CHS AP Psychology
Unit 3: Biological Psychology
Essential Task 3-5a.Describe the subdivisions and functions of the Central Nervous System
A. Brain
i. Brain Stem
Medulla, Pons, Reticular Formation, Cerebellum, and the Thalamus
ii. Limbic System
Hypothalamus, Amygdala, and the Hippocampus
iii. Cerebral Cortex (Left and Right Hemispheres and the corpus callosum)
Occipital Lobe, Parietal Lobe, Temporal Lobe, and the Frontal Lobe
Primary Motor Cortex and Primary Sensory Cortex
Wernicke's Area and Broca's Area
B. Spinal Cord
Essential
Task
3-5:
CNS
Outline
A. Brain
i. Brain Stem
Medulla, Pons, Reticular Formation, Cerebellum,
and the Thalamus
ii. Limbic System
Hypothalamus, Amygdala, and the Hippocampus
iii. Cerebral Cortex
(Left and Right Hemispheres and the corpus callosum)
Occipital Lobe, Parietal Lobe, Temporal Lobe, and the
Frontal Lobe Primary Motor Cortex and Primary Sensory
Cortex Wernicke's Area and Broca's Area
B. Spinal Cord
The Brain Stem (Automatic Functions)
Brain Structure
Primary Function
Secondary Function
Medulla
Respiration, blood
pressure, heart rate
Vomiting
Pons
Puts you to sleep
Reticular Formation
Attention, regulates
awareness
Cerebellum
Balance and
coordination
Thalamus
Directs sensory
information to the rest
of the brain
Older Brain Structures
The Brainstem is the oldest part of the brain,
beginning where the spinal cord swells and enters
the skull. It is responsible for automatic survival
functions.
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Brain Stem
The Medulla [muh-DULuh] is the base of the
brainstem
It controls autonomic
functions and relays nerve
signals between the brain
and spinal cord.
•respiration
•blood pressure
•heart rate
•reflex arcs
•vomiting
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Brain Stem
Pons and inside that the (Reticular
Formation) is a nerve network in the
brainstem that plays an important role in
controlling arousal.
•It is involved in motor control and sensory
analysis... for example, information from the
ear first enters the brain in the pons. It has
parts that are important for the level of
consciousness and for sleep.
The Reticular Formation controls:
•Attention
•Cardiac Reflexes
•Motor Functions
•Regulates Awareness
•Relays Nerve Signals to the Cerebral Cortex
•Sleep
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Brain Stem
The Medulla [muhDUL-uh] is the base of
the brainstem that
controls heartbeat and
breathing.
Reticular Formation is a
nerve network in the
brainstem that plays an
important role in
controlling arousal.
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Brain Stem
The Thalamus [THALuh-muss] is the brain’s
sensory switchboard,
located on top of the
brainstem. It directs
messages to the sensory
areas in the cortex and
transmits replies to the
cerebellum and
medulla.
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Cerebellum
The “little brain”
attached to the rear of
the brainstem. It helps
coordinate voluntary
movements and balance.
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Limbic System (Emotion Center)
Brain Structure
Primary Function
Secondary
Function
Hypothalamus
Drives: Hunger,
Thirst, Sex
Temperature
control
Amygdala
Fight or Flight
Hippocampus
STM (short term memory) to
LTM (long term memory)
The Limbic System
The Limbic System is a
doughnut-shaped
system of neural
structures at the border
of the brainstem and
cerebrum, associated
with emotions such as
fear, aggression and
drives for food and sex.
It includes the
hippocampus, amygdala,
and hypothalamus.
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Amygdala
The Amygdala [ah-MIGdah-la] consists of two
almond-shaped neural
clusters linked to the
emotions of fear and anger.
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Hypothalamus
The Hypothalamus lies
below (hypo) the
thalamus. It directs
several maintenance
activities like eating,
drinking, body
temperature, and
control of emotions. It
helps govern the
endocrine system via
the pituitary gland.
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Reward Center
Sanjiv Talwar, SUNY Downstate
Rats cross an
electrified grid for
self-stimulation
when electrodes are
placed in the reward
(hypothalamus)
center (top picture).
When the limbic
system is
manipulated, a rat
will navigate fields or
climb up a tree
(bottom picture).
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THE END FOR TODAY! 
Cerebral Cortex
Brain Structure
Primary Function
Occipital Lobe
Visual Processing
Parietal Lobe
Spatial Reasoning
Frontal Lobe
Temporal Lobe
Decision Making
Auditory sensory
information
Motor Cortex
Movement
Sensory Cortex
Sensation
Wernicke’s Area
Understanding
Speech
Broca’s Area
Producing Speech
Secondary
Function
The Cerebral Cortex
The intricate fabric of interconnected neural cells
that covers the cerebral hemispheres. It is the body’s
ultimate control and information processing center.
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Structure of the Cortex
Each brain hemisphere
is divided into four
lobes that are separated
by prominent fissures.
These lobes are the
frontal lobe (forehead),
parietal lobe (top to rear
head), occipital lobe
(back head) and
temporal lobe (side of
head).
Functions of the Cortex
The Motor Cortex is the area at the rear of the
frontal lobes that control voluntary
movements. The Sensory Cortex (parietal
cortex) receives information from skin
surface and sense organs.
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Visual Function
The functional MRI scan
shows the visual cortex
is active as the subject
looks at faces.
Auditory Function
The functional MRI scan
shows the auditory
cortex is active in
patients who hallucinate.
Association Areas
More intelligent animals have increased
“uncommitted” or association areas of the
cortex.
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Language
Aphasia is an impairment of language,
usually caused by left hemisphere damage
either to Broca’s area (impaired speaking) or
to Wernicke’s area (impaired
understanding).
Specialization & Integration
Brain activity when hearing, seeing, and
speaking words
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Done for Today!
Fun with your Hemispheres
• Rotate your dominant hand in one direction
while at the same time rotating the opposite
foot in the other direction.
– No problem since controlled by two hemispheres
• Now, rotate your dominant hand in one
direction while at the same time rotating the
foot on the same side in the other direction.
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Hemispheric Specialization
• Corpus Callosum
– Fibers that connect the
two hemispheres
– Allow close
communication between
left and right
hemisphere
• Each hemisphere
appears to specialize in
certain functions
Hemispheric Specialization
People with intact brains also show leftright hemispheric differences in mental
abilities.
A number of brain scan studies show
normal individuals engage their right
brain when completing a perceptual task
and their left brain when carrying out a
linguistic task.
Splitting the Brain
A procedure in which the two hemispheres of
the brain are isolated by cutting the
connecting fibers (mainly those of the corpus
callosum) between them.
Corpus Callosum
Split Brain Patients
With the corpus callosum
severed, objects (apple)
presented in the right
visual field can be named.
Objects (pencil) in the left
visual field cannot.
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Divided Consciousness
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