The Brain: Our Control Center

The Brain: Our Control Center
Chapter 3 Section 2
The Hindbrain
Medulla – vital function – heart
rate, blood pressure, and breathing
Pons – in the front of the Medulla
regulate body movement, attention,
sleep, and alertness.
Cerebellum – (“little brain”) balance
and coordination
The Midbrain
Located between the hindbrain the
forebrain area is involved in vision and
Reticular Activating System- (begins in
the hindbrain and rises to the
forebrain) this system is important to
attention, sleep, and arousal
(increasing heart rate, blood pressure,
and brain activity).
Some drugs (alcohol) reduce
the activity of the RAS. Loud noises can
stimulate this system.
The forebrain makes it
possible for humans to
engage in complex thinking.
The Forebrain
Thalamus- (“inner chamber”)
Relay station for sensory
stimulation. Sense organs
send information through the
thalamus to the higher levels
of the brain.
Hypothalamus -(“under”)
tiny area vital to regulating
body temperature, storage of
nutrients, areas of motivation
and emotion, as well as,
hunger, thirst, sexual
behavior, caring for offspring
and aggression.
(disturbances lead to unusual
eating or drinking behaviors.
Limbic system – forms a fringe
along the inner edge of the
cerebrum. It is involved in
memory, emotion, hunger, sex,
and aggression. Damage to
specific parts can cause loss of
new memories, aggressive or
passive behaviors, etc.
Cerebrum -(“Brain”)only human
cerebrums make up such a large
portion of the brain. 70% of the
weight of the brain.
The Forebrain
Cerebral cortex- (“bark of a
tree”)surface of the cerebrum
that is wrinkled and has valleys.
Deals with memory, language,
emotions, complex motor
functions, perception, etc.
Cerebral Cortex
Two sides : left and right
hemispheres (hemihalf)connected by the corpus
callosum. Information received
by one side of the body is
transmitted to the opposite
side’s hemisphere. Each side is
divided into 4 lobes:
Frontal lobe– behind the
Parietal lobe – to and rear of
the head
Temporal lobe – to the side just
below the ears
Occipital lobe- back of the head
Occipital Lobe – Primary
visual area of the cerebral
Damage to this
lobe may cause people to
recognize an object, but not
be able to differentiate
(facial recognition)
Temporal Lobe- hearing or
auditory area of the cortex
Parietal lobe- messages
received through the skin go
through the sensory cortex
in this lobe.
Frontal lobe – motor cortex
Association areas- shape information into something meaningful.
Left and Right Brains have many of the same
functions, but differ in a number of ways.
Most right handed people’s language function
in the left brain (and many left handed)
Wernicke’s Area (temporal lobe language
function area)- pieces together sights and
damage makes it difficult to
understand speech
Boca’s Area (frontal lobe near the motor
cortex)- control’s areas of the face used for
damage makes speaking difficult
• Psychologists learn about left and right brain
operations through split brain operations
where the corpus callosum is cut, often in
surgery’s for epilepsy. This procedure can
reduce the severity of seizures, but the
hemispheres cannot communicate with one
another. (People can sometimes describe
something held in their right hand, but not in
their left)
Methods of Studying the Brain
• Much of early research of the brain came from
studying those with brain injury, now
Psychologists use many methods
• Brain damage from head
injuries can result in loss
of vision, and hearing,
confusion, or loss of
• Loss of large areas of brain
may result in little loss of
function, whereas loss of
small vital areas a greater
• Electrical Stimulation of the Brain
• Electroencephalogram (EEG)
• Scans
EEG (Electroencephalogram)- a
device that records the electrical
activity of the brain. Used to
diagnose some psychological
disorders and to locate tumors
through brain wave activity.
CAT (Computerized Axial Tomography)- x-ray
beams are passed through the head by a moving
ring. Density of brain tissue determines how
much radiation is absorbed. The Computer
them measures the amounts of radiation and
pieces together a 3D view of the brain.
MRI (Magnetic Resonance Imaging ) – A
person lies in a powerful magnetic field.
Radio waves then cause parts of the brain to
give off extra energy. The energy is
measured at different angles and is
translated into a visual image of the brain’s
anatomy. MRI show details more clearly and
is more powerful that a CT scan.
PET (Positron Emissional Tomography)- a person in
injected with radioactive sugar. More of the radioactive
sugar is used where brain activity is greater. A computer
then uses sugar levels to create a image showing the
amount of activity in different areas of the brain.