Download Figure 3B.23 Testing the divided brain

The Brain
The Brain
• Made up of neurons
• 23 billion nerve cells
and 300 trillion
synapses
• Glial cells –
My husband is my glial cell.
He takes care of me!!!
Whose yours?
Ways we Study the Brain
Accidents
Phineas Gage
• Personality changed
after the accident.
What did this tell us?
• That different part
of the brain control
different aspects of
who we are.
Lesions
• Frontal
Lobotomy
Electroencephalogram
• EEG
• Detects brain
waves through
their electrical
output.
• Used mainly in
Computerized Axial Tomography
• CAT Scan
• 3D X-Ray of
the brain.
Magnetic Resonance Imaging
• MRI
Positron Emission Tomography
• PET Scan
Functional MRI
• Identifies most active areas of the brain
during a specific mental task
Brain Structures
• Scientists divide the
brain up into three
parts.
Brain Regions
•
– medulla, pons, reticular
formation, thalamus,
cerebellum
• Hippocampus,
Amygdala,
Hypothalamus
• frontal lobe, parietal
lobe, temporal lobe,
occipital lobe,
Brain Stem
• Part of the brain with the
oldest ancestry
• 5 Regions:
–
–
–
–
–
Medulla
Pons
Reticular formation
Thalamus
Cerebellum
Medulla Oblongata
• Brain’s Autopilot
works with nervous
systems…. Autonomic
nervous system
• Controls:
• Damage?
Pons
• Acts as a bridge
between the brain
stem and cerebellum
• Routes nerves from
left side of the body
to right side
• Damage?
Cerebellum
• “little brain” attached
near brain stem
• Relies on visual
information to coordinate
voluntary movement
• Example:
Reticular Formation
• Responsible for
arousal and ability
to focus
attention.
• Regulates sleep
wake cycle
If stimulated
• Ex. Arouses you
in AP Psych class
If destroyed
Thalamus
• Receives sensory information
from all senses except NOSE
• Like a switchboard.
• Example: routing information
from eyes to visual cortex
Limbic System
• EMOTIONAL CONTROL
CENTER of the brain.
• REWARD CENTER of the
brain (hypothalamus)
• Located between the
brainstem and cerebral
hemispheres
• Made up of Hypothalamus,
Amygdala and Hippocampus.
Hypothalamus
• Controls the 4 F’s.
–
–
–
–
Fight (endocrine system)
Flight
Food (hunger & thirst)
Fornication (sex drive)
• Endocrine System
– Influences Pituitary Gland to release
hormones
• Temperature
• Maintains homeostasis
• Brain’s Reward system – what
neurotransmitter?
• Damage? Inability to regulate…
– Example:
Hippocampus
• Hippocampus is
involved in
• Example
Amygdala
• Amygdala is vital for
our basic emotions.
– Example:
Figure 3B.11 Brain structures and their functions
© 2011 by Worth Publishers
Cerebral Cortex
• Cerebral cortex
– thin layer of interconnected neural cells
• Glial cells
• Fissures – folds that increase the
surface area of the brain.
Areas of the Cerebral Cortex
• Divided into eight
lobes, four in each
hemisphere
Parietal Lobes
• Located at the top
of our head.
Sensory Cortex
• Registers and
processes
• “Senses” motor
movement
Frontal Lobe
Motor Cortex
• Controls
• Located in the rear
portion of the frontal
lobe
• Most critical for sense
of touch
Figure 3B.13 Left hemisphere tissue devoted to each body part in
the motor cortex and the sensory cortex As you can see from this
classic though inexact representation, the amount of cortex devoted to a
body part is not proportional to that part’s size. Rather, the brain devotes
more tissue to sensitive areas and to areas requiring precise control.
Thus, the fingers have a greater representation in the cortex than does the
upper arm.
Temporal Lobes
• Processes
• Receive info from
the opposite ear.
• Auditory Cortex –
Occipital Lobes
• In the back of our
head.
•
• Right half of each
retina goes to left
occipital lobe and
vice versa.
• Visual cortex –
Association Areas
• Locate in cerebral cortex
• Not directly involved in sensory
and motor activity (sensory
cortex, motor cortex, visual
cortex or auditory cortex)
• Involved in higher mental
functions such as
• Example:
Figure 3B.16 Areas of the cortex in four mammals
More intelligent animals have increased
“uncommitted” or association areas of the cortex. These
vast areas of the brain are responsible for integrating and
acting on information received and processed by sensory
areas.
© 2011 by Worth Publishers
Language Development
• Aphasia –
• Frontal Lobe
– Broca’s Area –
• Temporal Lobe
– Wernicke’s Area –
• Parietal Lobe
– Angular Gyrus –
The Divided Brain
• Plasticity –
• .
• The younger you are, the more plastic your
brain is.
• Contraint induced therapy - teaching a
patient to regain the use of an impaired limb
by limiting the use of the good limb
• Neurogenesis –
What can you do to
produce
new neurons?
Hemispheres
• Brain Lateralization divided into a left and
right hemisphere.
• Contralateral
controlled- left controls
right side of body and
vice versa.
• Left Brain –
• Right Brain –
Split-Brain Patients
• Sperry and Gazzaniga
• Corpus Callosum –
connects two brain
hemispheres and carries
messages between them
• Removed in patients with
severe epilepsy
• When removed you have a
split-brain patient.
Figure 3B.22 The information highway from eye to
brain
Information from the left half of your field of vision
goes to your right hemisphere, and information from the
right half of your visual field goes to your left
hemisphere, which usually controls speech. (Note,
however, that each eye receives sensory information
from both the right and left visual fields.) Data received
by either hemisphere are quickly transmitted to the other
across the corpus callosum. In a person with a severed
corpus callosum, this information sharing does not take
place.
© 2011 by Worth Publishers
Figure 3B.23 Testing the
divided brain When an
experimenter flashes the word
HEART across the visual field, a
woman with a split brain
However, if asked to indicate
with her left hand what she saw,
.
From Gazzaniga, 1983
Figure 3B.25 Which one is happier? Look at
the center of one face, then the other. Does one
appear happier?
The Brain and Consciousness
• Consciousness –
• Dual Processing –