UNIT 2 BIOLOGICAL BASES OF BEHAVIOR
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UNIT 2
BIOLOGICAL BASES OF
BEHAVIOR
An Early History of Biopsychology
Plato: the mind is located in the brain
Franz Gall and Phrenology
– Early 1800s
– Read bumps on skull to understand traits
If I was to take your brain out of your body, place it into patient needing brain surgery, where would the new ‘self’ call home? Are you simply the end product of a biological and chemical reaction?
Biopsychology Today
Everything we do is ultimately controlled by our body and brain – Body/brain composed of cells
– Brain cells called neurons communicate electrically and chemically
– Different parts of the brain have specific functions
– Our brains create meaningful experiences from sensory information
– Brain structure and function is influenced by experience
AGENDA
1) Quiz 2) Stroke of Insight - Discussion 3) Todays Theme: Hemisphere
Dominance 4) VIDEO: Split Brain Patients 5) Hand back & Discuss Test
The Cortex Each hemisphere is divided
into 4 lobes Frontal lobe
Temporal lobe
Parietal lobe
Occipital lobe
The lobes are separated by deep convolutions known as
fissures
Cortex Breakdown…
Occipital Lobes – Visual cortex
– Damage?
Temporal Lobes – Auditory cortex
– Auditory hallucinations?
Parietal Lobes – Primary sensory or
somatosensory cortex
– Allocation of space?
Frontal Lobes – Most evolved
– Motor cortex, which allows us to move
– Allocation of space?
Some Hemispheric Strengths
Left Hemisphere Language
Logic
Right side of body
Right Hemisphere Perception
Sense of self
Inferences
Left side of body
Split-Brain
Epilepsy, seizures and the corpus callosum
Reduction in epileptic seizures
Different abilities in each hemisphere
https://www.youtube.com/watch?v=lfGwsAdS9Dc
TEST
• Only Counted Multiple Choice
• Those who scored over 10 points on FRQ received .5 extra credit for every point above.
HW: Re write ALL missed FRQ’s until they are perfect.
HOW TO ANSWER FRQ
“TUDA”
T – List the term U – Underline term D – Define term A – Answer QUESTION
FOR EXAMPLE
….. Genie…
• Case Study
• Case Study • Case Study • Case Study is an in-depth study of one extreme or unique individual in hopes of revealing universal principles
• Case Study is an in-depth study of one extreme or unique individual in hopes of revealing universal principles. This is why the study of Genie would be described as a Case Study.
FOR EXAMPLE
….. Acsh’s Study about conformity…
• Control Group
• Control Group • Control Group • Control Group is the group that is not exposed to the independent variable
• Control Group is the group that is not exposed to the independent variable, in Asch’s experiment this would be the participants who were not subjected to hear the groups responses prior to his own.
HOMEWORK: 1. REVISE ALL FRQ’s USING: “TUDA”
• I will not accept them until they are perfect. • This is worth 15 homework points.
2. TEST REFLECTION – 1 typed page • Go Question by question…Why did you get it
wrong? Did you not understand Q? Did you not understand the concept? Did you not study? Did you guess?
• What do we need to do in order to improve next exam?
BOTH DUE BY FRIDAY IN THE BASKET ON MY DESK
AGENDA:
1. Map the Brain with the Truine Model 2. COLLABORATION: Map brains parts together 3. Explain Unit Project 4. VIDEO: Secrets of the Mind
TRUINE MODEL: REPTILIAN BRAIN
• Primary focus is survival
• Instinct • Internal Functions • OLDEST STRUCTURE
TRUE STORY:
TRUINE MODEL: MAMALIAN BRAIN
• Contains the Limbic System (Seat of EMOTION)
• In charge of appetite, sex drives and some vision.
TRUINE MODEL: HUMAN BRAIN
• Youngest Part • Counteracts Emotions • Information Processing • Abstract Complex
Thoughts & Behaviors
Primitive Brain Structures “AUTOPILOT”
Brainstem Oldest part of brain Contains medulla, controlling heartbeat, blood pressure and breathing Also contains pons, which helps regulate sensory information and facial expressions Contains Reticular Formation (RF) for alertness/arousal, sleep/wakefulness
Thalamus Pair of egg-shaped structures on top of brainstem Routes all incoming sensory information except for smell to appropriate areas of brain
Cerebellum “little brain” at read of brainstem Controls coordination, balance, and muscle tone
These parts of the brain are our “autopilot” so other regions can deal with higher-level “human” functions
The Limbic System
Located in between the primitive parts of the brain and the cerebral hemispheres
Hippocampus processes new memories Amygdala controls emotions such as aggression and fear – in animals, the “attack” response Hypothalamus regulates hunger, thirst, body temperature and sex drive – also controls pituitary gland
PRIMARILY, the limbic system processes drives, smell and various emotional responses
The Cortex
• Most highly evolved part of the human brain
• Body’s ultimate control and information-processing center
• Reasoning Center
Limbic System vs. Cortex https://www.youtube.com/watch?v=u76jBk59RFk
NEURONS and SYNAPSES
Types of Neurons
Sensory Motor Interneurons
Sensory Neurons
From sensory organs to the brain and
spinal cord.
Drawing shows a somatosensory neuron Vision, hearing, taste and smell nerves are cranial, not spinal
Spinal
Cord
Brain Sensory
Neuron
Motor Neurons
From the brain and spinal cord to the
muscles and glands.
Spinal
Cord
Brain Sensory
Neuron
Motor
Neuron
Interneurons
Interneurons carry information
between other neurons only found in
the brain and spinal cord.
HOW LONG DOES THIS TAKE WITH
NORMAL STIMULI?
BUT HOW DO THESE
CELLS
COMMUNICATE?
Action potentials
• Brief Electrical charge that travels down an axon
Neurotransmitters:
Chemicals that transmit messages between neurons
STRUCTURES OF THE
NEURON
PLEASE DRAW THIS ON A BLANK SHEET
OF PAPER
THE CELL BODY
• CONTAINS THE CELL’S NUCLEUS
• Round, centrally located structure
• Contains DNA • Controls protein
manufacturing • Directs
metabolism • No role in neural
signaling
DENDRITES
• Information collectors
• Receive inputs from neighboring neurons
• Inputs may number in thousands
• If enough inputs the cell’s AXON may generate output.
DENDRITIC GROWH
• Mature neurons generally can’t divide….
• BUT new dendrites can grow.
• Provides room for more connections to other neurons.
• NEW CONNECTIONS ARE THE BASIS FOR LEARNING
AXON
• The cell’s output structure
• One axon per cell, 2 distinct parts:
AXON AXON TERMINAL
Myelin Sheath
• White fatty casing on axon • Acts as an electrical insulator • Not present on all cells • When present increases the speed of neural signals
Myelin Sheath
I. Action potentials
• Domino Effect
A. Resting State 1. Outside of the neuron membrane is positive
2. Inside of the membrane is negative (-70 mV)
3. More Na+ outside, more K+ inside
Why don’t the charges escape?
4. The membrane is selectively permeable
Selectively permeable
B. Depolarization (Rising Phase) Causes the inside of the membrane to become
positively charged (depolarized)
2) Repolarization (Falling Phase of Action Potential)
3) Refractory Period
• Short amount of time
when no new action
potentials can be fired
Resting potential (-70 mV) must
Be restored
Nerve Cell Membrane
•Each level contains about 10% o the energy in the previous level.
Voltage of Membrane
Neuron on Neuron
Axons branch out and end near dendrites of neighboring cells.
Axon terminals are the tips of the axon’s branches
Gap is the Synapse Cell
Body
Dendrite
Axon
Synapse
Axon terminals contain small storage sacks called synaptic vesicles
Vesicles contain neurotransmitter molecules
Sending Neuron
Synapse Axon
Terminal
Neurotransmitter Release • Action Potential Causes vesicle to open • Neurotransmitter released into synapse • Locks onto receptor molecule in postsynaptic
membrane.
Neurotransmitter molecules have specific shapes
Binding sites for NT’s
When NT binds to receptor, ions enter… Starts AP again…
What happens when the action potential reaches the terminal branch?
• Vesicles containing neurotransmitters are
released into the synapse
• Neurotransmitters bind to postsynaptic receptors
• Cause excitatory or inhibitory effects
http://www.youtube.com/watch?v=Ntenaz7Sf4k
Signals into the neuron
• Inhibitory: cause neuron to become hyperpolarized
• Hyperolarized =Inhibitory
• Excitatory: cause neuron to become depolarized
• Excitatory= depolarized
Neurotransmitters bind receptors in a lock-and-key model
Neurotransmitters
• Neurotransmitters can have an excitatory or inhibitory effect
– Excitatory- cause action potential to fire
– Inhibitory- prevent action potential from firing
Some Drugs work on
receptors • Some drugs are shaped like neurotransmitters.
• Agonists- “excites” mimics the effects of a
neurotransmitter example: morphine
• Antagonists- “inhibit” - inhibits release of
neurotransmitter or binds to receptor and blocks its function
example: curare
RECAP
Psychopharmacology
Botulism
Blocks release of ACh at the neuromuscular junction, causing paralysis
“Botox” is botulism toxin used to prevent facial muscles from making wrinkles
Curare – found in vines in S. America; used as poison
Can stun or kill prey quickly
Blocks ACh receptors causing paralysis
• Antipsychotic medications
– Block dopamine receptors
– Reduces schizophrenic hallucinations
• Caffeine
– Increases the release of excitatory neurotransmitters by blocking the inhibitory neurotransmitter adenosine
• Cocaine
– Prevents reuptake of dopamine
– Leads to heightened arousal of entire nervous system
ION CONCENTRATIONS
Cell Membrane in resting state
K+
Na+ Cl- K+ A-
Outside of Cell
Inside of Cell
Na+ Cl-
Cell membrane is Semi-
Permeable
Cell Membrane at rest
Na+ Cl- K+
Na+
Cl- K+ A-
Outside of Cell
Inside of Cell
Potassium (K+) can pass through to equalize its concentration
Sodium and Chlorine cannot pass through
Result - inside is negative relative to outside
- 70 mv
RESTING POTENTIAL
• At rest inside of the cell is at -70 microvolts • With inputs to dendrites inside becomes more positive • If resting potential rises above threshold and action potential
starts to travel from cell body down the axon. • Figure shows resting axon being approached by an AP
Depolarization ahead of AP
• AP opens cell membrane to allow sodium (NA+) in • Inside of cell rapidly becomes more positive than outside • This depolarization travels down the axon as leading edge of
the AP.
https://www.youtube.com/watch?v=sGWZFcsyMgA
https://www.youtube.com/watch?v=sGWZFcsyMgA
Fugu Fish
How do neurotoxins work?
AIM: How do neurotransmitters affect the nervous system?
Agenda
1. Quiz 2. REVIEW NERVE CELLS
3. CNS/PNS + Endocrine Systems 4. Stop 5 Minutes before end of class to hand back work
Nervous System
Central Nervous System (CNS)
= interneuron
Peripheral Nervous System (PNS)
Motor and Sensory neurons
Central Nervous System (CNS)
Brain Enables all functioning
Billions of neurons and their connections
These neurons work together in neural networks to facilitate efficient output.
As we learn, these networks strengthen
Spinal Cord Connects brain to PNS
Handles reflexes
Central Nervous System
Brain Spinal Cord
Central Nervous System
The Brain and Neural Networks
Complex Neural Network
Interconnected neurons form networks in the brain.
The Nerves
Nerves consist of neural “cables” containing many axons.
They are part of the peripheral nervous system
NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM Consists of the brain and spinal cord
PERIPHERAL NERVOUS SYSTEM Made up on nerve cells that send messages
between the central nervous system and all the parts of the body
Somatic Nervous System (Voluntary muscles and sense organs)
Transmits sensory messages to the central nervous system Activated by touch, pain, changes in temperature, and
changes in body position
Autonomic Nervous System (involuntary muscles and internal organs)
Regulates the body’s vital functions, such as heartbeat, digestion and blood pressure
Sensory (afferent) Nervous System
Sensory Input
Sensory (afferent) Nervous System
Motor Output
Sympathetic System Prepares body for action
“Fight or Flight”
Parasympathetic System Calms body after emergencies
Restores peace
What does the Nervous System do for us? • Involved in:
• Thinking, dreaming, feeling, moving, reacting to the external world
• It works day and night, regulates our internal functions
NERVOUS SYSTEM
Somatic Nervous System (Voluntary muscles and sense organs)
Transmits sensory messages to the central nervous system Activated by touch, pain, changes in temperature, and
changes in body position
Sensory (afferent) Nervous System
Sensory Input
Sensory (afferent) Nervous System
Motor Output
Autonomic Nervous System (involuntary muscles and internal organs)
Regulates the body’s vital functions, such as heartbeat, digestion and blood pressure
Figure 3.6 The dual functions of the autonomic
nervous system
Myers: Exploring Psychology, Sixth Edition in
Modules Copyright © 2005 by Worth Publishers
AUTONOMIC
NERVOUS SYSTEM
• Fight-or-flight response
• Sympathetic: Arouses
• Parasympathetic: Calms
AUTONOMIC
NERVOUS SYSTEM
• Can we influence the parasympathetic nervous system? – How?
The Endocrine System
The Endocrine System is the body’s
“slow” chemical communication
system. For example, epinephrine (adrenaline) increases heart rate, blood pressure, blood
sugar and feelings of excitement during emergency
situations.
The Endocrine System
• Derives its name from the fact that
various glands release hormones
directly into the blood, which in
turn transports the hormones to
target tissues via ducts.
• Helps coordinate and integrate complex psychological reactions
• Endocrine glands secrete hormones into the bloodstream
• Hormones serve to organize the nervous system and body
• Hormones also activate behavior, such as sexual behavior, hunger and aggression
The Endocrine System
• GROUP 1
– Hypothalamus
– Testis
• Group 2
– Pituitary Gland
– Ovary
• Group 3
– Pancreas
– Parathyroids
• Group 4
– Adrenal Glands
– Thyroid Gland
• IN YOUR EXPERT GROUP. BECOME AN EXPERT ON YOUR TWO LOCATIONS OF THE ES. ALL GROUPS MUST UNDERSTAND:
– FUNCTION
– STRUCTURE
• WHEN DONE YOU WILL BE RESPONSIBLE FOR TEACHING OTHERS.
Figure 3.8 The
body’s major
endocrine glands
Myers: Exploring
Psychology, Sixth
Edition in Modules Copyright © 2005 by
Worth Publishers
Th
e
En
do
crin
e
Syste
m
Pituitary Gland
Is called the “master gland.”
The anterior pituitary lobe releases hormones that regulate other glands.
The posterior lobe regulates water and salt balance and releases other hormones
Gigantism versus Dwarfism
Hypothalamus Controls Pituitary Links endocrine
And nervous system
Thyroid & Parathyroid Glands
Regulate metabolic and calcium rate.
Goiter’s Disease
Adrenal Glands
Adrenal glands consist of the adrenal medulla and the adrenal cortex.
The medulla secretes adrenal hormones The adrenal cortex regulates salt and carbohydrate
metabolism. Pancreas: sugar levels
Gonads
Sex glands: 1) regulate development 2) maintain reproductive organs in adults. Ovaries- secrete estrogen. Testes- secrete testosterone
Imagine you are an endocrinologist
Imagine you are an endocrinologist
1) The patient suffers from too little calcium in the blood
2) The patient is an adult male and is only 3 feet and 6 inches tall
3) The patient has goiters 4) The patient suffers from diabetes 5) The patient is a 24 year old female without
female secondary sexual characteristics
Five patients come to you with the following conditions. Diagnose which gland in the endocrine system may be
affected:
How would taking anabolic steroids (testosterone) cause the testis to shrink?
Mr. Musselman suffers from
HYPOGLYCEMIA
In what gland is the issue based?
http://www.pbs.org/wgbh/pages/frontline/video/flv/generic.html?s=frol02sfaaq392&continuous=1
MOOD SWINGS
http://www.pbs.org/wgbh/pages/frontline/video/flv/generic.html?s=frol02sfa8q392&continuous=1
Teenage Brain
• QUIZ • Ability Experiment • Biological Genetics • Evolutionary Psychology
AGENDA
FREE WRITE You are a novelist writing a mystery. You begin with a marvelous plot and the realization that your detective needs certain traits and abilities to be successful. This person needs to be sensitive enough to deal with witnesses and victims; tough enough to stay alive in the face of bombs, hired killers, and guard dogs; intelligent enough to break secret codes and outwit the criminal mastermind; and witty enough to be interesting and to find human in devastating situations.
Create a brief biography for this fictional character, in which you outline the heritable traits and life experiences that have allowed your detective to become this person. Which characteristics seem to be primarily “inborn”? Which ones were acquired by experience?
Behavior Genetics: What’s the Point?
• Behavior Genetics seeks to understand the relative influence of our heredity and our experiences
• Nature vs. Nurture? It’s both – but how much of each?
Behavior Genetics: Genetics Review
Chromosomes • Pairs of thread like bodies that contain
genes • Average human cell has 23 pairs • Sex cells?
Deoxyribonucleic acid (DNA) • Organic molecule arranged in a double-helix • Contains the “code of life”
Genes • Basic units of inheritance • Segment of DNA
Genome • “map” for an organism’s genetic complete
make-up • Human Genome Project
Heredity examines the transmission of trait from one generation to next
Nature vs. Nurture How might we study this?
FAMOUS TWIN STUDY
• Both twins are married to women named Betty and divorced from women named Linda. • One has named his first son James Alan while the other named his first son James Allan. • Both twins have an adopted brother whose name is Larry. • Both named their pet dog "Toy." • Both had some law-enforcement training and had been a part-time deputy sheriff in Ohio. • Each did poorly in spelling and well in math. • Each did carpentry, mechanical drawing, and block lettering. • Each vacation in Florida in the same three-block-long beach area. • Both twins began suffering from tension headaches at eighteen, gained ten pounds at the
same time, and are six feet tall and 180 pounds.
CURIOSITY?
Why are children in the same family so different?
Molecular Genetics • Studies how particular genes
influence behavior (and traits) • e.g. Is there a gene that
determines obesity? Sexual orientation?
• Can now reveal at-risk populations for diseases.
• Promise and peril of molecular genetics? • Genetic engineering • Eugenics • Pre-natal screening ethical
dilemmas
Heritability The extent to which differences among people are
attributed to genes.
1. If the heritability of intelligence is 50%, what does this mean?
2. A woman is 60-inches tall. She finds out that the heritability of height is 90%. Does this mean she can credit 54 inches to here genes and 6 inches to her environment?
3. AS ENVIRONMENTAL DIFFERENCE DECREASE… HERITABILITY INCREASES…
Behavior Genetics: Temperament
Temperament refers to emotional reactivity and seems to be set very early in life (Environment can enhance or diminish this
genetic predisposition)
My niece Gabby has always been very shy Slow to warm up
My cousin Nolan is very extroverted
Gene-Environment Interaction
Can changing the environment change the way gene are expressed?
Callused feet Non-callused feet
Gene-Environment Interaction
• Genes and environment work together like two hands clapping THEY INTERACT
• Environment can trigger genetic “switches”
Factors such as diet, drugs, and stress can affect epigenetic
molecules that regulate gene expression.
FORGET NATURE VS. NURTURE
THINK
NATURE VIA NURTURE
Evolutionary Psychology
• Whereas behavior geneticists seek to explain our behavioral differences in terms of our genes, evolutionary psychologists focus on our similarities, as dictated by natural selection.
Richard Dawkins The Selfish Gene (1976) • Varied organisms in a population compete to survive
• Certain biological and behavioral variations facilitate survival
• Surviving organisms may reproduce and pass on their genes
• This leads to overall changing characteristics in a population
Evolutionary Psychology
Evolution: • How does it work? • How long does it take?
Darwin Awards: https://www.youtube.com/watch?v=Lc5DNhMxYvk
Evolutionary Psychology • Today, evolutionary psychologists examine persistent trends in
human behavior and seek to explain them • Keep in mind, however, that genetically driven tendencies only
partially govern human behavior!
FOR INSTANCE: Sexuality and Mating
MALES • QUANTITY OVER QUALITY • INCREASE REPRODUCTIVE SUCCESS BY
SPREADING THEIR GENES AS WIDELY AS POSSIBLE
• ATTRACTION TO FERTILE FEMALES • NOT PHYSICALLY BOUND TO PREGNANCY
FEMALES • QUALITY OVER QUANTITY • MORE INVESTED IN BEARING/NURTURING
CHILDREN • SEEK MEN WHO EITHER PROVIDE SUPERB
GENES OR ARE GOOD PROVIDERS
Sexuality and Mating
Evolutionary Psychology
Perhaps males should invest more in child-
rearing?
CRITISISM
Evolutionary Psychology
• Do these arguments just provide excuses for bad behavior?
• Do humans have more of a social and cultural responsibility to make the world better?
• What about environmental influence? • How does the environment
reinforce these trends?
• How much of a role does environment play in the persistence of these roles?
• Who benefits?
CULTURAL INFLUENCES
Culture: • Distinctive values, beliefs, language
• Both tangible (food, clothing) and intangible (values, beliefs
Norms: • Rules that represent the typical
behaviors of a particular group. • Ex: “Personal Space”
Individualism vs Collectivism: • Individualist cultures place value of
singular person over that of a group. • What does your culture have? Why?
OTHER INFLUENCES • Gender Roles – expected behaviors for
males and females • Women as caregivers? • Men as breadwinners? • The Reality? Women now
OUTNUMBER men in the workplace in the US, yet in 87% of families with children, are still the primary caregivers.
• Variations across culture and time…
What do these roles and stereotypes provide us?
OTHER INFLUENCES (Gender Development)
• Aggression involves an intent to harm, whether verbal or physical: males admit to and exhibit more than females.
• Men are and are perceived as more powerful and engage in behaviors that exhibit and perpetuate this power inequity.
• Females place greater emphasis on social connections, choosing careers that involve social interaction or require nurturing roles
• Males have more difficulty admitting they are wrong
SCENARIO Early in 2000, a 6-year-old girl in Michigan was shot and killed by a first grade classmate. This young boy brought a loaded gun to school and shot her after a petty conflict developed during class. He later claimed that he had only intended to scare her but that the gun “went off.” The bullet struck the little girl in the throat and she died a short time later. No one was surprised to discover that the 6-year-old killer was being raised in neglectful and abusive circumstances, complicated by his caretaker’s drug abuse. Amid reactions of shock and outrage, one question was repeated over and over: How could it happen? Was there something biologically wrong with the child, so that he didn’t understand or couldn’t control what he was doing? Did his life experience make him prone to violence? Using the concepts from this chapter, provide your explanation of how the boy’s development-both nature and nurture- might have led to this tragedy. Explicitly discuss issues of genetics and environment, explaining how each factor might or might not have contributed to his behavior. YOU MIGHT FIND IT HELPFUL to organize your discussion around topics like: Temperament, prenatal environment, peer influence, culture, and gender.
Limitless
Trailer https://www.youtube.com/watch?v=jOLqNOfzus4
Neuron Firing:
Electro Chemical Process 1. Neuron at rest is polarized 2. Neuron receives signals from neighboring
neurons 3. Total excitatory input exceeds absolute threshold 4. Neuron fires according to all or none principle –
action potential shoots down the axon 5. Neurotransmitters are released across synapse. 6. Refractory period
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