AP Psychology – Guided Notes
Name:
Unit 3: Biological Bases of Behavior
1
Period:
Key Ideas:
- Techniques to learn about structure and
function
- Nervous system organization
- Brain structure and function
-
Neuron structure and functions
Endocrine system structure and function
Evolution and behavior
Genetics and behavior
:
-
psychologists who explore the relationships between
-
aka: biological psychologists,
and behavior.
, behavioral
geneticists, physiological psychologists, and
.
ORGANIZATION OF YOUR NERVOUS SYSTEM
-
All of the neurons in your body are organized into your
-
The two major subdivisions are the
.
nervous system and the
nervous system.
-
Central Nervous System (CNS): made up of the
o
and
.
: starts at the base of your back and extends upward to the
base of your skull where it joins your brains.
o Made mainly of
and
cells, which
are all bathed by cerebrospinal fluid produced by your glial cells.
-
(PNS): made
up the somatic and autonomic nervous systems, and spread around your body from your spinal cord
outwards.
o
Nervous System: motor neurons that stimulate skeletal (voluntary)
muscle.
o
Nervous System: motor neurons that stimulate smooth
(involuntary) and heart muscle.
-
The Autonomic Nervous System is divided into two parts:
o
Nervous System: Responses that help your body deal with
stressful events, including:

Dialation of pupils, release of glucose from your liver, dilation of bronchi, inhibition of
digestive functions, acceleration of heart rate, secretion of adrenalin from your adrenal
glands, acceleration of breathing rate, and inhibition of secretion of your tear glands.
AP Psychology – Guided Notes
o
Unit 3: Biological Bases of Behavior
2
Nervous System: Calms your body following sympathetic
stimulation by restoring digestive processes (salivation, peristalsis, enzyme secretion), returning
pupils to normal size, stimulating tear glands, restoring normal bladder contractions, slow
breathing and heart rate, etc.
NERVOUS SYSTEM “TREE”:
STRUCTURE AND FUNCTION OF THE NEURON
-
: the basic unit of structure and function of your nervous system.
o three major functions:
o
information,
it, and
it to
the rest of your body.
-
: guide the growth of developing neurons,
help provide nutrition for and get rid of wastes of the neuron, and form an insulating sheath around
neurons that speeds conduction.
-
(cyton or soma): contains cytoplasm and the
nucleus, which directs synthesis of neurotransmitters.
AP Psychology – Guided Notes
Unit 3: Biological Bases of Behavior
-
: branching tubular processes capable of receiving information.
-
: emerges from the cyton as a single conducting fiber (longer than a
3
dendrite) which branches.
-
(
or
synaptic knob): tip of the axon.
-
: fatty tissue created by glial cells that
insulate the axon and speeds up transmission.
-
: growth of new neurons that takes place throughout
life.
-
: chemicals stored in structures of the
terminal buttons called synaptic vesicles.
o Used by neurons to
with each other.
NEUROTRANSMITTERS - Directions: Fill in the chart below based on the other groups’
presentations. Don’t forget to include your own information!
Neurotransmitter:
Function:
Too much:
Too little:
acetylcholine
(ACh)
dopamine
AP Psychology – Guided Notes
Unit 3: Biological Bases of Behavior
4
glutamate
serotonin
endorphins
Gamma-aminobutyric
acid (GABA)
-
Other chemicals, like
, can interfere with the action of neurotransmitters.
o
may mimic a neurotransmitter and bind to
its receptor site to produce the effect of the neurotransmitter.
o
block a receptor site inhibiting the effect of
the neurotransmitter or agonist.
-
: the gap between neurons where neurotransmitters
are released to attach to specific receptor sites on membranes of dendrites of your postsynaptic neurons.
o This is called the “
concept” because
each neurotransmitter has a specific match on the dendrites, like a key fitting into a lock.
Neuron Functions
-
All behavior begins with the actions of your
-
A neuron gets incoming information from its receptors spread around its
-
.
.
AP Psychology – Guided Notes
- The info is then sent to the
Unit 3: Biological Bases of Behavior
5
, where it’s combined with
other incoming information.
-
Neural impulses are
in nature along the neuron.
-
The neuron at rest is more
inside the cell membrane relative to outside the
membrane.
o The neuron’s
results from
the selective permeability of its membrane and the presence of electrically charged particles
called ions near the inside and outside surfaces of the membrane in different concentrations.
o When sufficiently stimulated (to
), a net flow of sodium ions
into the cell causes a rapid change in potential across the membrane, known as
.

If your stimulation is
enough, your
neuron does not fire.

The strength of the action potential is
whenever it occurs.

-
This is called the “
principle.”
The wave of
and
is passed
along the axon to the terminal buttons, which release neurotransmitters. Spaces between segments of
myelin are called nodes of
-
.
conduction: When the axon is myelinated, conduction speed is
increased since depolarizations jump from node to node.
-
are released into the
Some synampes are
.
, meaning the NTs cause the neuron on the other
side to generate an action potential (to fire).
-
Other synapses are
o The
, reducing or preventing neural impulses.
of all excitatory and inhibitory inputs determines whether your next
neuron will fire and at what rate.
o The
of neurotransmitters regulates
metabolism, temperature, and respiration.
o It also enables you to
,
, and
.
AP Psychology – Guided Notes
Reflex Action
-
Unit 3: Biological Bases of Behavior
6
: simplest form of behavior, involving impulse conduction over a few
neurons.
o The path across maybe three neurons is called a
-
.
: sensory neurons that transmit impulses from your
sensory receptors to the spinal cord or brain.
-
: located entirely in your brain and spinal cord,
intervene between sensory and motor neurons.
-
: motor neurons transmit impulses form your
sensory or interneurons to muscle cells that contract or gland cells that secrete.
-
: muscle and gland cells.
Examples of
:
o pupillary, knee jerk, sneezing, and blinking.
: dendrites  to axons  terminal buttons; among neurons
from the receptor to the effector.
TECHNIQUES TO LEARN ABOUT STRUCTURE & FUNCTION
Clinical Observation (Case Study)
-
Look at
,
, etc.
Who was Phineas Gage?
-
Over 150 years ago people were studying patients with
and
linked loss of structure with loss of function.
-
Essentially losing brain
caused brain
-
.
was a level-headed, calm foreman of a
railroad crew in 1848.
-
An explosion shot an iron rod through his head, severing the connections between his
and his
.
-
Gage became hostile, impulsive, and unable to control his emotions or his obscene language.
-
Autopsy revealed that the relationship between frontal lobes and control of
.
Broca’s area
-
Paul Broca (1861) did an autopsy on a patient named Tan, who
even though there was no physical damage and he could understand language.
AP Psychology – Guided Notes
Unit 3: Biological Bases of Behavior
- Tan’s brain showed loss of tissue in part of the frontal lobe of the
7
cerebral hemisphere (as did several other similar cases).
It was concluded that damage to this so-called Broca’s area caused a loss of ability to speak, known as
-
.
Wernicke’s area
-
Carl Wernicke found another brain area involved with
in the left temporal lobe.
Destruction of Wernicke’s area results in loss of ability to comprehend written and spoken language,
-
known as
.
Split-Brained Patients
Studies of patients with “
-
” have shown that the
left and right hemispheres do not perform exactly the same functions.
Right hemisphere:
Left hemisphere:
-
-
-
-
-
-
-
-
Manipulating the brain
-
Scientists can electrically, chemically, or magnetically
various parts
of the brain and note effects.
-
Researchers have electrically stimulated different cortical areas of the brain during
-
It has enabled scientists to observe results, like:
.
o the frontal cortex at particular sites caused body movement for different body parts enabling
mapping of the
-
New research has found that you can
the brain (temporary and so far has shown no harm)
.
lesion parts of
AP Psychology – Guided Notes
Unit 3: Biological Bases of Behavior
8
STUDYING THE BRAIN -Directions: Fill in the chart below based on the other groups’ presentations.
Don’t forget to include your own information!
Method:
Description/Example:
Strength:
Weakness:
Lesions
Computerized axial
tomography (CAT or
CT)
magnetic resonance
imaging (MRI)
electroencephalogram
(EEG)
functional magnetic
resonance imaging
(fMRI)
positron emission
tomography (PET) scan
The Brain
-
Covered by protective tissue called
and housed in your skull.
AP Psychology – Guided Notes
- The
Unit 3: Biological Bases of Behavior
perspective studies how the human brain has evolved.
9
One theory breaks the brain into three sections:
o The reptilian brain is similar to the
in humans, and is
responsible for maintaining homeostasis and instinctive behavior.
o The old mammalian brain roughly corresponds to the
system that controls emotional behavior, memory, and vision.
o The new mammalian brain or
, accounts for
80% of the brain’s volume and is associated with higher functions of judgment, decision-making,
abstract thought, foresight, hindsight, and insight.

The surface of the cortex has peaks (
) and valleys (
), which form
convolutions that increase the surface area of your cortex.

Deeper valleys are called

The last evolutionary development of the brain is localization of functions on
.
of your brain.
LOCALIZATION AND LETERALIZTION OF THE BRAIN’S FUNCTION
-
: regions of the cerebral cortex that do not
have specific sensory or motor functions, but are involved in higher mental functions, such as thinking,
planning, remembering, and communicating.
-
: control of one side of your body by the opposite side of
your brain.
o The
side of your brain controls the right side of your body.
o The
side of your brain controls the left side of your body.
Structure of Brain
-
: where most fibers cross above the brain stem, resulting in
contralateral (opposite side) control.
o regulates
.
-
: right above the medulla, helps coordinate movement, and is the bridge
between cerebral hemispheres and both medulla and cerebellum.
-
: a nerve network in the brainstem (pons)
that plays an important role in controlling arousal.
AP Psychology – Guided Notes
-
Unit 3: Biological Bases of Behavior
: coordinates motor function integrating motion and positional
10
information from the inner ear and muscles.
o helps maintain balance.
-
(basal nuclei): links the thalamus with the motor cortex and
other motor areas.
o regulates initiation of
o Involved in
learning and focus.
o Some
(neural clusters) involved in emotion.
: relay “station” for sensory pathways carrying visual, auditory,
-
taste, and somatosensory information to/from appropriate areas of cerebral cortex.
o Located at the top of the brain stem.
-
: controls autonomic functions such as body temperature
and heart rate via control of sympathetic and parasympathetic centers in the medulla.
o Sets
(e.g. thirst, hunger, sexual desire) and behavior.
o Sets
, such as rage, with the limbic system.
o Integrates with
by secretion of
hormones that regulate hormones from the pituitary.
o Helps determine
-
.
: influences aggression and fear. Coordinates fight-or-flight response.
o important in formation of
-
.
: Enables formation of new long-term memories.
-
: receives and processes sensory information and
directs movement.
o Center for higher order process such as
-
: Motor cortex strip just in front of somatosensory cortex
initiates movements and integrates activities of skeletal muscles.
o
-
: right/left hemisphere controls other side of body.
: in left frontal lobe controls production of speech.
o Interpret and control emotional behaviors, make decisions, carry out plan.
-
: center for hearing.
AP Psychology – Guided Notes
-
Unit 3: Biological Bases of Behavior
: in left temporal lobe, plays role in
11
understanding language and making meaningful sentences.
o Right temporal lobe important for understanding
.
o Sound from both ears is processed mostly
.
o Smell processed near front of
.
-
: when one region of the brain is damaged, the brain can
reorganize to take over its function.
o e.g.
THE ENDOCRINE SYSTEM
-
: consists of glands that secrete
chemical messengers called hormones in your blood.
o
travel to target organs where they bind to specific
receptors.
-
: produces melatonin that helps regulate circadian
rhythms and is associated with seasonal affective disorder.
-
: produces hormones that stimulate or inhibit secretion of
hormones by the pituitary.
: Sometimes called the “master gland” because it
-
produces stimulating hormones that promote secretion by other glands including:
o
: thyroid-stimulating hormone
o
: adrenocorticotropic hormone stimulates adrenal cortex
o
: stimulates egg or sperm production
o Produces
(antidiuretic hormone) to help retain water in your body and
(human growth hormone).
-
: produces thyroxine, which stimulates and maintains
metabolic activities.
o Lack of thyroxine in children can result in
-
.
: Produce parathyroid hormone that helps maintain calcium
ion level in blood necessary for normal functioning of neurons.
-
: adrenal cortex, the outer layer, produces steroid hormones
such as cortisol, which is a stress hormone.
AP Psychology – Guided Notes
Unit 3: Biological Bases of Behavior
o Adrenal medulla, the core, secretes
(epinephrine) and
12
(norepinephrine), which prepare the body for “fight
or flight,” like the sympathetic nervous system.
-
: insulin and glucagon regulate blood sugar that fuels all behavioral
processes.
o
result in diabetes and hypoglycemia, respectively.
-
and
: gonads in females and males
respectively, necessary for reproduction and development of secondary sex characteristics.
GENETICS & EVOLUTIONARY PSYCHOLOGY
-
: the debate about
whether your behavior is determined by your heredity or history/environment.
-
: study how natural
selection favored behaviors that contributed to survival and spread of our ancestors’ genes, and may
currently contribute to our survival into the next generations.
o They look at behaviors that are
shared by all people.
GENETICS & BEHAVIOR
-
: study the role played by our
genes and our environment in mental ability, emotional stability, temperament, personality, interests,
etc.
o They look at the causes of our
o They believe that
-
.
predispose our behavior.
studies are used to study the contributions of heredity and environment.
o
: two individuals who share all the
same genes/heredity because they develop from the same fertilized egg or zygote.

aka
o
twins
: siblings that share about half of the
same genes because they develop from two different fertilized eggs or zygotes.

aka
twins
AP Psychology – Guided Notes
-
Unit 3: Biological Bases of Behavior
: the proportion of variation among individuals in a
13
population that is due to genetic causes.
o Schizophrenia and general intelligence are more similar in
twins
are behaviorally more similar than

twins.
If monozygotic twins are separated at birth and raised in different environments
(
), behavioral
differences may reveal the contribution of environment to behavior; similarities may
reveal the contribution of heredity.
-
Adoption studies assess
influence by comparing resemblance of adopted
children to both their adoptive and biological parents.
o The children must have been adopted as
without contact with their
biological parents.
o If the children resemble their
parents, but not their adoptive families, with
respect to a given trait, researchers infer a genetic component for that trait.
o Alcoholism, schizophrenia, and general intelligence have shown both
and
components.
Transmission of Hereditary Characteristics
-
Heredity characteristics are passed down by
-
Each DNA segment of a chromosome that determines that determines a trait is a
-
process.
.
carry information stored in genes to new cells during
reproduction.
o Normal human body cells have
have
-
chromosomes, except for eggs and sperms that
chromosomes.
o Males have 44 chromosomes, plus
.
o Females have 44 chromosomes, plus
.
At fertilization,
the egg to form a zygote with
chromosomes from the sperm unite with
chromosomes from
chromosomes.
o If the male contributes a Y chromosome, the baby is male.
-
Fertilization with the wrong amount of chromosomes results in an individual with
.
o
: girls with only one X
chromosome (XO) who are short, often sterile, and have difficulty calculating.
AP Psychology – Guided Notes
o
Unit 3: Biological Bases of Behavior
14
: males with an XXY
zygote. They lack male secondary sex characteristics at puberty, develop breast tissue, and tend
to be passive.
o
: individuals with three
copies of chromosome-21. They are typically mentally retarded and have a round head, a flat
nasal bridge, a protruding tongue, small round ears, a fold in the eyelid, and a poor muscle tone
and coordination.
-
: the genetic makeup for a trait of an individual.
-
: the expression of the genes.
-
: the condition when both genes for a trait are the
same.
-
: also called hybrid, the condition when genes for a trait are
different.
-
gene: the expressed heterozygous gene.
-
gene: a gene that is hidden or not expressed when the genes for a trait are
different.
-
: caused by a recessive gene and can
result in progressive loss of nervous function and death in a baby.
-
: recessive trait that produces lack of pigment and involves quivering eyes
and inability to perceive depth with both eyes.
-
(PKU): a recessive trait that results in
severe, irreversible brain damage unless the baby is fed a special diet low in phenylalanine within 30
days of birth.
-
: a dominant gene
defect that involves degeneration of the nervous system characterized by tremors, jerky motions,
blindness, and death.
-
: recessive genes
located on the X chromosome with no corresponding gene on the Y chromosome, which result in
expression of recessive trait more frequently in males.
o e.g.
: sex-linked trait with which
individual cannot see certain colors, most often red and green.