Thursday Dec 9 Paper 4 due Dec 9 or 10 absolutely no later than Monday, Dec 16, 4:00 PM Exam IV will

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Thursday Dec 9Paper 4 due Dec 9 or 10
absolutely no later than Monday, Dec 16, 400
PM Exam IV will be on the last day of classes
Tues, Dec 14Optional Comprehensive Final will
be Friday, Dec 17 at 900 AM in McC 4th floor
Rm 272
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Visual field for each eye has two halves Left
visual half field (left side of left and left
side of right eye) - sends information to the
left hemisphere Right visual half field (right
side of left and right side of right eye) - sends
information to the right hemisphere In normal
brain, info. then crosses over to other side via
corpus callossum this allows an integrated
image to be formed. In split brain, info. cannot
cross. Thus, info can be selectively sent to one
hemisphere.
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• Split Brain
• corpus callossum is cut
• optic chiasm is intact
• Deliver info selectively to left hemisphere via
  left half-field - it cannot then cross over.
  Info sent to left hemisphere only.
• Or deliver selectively to right hemisphere.

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Delivery of info to right visual half field gt
right hemisphere
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Results of split brain research 1. LH able to
name objects RH not. 2. RH can identify by
pointing (or drawing) with left hand, but not by
naming. Note the organization of hemispheric
control of the hand RH controls left hand. LH
controls right hand. Known as contralateral
organization. 3. LH can also point using right
(contralateral) hand. 4. When different info
presented to each hemisphere, will name what the
left hemisphere saw, but draw what the right
hemisphere saw. (simply asked to name or draw
not told which hand to use)
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Arrow to RH
Bow to LH
Scraper to RH
Sky to LH
5. Show different words to each hemisphere and
ask patient to draw what they saw, 1st using left
hand then using right hand. Multiple examples
show that the brain does not integrate most
trials look like skyscraper example. The bow and
arrow is just a fluke patient drew the arrow on
top of the bow.

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Results of split brain research 6. If different
picture shown to each hemisphere and patient is
asked to point to what they saw, do so correctly
with left hand pointing to what RH saw, and right
hand pointing to what LH saw. Ask subject to
describe why LH pointing to the picture, 1st say
they do not know, then make up an explanation. LH
is interpreter job is to make up explanation.
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7. LH is interpreter job is to make up
explanation. RH is literal and truthful. Have
patient do a task press button to indicate
where a light will come on. Experience is that
light comes on at top 80 of time at bottom
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elaborate reasons for guessing that way. RH gets
nearly 80 correct and explains rule. In normal
people, tendency to only get about 68 correct.
Normals take LH strategy. Rats and other animals
do also. Gazzaniga argues that we have replaced
equally organized brain with laterally organized
one to allow language lost some role as a
result.
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8. Perception of visual contours illusory
rectangles seen by LH or RH, unless lines drawn
around circle stimuli. When lines are present,
LH no longer sees illusory rectangles RH still
does. Mice still see illusory rectangles with LH
or RH. Again, we may have sacrificed some
abilities to evolutionarily create specialization
of left hemisphere for speech.
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9. Experiments with the olfactory system -
smell Left nostril - sends odor info to left
hemisphere Right nostril - sends odor info to
right hemisphere Right hemisphere cant name the
odor, but it can direct the left hand to select
the object smelled. LH can name it. 10. Similar
findings for hearing and touch senses.
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Rose smell delivered via right nostril to the
right hemisphere. Subject cant name it but can
choose a rose with left hand.
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Other research on intact brain also examines
laterality Auditory studies - can selectively
deliver to right or left hemisphere Info to left
ear gt right hemisphere. In normal brain, it then
crosses back over to left hemisphere where sound
can then be described thru speech. Info to right
ear - left hemisphere Already in the correct
location (LH) to allow describing - can do so
faster. The right ear advantage.
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Auditory paths in normal brain
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Results of other research 1. LH better at
language/speech. 2. LH better at language-related
sounds 3. LH better at verbal memory 4. LH better
at math and science. 5. LH better at logic and
analytic thought.
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Results of other research 1. RH better at visual
memory 2. RH better for environmental sounds. 3.
RH better for face perception and emotion
recognition. 4. RH superior for visuospatial
skills. Puzzles Sense of direction
Geometry Mental rotation of shapes
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Language
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• The Wada Technique
• blood supply to most of each cerebral hemisphere
  is carried by the carotid artery
• inject a fast-acting anesthetic into the carotid
  artery going to one side of brain
• briefly deadens brain and prevents responses
• ask questions, if patient cannot speak, then
  that side of brain controls their speech
• 95 have left hemisphere specialization for
  speech (97 of righthanded 70 of lefthanded)

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Substrates for Speech and Language (or sign
language) 1. Most have left hemisphere
specialization for speech 2. Most cases of speech
impairment follow damage to left inferior frontal
region - Brocas area - speak in hesitant way -
trouble naming people or objects - reading and
writing are impaired - automatic (reflexive)
speech is okay - comprehension okay - often
accompanied by motor apraxia and partial
paralysis on right side of body
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Substrates for Speech and Language 2. Most cases
of speech impairment follow damage to left
inferior frontal region - Brocas area - speak
in hesitant way - trouble naming people or
objects - reading and writing are impaired -
automatic (reflexive) speech is okay -
comprehension okay - often accompanied by motor
apraxia and partial paralysis on right side of
body Symptoms describe Brocas Aphasia - a type
of language impairment
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2. Most cases of speech impairment follow damage
to left inferior frontal region - Brocas area -
Brocas aphasia 3. Other cases of language
impairment follow damage to left temporoparietal
cortex - Wernickes area, angular gyrus,
supramarginal gyrus - fluent speech, but often
does not make sense - structure okay, content
meaningless - substitute sounds (girl --gt
curl) - substitute categorical words (bread --gt
cake) - trouble understanding what they hear or
read - not accompanied by other physical
problems Wernickes Aphasia
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4. Broader damage to left hemisphere regions -
Global Aphasia - loss of ability to understand
spoken or written language, to speak, or to
write
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5. Narrower damage to cortical regions - more
specific language impairments Anomia -
difficulty naming Different frontal cortical
areas associated with naming objects vs animals
vs people.
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Spatial Processing and the Parietal Lobes
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Types of Spatial Processing Tasks
Category Function Brain
area 1) Spatial Attention Attention to left
hemispace Right parietal Attention
to right hemispace Left parietal 2) Spatial
Perception Object Localization RL
occipital and parietal
lobes Line orientation Right
parietal 3) Spatial Construction Building with
blocks RL parietal
Puzzles 4) Spatial mental Mental Rotation
Right parietal operations Mental
Imagery posterior
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I. Spatial attention Neurological damage and
visual attention A. Unilateral (one side) damage
to the parietal lobe Neglect syndrome - patients
spontaneously fail to process info on side
opposite to the damage Neglect contralateral
space - do not see people on one side of room
eat from only one side of the plate draw half of
an object. (But can adapt by learning to turn
plate to turn head to move objects across
visual field.)
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Neurological damage and visual attention A.
Unilateral (one side) damage to the parietal
lobe Neglect syndrome - patients spontaneously
fail to process info on side opposite to the
damage Neglect also seen for visual images in
memory - describe a well-known scene (home
town)from one point of view describe half of it.
Asked to describe it if looking at same scene
from another point of view - describe other half
of it. Info is processed or existent in memory -
but not attended to or brought to conscious
awareness! Neglect for words in non-attended
part of visual field - still get priming effects.
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Neurological damage and visual attention B.
Bilateral (both sides, RH and LH) damage to
posterior parietal lobes and part of occipital
cortex - Balints Syndrome Can perceive objects -
but only one at a time. Show 3 things - report
seeing only one (even when very close together).
Which one varies - cannot control the direction
of attention. Show person wearing glasses -
report person or glasses.
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II. Spatial Perception Object localization -
usually tested in visual domain - position of an
object relative to your own body (Is it lined
up straight? To left? to right?) - position of
object relative to some point in space (How
close is dot to edge of card?) Line orientation
detection - Benton test often used (visual)
line segments - Tactile test (metal rod) feel
its position (blindfolded)
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III. Spatial Construction Tasks Block
Design Object Assembly
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IV. Spatial mental operations Mental Rotation
Mental Imagery Mental Rotation -
manipulating objects through mental space
manipulate through 360 degrees of rotation -
task is to determine if stimulus object 1 would
look like stimulus object 2 if rotated into that
position or is stimulus object 2 a mirror image
of 1? - use asymmetric stimuli B E R
P F K L Mental Imagery - describe a
scene from memory perform tasks (What color is a
banana, etc? What is bigger an orange or a lemon?
What is darker lettuce or a green pepper?