Transcript Chapter 2

Biopsychology
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What is Biopsychology?

Biopsychology
– The specialty in psychology that studies the
interaction of biology, behavior, and the environment

Neuroscience
–
An Interdisciplinary field that focuses on the brain
and its role in psychological processes
Question: This unit is all about biology, but the class is supposed to be
about psychology. Why do you think we have to study all this
biology junk?
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Nature or Nurture?
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Biopsychology is all about nature
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Our nature refers to our biology:
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our organs, the brain and chemicals that control us.
Nurture (on the other hand) refers to our interaction
with the environment:
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our parent’s love, shelter, nutrition and education.
Question: Which is more important: Nature or Nurture? This is
an argument of epic proportions in psychology and a theme
we will continue to see throughout our studies.
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Natural Selection
Proposed by - Charles Darwin in 1859
Natural selection is the driving force behind evolution, by
which the environment “selects” the fittest organisms.
However, the environment is neutral. It is passive not
active. So it is incorrect to say the environment “selects”
anything.
Instead we say that some animals have a “selective
advantage”. They “fit” the environment better than other
animals and so they survive better and produce more
offspring. Organisms well adapted to their environment
will propagate and out produce the competition.
Therefore the course of evolution is known as “the
survival of the fittest”.
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Evolution and Natural Selection
Creation vs. Evolution
This course is not about theology and we are not going to
debate how everything got onto the planet. We can all
agree that life has been on earth for over 5700 years and
that life changes. Humans live longer than they did 100
years ago. Crops give better yields. Dogs are bred into
specific types for specific functions. Species go extinct.
We will talk about how the creatures presently on the earth
change over time. I will use the word “evolved” when I
talk about how life changed while it was on the earth and
leave how they got on the earth for a different course.
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DNA, Chromosomes and Genes
DNA –
All organic life has DNA which is a
long, complex molecule that
encodes genetic characteristics.
Normal Chromosomes contain two
strands of DNA.
Genes are the functional units of a chromosome. There
are thousands of genes in one chromosome. Genes
contain the instructions for creating proteins.
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Basic Genetics
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An unfertilized egg contains 23 chromosomes.
A sperm also contains 23 chromosomes.
Put the two together and you get 23 “pairs” of
chromosomes.
– There are 22 pairs of Autosomes and 1 pair of Sex
chromosomes = 23 pairs
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The Autosomes are almost duplicates of each other. The
genes can be slightly different on each strand.
The sex chromosomes can be very different. They contain an
X from the mother and a Y or X from the father.
Almost every cell in your body contains chromosomes.
Sometimes the Chromosomes are damaged.
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Genes and Inheritance
Genotype –
An organism’s genetic
makeup - DNA
Phenotype –
An organism’s observable physical
characteristics – Hair Color, Skin
Color, Eye Color
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How Are Genes and
Behavior Linked?
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Behavior that is consistently found in a species
is likely to have a genetic basis.
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We can say the behavior became this way
(evolved) because the behavior has been
adaptive to living. Or it was specifically selected
for by a breeder.
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More Genetic Terms
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Adaptive –
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Adaptation –
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Inborn; present at birth; part of the organism’s biological heritage
Evolution –
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When a condition becomes predominant in a population because
it is Adaptive.
Innate –
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The presence of a condition which increases the likelihood of
survival.
The gradual process of biological change that occurs in a
species as it adapts to its environment (as adaptation occurs).
Mutations –
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Genetic variations, which occur randomly, especially during the
recombination of chromosomes in sexual reproduction.
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How Natural Selection Works
Environmental pressure
(changes in the environment)
Competition (for resources)
Selection of fittest phenotype
Reproductive success
(genotype corresponding to fittest
phenotypes passed to next generation)
Frequency of that genotype increases
(in next generation)
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Genetic Explanations for Psychological Processes
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Behavior genetics
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studying behavior based on the principles of genetics.
In order to study behavior as it relates to genetics, we
must know what each gene is.
The Human genome project
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attempted to map all the genes in the human DNA.
They found close to 25,000 genes among the
chromosomes of the human body. Are there really
only 25,000 genes directed our growth and control
our behavior? If we live long enough, we should know
that answer in this century.
There are also another 25,000 dead spaces on the
chromosome. We still do not know how those areas
are used.
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Genetic Explanations for Psychological Processes
Remember you can click on the blue underlines to see more information on the internet
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Down syndrome is a genetic condition caused by
specific chromosomal damage in the 21st chromosomal
pair. There are actually three strands of DNA instead of
two. You might think more chromosomes is a good thing – nope!
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Genetic Explanations for Psychological Processes
Remember you can click on the blue underlines to see more information on the internet
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Most people have two sex chromosomes.
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An X from the mother and an X from the father makes a female.
An X from the mother and a Y from the father makes a male.
Some people have more than or less than they should
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Turners syndrome is a single X chromosome
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When the embryo has only a Y it spontaneously aborts
(miscarriage) and never comes to term.
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Super males have an extra Y or (XYY) – this is correlated to
criminality (stronger, lower intellect and less control over emotions)
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Fragile X syndrome contains a damaged X
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This is worse in males because they have no backup
Klinefelters syndrome people have two Xs or (XXY)
Questions: Is Nature or Nurture more important in these conditions? How
would we be able to determine the importance scientifically?
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Twin Studies
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Psychologists can use twins to study the importance of
Nature Vs. Nurture.
 Monozygotic twins have 100% identical DNA.
 Dizygotic twins have 50% identical DNA.
 We do not purposefully separate children from their
parents and each other, but situations arise where twins
are separated at birth and we can take advantage of
those conditions and study the differences and
similarities between the twins.
 Similarities are attributed to Genetics and Differences
are attributed to the environment.
 We will talk about some of the similarities and
differences in later chapters.
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How Does the Body Communicate Internally?
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The body’s two communication systems, the
nervous system and the endocrine system,
both use chemical messengers to communicate
with targets throughout the body.
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First we will discuss the Nervous system.
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Nerve communication is in one direction. So, we need
two pathways for the nerves. One path is for the senses
and the other is for the motor functions.
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THE CNS & PNS
The Central Nervous System (CNS) is comprised
of the brain and spinal cord.
The Peripheral Nervous system (PNS) is
composed of other nerves in the body that
connect the CNS to your senses and organs.
The CNS and PNS use Neurons and Nerves.
Some people call the CNS cells neurons and PNS
cells nerves and they define the difference as
“nerves regenerate” while neurons do not.
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THE CNS
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The CNS:
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The job of the CNS is to integrate and coordinate all
bodily functions, process all incoming neural
messages and send out commands.
– A spinal cord coordinates the activities of the left and
right sides of the body.
– The spinal cord is also responsible for simple, fast
action reflexes that do not involve the brain.
– A spinal Reflex is an unlearned response controlled
by one efferent (motor) and one afferent (sensory)
neuron. Check out this site.
– Spinal reflexes allow us to move when we are in
danger before the brain knows what the danger is.
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THE PNS
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The PNS:
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The PNS has two parts:
» The Somatic and Autonomic divisions.
The Somatic system regulates the actions of the
skeletal muscles (soma means body) and contains
the sensory nerves (like sight and smell).
The Autonomic division regulates the heart,
respiration and digestion.
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THE Autonomic System
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The Autonomic system is so complex it is
divided into two subsections: the Sympathetic
and Parasympathetic systems.
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The Sympathetic system deals with emergency
responses and mobilizes energy reserves.
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The Parasympathetic system monitors the routine
operations of the body and conserves and restores
energy.
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Increases heart & lung activity and inhibits most everything
else
Decreases heart & lung activity and stimulates most
everything else.
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A Visual Organization of the
Nervous System
Nervous system
Peripheral nervous
system
Autonomic
nervous system
Sympathetic
nervous system
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Central nervous
system (CNS)
Somatic
nervous system
Parasympathetic
nervous system
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The Neuron: Building Block of the
Nervous System
A neuron is a cell in the body specialized for receiving and
transmitting information. I do not make a distinction between
neurons and nerves.
Types of Neurons:
- Sensory (afferent) neurons (carry messages from
sense receptors towards the CNS)
Motor (efferent) neurons (carry messages away
from the CNS toward muscles and glands)
Interneurons (carry messages between
nerve cells)
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The Neuron:
looks like something from a science fiction movie!
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Two Neurons
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Neuron Anatomy
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Dendrites
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Nucleus
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Nutrient material
Axon
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contains the chromosomes of the cell
Soma
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Receive signals from another neuron
Long leg of the neuron which transmits in only one
direction
Myelin Sheath – Glial Cells –
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protects, provides nutrients and removes waste for
the Axon and speeds up the signal. A breakdown of
Glial cells is implicated in Multiple Sclerosis.
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Neuron Anatomy (cont.)
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Nodes of Ranvier
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Terminal Buttons
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Contain the chemicals for communications in synaptic
vesicles.
Synapse
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places between the myelin sheaths
The space between the neuron’s terminal buttons and
the dendrites of the next neuron
Lesions
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Tissue damage that results from disease or injury
(purposeful or accidental).
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The Neural Impulse
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Neural impulse
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Ions
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Brief electric (ionic) surge that carries the neuron’s
message in one direction (dendrites, soma, axon,
terminal buttons) ending in the terminal buttons with a
release of neural transmitters that cross the synaptic
cleft and bind to the dendrites of the next neuron (or
receptors of the next cell). If enough transmitters bind
to the next cell the signal continues to the destination
(or trigger a reaction in the cell).
Charged particles that are moved across the cell
membrane. Na & K & Cl
Neural Transmitters
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Chemicals that continue the neural impulse.
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The Neural Impulse terms
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Resting potential
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Action potential
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-70mv
This is the neuron’s charge when it is ready to send a
signal.
Goes from -70mv to +30mv
This is the change in electrical potential in a neuron
when it is sending the signal.
Refractory Period
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restorative period where the cell is unable to respond
until it re acquires “accumulates” its charge.
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The Neural Impulse terms
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Synapse
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Also called the synaptic cleft
This is the space between neurons.
Synaptic transmission
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A chemical (neurotransmitters) released by the first
neuron into the synaptic cleft where the
neurotransmitters float to the adjoining neuron, bind
to that neuron and if enough chemical binding occurs,
create the next electric charge.
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Neurotransmitters
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Neurotransmitters
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Are chemical messengers that relay neural messages across the
synapse. We are not simply electrical signals moving through
our bodies. Without chemicals to pass the signal from one
neuron to the next, the electrical impulse would stop – no life.
These chemicals work to either suppress or stimulate other
nerves. We will talk about seven important Neurotransmitters.
Dopamine
Acetylcholine
Serotonin
GABA
Norepinephrine
Glutamine
Endorphins
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Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Acetylcholine
Hint: Different Neurotransmitters are found in
different areas of the brain
Normal Function:
Dopamine starts in the Substantia nigra. It
produces sensations of pleasure and
reward; influences learning and attention;
and is used by the CNS neurons in
voluntary movement
Problems with Imbalance:
GABA
Too much causes Schizophrenia,
Too little Parkinson’s disease
Glutamine
Substances that Affect:
Endorphins
Cocaine, amphetamines, Ritalin,
alcohol
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Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Normal Function:
Regulates sleep and dreaming,
moods, pain, aggression, appetite
and sexual behavior
Problems with Imbalance:
Acetylcholine
GABA
Glutamine
Too little is linked to Depression,
certain anxiety disorders &
obsessive-compulsive disorder
Substances that Affect:
Prozac, hallucinogenics (e.g. LSD)
Endorphins
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Neurotransmitters
Dopamine
Normal Function:
Norepinephrine
Produced in the Reticular Formation.
It controls the ANS, heart rate, sleep,
sexual responsiveness, stress,
vigilance and appetite
Acetylcholine
Problems with Imbalance:
Serotonin
High blood pressure, depression
GABA
Substances that Affect:
Glutamine
Tricyclic antidepressants, beta
blockers
Endorphins
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Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Acetylcholine
GABA
Normal Function:
Primary transmitter used by efferent
neurons carrying messages from the
CNS; involved in some kinds of
learning and memory
Problems with Imbalance:
Certain muscular disorders &
Alzheimer’s disease
Substances that Affect:
Glutamine
Endorphins
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Nicotine, botulism toxin, curare,
atropine, Black Widow Venom (which
blocks Acetylcholine causing muscle
paralysis - including the heart)
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Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Normal Function:
Most prevalent inhibitory
neurotransmitter in neurons of CNS.
It is as much as 1000 times more
than any other.
Acetylcholine
Problems with Imbalance:
GABA
Too little can cause epilepsy,
insomnia and tremors
Glutamine
Substances that Affect:
Endorphins
Barbiturates, tranquilizers (e.g.
Valium, Librium), alcohol
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Neurotransmitters
Dopamine
Serotonin
Normal Function:
Norepinephrine
Primary excitatory neurotransmitter
in CNS; involved in learning and
memory
Acetylcholine
Problems with Imbalance:
GABA
Too much can cause migraines and
seizures
Glutamine
Substances that Affect:
Endorphins
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MSG (Foods – especially Chinese)
& PCP (“angel dust”)
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Neurotransmitters
Dopamine
Normal Function:
Serotonin
Norepinephrine
Pleasurable sensations and control
of pain
Problems with Imbalance:
GABA
Low amounts cause depression,
chronic unexplained pain, and a low
tolerance for pain. Opiate use
produces lowered levels.
Glutamine
Substances that Affect:
Acetylcholine
Endorphins
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Opiates: opium, heroin, morphine,
methadone
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Plasticity

Plasticity is the ability of the brain to change shape and
function. The nervous system adapts or change as a
result of experience. This ability sometimes helps the
nervous system adapt to physical damage.
– Function can change –
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Structure can change in the 100 billion neural cells
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such as the occipital lobe in blind people activates when they
are reading brail.
They can change connections as a result of learning.
How do we know?
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How can we tell when the brain is functioning properly?
How do we look into the working brain?
How do we know what a properly functioning brain looks like?
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Windows on the Brain
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EEG (electroencephalograph)
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Device for recording brain waves, typically by
electrodes placed on the scalp.
Shows electrical activity like a telegraph Morse code.
Brain waves
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Patterns of electrical activity generated by the brain.
Measured in amplitude and frequency (Cycles per
second). We will talk more about these later.
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Windows on the Brain
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Brain scans
Recordings of the brain’s electrical or
biochemical activity at specific sites
– CT scanning (computerized tomography)
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PET scanning (positron emission
tomography)
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Shows structure of the brain.
shows functioning of the brain.
MRI (magnetic resonance imaging)
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can show either function or structure.
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FMRI and DTI
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Brain Scanning
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Layers of the Brain
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Three Layers of the Brain
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Three layers of the brain are the Hind Brain, The Mid
Brain and the Cortex.
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The Hind Brain (layer 1) contains the Brain stem, Pons,
Medulla, Reticular Formation and Cerebellum.
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The Pons links the spinal cord and the brain to each other and
regulates the brains activity during sleep.
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Medulla regulates heart rate and breathing.
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The Reticular Formation is involved in maintaining
consciousness and waking from sleep and alerting that there is
incoming data – narcolepsy.
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The Cerebellum regulates motor coordination, posture and
balance. According to recent research, this structure may be
involved in classical conditioning.
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Three Layers of the Brain
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Limbic system (layer 2)
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Regulates our emotions, complex motives and urges and helps
increase memory abilities.
The Hippocampus is involved in explicit long term memory. In
the Multiple memory Trace Theory (MMT), proposed by Nadel
and Moscovitch (1997), the assertion is made that the
hippocampus is permanently involved in the retention and
retrieval of long term episodic, but not semantic memory.
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Episodic is the first to go in Alzheimer's disease and vascular dementia -
The Amygdala controls emotions like aggression and fear and
the formation of emotional memories. Cutting the Amygdala will
decrease aggression. If you Lesion the Amygdala in cats you get
an excessively tame animal but if you stimulate the Amygdala
you get hissing and aggressive posturing.
The Hypothalamus is involved in regulating body temperature,
hunger, thirst and emotions & sex.
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The Limbic System
Hypothalamus –
Serves as the
brain’s blood-testing
laboratory,
constantly monitors
blood to determine
the condition of the
body. Maintains
homeostasis.
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The Limbic System
Amygdala –
Involved in
memory and
emotion,
particularly fear
and aggression
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The Limbic System
Hippocampus –
Involved in establishing
long-term memories.
Remembering the
location of items in
space and connects our
present and past.
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Three Layers of the Brain
Cerebrum – (Layer 3)
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
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Three Layers of the Brain
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Cerebrum
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Enables reasoning, planning, creating, problem
solving, and higher cognitive functions.
– It is the largest mass of the brain. The Cortex is the
outer most part of the cerebrum. Cortex comes from
the Latin word meaning shell or bark.
– The cerebrum is divided into two halves connected by
a mass of fibers called the corpus callosum. This
bundle of nerves allows one half of the brain to “talk”
to the other half.
– Fissures are the valleys of the brain. The brain is too
big to fit into the skull so it is folded onto itself creating
hills and valleys. Many of the valleys are found in the
majority of humans.
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Three Layers of the Brain
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Cerebrum (Cont.)
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Two important areas in the frontal & temporal lobes
are Broca’s and Wernicke’s areas.
Broca 1824 – 1880 found the center of the brain used
to translate thoughts (outgoing) into speech.
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Wernicke 1848 – 1904 found the center of the brain
used for understanding (Incoming) speech.
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It is only found in the LEFT Frontal lobe.
Broca was the first to prove functioning relates to brain
structures.
In the LEFT Temporal lobe.
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The Four Lobes of the Cerebral Cortex
Frontal Lobe
Controls
Movement &
Thinking &
Personality,
(Lobotomy)
Contains the motor
Cortex and
Broca’s Area.
Temporal lobe
Processes Sounds,
including Speech
includes Wernicke’s
area.
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Parietal lobe
processes
touch sensation
and spatial
relationships.
Contains the
Somatosensory
cortex.
Occipital lobe
contains the
visual cortex
for processing
vision.
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Lateralization
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How is the brain different on the left and right
sides?
 Lateralization of the cerebrum
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The left side of the brain is more responsible for
hearing and speech (women use more of both sides)
The right side of the brain is mostly involved in spatial
and visual activities.
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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
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The Split Brain
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Split-brain patients
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Duality of consciousness
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Individuals who have had the corpus callosum
surgically severed. In many cases to stop
occurrences of severe dangerous epilepsy.
Condition in which a split-brain patient has a separate
consciousness in each hemisphere. How neat is that!
Now that we have discussed the nervous system
and the brain, let’s take a look at the other
transmission system in the body:
The Endocrine system.
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The Endocrine System
There are basic brain structures that
control the endocrine system.
• The Pituitary gland –
– Also called the Master gland. It produces
hormones influencing the secretions or
retentions of all endocrine glands and
produces a hormone that influences growth. It
is attached to the hypothalamus in the brain.
• The Hypothalamus
– attempts to maintain homeostasis (balance)
within the body.
• What are Hormones
– They are molecules that are slow to function
(compared to neurons) but their effects are
long lasting. They must be metabolized before
their effects wear off.
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The Endocrine System
(the body’s chemical messenger system)
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Hormones – to name a few.
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Thyroid produces T3 and T4
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Pancreas produces Insulin
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Every cell in the body depends upon thyroid hormones for
regulation of their metabolism. These hormones help convert
oxygen and calories into energy. The thyroid also regulates
growth.
Controls blood sugar levels - Diabetes
Adrenals produce Glucocorticoids &
Adrenaline
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to reduce the inflammatory destruction of rheumatoid arthritis
and other autoimmune diseases
to prevent the rejection of transplanted organs
to control asthma
hair stands on end ("goosebumps“)
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Hormones – to name a few.
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Testes produce Testosterone
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The growth and development of the male reproductive structures
Increased skeletal and muscular growth
Enlargement of the larynx accompanied by voice changes
Growth and distribution of body hair & an increased male sexual
drive
The brain regulates (controls the amount of)
these chemicals in the body
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A few extras
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Happiness is genetic
– We are all predisposed to a specific average of
happiness
– We fluctuate around that average
Heredity is the biological transmission of traits from
generation to generation
Genetics is the study of inheritance of physical and
psychological traits from our ancestors
Men’s brains are larger than women’s by as much as
15%
Women use their brain more – it is hotter
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A few extras
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Epilepsy is a sudden uncontrolled electrical discharge of
the neurons of the brain.
– Surgeons will separate the two halves of the brain
(creating a split brained human) to keep the worst
cases of epilepsy from killing the patient.
– If a split brained patient holds something hidden in the
left hand (keys) they can not speak its name.
– If the object is transferred to the right hand they have
no problem identifying it by name.
Experimental work with lesions is done exclusively with
non humans animals.
Brain surgery can be performed while the patient is
conscious and communicating with the surgeons.
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The End of the Biopsychology presentation
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