THE BRAIN
PART II-A
The scans that we are going to discuss involve:
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Diagnosing Psychological Disorders
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Determining How Drugs Affect the Brain and Body
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Assessing the usefulness of hypnosis
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Examining whether the unconscious processes affects
behavior
Exploring the Interaction of Sensation and Perception
RECORDING THE BRAIN’S
ELECTRICAL ACTIVITY
You may have heard of an EEG:
electroencephalogram. It is an
amplified readout of soundwaves.
Studying an EEG of the brain is
like studying a car engine by
listening to its hum. By presenting
a stimulus repeatedly and having a
computer filter out brain activity
unrelated to the stimulus, one can
identify the electrical wave evoked
by the stimulus
THIS IS WHAT IT LOOKS LIKE
IN THE PREVIOUS PICTURE…
The girl in the picture is a
4-year-old girl suffering
from epilepsy. The EEG is
recording her brain
activity.
CT SCAN
A series of X-Ray photographs
taken from different angles and
combined by computer to into a
composite representation of a slice
through the body. Sometimes
called a CAT Scan.
CT Scans can reveal brain damage.
CT=Computed Tomography
PET SCAN
PET SCAN
Depicts brain activity by showing each brain
area’s consumption of it’s chemical fuel, the sugar
glucose. Active neurons are glucose hogs. After a
person receives temporary radioactive glucose,
the PET scan detects where this “food for
thought” goes by locating radioactivity. Rather
like weather radar showing rain activity, PET
scan “hot spots” show which brain areas are most
active as the person performs mathematical
calculations, looks at images of faces, or
daydreams.
MRI
Magnetic Resonance Imaging
A technique that uses magnetic fields and radio
waves to produce computer generated images of
soft tissue. MRI Scans show brain anatomy.
MRI OF 2 BRAINS, BRAIN ON R ENLARGED AND
FLUID-FILLED DUE TO SCHIZOPHRENIA
OLDER BRAIN STRUCTURES
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Brainstem: begins where the spinal cord swells
slightly after entering the skull; the brainstem is
responsible for automatic survival functions.
Medulla: Base of the Brainstem. Controls
heartbeat and breathing.
THE THALAMUS
The brain’s sensory
switchboard, located on top of
the brainstem. It directs
messages to the sensory
receiving areas in the cortex
and transmits replies to the
cerebellum and medulla.
THE CEREBELLUM
The “little brain.”
The cerebellum exists at the rear of
the brain stem; functions include
processing sensory input and
coordinating movement and balance.
MORE ON THE CEREBELLUM
Myers says:
“When David Beckham fires the ball into the net
with a perfectly timed kick, give his cerebellum
some credit. If you injured your cerebellum, you
would have difficulty walking, keeping your
balance, or shaking hands. Your movements
would be jerky and exaggerated. Under alcohol’s
influence on the cerebellum, walking may lack
coordination, as many a driver has learned after
being pulled over and given a roadside test.”
THE LIMBIC SYSTEM
Neural System which includes
the hippocampus, amygdala, and
hypothalamus. Located below
the cerebral hemispheres;
associated with emotions and
drives.
LIMBIC SYSTEM
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Hypothalamus: directs several maintenance
activities (eating, drinking, and body temp).
Helps govern the endocrine system via the
pituitary gland, and is linked to emotion and
reward.
Amygdala: 2 clusters in the limbic system linked
to emotion.
Hippocampus: linked to memory