IV. Neuroscience
The relationship between brain
and behavior.
A. Earliest work...
Brain/body and behavior connection.
– Hippocrates: brain injury and behavior
– Phrenology (Franz Gall – 1800’s)
What does your skull say about you?
B. The body’s basic communication network.
 The
1. “Communication system”.
nervous system:
Encounter a bear in the woods.....
Coordinates the body and environment.
– “Electrochemical”
receives messages
organizes messages
sends out messages
B. The body’s basic communication
2. Two components:
– a. Central Nervous System (CNS)
Brain and spinal cord.
B. The body’s basic
communication network
2. Two components:
– b. Peripheral Nervous System.
Connects CNS with rest of body.
Controls skeletal movement and internal
Nervous System
(brain and
spinal cord)
Autonomic (controls
self-regulated action of
internal organs and glands)
Skeletal (controls
voluntary movements of
skeletal muscles)
C. Basic Building Blocks of Neural
– A neuron is a single nerve cell
– A nerve is a bundle of neurons
Nerve cell - most basic component.
Information carrier and integrator.
“Talks” to other cells, muscles, etc.
1. 3 different kinds of neurons:
– Sensory:
– Interneuron:
– Motor:
2. Structure of a Neuron
C. Basic Building Blocks of
Neural Communication
2. Structure of neuron:
– Dendrites receive signals.
Carry info to cell body.
– Cell body synthesizes these signals.
– Signal travels down axon.
Away from cell body.
– Helped along by myelin sheath.
Made up of glial cells.
C. Basic Building Blocks of Neural
3. How neurons communicate.
 a. Chemistry-to-electricity process.
– Within neuron part:
– Neuron at rest – electrically charged.
Resting potential.
Ions exist outside/inside of cell membrane.
More negative ions inside of membrane.
– Gets stimulated (by light, heat, pressure,
chemicals from other neurons).
C. Basic Building Blocks of
Neural Communication
3. How neurons communicate (with neuron).
a. Chemistry-to-electricity process.
– Positive ions move into cell – if strong enough –
causes depolarization
– But – strong enough means must reach:
– Threshold 
– Fires signal/electric impulse down axon 
called Action potential.
“All-or-none process”
C. Basic Building Blocks of
Neural Communication
3. How neurons communicate.
b. Importance of neurotransmitters.
Between neuron communication.
Synapse: Junction between axon tip of sending
neuron and dendrites of receiving neuron.
Synaptic Gap - tiny gap between neurons.
Action potential fires, travels down axon – releases 
Neurotransmitters - chemical messengers 
cross the synaptic gap, binds to sites on receiving
3. How neurons communicate
a. Importance of Neurotransmitters.
Found in different places, do different jobs.
- Acetylcholine (learning, memory, muscle contraction,)
- Endorphins (mood/pain)
- Dopamine (smooth movement)
- Norepinephrine (alertness, arousal)
- Serotonin (mood, hunger, sleep)
3. How neurons communicate
c. Neurotransmitters and drugs.
Agonist: EXCITES.
Drug/toxin mimics the effects of
neurotransmitter, or heightens activity of
Antagonists: INHIBITS
Drug/toxin that inhibits release or blocks
absorption of neurotransmitters.
Influence of drugs on neurotransmitters:
Example: Cocaine
Importance of REUPTAKE.
– Agonists heighten neurotransmitter activity by
blocking reuptake of the chemical.
– Then, body stops producing own
neurotransmitters – acts like antagonist.
D. Brain
2. Structure
 a. Lower Level
– Brainstem: oldest, innermost region
controls arousal.
– Thalamus: “switchboard”
– Cerebellum: little brain
coordinates movement and balance
The Brain
2a. Lower level brain structure
– Limbic system:
amygdala - aggression, fear
hypothalamus - hunger, thirst, sexual behavior.
– “reward center”
hippocampus - memory.
The Limbic System
2. Structure of brain:
a. Lower Level
2. Structure of Brain:
b. Cerebral Cortex
1. “Bark” of the brain
2. Structure of Brain:
b. Cerebral Cortex
2. Function of 4 Lobes:
Frontal: Motor Cortex
Specific areas stimulate movement.
Parietal: Sensory Cortex
Receives information from skin and
body parts (touch/movement).
2. Structure of Brain:
b. Cerebral Cortex
2. Functions of 4 Lobes, cont’d.
Occipital: processes visual information,
sends it elsewhere to be decoded.
Temporal: processes sound.
Sensory and motor cortex, and visual and
auditory areas take up 1/4 of brain.
2. Structure of Brain:
b. Cerebral Cortex
Association Areas:
Other “3/4” of cerebral cortex.
Integrates, interprets, acts on information.
(i.e. important to communication).
Areas and their associated behaviors have
been identified based on what happens
when those areas are damaged.
B. Association Areas
Frontal Lobe:
- cannot plan or judge.
- alters personality - Phinneas Gage
- speech production- Broca’s Area
Temporal Lobe:
- can’t recognize faces.
- speech understanding - Wernicke’s Area
C. Two Hemispheres of Brain
Brain’s sides (left and right) serve
different purposes.
 Stroke?
 Damage to left side - reading, writing,
speaking, understanding.
- considered “major”, verbal hemisphere
 Damage to right side - not as dramatic
C. Two Hemispheres of Brain
Corpus callosum
Important - how sides
communicate with each
– Corpus Callosum: bundle
of neural fibers
connecting both sides,
carries messages
between them.
– If severed, demonstrates
how both sides work
c. Two Hemispheres of Brain
Talents of each hemisphere.
Right: perceptual
picture recognition
emotion, expression, creativity
Left: speaking, calculating numbers
word recognition
analytical, logical
There is no psychology without biology.
 From the neuron to the brain:
– How information/stimuli are taken in,
integrated, and responses (behavior) are
generated based on the body’s
communication system – nervous system.
Neural Systems
Neurons in the brain
connect with one
another to form networks
The brain learns by modifying
certain connections in
response to feedback
Neural Networks
interconnected neural
with experience,
networks can learn