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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Chapter 2: Brain and Behavior
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
If we were to
reduce behavior
to its smallest entity….
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
100 billion
neurons in the
brain
Synapse
To next neuron
Axons send messages
Myelin: Fatty layer of
tissue that coats axons
Dendrites receive messages
Figure 2.1
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
The Nerve Impulse
•
•
•
Resting Potential:
electrical charge of an
inactive neuron – 70
millivolts.
Threshold: Trigger
point for a neuron’s
firing – 20 mv.
Action Potential: Nerve
impulse
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Figure 2.6
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Figure 2.8
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Figure 2.7
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Figure 2.9
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Chemicals that neurons send are called:
Neurotransmitters
• Alter activity in neurons; brain chemicals
•
– Acetylcholine: Activates muscles
– Dopamine: Muscle control
– Serotonin: Mood and appetite control
Receptor Site: Areas on the surface of
neurons and other cells that are sensitive to
neurotransmitters or hormones
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Neural Regulators
• Neuropeptides: Brain chemicals that regulate
activity of other neurons
– Enkephalins: Relieve pain and stress;
similar to endorphins
– Endorphins: Released by pituitary gland;
also help to relieve pain
• Placebos raise endorphin levels
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Nerves and Neurons
• Nerve: bundles of neurons
• Neurilemma: Thin layer of cells wrapped
•
around axons outside brain and spinal cord;
forms a tunnel that damaged fibers can follow
as they repair themselves
Neurogenesis: Production of new brain cells;
brain loses thousands of cells each day and
grows new neurons at same time to replace
them
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
•
•
Two Divisions of the Peripheral Nervous
System
Somatic System: Links spinal cord with body
and sense organs; controls voluntary
behavior
Autonomic System: Serves internal organs
and glands; controls automatic functions such
as heart rate and blood pressure
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
The Spinal Cord
• Spinal Nerves: 31 of them; carry sensory and
motor messages to and from the spinal cord
• Cranial Nerves: 12 pairs that leave the brain
directly without passing through the spinal
cord; also work to communicate messages
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
The Spinal Cord and Behavior
• Reflex Arc: Simplest behavior in which a
stimulus provokes an automatic response
• Sensory Neuron: Nerve cell that carries
messages from the senses toward the CNS
• Motor Neuron: Cell that carries commands
from the CNS to the muscles and glands
• Effector Cells: Cells capable of producing a
response
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Figure 2.10
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Researching the Brain
• Ablation: Surgical removal of tissue
• Deep Lesioning: A thin wire electrode is
•
•
lowered into a specific area inside the brain;
Electrical current is then used to destroy a
small amount of brain tissue
Electrical Stimulation of the Brain (ESB):
When an electrode is used to activate target
areas in the brain
Electroencephalograph (EEG): A device that
detects, amplifies, and records electrical
activity in the brain
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Brain Imaging Techniques
• Computed
Tomographic
Scanning (CT):
Computerenhanced X-ray
of the brain or
body
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
• Magnetic
Resonance
Imaging (MRI):
Uses a strong
magnetic field,
not an X-ray, to
produce an
image of the
brain and body
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
More Brain Imaging Techniques
• Positron
Emission
Tomography
(PET):
Computergenerated color
image of brain
activity, based
on glucose
consumption in
the brain
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Cerebral Cortex
• Outer layer of the cerebrum
• Cerebrum: Two large hemispheres that cover
upper part of the brain
• Corticalization: Increase in size and wrinkling
•
of the cortex
Cerebral Hemispheres: Right and left halves
of the cerebrum
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
The Brain
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Figure 2.23
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Figure 2.18
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Figure 2.26
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Right Brain/Left Brain
• Humans use 95 percent of our left brain for
language
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Split Brain/Visual pathway
Figure 2.20
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Figure 2.30
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
When the Brain Fails to Function Properly
• Association Cortex: All areas of the cerebral
•
cortex that are not primarily sensory or motor
in function
Aphasia: Speech disturbance resulting from
brain damage
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Brain abnormalities
Damage to …
•
•
Broca’s area – know what you want to say just can’t say it
Wernicke’s Area – language comprehension, does not
understand the meaning of words
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Subcortex
• All brain structures below cerebral cortex;
immediately below cerebral hemispheres
• Hindbrain (Brainstem)
• Medulla: Connects brain with the spinal cord
and controls vital life functions such as heart
rate and breathing
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
More Subcortex Structures
• Pons (Bridge): Acts as a bridge between
•
brainstem and other structures; influences
sleep and arousal
Cerebellum: Located at base of brain;
regulates posture, muscle tone, and muscular
coordination
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Endocrine System
Glands that pour hormones directly into the
bloodstream or lymph system, e.g. Pituitary
gland…
•
Pituitary governs functioning of thyroid, adrenals, and
gonads. Also regulates growth.
– Too little = small than average…
• Hypopituitary Dwarfs: As adults, perfectly
proportioned but tiny
• Treatable by using growth hormone; will add a
few inches
• Treatment is long and expensive
Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Pituitary Gland (cont.)
•
Too much = giantism
(excessive body growth)
– Acromegaly: Enlargement
of arms, hands, feet, and
facial bones; due to too
much growth hormone
released late in growth
period, e.g., Andre the
Giant, 7’4”, 500 lbs.
– Pituitary also governs
functioning of thyroid,
adrenals, and gonads
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Psychology: A Modular Approach to Mind and Behavior, Tenth Edition, Dennis Coon
Chapter 2
Adrenal Hormones
Epinephrine arouses body;
is associated with fear.
Norepinephrine arouses
body; is linked with anger
Figure 2.29
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