Download PSYC 2301 Chapter 2

DE BO R AH M.
L IGH T
MIST Y
G.
H UL L
CO CO
BAL L ANT Y NE
Chapter 2: Biology and behavior
Courtesy Dr. Julie Gralow
Copyright © Macmillan education 2015
LEARNING OBJECTIVES: Part 1
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LO 1 Define neuroscience and explain its contributions to our understanding of
behavior.
LO 2 Label the parts of a neuron and describe an action potential.
LO 3 Illustrate how neurons communicate with each other.
LO 4 Summarize various neurotransmitters and the roles they play in human
behavior.
LO 5 Recognize the connections between the central and peripheral nervous
systems.
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LEARNING OBJECTIVES: Part 2
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LO 6 Evaluate pseudo psychology and its relationship to critical thinking.
LO 7 Describe how psychologists use the scientific method.
LO 8 Summarize the importance of a random sample.
LO 9 Recognize the forms of descriptive research.
LO 10 Explain how the experimental method relates to cause and effect.
LO 11 Demonstrate an understanding of research ethics.
LO 12 Compare and contrast tools scientists use to study the brain.
LO 13 Identify the lobes of the cortex and explain their functions.
LO 14 Recognize the association areas and identify their functions.
LO 15 Distinguish the structures and functions of the limbic system.
LO 16 Distinguish the structures and functions of the brainstem and cerebellum.
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Biology and Behavior: Studying the Last Frontier – Part 1
Neuroscience
 Involves study of the brain and nervous system
Biological psychology
 Focuses on how the brain and other biological systems influence
human behavior
Contributions
 Examination of extent of experience-induced neural plasticity
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Biology and Behavior: Studying the Last Frontier – Part 2
 Brandon Burns poses for a photo at the Marine Corps
Recruit Depot in Parris Island, South Carolina in the fall
of 2003. The following year, he was shot in the head by
an enemy sniper in the Battle of Fallujah.
 Doctors concluded that some parts of his brain were no
longer viable. “They removed part of my skull and dug
out the injured part of my brain,” and now, Brandon
says, “one third of my brain is gone.”
 What were the consequences of his injury?
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The Neuron
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Can you identify the structure of a typical neuron?
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Cell body
Dendrites
Axon
Terminal buds
Myelin sheath
Synapse
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Biology and Behavior
Glia to the Rescue
 A scanning electron micrograph shows neurons (green)
and glia (orange).
 Glial cells serve as the “glue” of the nervous system,
providing cohesion and support for the neurons.
Thomas Deerinck, NCMIR
Some classes of glial cells
 Microglia
 Astrocytes
 Schwann
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Communication Within Neurons
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Biology and Behavior: Studying the Last Frontier – Part 3
COMMUNICATION WITHIN AND BETWEEN
Resting potential
 Electrical potential of cell at rest
 Solutions on either side of the membrane wall come into equilibrium;
slightly more negative charge inside
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Biology and Behavior: Studying the Last Frontier – Part 4
COMMUNICATION WITHIN AND BETWEEN
Action potential
 Involves spike in electrical energy that passes through the axon of a
neuron, the purpose of which is to convey information
 Is all-or-none
Every time a segment of the axon fires
 Positive sodium ions flood in from the outside of the cell, while the
prior segment returns to its resting potential, all along the length of
the axon to its end
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Biology and Behavior: Studying the Last Frontier – Part 5
COMMUNICATION WITHIN AND BETWEEN
Excitatory signals
 Occur when enough combine, sending neurons signal the receiving
neuron to pass along message
Inhibitory signals
 Inhibit neuron from releasing a signal through the axon
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Biology and Behavior: Communication Within and Between
 Myelin sheath insulates and protects the tiny
spikes in electricity happening inside the axon.
 Action potential “skips” over the segments of
myelin, hopping from one node to the next,
instead of traversing the entire length of the
axon.
MYELIN
 Protein that envelops and insulates the axon,
facilitating faster transmission of the impulse.
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Biology and Behavior: Studying the Last Frontier – Part 6
COMMUNICATION BETWEEN
Neurotransmitters
 Chemical messengers that neurons use to communicate at the synapse
Receptor sites
 Location where neurotransmitters attach on the receiving side of the
synaptic gap
Reuptake
 Process by which neurotransmitters are reabsorbed by the sending
terminal bud
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Biology and Behavior: The Synapse
 Axon terminal of a sending neuron interacts with the
dendrites of a receiving neuron by releasing chemical
messengers (neurotransmitters) into the synapse.
 Once the neurotransmitters migrate across the gap and
latch onto the dendrite’s receptor sites, the message
has been conveyed.
The Synapse
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Biology and Behavior: Studying the Last Frontier – Part 7
COMMUNICATION WITHIN AND BETWEEN
Reuptake
 Occurs when neurotransmitters are reabsorbed by the sending bud
Diffusion
 Occurs when neurotransmitters are not reabsorbed and drift out of the
synaptic gap
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Communication Between Neurons
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Biology and Behavior: Studying the Last Frontier – Part 8
NEUROTRANSMITTERS
Acetylcholine
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Relays messages from motor neurons to muscles, enabling movement; involved in
memory
Too much = spasms; too little = paralysis
Glutamate
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Makes neurons fire; central role in memory and learning
Too much = strokes; too little = symptoms of schizophrenia
GABA
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Inhibits neurotransmitter firing; contributes to motor control, vision
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Biology and Behavior: Studying the Last Frontier – Part 9
NEUROTRANSMITTERS
Norepinephrine
 Has variety of effects in CNS; helps body prepare for stress
Serotonin
 Plays key role in controlling appetite, aggression, and mood; regulates
sleep and breathing
Dopamine
 Plays role in modulating mood; plays central role in positive
reinforcement and dependency
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Biology and Behavior: Studying the Last Frontier – Part 10
NEUROTRANSMITTERS
Endorphins
 Regulates secretion of other neurotransmitter; naturally produced
opioids; reduces pain and elevates mood
Agonists
 Interfere at level of synapse; increase normal neurotransmitter activity
Antagonists
 Interfere at level of synapse; decrease normal neurotransmitter activity
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Biology and Behavior: Neurotransmitters
Caffeine
 Blocks receptors for adenosine
 Increases activity in branch of nervous system
serving the body
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SHOW WHAT YOU KNOW – Part 1
1. Many axons are surrounded by a ______ , which is a fatty substance that insulates
the axon.
2. When Brandon was injured, _____ played an important role in his recovery by
defending against infection and inflammation of the brain, as well as holding neurons
together and maintaining the structure of the nervous system.
a. glial cells
b. dendrites
c. action potentials
d. sodium ions
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SHOW WHAT YOU KNOW – Part 2
3. ________ are released into the ________ when an action potential reaches the
branches of the terminal buds.
a. Sodium ions; synaptic gap
b. Neurotransmitters; synaptic gap
c. Potassium ions; cell membrane
d. Neurotransmitters; sodium gates
4. Neural communication is very complicated. Draw a diagram depicting the process of
neural communication, then explain it to yourself while looking at what you have
drawn.
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The Supporting Systems: Infrastructure
Brain needs supporting infrastructure to carry out directives and relay
essential information from outside
 Central nervous system (CNS)
 Peripheral nervous system (PNS)
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The Supporting Systems: Overview of the Nervous System
The nervous system is made up of the central
nervous system, which includes the brain and
spinal cord, and the peripheral nervous system.
moodboard/Alamy
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The Supporting Systems: Part 1
Spinal cord
 Includes bundle of neurons
 Allows communication between the brain and the peripheral nervous
system
 Connects with the body’s muscles, glands, and organs
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The Supporting Systems: Part 2
Sensory neurons
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Receive information
about the environment
from the sensory
systems and convey this
to the brain for
processing
Interneurons
Motor neurons
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Carry information from
CNS to produce
movement; provide
mechanism regulated by
spinal cord and brain
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Resides in brain and
spinal cord; act as
bridges connecting
sensory and motor
neurons
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THE SPINAL CORD AND REFLEX ARC
Without any input from the brain, the spinal cord neurons are capable of creating some
simple reflexive behavior.
While the spinal reflex occurs, sensory neurons also send messages to the brain, letting it
know what has happened.
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Try This
 Test your knowledge of the reflex arc using Brandon as an example. As
you recall, Brandon’s brain injury led to paralysis on the right side of his
body.
 What do you think would happen if a doctor tapped on his right
knee—would he experience a reflex?
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What Lies Beyond: The Peripheral Nervous System – Part 1
Peripheral nervous system
 Includes all neurons not in CNS
 Involves neurons that are bundled together to carry signals throughout
body
Nerves
 Act as primary communication system for PNS
 Supply CNS with information about body’s environment
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What Lies Beyond: The Peripheral Nervous System – Part 2
SOMATIC NERVOUS SYSTEM
Characteristics
 Involves branch of the parasympathetic nervous system
 Includes sensory nerves and motor nerves
 Gathers information from sensory receptors
 Controls the skeletal muscles responsible for voluntary movement
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What Lies Beyond: The Peripheral Nervous System – Part 3
AUTONOMIC NERVOUS SYSTEM
Characteristics
 Regulates involuntary activity
 Has two divisions involved in physiological responses to stress or crisis
situations
 Sympathetic nervous system
 Parasympathetic nervous system
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The Sympathetic and Parasympathetic Nervous System
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What Lies Beyond: The Peripheral Nervous System
TEND AND BEFRIEND
Female response to stress
 Many women have inclination to direct energy toward nurturing and
forging social bonds as a stress response.
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Think Again
MALE BRAIN, FEMALE BRAIN
 Studies suggest gender stereotypes can influence performance in math
and science.
 Research also shows that male and female brains are far more alike
than they are different, but...
 Certain regions of the limbic cortex and the frontal lobes were larger in
women.
 Areas of the parietal cortex, the amygdala, and hypothalamus were
larger in men.
So is nature or nurture responsible for gender imbalance in math and
science?
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The Endocrine System and Its Slowpoke Messengers
ENDOCRINE SYSTEM
1. Hormones
2. Pituitary gland
3. Thyroid gland
4. Adrenal glands
Can you define each of these?
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The Endocrine System
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The Endocrine System and Its Slowpoke Messengers
Other Endocrine Glands and Organs
Pineal gland
 Secretes melatonin
Pancreas
 Secretes insulin
Ovaries and testes
 Secrete sex hormones
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SHOW WHAT YOU KNOW – Part 3
1. ________ carry information from the central nervous system to activate
various parts of the body, such as muscles and glands.
a. Interneurons
b. Dendrites
c. Sensory neurons
d. Motor neurons
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SHOW WHAT YOU KNOW – Part 4
2. When a stimulus causes an involuntary response, we refer to it as a
reflex arc. The simple communication pathway goes from a sensory
neuron through interneurons in the _____ and back out through motor
neurons.
a. brain
b. spinal cord
c. axon hillock
d. nodes of Ranvier
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SHOW WHAT YOU KNOW – Part 5
3. The ________ gland, located in the center of the brain, just under the
hypothalamus, is in charge of the endocrine system.
4. When confronted with a potentially threatening situation, the
sympathetic nervous system sometimes prepares for “fight or flight”
and/or “tend and befriend.” How would you explain these two very
different responses using the evolutionary perspective?
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The Hemispheres
RIGHT BRAIN, LEFT BRAIN: THE TWO HEMISPHERES
Cerebrum
 Includes largest, most highly developed part of brain
 Involved in intelligence, personality, thinking, perceiving, planning and
organization, language, sensation, motor functions
 Divided into right and left hemispheres and covered by corpus
callosum
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Two Hemispheres
 The right hemisphere controls the left side of the body,
and the left hemisphere controls the right.
 This explains why Brandon, who was shot on the left
side of his head, suffered paralysis and loss of sensation
on the right half of his body.
 The cerebrum looks like a walnut with its two wrinkled
halves. Regions of the left and right hemispheres
specialize in different activities, but the two sides of the
brain are constantly communicating and collaborating.
Science Source/Photo Researchers, Inc. Colorization by:
Eric Cohen
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The Hemispheres: Hemispherectomy
 Christina Santhouse relaxes with her mother at
Johns Hopkins, where she had a dramatic brain
surgery known as a hemispherectomy.
 Prior to the operation, Christina experienced
over 100 seizures a day.
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The Hemispheres: Split Brain
Hemispherectomies
 Exceptionally rare; last resort
Callostomies (Split-brain operations)
 Right and left hemisphere disconnected
MRI SCAN
 Both hemispheres Intact
 After hemispherectomy
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The Split-Brain Experiment
The image to the right shows a top view of the corpus callosum, the bundle of neurons
linking the right and left hemispheres. When the corpus callosum is severed, we can easily
see functional differences between the two sides of the brain. Studies of people who have
undergone this procedure are shown here.
Terence H. Williams, Nedzad Gluhbegovic/Wolters Kluwer
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The Hemispheres: Lateralization
Generalization
 Left hemisphere plays a crucial role in language processing and right
hemisphere plays a crucial role in managing visual spatial tasks.
But
 Hemispheres constantly integrate and share information.
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The Hemispheres: Language and the Left
Handedness and dominance
 Left hemisphere controls language in most people; does not
necessarily correspond to handedness.
Language dominance
 Broca’s area
 Wernicke’s area
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Speak Again
Brandon works on his pronunciation in front of a mirror
during a speech therapy session at the Memphis VA
hospital. You can see the extent of his injury on the left
side of his head. Upon awakening from his coma, Brandon
could not articulate a single word. Today, he can hold his
own in complex conversations.
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The Hemispheres: Language Area and The Brain
1. Broca’s area
2. Wernicke’s area
Can you identify the role each structure plays in
language production and comprehension?
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The Hemispheres: The Role of The Right
Research: Right hemisphere
 More proficient in some visual tasks
 Critical for understanding abstract and humorous use of language
 Better for following conversations that change topics
 Important for recognizing faces
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SHOW WHAT YOU KNOW – Part 6
1. The left hemisphere excels in language and the right hemisphere excels
in visual spatial tasks. This specialization of the two hemispheres is known
as:
a. split-brain.
b. callostomy.
c. hemispherectomy.
d. lateralization.
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SHOW WHAT YOU KNOW – Part 7
2. A man involved in a car accident suffered severe brain trauma. As he
recovered, it became clear he was having difficulty producing speech,
even though he could understand what people were saying to him. It is
very likely he had suffered damage to the left frontal lobe in a part of the
brain referred to as:
a. Wernicke’s area.
b. Broca’s area.
c. the visual field.
d. the corpus callosum.
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SHOW WHAT YOU KNOW – Part 8
3. On rare occasions, medication does not work for people with severe
seizures. In those cases, doctors might suggest a procedure known as a
_____, which essentially disconnects the right and left hemispheres.
4. The corpus callosum enables information sharing between the two
hemispheres. In some cases, surgeons sever the corpus callosum to
prevent seizures from spreading between the two hemispheres. How
would you explain to a middle school student why this surgical procedure
is used and how it is helpful?
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The Amazing Brain: Neuroplasticity
Brain undergoes constant alterations
 Physical adaptation and repair—even after
hemispherectomy
 Growth of new connections and reorganization
Stem cells
 Responsible for creating new neurons
HUMAN STEM CELL
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Across the World
THE PLASTIC BRAINS OF OUR CHILDREN
Children and music
 Chinese parents believe that piano instruction for their kindergarteners
will help school performance.
 American parents play classical music to fetuses and show DVDs to
their infants and toddlers to promote brain development.
Are these parents right in their assumptions?
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The Amazing Brain: Part 1
ALL IN YOUR HEAD
 Are you a secretive person? How high is your
self-esteem?
 The answers to these questions lie on the
surface of the skull, or so claimed nineteenthcentury phrenologists.
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The Amazing Brain: Part 2
TOOLS FOR STUDYING THE BRAIN
 Electroencephalogram (EEG)
 Computerized Axial Tomography (CAT scan or CT scan)
 Positron Emission Tomography (PET)
 Magnetic Resonance Imaging (MRI)
 Functional Magnetic Resonance Imaging (fMRI)
What are the strengths and limitations of each of these tools?
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Social Media and Psychology
FACEBOOK IN THE BRAIN
 Facebook friends range from zero to 5000, averaging 245.
 A preliminary study suggests friend volume may reflex something
about a user’s brain.
 There is a correlation between number of Facebook friends and
density of gray matter in areas of brain known for social interaction
and facial recognition.
So…are your Facebook friends a gray matter?
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Electric Surprise
STIMULATING BRAIN CELLS MAY BE TRICKIER THAN
WE THOUGHT
Using a new type of optical imaging, Harvard Medical School researchers observed
neurons as they were stimulated by an electrode.
 Electrodes caused sparse strings of neurons, rather than a small sphere of
surrounding neurons.
 Findings suggests a much smaller margin of error during brain surgery and design
of neural prosthetics.
Melinda Wenner. Reproduced with permission. Copyright © 2010 Scientific American,
a division of Nature America, Inc. All rights reserved.
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SHOW WHAT YOU KNOW – Part 9
1. Scientists hope that in the future they will be able to discover how we
can use stem cells to help people like Brandon and Christina. The goal
would be for doctors to induce the process of _____ to restore the lost
brain tissue.
a. ablation
b. agonists
c. neurogenesis
d. lateralization
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SHOW WHAT YOU KNOW – Part 10
2. You have been asked to set up an experiment to determine if playing
classical music to infants leads to improved cognitive abilities. What would
your independent and dependent variables be? How would your
experimental and control groups be treated differently?
3. ________ are responsible for creating new neurons.
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SHOW WHAT YOU KNOW – Part 11
4. The brain is constantly undergoing alterations in response to
experiences and is capable of a certain degree of physical adaptation and
repair. This ability is known as:
a. neuroplasticity
b. phrenology
c. ablation
d. lateralization
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Ways to Study the Living Brain
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The Cortex: A Peek Beneath the Skull – Part 1
THE CORTEX
Cerebral cortex
 Processes information and surrounds nearly all of the
brain structure
Association areas
 Involves region of cortex that integrates information
from all over the brain
What does it require to study the brain?
Look at the above illustration for clues.
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THE LOBES: UP CLOSE AND PERSONAL
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The Cortex: A Peek Beneath the Skull – Part 2
Phineas Gage and the
frontal lobes
 In 1848, Gage was
impaled by a 3-foot
tamping rod through his
cheek, brain, and skull
and caused dramatic
changes in his
personality.
Fritsch and Hitzig and the
motor cortex
 By applying mild shock
to dogs’ cortex,
researchers
demonstrated motor
cortex region
involvement in muscle
movement.
Albert Einstein and the
parietal lobes
 Postmortem comparison
of 35 male brain
specimens and
Einstein’s brain found
the region of Einstein’s
parietal lobe responsible
for visual spatial
cognition and
mathematical thinking
15 percent larger than
those of the control
group.
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The Cortex: A Peek Beneath the Skull – Part 3
THE LOBES: UP CLOSE AND PERSONAL
Penfield
 Used method similar to Fritsch and Hitzig, showing which points along
the motor cortex and somatosensory cortex corresponded to parts of
the body
 Developed model often represented by oversimplified “homunculus”
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PENFIELD’S MAP
The Motor and Somatosensory Cortex
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The Cortex: A Peek Beneath the Skull – Part 4
THE LOBES: UP CLOSE AND PERSONAL
Occipital lobes
 Initial processing site for visual information
Primary visual cortex
 Connects to optic nerve where visual information is received and
interpreted
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SHOW WHAT YOU KNOW – Part 12
1. The major function of the _____ is to organize information among the other lobes of
the brain.
a. parietal lobes
b. frontal lobes
c. corpus callosum
d. temporal lobes
2. The ________ integrate information from all over the brain, allowing us to learn,
have abstract thoughts, and carry out complex behaviors.
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SHOW WHAT YOU KNOW – Part 13
3. This section introduces the lobes of the cortex and their associated functions.
Create a way to remember the lobes and their specific functions using a rhyme or
another memorization technique you know.
4. Phineas Gage suffered a horrific accident in the mid-1800s, when an explosion sent
a metal rod through his brain and out the top of his skull. Which caused the sudden
change in his personality following the accident?
a. damage to his occipital lobes
b. damage to his temporal lobes
c. damage to his frontal lobes
d. damage to his somatosensory cortex
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Digging Below the Cortex
DRAMA CENTRAL: THE LIMBIC SYSTEM
Limbic system fuels basic drives and processes
emotions and memories.
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Digging Below the Cortex: Identify Functions
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Hippocampus
Amygdala
Thalamus
Hypothalamus
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Digging Below the Cortex
Deeper Yet: The Brainstem and Cerebellum
Brainstem
 Includes the brain’s core
 Extends from spinal cord to forebrain
Forebrain
 Involves largest part of brain and includes cerebral cortex and limbic
system
Midbrain
 Involves brainstem part involved in arousal levels, responsible for
generating movement patterns in response to sensory input
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Digging Below the Cortex: Brainstem and Cerebellum
Reticular formation
 Involves network of neurons running through the midbrain
 Controls levels of arousal and quickly analyzes sensory information on
its way to the cortex
 Hindbrain
 Pons
 Medulla
Cerebellum
 Involves muscle coordination and balance
 May also affect fine distinctions in cognition
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Amazing Brains: Amazing People
Three years after his traumatic brain injury,
Brandon celebrated his marriage to Laura. The
couple recently had their third child, a daughter
named MacCrea Iona.
With her master’s degree in speech–language
pathology, Christina now works full time in
Pennsylvania’s public school system.
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SHOW WHAT YOU KNOW – Part 14
1. The _____ represents a group of interconnected structures that process
emotions, memories, and basic drives.
a. left hemisphere
b. limbic system
c. corpus callosum
d. superior temporal sulcus
2. The specific part of the brain that processes basic emotions, such as
fear and aggression and the memories associated with them, is the
______.
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SHOW WHAT YOU KNOW – Part 15
3. How might the specific structures of the limbic system, the brainstem,
and the cerebellum come into play if you were out on a first date?
4. The primary role of the thalamus is to:
a. relay sensory information.
b. keep the body’s systems in a steady state.
c. generate movement patterns in response to sensory input.
d. regulate sleep–wake cycles.
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