, each hemisphere functions independently
Studying split-brain and monkeys– transect corpus callosum and optic chiasm so that visual information can’t cross
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RIGHT-BRAIN SPECIALTIES:
Synthetic and Creative Activities
Holistic Processing, Gestalts, and Overall Patterns
Spatial Relations
Nonspeech Sounds
Music Appreciation
Emotion
(Heny 643)
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LEFT-BRAIN SPECIALTIES:
Analytical Processing
Temporal Relations
Speech Sounds
Mathematics
Intellectual Activities
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Dichotic listening
Verbal and nonverbal stimuli
Event-related bran potentials
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THE CRITICAL AGE FOR
LANGUAGE LEARNING
For human babies, the brain is very flexible, and the left hemisphere is not dominant. By the Critical Age, the left hemisphere is dominant and Broca’s area and Wernicke’s area become less adaptable to new language stimuli.
(Heny 649)
“The critical-age hypothesis assumes that language is biologically based and states that the ability to learn a native language develops within a fixed period, from birth to middle childhood.”
(Fromkin Rodman Hyams [2007] 53)
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Autonomy of language
Specific language impairment
Savants
Genetic disorders
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Theories about the Origin of Language
Otto Jespersen (1921):
Human language originated while
human beings were enjoying
themselves
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The Divine Source Theory
In most religions: divine source provides
humans with language
Genesis (2:19): God created Adam and
‘whatsoever Adam called every living
creature that was the name thereof‘
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The Divine Source Theory
Hindu:
Language comes from goddess
Sarasvati, wife of Brahma, creator of
the universe
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Experiments
Egyptian pharaoh Psammetichus (600 B.C)
two new-born infants
two years in the company of a mute shepard
Phrygian word: bekos (meaning bread)
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Experiments
James IV of Scotland:
similar experiment
children were reported to have started
speaking Hebrew
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The Natural Sounds Source Theory
Hypothesis: primitive words are
imitations of the natural sounds which
early man and women heard around
them
E.g.: object flew by cuckoo
soundname cuckoo
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The Natural Sounds Source Theory
Explanation for onomatopoe(t)ic words:
splash, bang, boom, rattle, buzz, hiss
Also called bow-wow (Wauwau) theory of language
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The Natural Sounds Source Theory
Natural cries of emotion: pain, anger, joy:
e.g. ouch
Yo-heave-ho theory: sounds of a person involved
in physical effort e.g. when lifting trees or
mammoths
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The Oral Gesture Source Theory
hypothesis: link between physical gesture and
orally produced sounds
developed by Sir Richard Paget (1930)
movement of the tongue when saying goodbye
resembles movement of waving of the hand
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Physiological Adaptation Theory
physical features of human beings:
good clues for their capacity for speech
human teeth: upright, even in height
human lips: flexibility, needed for sounds like p,b
and w
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Physiological Adaptation Theory
human larynx (Kehlkopf): position lower than with
monkeys
longer cavity called pharynx (Rachenhöhle)
acts as resonator
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Physiological Adaptation Theory
human brain: lateralized
has special functions in each of the two hemispheres
left hemisphere: analytic, tool using, language
right hemisphere: holistic, music, visuo-spatial skills
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