10/13/2015
Brain Reorganization (84)
• Plasticity - the brain can change and reorganize
itself following damage
• Ex - scientists severed the neural pathways for
sensory information coming from the arm to the
brain. The area of the sensory cortex shifted its
function and began to respond when the monkey
was touched on the face
Divided Brain (85)
• Left side - generally is the dominant side in most people it controls reading, writing,
speaking, math
• Left side of brain controls right side of body
• Right side - more emotion, music, art,
spatial relations
Corpus Callosum (86)
• Band of neural fibers that
connects the two
hemispheres of the brain.
• It does serve a purpose
• Enter - the split brain
patients!!!!!
Brain Reorganization (84)
• Kempermann and Gage (1999) discover that adult
mice and humans can generate new brain cells
• Stem cells can develop into any type of brain cell
have been discovered in the fetal brain
• Phantom limbs
• Hemispherectomies - people retain their memory,
personality, humour
Splitting the Brain (85)
• 1961 - neurosurgeons Vogel and Bogen
sever the Corpus Collosum in epileptic
patients. The seizures stop and their
personalities and intellect were hardly
affected.
• Sperry, Myers and Gazzaniga had
previously divided cat and monkey brains
Vision with a Normal Brain (86)
• Information from the
left visual field goes to
the right hemisphere
(and vice versa). Then
the corpus callosum
shares the information
from side to side.
• Split brains don’t
share the information
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10/13/2015
Split Brain Experiment
Gazzaniga (86)
http://www.youtube.com/watch?v=aCv4K5aStdU
• Left Visual Field
HE
This goes from left
visual field to right
brain. The right side
brain controls the left
hand so the left hand
points to “HE”
• Right Visual Field
ART
This goes from right
visual field to left
brain which controls
speech. Patient says
“ART”.
Handedness
Brain Organization and
Handedness (89)
• 90% are right handed and 95% of these
process speech in their left hemispheres
• 10% are left handed - 50% process speech
in their left hemispheres - 25% process it in
the right - 25% process it in both!
• 9 in 10 fetuses suck their right thumbs
• Babies will show a R or L preference within
2 days of birth - they turn their heads R or L
Brain Parts Review!!!
• Geschwind and Behan (1984) - Left handers have
more reading disabilities, allergies, migranes
• Left handers are more common among musicians,
mathematicians, baseball players, architects
• Coren (1993) - found that left handed people are
15% of 10 year olds, 5% of 50 year olds and less
than 1% of 80 years olds. WHY - Coren thinks it
may be that lefties die younger!!!!!
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