Download Ch. 3–Biological Basis of Behavior PPT

Chapter 3
Biopsychology and the
Foundations of
Neuroscience
Copyright © Allyn & Bacon 2007
This will be on every test from now on
Psychology: The study of the nervous
system, mental processes, and
behavior
Copyright © Allyn & Bacon 2007
Neuroscience and Biopsychology
Neuroscience –
field that focuses on the nervous system
and the brain
Biopsychology –
studies the interaction of biology,
behavior, and the environment
i.e. a combo of neuroscience and psychology
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
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Different types of neurons
A. Purkinje cell B. Granule cell C. Motor neuron D. Tripolar neuron
E. Pyramidal Cell F. Chandelier cell G. Spindle neuron H. Stellate cell
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The Neuron
Types of Neurons
Sensory (afferent) neurons (carry
messages from sense receptors
towards the CNS [brain & spinal cord])
Motor (efferent) neurons (carry messages
from CNS toward muscles and glands)
Interneurons (carry messages
between nerve cells, as in the
brain and spinal cord)
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The Structure of a Neuron
Dendrite: receives NTs and carries info to the
soma
Soma: the cell body
Hillock: where soma meets axon
Axon: the long fiber that conducts info
Myelin sheath: insulation on axon
Nodes of Ranvier: spaces in sheath
Terminal button: the end of the neuron
Vesicles: where NTs are stored
Synapse: the gap thru which NTs pass
Copyright © Allyn & Bacon 2007
Now try drawing your own neuron
Label these parts:
Soma, Dendrite, Axon, Myelin sheath,
Nodes of Ranvier, Terminal buttons,
Vesicles, Synapse
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The Neural Impulse
Resting potential: a neuron at rest
Action potential: a neural impulse
caused by K and Na ions
(a neuron is a salty banana: Na on the outside, K
on the inside)
-initiates at or near the hillock
All-or-nothing principle: a neuron fires
fully or not at all
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Other types of cells
Glial cells
• Provide structural support for neurons
• Help in forming new synapses
• Form myelin sheath
(specifically, Schwann cells)
• Mirror neurons
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Neurotransmitters
Neurotransmitters –
Chemical messengers that carry neural
messages across the synapse
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Neurotransmitters
Normal Function:
Serotonin
brain: sensations of
pleasure and reward-body: voluntary movement
Norepinephrine
Problems with Imbalance:
Acetylcholine
Schizophrenia, Parkinson’s
disease
Dopamine
GABA
Glutamate (ine)
Endorphins
Substances that Affect:
Cocaine, amphetamines,
meth, Ritalin, alcohol,
marijuana
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Neurotransmitters
Dopamine
Serotonin
Normal Function:
Regulates sleep and
dreaming, mood,
aggression, and sexual
behavior
Norepinephrine
Problems with Imbalance:
Acetylcholine
GABA
Depression, some anxiety
disorders, OCD
Glutamate (ine)
Substances that Affect:
Endorphins
Prozac, Ecstasy,
hallucinogenics (e.g. LSD)
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Neurotransmitters
Dopamine
Serotonin
Normal Function:
Controls heart rate,
arousal, alertness and
appetite—it’s adrenaline
Norepinephrine
Problems with Imbalance:
Acetylcholine
GABA
Glutamate (ine)
Endorphins
High blood pressure,
depression
Substances that Affect:
Tricyclic antidepressants,
beta blockers
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Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Acetylcholine
Normal Function:
Primary transmitter of CNS
for muscle contractions;
involved in learning and
memory
Problems with Imbalance:
GABA
muscular disorders,
Alzheimer’s disease
Glutamate (ine)
Substances that Affect:
Endorphins
Nicotine (agonist), botulism
toxin (antagonist)
Copyright © Allyn & Bacon 2007
Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Acetylcholine
GABA
Glutamate (ine)
Endorphins
Normal Function:
Most common inhibitory
neurotransmitter; reduces
excessive brain activity
Problems with Imbalance:
Anxiety, insomnia, epilepsy
Substances that Affect:
Barbiturates, tranquilizers
(e.g. Valium)
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Neurotransmitters
Dopamine
Normal Function:
Norepinephrine
Excitatory neurotransmitter;
involved in learning and
memory (long term
potentiation)
Acetylcholine
Problems with Imbalance:
GABA
Migraines, epilepsy, brain
damage after stroke, ALS
Glutamate (ine)
Substances that Affect:
Endorphins
PCP (angel dust)
Serotonin
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Neurotransmitters
Dopamine
Normal Function:
Serotonin
control of pain
Norepinephrine
Problems with Imbalance:
Acetylcholine
Lowered levels resulting
from opiate addiction
GABA
Glutamate (ine)
Endorphins
Substances that Affect:
Opiates: opium, heroin,
morphine, methadone
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Drugs
Some drugs are:
Agonists: chemical that amplifies NT
response (e.g. heroin)
Antagonists: chemical that blocks NT
response (e.g. Botox)
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Talk to your aisle partner
Play the “Which neurotransmitter are you?”
game here.
Develop a mnemonic device for each NT,
what it does, and a disorder related to the
NT. I will ask you to share in a few
moments.
Copyright © Allyn & Bacon 2007
Videos to help understand NTs
Mouse Party:
How certain drugs affect the synapses
and the brain.
See the Crash Course on
neurotransmitters here.
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The Organization of the
Nervous System
Nervous system
Peripheral nervous
system
Autonomic
nervous system
Sympathetic
nervous system
Central nervous
system (CNS)
Somatic
nervous system
Parasympathetic
nervous system
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Nervous system
CNS: central=spine and brain
Spine: controls reflexes
Brain: voluntary movements
PNS: peripheral=outside
delivery service for CNS
SNS: somatic=soma=body
controlled by motor cortex
afferent: signal in (sensory)
efferent: signal out (motor)
ANS: autonomic=independent=no consciousness
controlled by brain stem
sympathetic=arousing
parasympathetic=calming
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The Endocrine System
(the body’s chemical messenger system)
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The Endocrine System
Pituitary gland –
Master gland that produces
hormones (a chemical signal in
your blood) influencing the
secretions of all other endocrine
glands;
produces HGH and oxytocin (the
love hormone)
attached to (and responds to
signals from) hypothalamus
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Other glands and hormones
Pineal gland: releases melatonin, which
helps regulate sleep
Adrenal glands: adrenaline (epinephrine)
and cortisol —stress hormones
Testes: testosterone/Ovaries: estrogen
Thyroid: thyroxin regulates metabolism
Pancreas: releases insulin, which
regulates blood sugar
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Windows on the Brain
Brain scans –
Recordings of the brain’s electrical or
biochemical activity at specific sites
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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
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Windows on the Brain
CT scanning (computerized tomography)—basically a
cross-sectional x-ray
Best for viewing bone injuries, diagnosing lung and chest
problems, and detecting cancers
PROS: Takes only a few minutes
Less expensive than other scans
CONS: Can’t do too often—radiation
Can take an hour to get results
Not very detailed
CT scan of a brain
hemorrhage
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Windows on the Brain
MRI: (magnetic resonance imaging)—a 3D image best
for looking at soft tissue like ligaments, tendons
and brain tumors, spinal cord
PROS:
No radiation
Much higher soft tissue detail than CT scan
CONS:
More expensive
Takes at least 30 minutes
fMRI: a 4D image (time) of
glucose metabolism
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Windows on the Brain
PET scanning (positron emission tomography) – useful to
detect tumors and seizures
PROS: Measures FUNCTION (how something is
working), not just location
3D and in color
CONS: requires radiation injection
Most expensive scan
Takes up to four hours
Patient can move
during a PET scan,
but the images are
not as hi-res as an
fMRI
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Quiz on scans
EEG, CT, MRI, fMRI, PET
Which scans show activity/function in the brain?
EEG, fMRI, PET
Which are in color?
fMRI, PET
Which use radiation?
CT, PET
Which show the brain itself?
CT, MRI, fMRI, PET
Which would be MOST useful for showing soft tissue?
MRI
Which are 3D?
CT, MRI, fMRI, PET
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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
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The Brain Stem and Cerebellum
Thalamus (relays sensorimotor info to the
cortex; regulates consciousness)
Pons (bridge [to cerebellum]) (sleeping, MANY other
autonomic functions)
Cerebellum (coordination and timing of
motor control, balance)
Brain stem
(regulates CNS and ANS, pretty much all
your vital functions)
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The Brain Stem
Reticular activating system/
aka reticular formation
(arousal; sleep/wake)
Medulla oblongata
(cardiovascular, breathing and puking)
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The Limbic System
Hypothalamus –
links nervous
system to
endocrine system
via pituitary;
regulates
temperature,
hunger &
circadian rhythms
TRIVIA: Together, the
thalamus and the hypothalamus
are called the diencephalon.
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The Limbic System
Amygdala –
Involved in
motivation and
emotion;
particularly fear
and aggression
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The Limbic System
Hippocampus –
Involved in establishing
long-term memories
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The Limbic System
Basal Ganglia (the conductor)
voluntary motor control and procedural
learning.
Current theories suggest the BG execute
action selection--that is, the decision of
which behavior to execute
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3D brain
Now let’s take a look at all these parts on
3D Brain
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Review
Brain stem:
vital functions
Pons:
sleep
Reticular formation:
arousal
Medulla:
vomiting
Cerebellum:
coordination and balance
Hypothalamus:
hormones
Thalamus:
switchboard
Hippocampus:
memory
Amygdala:
emotion
Basal ganglia:
conductor
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The Cerebrum
Cerebrum –
Topmost layer of the brain
Cerebral cortex –
Thin gray-matter covering of the
cerebrum; thinking and perceiving
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The Four Lobes of the
Cerebral Cortex
Frontal lobes
(thinking; motor cortex)
Parietal lobes
(somatosensory cortex and
spatial relationships)
Occipital lobes
(contain visual cortex)
Temporal lobes
(memory, hearing [language]
emotion [limbic system])
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Homunculus
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Association areas
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Plasticity
Plasticity –
the brain’s ability to change, especially during
childhood, by reorganizing after damage or by
building new pathways
See what happens when the right hemisphere is
removed from a young girl’s head.
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How the brain puts language together
Both in left hemisphere:
Wernicke’s area: small region in the
temporal lobe responsible for
understanding language
Broca’s area: small region in the frontal
lobe responsible for speech and
grammar
A synthesis of the two language areas
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Language and the Brain
Aphasia –
The loss of speech caused by brain
damage
>Wernicke’s aphasia
>Broca’s aphasia
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The Split Brain
Cerebral hemispheres –
The two halves of the cerebrum,
connected by the corpus callosum
Cerebral dominance –
Tendency of each brain hemisphere to
exert control over different functions
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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
• Repetitive but not
spontaneous
speaking
• Responses to simple
commands
• Facial recognition
• Memory for shapes
and music
• Spatial interpretation
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Which face looks happier?
Most people choose the face on the left side, because our
right hemisphere, which is better for facial recognition,
registers the smiling left side of the face.
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Experiment
Get a writing utensil in each hand.
I will flash two shapes. Try to draw the
shape on the left with your left hand at
the SAME TIME that you draw the shape
on your right with your right hand.
DO NOT look at your hands. Just look at
the shapes.
Ready?...
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How did you do?
Let’s try it again with two different shapes.
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How did you do?
Why is that so hard? Because our
hemispheres are communicating with
each other across the corpus collosum
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The Split Brain
Anesthetic to each hemisphere causes changes to
language and movement—video here.
Split-brain patients –
Individuals who have had the corpus callosum
surgically severed
The future of neuroscience in light activated neurons?
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Wanna Look at a Real Brain?
If you are squeamish, you might want to
look away or step into the hall for six
minutes…
Here, a scientist shows us a brain from a
recent autopsy.
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Putting it all together:
Describe the parts of the nervous system
/endocrine system/brain activated in this
situation and what they are doing in Crazy
Eddie’s body:
Crazy Eddie, the professional wrestler, is in the
ring wrestling. The crowd is yelling and his
opponent is taunting him. Eddie yells back at
his opponent. The two of them are out of
breath and sweating profusely. They continue
their well-orchestrated series of wrestling
moves.
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Twin studies
Heritability
Epigenetics
Molecular genetics
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How Are Genes and
Behavior Linked?
Evolution has shaped
psychological processes
because it favors genetic
variations that produce
adaptive behavior
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How did the brain develop?
Natural selection –
The driving force behind evolution,
by which the environment “selects”
the fittest organisms
the gradual process by which biological traits become either more or less common in a population
Evolution –
The process of biological change in a
species as it adapts to its environment
-change in the inherited characteristics of biological populations over successive generations.
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Mutations
Nature/nurture
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Evolution and Natural Selection
Why do we like sweets and fats, and dislike
bitter foods? Why do we sleep at night
and not during the day? Why do men like
shapely women? Why do women like
strong men?
Evolutionary psychology–
Sees psychology in terms of its genetic
adaptations for survival and reproduction
A video about evolutionary psychology
See Steven Pinker’s TED talk on the topic
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How evolutionary psychology “works”
Evolutionary psychologists use several strategies to develop and test hypotheses
about whether a psychological trait is likely to be an evolved adaptation.
Cross-cultural Consistency. Characteristics that have been demonstrated to be
cross cultural human universals such as smiling, crying, facial expressions are
presumed to be evolved psychological adaptations. Several evolutionary
psychologists have collected massive datasets from cultures around the world to
assess cross-cultural universality.
Function to Form (or "problem to solution"). The fact that males, but not females,
risk potential misidentification of genetic offspring (referred to as "paternity
insecurity") led evolutionary psychologists to hypothesize that, compared to
females, male jealousy would be more focused on sexual, rather than emotional,
infidelity.
Form to Function (reverse-engineering – or "solution to problem"). Morning
sickness, and associated aversions to certain types of food, during pregnancy
seemed to have the characteristics of an evolved adaptation (complexity and
universality). Margie Profet hypothesized that the function was to avoid the
ingestion of toxins during early pregnancy that could damage fetus (but which are
otherwise likely to be harmless to healthy non-pregnant women).
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End of Chapter 3
Copyright © Allyn & Bacon 2007