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The Biology of Mind.
Consciousness and the
Two-Track Mind.
Neuroscience and Behavior
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Biological psychology is the scientific study of the
biological bases of behavior and mental processes.
This area of research is also called biopsychology.
Both terms emphasize the idea of a biological
approach to the study of psychological processes.
Biological psychology is one of the scientific
disciplines that makes important contributions to
neuroscience—the scientific study of the nervous
system. As neuroscientists, biopsychologists bring
their expertise in behavior and behavioral research to
this scientific endeavor.
Some of the other scientific disciplines that contribute
to neuroscience include physiology, pharmacology,
biology, and neurology.
Neurons

Communication
throughout the
nervous system
takes place via
neurons—cells
that are highly
specialized to
receive and
transmit
information from
one part of the
body to another.
Glial cells
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Along with
neurons, the human
nervous system is
made up of other
types of
specialized cells,
called glial cells
between neurons
and blood vessels
in the brain.
Glia and Blood-Brain Barrier
Basic types of neurons
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There are three basic types of neurons, each
communicating different kinds of information:
Sensory neurons convey information about the
environment, such as light or sound, from specialized
receptor cells in the sense organs to the brain.
Sensory neurons also carry information from the skin
and internal organs to the brain.
Motor neurons communicate information to the
muscles and glands of the body. blinking your eyes
activates thousands of motor neurons.
Interneurons communicate information between
neurons. By far, most of the neurons in the human
nervous system are interneurons, and many
interneurons connect to other interneurons.
Characteristics of the
Neuron
• Most neurons have three
basic components: a cell
body, dendrites, and an
axon. The cell body
contains the nucleus,
which provides energy
for the neuron to carry
out its functions. The cell
body also contains
genetic material and
other structures that are
found in virtually all the
cells in the body
Components of the neuron
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The cell body contains the nucleus, which provides energy for
the neuron to carry out its functions. The cell body also
contains genetic material and other structures that are found in
virtually all the cells in the body.
Extending out from the cell body are many short, branching
fibers, called dendrites. Dendrites receive messages from
other neurons or specialized cells.
The axon is a single, elongated tube that extends from the cell
body in most, though not all, neurons. Axons carry
information from the neuron to other cells in the body,
including other neurons, glands, and muscles.
The axons of many, though not all, neurons are surrounded by
the myelin sheath. The myelin sheath is a white, fatty
covering anufactured by special glial cells.
The Neuron
Soma
Dendrites
Myelin
Sheath
Axon
Axon
Terminals
Function of ion gate
Action Potentials
Communication Between Neurons

In the brain, as in
the rest of the
nervous system,
information is
transmitted by
electrical impulses
that speed from
one neuron to the
next.
The Synapse
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The point of
communication
between two
neurons
is called the
synapse.
The transmission
of information
between two
neurons occurs in
one of two
ways: electrically
or chemically.
Chemical Signals
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One neuron will transmit info to another neuron or to a muscle or
gland cell by releasing chemicals called neurotransmitters.
The site of this chemical interplay is known as the synapse.
 An axon terminal (synaptic knob) will abut another cell, a
neuron, muscle fiber, or gland cell.
 This is the site of transduction – the conversion of an electrical
signal into a chemical signal.
Synaptic
Transmission
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An AP reaches the axon
terminal of the
presynaptic cell and
causes V-gated Ca2+
channels to open.
Ca2+ rushes in, binds to
regulatory proteins &
initiates NT exocytosis.
NTs diffuse across the
synaptic cleft and then
bind to receptors on the
postsynaptic membrane
and initiate some sort of
response on the
postsynaptic cell.
Important
Neurotransmitters
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Acetylcholine -learning,
memory, muscle contractions
Dopamine – movement,
thought processes, rewarding
sensations
Serotonin - emotional states,
sleep
Norepinephrine - physical
arousal, learning, memory
GABA - Inhibition of brain
activity
Endorphins Pain perception
Positive emotions
Central & peripheral
nervous system
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The central nervous
system includes the brain
and the spinal cord.
Bundles of neuron axons
that carry information in the
peripheral nervous
system.
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Reflex
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a simple, automatic, inborn response to a sensory stimulus
Brain
Sensory neuron
(incoming information)
Interneuron
Motor neuron
(outgoing
information)
Muscle
Skin
receptors
Spinal cord

Neural Networks

Neurons in the brain
connect with one
another to form networks

Inputs
Outputs
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The brain learns by modifying
certain connections in
response to feedback
interconnected
neural cells
with experience,
networks can
learn, as feedback
strengthens or
inhibits
connections that
produce certain
results
computer
simulations of
neural networks
show analogous
learning
Specialized Cortical Regions
revealed with PET scan
Brain scan images
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Brain scan images have
become so commonplace
in news articles and
popular magazines that
it’s easy to forget just
how revolutionary brain
imaging technology has
been to the field of
neuroscience
Looking at Brain-Scan Images
The ‘Split Brain’ studies
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Surgery for epilepsy : cut
the corpus callosum
Roger Sperry, 1960’s
Special apparatus
 picture input to just
one side of brain
 screen blocks objects
on table from view
Verbal
left
hemisphere
Nonverbal
right
hemisphere
The ‘Split Brain’ studies
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Picture to right brain
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can’t name the object
“What
“Using
“What
yourdid
left
did hand,
see?”
Pick you
up
you
what
see?”
you saw.”
left hand can identify by
touch
Picture to left brain
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can name the object
left hand cannot identify
by touch
??
I saw an
Verbal
Verbal
apple.
leftleft
hemisphere
hemisphere
Nonverbal
right
hemisphere