Download The Brain

Language, in all its forms, is processed,
created and understood in various parts of
the brain.
 Through research, it has been determined
that there is localization of brain function
related to language.
 The term aphasia is used to indicate an
impairment of language. This impairment
can show up in language use (speaking for
example) or in language processing
(comprehension)
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Based on early research of Paul Broca, Carl
Wernicke, Norman Geschwind mapped the
basic process of language usage.
 For example, when you read aloud– the
words register in the visual area—are
relayed to the angular gyrus, which
transforms the words into an auditory
code—which is received and processed by
Wernicke’s area—sent to Broca’s area
which—controls the motor cortex to
pronounce the word
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Broca’s area: controls language
expression—usually in the left frontal
lobe, controls the muscle movements
involved in speech
 Discovered by Paul Broca, in 1865. Tan.
Patients can comprehend language
and are able to sing but struggle to
speak. Broca’s aphasia: disruption of the
ability to speak
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Carl Wernicke, in 1874, discovered the people
with damage to the left temporal lobe could
only speak meaningless words.
Wernicke’s area controls understanding of
language. Wernicke’s aphasia is the inability to
understand language but the ability to speak is
not impacted.
The angular gyrus is involved in reading aloud.
It processes the visual clues and turns them into
code that is understood by Wernicke’s area.
Damage to it leaves you able to speak and
understand but unable to read aloud.
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Using fMRI, the neural areas used in language
processing can be mapped even further.
These studies show that different neural
networks are activated for nouns and verbs
and that language is processed differently
dependent on when you learned the
languages. Bilingual from early childhood
individuals, use the same area (Broca’s) when
recounting events in either language. Those
who learn a second language later in life use a
larger and adjacent area of the brain when
recounting the events in the second language.
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The brain’s ability to reshape itself after
damage is known as plasticity. Plasticity also
refers to the brain’s process of building new
pathways based on experience.
The brain is most plastic when we are young.
Brain areas that are not used (temporal lobe
area in the deaf)(visual cortex for the blind)
often repurpose themselves. For example, the
sense of touch (reading Braille) enlarges and
spreads to the visual cortex in the blind. Many
deaf individuals report having better than
normal peripheral vision. The temporal lobe
helps process visual stimulation.
Although it has long been held as true that
brain cells are not created later in life, there
is new research to indicate that they do.
 Neurogenesis is the formation of new
neurons.
 In 2007, Gould discovered that monkey
brains are forming new neurons. These
neurons form deep in the brain and then
migrate and form connections with other
neurons.
 There is also new research on the use of
stem cells to create new brain cells.
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In 1961, Philip Vogel and Joseph Bogen
believed that major epileptic seizures
were caused by abnormal activity
between the two hemispheres across the
corpus callosum.
 The corpus callosum is a band of neural
fibers that connect the two hemispheres
and carry messages between the two
hemispheres.
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Vogel and Bogen knew that there had
been research done on split brains in
animals (cats and monkeys) with no ill
effects. (Sperry, Myers and Gazzaniga)
 The surgery cured the patient of the
seizures.
 Sperry and Gazzaniga have done extensive
research with split brain patients. This has
helped us to understand the
complementary functions of the two
hemispheres.
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The split brain surgery, allows researchers to quiz the
hemispheres separately.
In 1967, the HE-ART experiment, led to new
knowledge about our processing of visual information
and language.
Stare at the dot, as the patient is staring HE-ART is
flashed on the screen. HE appears in the left visual
field and ART in the right. Left visual field transmits to
right hemisphere and vice versa. When asked what
they had seen, the patients responded ART. When
asked to point with their left hand, they pointed at
HE. Each hemisphere knew what it had seen but had
to be given an opportunity to express itself.
The hidden object– patients are shown (to
the right hemisphere)an object. When
asked what they saw, they cannot say
what they saw. When asked to feel hidden
objects with the left hand, they can choose
the correct object. But do not understand
how they chose it.
 People with a split brain are in essence
people of two minds. Sometimes these
minds are at odds with each other. The left
hemisphere will try to solve unexplainable
actions with logic.
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Left hemisphere: active when we deliberate a
decision, when active we are more likely to
discount disagreeable information
Right hemisphere: understands simple requests,
easily perceives objects, more engaged with
quick/intuitive responses, better at copying
drawings and recognizing faces, skilled at
perceiving emotion and portraying emotion
(left side of face)
No activity where only one hemisphere makes
a contribution
Logic not confined to left hemisphere
 No evidence that creativity or intuition is
an exclusive property of the right
hemisphere
 Impossible to educate one hemisphere
at a time
 No evidence that people are purely leftbrained or right-brained
 (Jerre Levy)
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When perceptual tasks are performed there is
increased blood flow, glucose consumption in the
right hemisphere
When we speak or calculate, left hemisphere.
Left good at making quick, literal interpretation of
language; right excels at making inferences.
Right helps us modulate speech, to make meaning
clear.
For example, “What’s that in the road ahead?” as
opposed to “What’s that in the road, a head?”
Right seems to orchestrate our sense of self
We have unified brains with specialized parts.