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Chapter 3
Biopsychology and the Foundations of
Neuroscience
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ISBN: 0-131-73180-7
Copyright © Allyn & Bacon 2007
What is Biopsychology?
Biopsychology –
The specialty in psychology that studies
the interaction of biology, behavior, and
the environment
Neuroscience –
Interdisciplinary field that focuses on the
brain and its role in psychological
processes
Copyright © Allyn & Bacon 2007
How Does the Body
Communicate Internally?
The body’s two
communication systems, the
nervous system and the
endocrine system, both use
chemical messengers to
communicate with targets
throughout the body
Copyright © Allyn & Bacon 2007
The Neuron
Types of Neurons
Sensory neurons (carry messages from
sense receptors towards the CNS)
Motor neurons (carry messages from
CNS toward muscles and glands)
Interneurons (carry messages
between nerve cells)
Copyright © Allyn & Bacon 2007
The Structure of a Neuron
Copyright © Allyn & Bacon 2007
Parts of a Neuron
Cell Body: Life support center of the neuron.
Dendrites: Branching extensions at the cell body.
Receive messages from other neurons.
Axon: Long single extension of a neuron, covered with
myelin [MY-uh-lin] sheath to insulate and speed up
messages through neurons.
Terminal Branches of axon: Branched endings of an
axon that transmit messages to other neurons.
The Neural Impulse
Neural impulse –
Brief electric surge that carries the neuron’s message
Ions –
Charged particles that are moved across the cell
membrane
Copyright © Allyn & Bacon 2007
The Neural Impulse
Resting potential
Action potential
Synapse
Synaptic transmission
Copyright © Allyn & Bacon 2007
Action Potential Properties
All-or-None Response: A strong stimulus can
trigger more neurons to fire, and to fire more
often, but it does not affect the action potentials
strength or speed.
Intensity of an action potential remains the
same throughout the length of the axon.
Neurotransmitters
Neurotransmitters –
Chemical messengers that relay neural
messages across the synapse
Copyright © Allyn & Bacon 2007
Neurotransmitters
Neurotransmitters
(chemicals) released
from the sending
neuron travel across the
synapse and bind to
receptor sites on the
receiving neuron,
thereby influencing it to
generate an action
potential.
How Neurotransmitters Influence Us
Serotonin pathways are
involved with mood
regulation.
From Mapping the Mind, Rita Carter, © 1989
University of California Press
Dopamine Pathways
Dopamine pathways
are involved with
diseases such as
schizophrenia and
Parkinson’s disease.
From Mapping the Mind, Rita Carter, © 1989
University of California Press
Neurotransmitters
Seven Important Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Acetylcholine
GABA
Glutamine
Endorphins
Copyright © Allyn & Bacon 2007
Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Normal Function:
Produces sensations of
pleasure and reward; used
by CNS neurons in
voluntary movement
Problems with Imbalance:
Acetylcholine
GABA
Glutamine
Endorphins
Schizophrenia, Parkinson’s
disease
Substances that Affect:
Cocaine, amphetamines,
Ritalin, alcohol
Copyright © Allyn & Bacon 2007
Neurotransmitters
Dopamine
Serotonin
Normal Function:
Regulates sleep and
dreaming, mood, pain,
aggression, appetite and
sexual behavior
Norepinephrine
Problems with Imbalance:
Acetylcholine
GABA
Depression, certain anxiety
disorders, obsessivecompulsive disorder
Glutamine
Substances that Affect:
Endorphins
Prozac, hallucinogenics
(e.g. LSD)
Copyright © Allyn & Bacon 2007
Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Normal Function:
Controls heart rate, sleep,
sexual responsiveness,
stress, vigilance and
appetite
Problems with Imbalance:
Acetylcholine
GABA
Glutamine
Endorphins
High blood pressure,
depression
Substances that Affect:
Tricyclic antidepressants,
beta blockers
Copyright © Allyn & Bacon 2007
Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Acetylcholine
Normal Function:
Primary transmitter used by
neurons carrying messages
from CNS; involved in
some kinds of learning and
memory
Problems with Imbalance:
GABA
Certain muscular disorders,
Alzheimer’s disease
Glutamine
Substances that Affect:
Endorphins
Nicotine, botulism toxin,
curare, atropine
Copyright © Allyn & Bacon 2007
Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Normal Function:
Most prevalent inhibitory
neurotransmitter in neurons
of CNS
Problems with Imbalance:
Acetylcholine
Anxiety, epilepsy
GABA
Substances that Affect:
Glutamine
Endorphins
Barbiturates, tranquilizers
(e.g. Valium, Librium),
alcohol
Copyright © Allyn & Bacon 2007
Neurotransmitters
Dopamine
Normal Function:
Norepinephrine
Primary excitatory
neurotransmitter in CNS;
involved in learning and
memory
Acetylcholine
Problems with Imbalance:
Serotonin
GABA
Glutamine
Brain damage after stroke
Substances that Affect:
PCP (“angel dust”)
Endorphins
Copyright © Allyn & Bacon 2007
Neurotransmitters
Dopamine
Normal Function:
Serotonin
Pleasurable sensations and
control of pain
Norepinephrine
Problems with Imbalance:
Acetylcholine
Lowered levels resulting
from opiate addiction
GABA
Glutamine
Endorphins
Substances that Affect:
Opiates: opium, heroin,
morphine, methadone
Copyright © Allyn & Bacon 2007
Plasticity
Plasticity –
Ability of the nervous system to adapt or change as the
result of experience; sometimes helps the nervous
system adapt to physical damage
Copyright © Allyn & Bacon 2007
Glial Cells
Glial cells
• Provide structural support for neurons
• Help in forming new synapses
• Form myelin sheath
Copyright © Allyn & Bacon 2007
How Does the Brain
Produce Behavior and
Mental Processes?
The brain is composed of
many specialized modules
that work together to create
mind and behavior
Copyright © Allyn & Bacon 2007
Windows on the Brain
EEG (electroencephalograph) –
Device for recording brain waves, typically by electrodes
placed on the scalp
Brain waves –
Patterns of electrical activity generated by the brain
Copyright © Allyn & Bacon 2007
Windows on the Brain
Epilepsy –
Brain disorder that is often marked by seizures and loss
of consciousness; caused by out-of-control electrical
activity in the brain
Copyright © Allyn & Bacon 2007
Windows on the Brain
Lesions –
Tissue damage that results from disease or injury
Copyright © Allyn & Bacon 2007
Windows on the Brain
Brain scans –
Recordings of the brain’s electrical or biochemical
activity at specific sites
• CT scanning (computerized tomography)
• PET scanning (positron emission tomography)
• MRI (magnetic resonance imaging)
Copyright © Allyn & Bacon 2007
PET Scan
Courtesy of National Brookhaven National Laboratories
PET (positron emission
tomography) Scan is a
visual display of brain
activity that detects a
radioactive form of
glucose while the brain
performs a given task.
MRI Scan
MRI (magnetic resonance
imaging) uses magnetic
fields and radio waves to
produce computergenerated images that
distinguish among
different types of brain
tissue. Top images show
ventricular enlargement in
a schizophrenic patient.
Bottom image shows brain
regions when a
participants lies.
Both photos from Daniel Weinberger, M.D., CBDB, NIMH
James Salzano/ Salzano Photo
Lucy Reading/ Lucy Illustrations
Three Layers of the Brain
Brain stem and cerebellum
Drive vital functions, such as heart rate,
breathing, digestion
Limbic system
Adds emotions, complex motives, increased
memory abilities
Cerebrum
Enables reasoning, planning, creating,
problem solving
Copyright © Allyn & Bacon 2007
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.
Brainstem
The Medulla [muhDUL-uh] is the base of
the brainstem that
controls heartbeat and
breathing.
Brainstem
The Thalamus [THAL-uh-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.
Brainstem
Reticular Formation is a
nerve network in the
brainstem that plays an
important role in
controlling arousal.
Cerebellum
The “little brain”
attached to the rear of
the brainstem. It helps
coordinate voluntary
movements and
balance.
The Brain Stem and Cerebellum
Thalamus
Pons
Cerebellum
Medulla
Brain stem
Copyright © Allyn & Bacon 2007
The Limbic System
Hypothalamus –
Serves as the
brain’s bloodtesting
laboratory,
constantly
monitors blood to
determine the
condition of the
body
Copyright © Allyn & Bacon 2007
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.
Amygdala
The Amygdala [ah-MIGdah-la] consists of two lima
bean-sized neural clusters
linked to the emotions of
fear and anger.
The Limbic System
Amygdala –
Involved in
memory and
emotion,
particularly fear
and aggression
Copyright © Allyn & Bacon 2007
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.
The Limbic System
Hippocampus –
Involved in establishing
long-term memories
Copyright © Allyn & Bacon 2007
The Cerebrum
Cerebrum –
Topmost layer of the brain; the
bulbous cap over the limbic system
Cerebral cortex –
Thin gray-matter covering of the
cerebrum; carries on thinking and
perceiving
Cerebral hemispheres –
The two walnut shaped halves of the
cerebrum, connected by the corpus
callosum
Copyright © Allyn & Bacon 2007
The Four Lobes of the
Cerebral Cortex
Frontal lobes
(movement and thinking)
Parietal lobes
(touch sensation and spatial
relationships)
Occipital lobes
(contain visual cortex)
Temporal lobes
(process sounds, including
speech)
Copyright © Allyn & Bacon 2007
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.
The Cooperative Brain
Association cortex –
Cortical regions that combine information from various
other parts of the brain
Copyright © Allyn & Bacon 2007
Cerebral Dominance
Cerebral dominance –
Tendency of each brain hemisphere to
exert control over different functions
Aphasia –
The loss of speech caused be brain
damage
Copyright © Allyn & Bacon 2007
Specialization of the
Cerebral Hemispheres
Left Hemisphere
Right Hemisphere
• Spontaneous
speaking and
writing
• Responses to
complex commands
• Word recognition
• Memory for words
and numbers
• Sequences of
movements
• Feelings of anxiety
• Positive emotion
• Repetitive but not
spontaneous
speaking
• Responses to simple
commands
• Facial recognition
• Memory for shapes
and music
• Spatial interpretation
• Emotional
responsiveness
• Negative emotion
Copyright © Allyn & Bacon 2007
Our Divided Brain
Our brain is divided into two hemispheres.
The left hemisphere processes reading, writing,
speaking, mathematics, and comprehension
skills. In the 1960s, it was termed as the
dominant brain.
The Split Brain
Split-brain patients –
Individuals who have had the corpus callosum surgically
severed
Duality of consciousness –
Condition in which a split-brain patient has a separate
consciousness in each hemisphere
Copyright © Allyn & Bacon 2007
End of Chapter 3
Copyright © Allyn & Bacon 2007