Biological Basis for Behavior Resources

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CHAPTER CONTENTS

Overview 4

Learning Objectives 4

Chapter Outline 5

Approaching Your Lecture 14

Class Activities

I. Introduction: Neuroscience and Behavior

Activity: Neurophysiology and the Internet, p. 17

Discussion: Ethics and the Biology of Behavior, p. 17

ActivePsych: Video: Program 2, Neuroimaging: Assessing What’s Cool, p. 18

Web Resources: Neuropsychology Central, p. 17Neuroscience for Kids, p. 17Neurosciences on the Internet, p. 18

II. The Neuron: The Basic Unit of Communication

ActivePsych: Flash-based Interactive Demonstrations: Nerve Cell Demonstrations, p. 18Synaptic Transmission and Neurotransmitters, p. 18

Web Resources: Basic Neural Processes Tutorials, p. 18

A. Characteristics of the NeuronVideo: Psychology: The Human Experience: Segment 6, Neurological Disorder, p. 18

B. Communication Within the Neuron: The All-or-None Action PotentialActivities: Using Dominoes to Illustrate the Action Potential, p. 18

Racing Neurons! p. 18

C. Communication Between Neurons: Bridging the GapPsychSim 5: Neural Messages, p. 19

In the News: Neural Inhibition and Excitation, p. 19

Videos: The Brain Teaching Modules, Second Edition: Module 17, Learning as Synaptic Change,p. 19Digital Media Archive: Segment 1, Neural Communication, p. 19

ActivePsych: Video: Segment 1, Neural Communication: Impulse Transmission Across theSynapse, p. 19

Video Tool Kit for Introductory Psychology: Neural Communication: Impulse TransmissionAcross the Synapse, p. 19

Neuroscience andBehavior

CHAPTER 2CHAPTER

2

D. Neurotransmitters and Their EffectsLecture: Parkinson’s Disease, p. 20

Videos: The Mind Teaching Modules, Second Edition: Module 5, Endorphins: The Brain’sNatural Morphine, p. 19The Brain Teaching Modules, Second Edition: Module 31, Brain Transplants inParkinson’s Patients, p. 20Moving Images: Exploring Psychology Through Film: Program 2, NeuralCommunication: Neurotransmitter Acetylcholine, p. 20

Video Tool Kit for Introductory Psychology: Compulsive Gambling and the Brain's PleasureCenter, p. 20Parkinson's Disease: A Case Study, p. 20Treating Parkinson's Disease: Deep Brain ElectrodeImplantation, p. 20

Popular Films: Iris, p. 20Eden, p. 20

E. How Drugs Affect Synaptic Transmission

III. The Nervous System and the Endocrine System: Communication Throughout the Body

A. The Central Nervous SystemB. The Peripheral Nervous System

Activity: Reaction Time, p. 20

In the News: Nerve Therapy to Treat Depression, p. 21

C. The Endocrine SystemPopular Film: Open Water, p. 21

In the News: Hormones Build Trust, p. 21

IV. A Guided Tour of the Brain

Activity: Viewing the Brain, p. 22

ActivePsych: PowerPoint Demonstration: Name That Brain Damage, p. 22

PsychSim 5: Brain and Behavior, p. 22

Video: The Brain Teaching Modules, Second Edition: Module 1, Organization and Evaluationof Brain Function, p. 22

A. The Dynamic Brain: Plasticity and NeurogenesisVideos: Psychology: The Human Experience: Segment 5, Brain Plasticity, p. 22

The Brain Teaching Modules, Second Edition: Module 7, Brain Anomaly and Plasticity:Hydrocephalus, p. 22

ActivePsych: Video: Program 3, Brain Plasticity: Rewiring the Visual Cortex, p. 22

Video Tool Kit for Introductory Psychology: Language and Brain Plasticity, p. 22Rewiring the Brain, p. 22

B. NeurogenesisVideos: The Brain Teaching Modules, Second Edition: Module 32, Neurorehabilitation, p. 22

Moving Images: Exploring Psychology Through Film: Program 4, Brain Reorganization:Phantom Limb Sensations, p. 22

C. The Brainstem: Hindbrain and Midbrain StructuresD. The Forebrain

Lectures: Experimental Treatments for Brain Injuries and Degeneration, p. 22The Thalamus and Consciousness, p. 23Attention-Deficit Hyperactivity Disorder (ADHD) and the Brain, p. 23 The Curious Case of Phineas Gage, p. 24 (Handout 2.1, p. 50)

Activities: Demonstrating the Somatosensory Cortex, p. 24How the Brain Takes a Blow, p. 24

2 Chapter 2 Neuroscience and Behavior

Videos: The Mind Teaching Modules, Second Edition: Module 7, The Frontal Lobes: Cognitionand Awareness, p. 24Psychology: The Human Experience: Segment 7, Brain Surgery for Neurological Illness,p. 24The Brain Teaching Modules, Second Edition: Module 25, The Frontal Lobes andBehavior: The Story of Phineas Gage, p. 24

Moving Images: Exploring Psychology Through Film: Program 3, A ContemporaryPhineas Gage, p. 24The Brain Teaching Modules, Second Edition: Module 24, Aggression, Violence, andthe Brain, p. 24Digital Media Archive: Segment 26, Self-Stimulation in Rats, p. 24

ActivePsych: Video: Program 1, Brain and Behavior: Phineas Gage Revisited, p. 24

Video Tool Kit for Introductory Psychology: Mapping the Brain Through Electrical Stimulation,p. 24Planning, Life Goals, and the Frontal Lobe, p. 24

V. Specialization in the Cerebral Hemispheres

Discussion: Left Brain/Right Brain: Which Is Right? p. 25

ActivePsych: Flash-based Interactive Demonstration: Hemispheric Pathways, p. 25Video: Program 4, Achieving Hemispheric Balance: Improving Sports Performance,p. 25

PsychSim 5: Hemispheric Specialization, p. 25Dueling Brains, p. 25

Video: Scientific American Frontiers Video Collection: Segment 8, Old Brain, New Tricks, p. 25

A. Language and the Left Hemisphere: The Early Work of Broca and WernickeVideos: Psychology: The Human Experience: Segment 16, Language Centers in the Brain, p. 25

The Mind Teaching Modules, Second Edition: Module 8, Language Processing in theBrain, p. 25The Mind Teaching Modules, Second Edition: Module 26, The Bilingual Brain, p. 25The Brain Teaching Modules, Second Edition: Module 6, Language and Speech: Broca’sand Wernicke’s Areas, p. 25

B. Cutting the Corpus Callosum: The Split BrainActivities: Integrated Functioning and the Cerebral Cortex, p. 25

Testing Hemispheric Lateralization, p. 26Right-Brain/Left-Brain Quiz, p. 26 (Handouts 2.2 and 2.3, pp. 30–31)Cerebral Lateralization, p. 27The Interdependence of the Brain and Both Hands, p. 27

Videos: Scientific American Frontiers Video Collection, Second Edition: Segment 7, SeveredCorpus Callosum, p. 25The Brain Teaching Modules, Second Edition: Module 5, The Divided Brain, p. 25Psychology: The Human Experience: Segment 4, A Case Study of Brain Damage, p. 28

Video Tool Kit for Introductory Psychology: The Split Brain: Lessons on Language, Vision, andFree Will, p. 25The Split Brain: Lessons on Cognition and theCerebral Hemispheres, p. 25

VI. Enhancing Well-Being with Psychology: Pumping Neurons: Maximizing Your Brain’s Potential

Discussions: Keeping the Brain Healthy: Exercise Your Mind, p. 28Should We “Enhance” Humans Through Neuroendocrine Treatments? p. 29

Video: The Mind Teaching Modules, Second Edition: Module 18, Effects of Mental and PhysicalActivity on the Brain, p. 28

ActivePsych: Videos: Segment 2, Activity, Exercise, and the Brain, p. 28Program 12: Experience and Exercise: Generating New Brain Cells, p. 28

Chapter 2 Neuroscience and Behavior 3

OVERVIEW Chapter 2 first outlines the scope and diversity of biological psychology and notesthat it is one of the scientific disciplines that makes important contributions toneuroscience. Biological psychologists (biopsychologists or psychobiologists) inves-tigate the physical processes underlying psychological experiences, mentalprocesses, and behavior. The first section describes the structure and functions ofthe neuron. Next, neural activation, synaptic transmission, and the role of neuro-transmitters are outlined. The functions and effects of several neurotransmittersare discussed, as are the effects of certain drugs on neurotransmission.

The next section discusses the structures and functions of the divisions of thenervous system: the central nervous system, which consists of the brain andspinal cord; and the peripheral nervous system, which includes the somatic andautonomic nervous systems. The sympathetic and parasympathetic systems,which make up the autonomic nervous system, are described. This section endsby focusing on the endocrine system, its glands, and its chemical messengers,called hormones.

The section on the brain begins with a discussion of plasticity and neurogene-sis, providing an emphasis on plasticity as an important theme in brain function-ing. The section then takes you through the regions of the hindbrain, midbrain,and forebrain, including their structures and functions. The different roles of thefour lobes of each of the brain’s cerebral hemispheres (temporal, occipital, pari-etal, and frontal) are explained, and the functions of forebrain structures in thelimbic system—the hippocampus, thalamus, hypothalamus, and amygdala—aredescribed.

The chapter ends with a discussion of hemispheric specialization and the partplayed by split-brain patients in discovering the specialized functions of thebrain’s hemispheres. Enhancing Well-Being with Psychology suggests ways ofmaximizing your brain’s potential.

LEARNING OBJECTIVES When your students finish studying this chapter, they should be able to:

Introduction: Neuroscience and Behavior1. Define biological psychology and neuroscience, and explain why psychologistsstudy the biological basis of behavior.

The Neuron: The Basic Unit of Communication2. Describe the functions of neurons and glial cells, and distinguish among thethree types of neurons.

3. Identify the basic components of the neuron, describe the action potential, andexplain the processes that take place within the neuron when it is activated.

4. Explain how information is communicated between neurons, and distinguishbetween excitatory and inhibitory messages.

5. Describe how neurotransmitters affect synaptic transmission, identify siximportant neurotransmitters, and explain their effects on behavior.

6. (Focus on Neuroscience) Explain what is meant by “runner’s high” and discussthe role of endorphins in this phenomenon.

7. Identify and explain several ways in which drugs can affect brain activity byinterfering with synaptic transmission.

The Nervous System and the Endocrine System: CommunicationThroughout the Body8. Describe the functions of the two major parts of the central nervous system,and explain how spinal reflexes work.

9. Identify the divisions and subdivisions of the peripheral nervous system, anddescribe their functions.

10. Describe the general functions of the endocrine system, and explain the rolehormones play.


11. Identify the functions of the major endocrine glands, and explain the relation-ship between the hypothalamus and the endocrine glands.

A Guided Tour of the Brain12. Discuss how the pseudoscience called phrenology evolved, and how it ultimate-

ly helped advance the idea of cortical localization.13. State what neural pathways are, distinguish between functional and structur-

al plasticity, and explain what neurogenesis is.14. (Focus on Neuroscience) Summarize the research involving juggling and brain

plasticity, and explain what the findings suggest about how learning a newmotor skill affects the adult brain.

15. Identify the structures of the brainstem, and describe their functions.16. Describe the forebrain’s cerebral cortex, and explain the functions of its four

lobes and association areas. 17. Describe the limbic system and the functions of the brain structures that com-

prise it.

Specialization in the Cerebral Hemispheres18. (Critical Thinking) Describe the differences in male and female brains, and

explain what these differences do and do not mean.19. State what cortical localization is, and explain how the findings of Broca and

Wernicke provided early clinical evidence for lateralization of function, thedevelopment of different types of aphasia, and language specialization in theleft hemisphere.

20. Describe the work of Roger Sperry, discuss the split-brain operation, andexplain how it provided evidence for the differing abilities of left and righthemispheres.

21. (Science Versus Pseudoscience) Identify and discuss the myth about how muchof our brain we use, explain left and right hemisphere functioning, and list thefacts related to being left-handed or right-handed.

Enhancing Well-Being with Psychology: Pumping Neurons: MaximizingYour Brain’s Potential

22. Describe the research findings from studies on enriched versus impoverishedenvironments using both nonhumans and humans, and list some of the practi-cal implications of this research.

CHAPTEROUTLINE I. Introduction: Neuroscience and Behavior

Biological psychology (also called biopsychology or psychobiology) is thescientific study of the biological bases of behavior and mental processes.Biological psychology makes important contributions to neuroscience—thescientific study of the nervous system.

II. The Neuron: The Basic Unit of Communication1. Communication throughout the nervous system takes place via

neurons, cells that are highly specialized to receive and transmitinformation from one part of the body to another.

2. The human nervous system is made up of other types of specializedcells, called glial cells or glia, which support neurons by providingstructural support and nutrition, removing cell wastes, and providean active role in brain development and function.

3. There are three basic types of neurons. a. Sensory neurons convey information from specialized receptor

cells in the sense organs, the skin, and the internal organs to thebrain.


b. Motor neurons communicate information to the muscles andglands of the body.

c. Interneurons communicate information between neurons; theyare the most common type of neuron found in the human ner-vous system.

A. Characteristics of the NeuronMost neurons have three basic components. 1. The cell body (also called the soma) contains the nucleus, which

provides energy for the neuron to carry out its functions.2. Dendrites are short, branching fibers extending out from the cell

body that receive information from other neurons or specializedcells.

3. The axon is a single, elongated tube that extends from the cell bodyand carries information from the neuron to other neurons, glands,and muscles. Axons vary in length from a few thousandths of an inchto about four feet.a. Many axons are surrounded by a myelin sheath, a white, fatty

covering that insulates axons from one another and increases theneuron’s communication speed.

b. Nodes of Ranvier are small gaps in the myelin sheath.B. Communication Within the Neuron: The All-or-None Action Potential

In general, messages are gathered by the dendrites and cell body andthen transmitted along the axon in the form of a brief electrical impulsecalled an action potential.1. Each neuron has a stimulus threshold—a minimum level of stimu-

lation from other neurons or sensory receptors to activate it.2. While waiting for sufficient stimulation to activate it, the neuron is

polarized; that is, the axon’s interior is more negatively charged thanthe fluid surrounding the axon. The resting potential, or the nega-tive electrical charge of the axon’s interior, is –70 millivolts. It hasmore sodium ions outside and more potassium ions inside.

3. When sufficiently stimulated by other neurons or sensory recep-tors—that is, when the neuron reaches its stimulus threshold—theaxon depolarizes, beginning the action potential.a. Sodium ion channels open; sodium ions rush into the axon.b. Then sodium channels close, and potassium ion channels open,

allowing potassium ions to rush out of the axon.c. Finally, potassium channels close.d. This sequence of depolarization and ion movement continues in a

self-sustaining fashion down the entire length of the axon.e. The result is a brief positive electrical impulse (+30 millivolts)

that progressively occurs at each segment down the axon—theaction potential.

4. The all-or-none law is the principle that either a neuron is sufficiently stimulated and an action potential occurs or a neuron isnot sufficiently stimulated and an action potential does not occur.

5. Following the action potential, a refractory period occurs duringwhich the neuron is unable to fire. During this thousandth of a second or less, the neuron repolarizes; that is, it reestablishes theresting potential conditions.

6. Two factors affect the speed of the action potential.a. Axon diameter—thicker axons are faster.b. Myelin sheath—myelinated axons are faster.


C. Communication Between Neurons: Bridging the Gap1. The point of communication between two neurons is called the

synapse.a. The message-sending neuron is referred to as the presynaptic

neuron.b. The message-receiving neuron is called the postsynaptic neuron.c. Synaptic gap: the tiny, fluid-filled space only five-millionths of

an inch wide between the axon terminal of one neuron and thedendrite of the adjoining neuron.

2. Transmission of information between neurons occurs in one of twoways. a. Electrical: Ion channels bridge the narrow gap between neurons;

communication is virtually instantaneous.b. Chemical: The presynaptic neuron creates a chemical substance

(a neurotransmitter) that diffuses across the synaptic gap and isdetected by the postsynaptic neuron (over 99 percent of thesynapses in the brain use chemical transmission). (1) An action potential arrives at the axon terminals; these

branches at the end of the axon contain tiny pouches or sacscalled synaptic vesicles, which contain special chemicalmessengers called neurotransmitters.

(2) The synaptic vesicles release the neurotransmitters into thesynaptic gap.

(3) Synaptic transmission is the process through which neu-rotransmitters are released by one neuron, cross the synapticgap, and affect surrounding neurons by attaching to receptorsites on their dendrites.

(4) After synaptic transmission, the following may occur.(a) Reuptake: the process by which neurotransmitter mole-

cules detach from a postsynaptic neuron and are reab-sorbed by a presynaptic neuron so they can be recycledand used again.

(b) Enzymatic destruction or breakdown.(5) Each neurotransmitter has a chemically distinct, different

shape. For a neurotransmitter to affect a neuron, it mustperfectly fit the receptor site.

3. Excitatory and inhibitory messages A neurotransmitter communicates either an excitatory message or aninhibitory message to a postsynaptic neuron. a. An excitatory message increases the likelihood that the neuron

will activate; an inhibitory message decreases the likelihood thatit will activate. The postsynaptic neuron will depolarize only ifthe net result is a sufficient number of excitatory messages.

b. Depending on the receptor site to which it binds, the same neuro-transmitter can have an inhibitory effect on one neuron and anexcitatory effect on another neuron.

c. On the average, each neuron in the brain communicates directlywith 1,000 other neurons.

D. Neurotransmitters and Their Effects

Researchers have linked abnormal levels of specific neurotransmitters tovarious physical and behavioral problems.1. Important Neurotransmitters

a. Acetylcholine stimulates muscles to contract and is importantin memory, learning, and general intellectual functioning. Levels


of acetylcholine are severely reduced in people with Alzheimer’s disease.

b. Dopamine is involved in movement, attention, learning, andpleasurable or rewarding sensations.

c. Degeneration of neurons that produce dopamine in one brainarea causes Parkinson’s disease. Symptoms of Parkinson’s disease can be alleviated by a drug called L-dopa, which convertsto dopamine in the brain.

d. Excessive brain levels of dopamine are sometimes involved inthe hallucinations and perceptual distortions that characterize schizophrenia. Some antipsychotic drugs work by blockingdopamine receptors and reducing dopamine activity in the brain.

e. Serotonin is involved in sleep, moods, and emotional states,including depression. Antidepressant drugs such as Prozacincrease the availability of serotonin in certain brain regions.

f. Norepinephrine activates neurons throughout the brain,assists in the body’s response to danger or threat, and is involvedin learning and memory retrieval. Norepinephrine dysfunction isalso involved in some mental disorders, especially depression.

g. GABA (gamma-aminobutyric acid) usually communicates aninhibitory message to other neurons, reducing brain activity.Antianxiety medications work by increasing GABA activity.

2. Endorphins: Regulating the Perception of Pain a. Pert & Synder (1973) discovered the brain contains receptor sites

specific for opiates.b. Endorphins are chemicals released by the brain in response to

stress or trauma. c. Endorphins are associated with the pain-reducing effects of

acupuncture.3. Focus on Neuroscience: Is “Runner’s High” an Endorphin Rush?

a. “Runner’s high,” the rush of endorphins experienced after sus-tained aerobic exercise, was the subject of an experiment byBoecker et al., using a PET scan to detect a chemical that bindsto opioid receptors.

b. The experiment provided the first real evidence that “runner’shigh” is at least partly due to the release of endorphins in thebrain.

E. How Drugs Affect Synaptic Transmission Many drugs, especially those that affect moods or behavior, work byinterfering with the normal functioning of neurotransmitters in thesynapse. 1. Drugs may increase or decrease the amount of neurotransmitter

released by neurons.2. Drugs may affect the length of time the neurotransmitter remains in

the synaptic gap, either increasing or decreasing the amount avail-able to the postsynaptic receptor.

3. Drugs may prolong the effects of the neurotransmitter by blockingits reuptake by the sending neuron.

4. Drugs can mimic specific neurotransmitters. 5. Drugs can mimic or block the effect of a neurotransmitter by fitting

into receptor sites and preventing the neurotransmitter from acting.


III. The Nervous System and the Endocrine System: CommunicationThroughout the BodyThe nervous system is the complex, organized communication network ofneurons; its two main divisions are the central nervous system and theperipheral nervous system. In the peripheral nervous system, nerves aremade up of large bundles of neuron axons. A. The Central Nervous System

1. The central nervous system includes the brain and the spinalcord, which are suspended in cerebrospinal fluid for protection.

2. Spinal reflexes are simple, automatic behaviors that are processedin the spinal cord.

3. One of the simplest spinal reflexes involves a three-neuron loop ofrapid communication—a sensory neuron that communicates sensa-tion to the spinal cord, an interneuron that relays information withinthe spinal cord, and a motor neuron leading from the spinal cordthat signals muscles to react.

B. The Peripheral Nervous SystemThe peripheral nervous system comprises all the nerves outside thecentral nervous system; its two subdivisions are the somatic nervoussystem and the autonomic nervous system. 1. The somatic nervous system communicates sensory information

received by sensory receptors along sensory nerves to the centralnervous system and carries messages from the central nervous system along motor nerves to perform voluntary muscle movements.

2. The autonomic nervous system regulates involuntary functionssuch as heartbeat, blood pressure, breathing, and digestion; its twobranches are the sympathetic nervous system and parasympatheticnervous system. a. The sympathetic nervous system produces rapid physiological

arousal in response to perceived threats or emergencies. Thesebodily changes collectively represent the fight-or-flightresponse—they physically prepare you to fight or flee from a perceived danger.

b. The parasympathetic nervous system conserves and main-tains the body’s physical resources.

C. The Endocrine SystemThe endocrine system is made up of glands located throughout thebody that secrete hormones into the bloodstream. Communication in theendocrine system takes place much more slowly than in the nervous system.1. Hormones are chemical messengers secreted into the bloodstream

primarily by endocrine glands. They interact with the nervous system and affect internal organs and body tissues. Some of theprocesses they regulate are metabolism, growth rate, digestion, bloodpressure, and sexual development and reproduction.

2. A brain structure called the hypothalamus serves as the main linkbetween the nervous system and the endocrine system. It directlyregulates the release of hormones by the pituitary gland.

3. The pituitary gland, a pea-sized gland just under the brain, con-trols hormone production in other endocrine glands. It also producessome hormones directly, such as growth hormone and prolactin.


4. A set of glands called the adrenal glands is involved in the humanstress response.a. The adrenal cortex, the outer portion of each adrenal gland,

also interacts with the immune system. b. The adrenal medulla, the inner portion of the adrenal glands,

secretes epinephrine (or adrenaline) and norepinephrine. 5. The gonads, or sex organs, are the ovaries in females and testes in

males. These sex hormones regulate sexual development, reproduc-tion, and sexual behavior.


Brain functions involve the activation of neural pathways that link dif-ferent brain structures; however, the best way to think of the brain is asan integrated system.1. Science Versus Pseudoscience: Phrenology

a. In the early 1800s, Franz Gall developed phrenology, whichwas based on the idea that specific skull locations were associat-ed with various personality characteristics, moral character, andintelligence.

b. Although later shown to be a pseudoscience, phrenology trig-gered scientific interest in the possibility of cortical localiza-tion (or localization of function)—the idea that specific psycho-logical and mental functions are localized in specific brain areas.

A. The Dynamic Brain: Plasticity and Neurogenesis

Plasticity is the brain’s ability to change structure and function. Untilthe mid-1960s, it was believed that the brain’s physical structure washard-wired or fixed for life.1. Functional plasticity is the brain’s ability to shift functions from

damaged to undamaged areas.2. Structural plasticity is a phenomenon in which brain structures

physically change in response to environmental influences.3. Focus on Neuroscience: Juggling and Brain Plasticity

a. Research by Draganski et al. (2004) provides evidence thatlearning a new skill produces structural changes in the brain.

b. Participants in a study, divided into “jugglers” and “nonjugglers,”were given MRI brain scans to detect changes over time.

B. Neurogenesis1. Neurogenesis is the development of new neurons after birth.

a. Research by Gould (1998) showed generation of new neuronsevery day in the hippocampus in adult marmoset monkeys.

b. Further research by Eriksson and Gage (1998) on adult cancerpatients provided the first evidence that the human brain hasthe capacity to generate new neurons.

C. The Brainstem: Hindbrain and Midbrain Structures

The brainstem is made up of the hindbrain and the midbrain, whichare located at the base of the brain.1. The hindbrain connects the spinal cord with the rest of the brain.

In the hindbrain, incoming sensory messages cross over to the otherside of the brain, and outgoing motor messages cross over to theother side of the body. This is referred to as contralateral organiza-tion. Three structures make up the hindbrain: the medulla, the pons,and the cerebellum.


a. The medulla lies directly above the spinal cord and controlsvital autonomic functions such as breathing, heart rate, anddigestion.

b. The pons lies just above the medulla. Large bundles of axons onboth sides of the pons connect it to the cerebellum. Informationfrom other brain regions higher up in the brain is relayed to thecerebellum via the pons.

c. The cerebellum bulges out behind the pons; it is involved in thecontrol of balance, muscle tone, coordinated muscle movements,and the learning of automatic movements and motor skills.

d. The reticular formation (or the reticular activating system) isa network of neurons at the core of the medulla and the pons.The neurons project up to higher brain regions and down to thespinal cord. The reticular formation plays an important role inregulating attention and sleep.

2. The midbraina. The midbrain is an important relay station and contains cen-

ters important to the processing of auditory and visual sensoryinformation before sending them to higher brain centers.

b. The substantia nigra is an area of the midbrain that isinvolved in motor control and contains a large concentration ofdopamine-producing neurons.

D. The ForebrainThe forebrain, or cerebrum, is the largest and most complex brainregion. 1. The cerebral cortex is the grayish, quarter-inch-thick, wrinkled

outer portion of the forebrain that is sometimes described as beingcomposed of gray matter. Extending inward from the cerebral cortexare white myelinated axons, sometimes referred to as white matter,that connect the cerebral cortex to other brain regions. a. The cerebral cortex is divided into two cerebral hemispheres.b. The corpus callosum is a thick band of axons that connects

the two hemispheres of the cerebral cortex and serves as the pri-mary communication link between them.

c. Each cerebral hemisphere is divided into four regions, or lobes.(1) The temporal lobe, located near the temples, is the primary

receiving area for auditory information (primary auditorycortex).

(2) The occipital lobe, at the back of each cerebral hemisphere, isthe primary receiving area for visual information (primaryvisual cortex).

(3) The parietal lobe, located above the temporal lobe, processesbodily, or somatosensory, information, including touch, tem-perature, pressure, and information from receptors in themuscles and joints. A band of tissue on the parietal lobe,called the somatosensory cortex, receives information fromtouch receptors in different parts of the body. Body parts arerepresented in proportion to their sensitivity to somatic sen-sations.

(4) The frontal lobe, the largest lobe of the cerebral cortex, islocated behind and above the eyes; it is involved in planning,initiating, and executing voluntary movements. The move-ments of different body parts are represented in a band oftissue on the frontal lobe called the primary motor cortex.


d. The bulk of the cerebral cortex consists mostly of associationareas, which are generally thought to be involved in processingand integrating sensory and motor information.

2. The limbic system is a group of forebrain structures that form aborder around the brainstem and are involved in emotion, motiva-tion, learning, and memory.a. The hippocampus is a large structure embedded in the tempo-

ral lobe that plays a role in the ability to form new memories ofevents and information. Neurogenesis takes place in the adulthippocampus.

b. The thalamus is a rounded mass of cell bodies that processesand distributes motor and sensory (except for smell) informationgoing to and from the cerebral cortex. It is thought to be involvedin regulating levels of awareness, attention, motivation, andemotional aspects of sensations.

c. The hypothalamus is a peanut-sized structure that regulatesboth divisions of the autonomic nervous system and behaviorsrelated to survival, such as eating, drinking, frequency of sexualactivity, fear, and aggression. (1) One area of the hypothalamus, the suprachiasmatic nucleus

(SCN), plays a key role in regulating daily sleep–wake cyclesand other rhythms of the body.

(2) The hypothalamus produces both neurotransmitters and hor-mones that directly influence the pituitary gland.

d. The amygdala is an almond-shaped clump of neuron cell bodiesthat is involved in a variety of emotional response patterns,including fear, anger, and disgust. It is also involved in learningand in memory formation, especially emotional memories.

V. Specialization in the Cerebral HemispheresAlthough the left and right hemispheres are very similar in appearance,they are not identical in structure or function.

A. Language and the Left Hemisphere: The Early Work of Broca andWernicke

Cortical localization, as noted in the box on phrenology, refers to theidea that particular areas of the human brain are associated with particular functions.1. Pierre Paul Broca was a French surgeon and neuroanatomist who,

in the 1860s, discovered an area on the lower left frontal lobe of thecerebral cortex that, when damaged, produces great difficulties inspeaking but no loss of comprehension. Today, this area is known asBroca’s area.

2. Karl Wernicke was a German neurologist who, in the 1870s, dis-covered an area on the left temporal lobe of the cerebral cortex that,when damaged, produces meaningless or nonsensical speech and dif-ficulties in verbal or written comprehension. Today, this is known asWernicke’s area.

3. Lateralization of function is the notion that one hemisphereexerts more control over the processing of a particular psychologicalfunction (e.g., speech and language functions are lateralized on theleft hemisphere).

4. Aphasia refers to the partial or complete inability to articulateideas or understand spoken or written language because of braininjury or damage.


a. People with Broca’s aphasia find it difficult or impossible to produce speech, but their comprehension of verbal or writtenwords is relatively unaffected.

b. People with Wernicke’s aphasia can speak, but they often havetrouble finding the correct words and have great difficulty comprehending written or spoken communication.

5. Critical Thinking: “His” and “Her” Brains?a. Some researchers argue that gender differences in cognitive abil-

ities and personality characteristics are due to differences inbrain structure, organization, and function.

b. Both hormones and genes seem to influence gender differencesin brain development

c. Men’s brains tend to be larger, have a higher percentage of whitematter (which is evenly distributed throughout the brain), andhave more cerebrospinal fluid. Women’s brains have a higherpercentage of gray matter, have a greater concentration of whitematter in the corpus callosum, and display more cortical com-plexity.

d. Men and women seem to use their brains equally, but differently.A recent study found that some of the brain regions correlatedwith intelligence were more prominent in women and some weremore prominent in men.

e. Studies of gender differences should be examined critically, keep-ing in mind that male and female brains are much more alikethan they are dissimilar.

B. Cutting the Corpus Callosum: The Split Brain 1. A split-brain operation is a surgical procedure that involves cut-

ting the corpus callosum in order to stop or reduce epileptic seizures.2. Roger Sperry was an American psychologist and neuroscientist

who did pioneering research on hemispheric specialization usingsplit-brain patients.a. Typical Sperry experiment

(1) Sperry projected the image of an object to the left of the midpoint on a screen; the image was sent to the right nonverbal hemisphere.

(2) If a split-brain subject was asked to verbally identify theimage flashed on the screen, he could not do so. However, thesplit-brain subject’s right hemisphere still processed theinformation and expressed itself nonverbally: the subject wasable to pick up the correct object with his left hand.

b. Sperry’s experiments reconfirmed the specialized language abilities of the left hemisphere.

c. Results from other brain research(1) The left hemisphere is superior in language abilities, speech,

reading, and writing. (2) The right hemisphere is more involved in nonverbal

emotional expression and visual-spatial tasks that involvedeciphering complex visual clues; it also excels in recognizingfaces and emotional facial cues, reading maps, copyingdesigns, and drawing; it also shows a higher degree of specialization for appreciating or responding to music.

d. In the normal brain, the left and right hemispheres function inan integrated fashion, constantly exchanging information.


C. Science Versus Pseudoscience: Brain MythsSix questions about myths are answered, including “Do we use only 10percent of our brain?” and “Are we left-brained or right-brained?”

VI. Enhancing Well-Being with Psychology: Pumping Neurons:Maximizing Your Brain’s Potential

A. Studies first conducted in the 1960s demonstrated that rats raised inenriched environments produce more synaptic connections between brainneurons, whereas impoverished environments decrease synaptic connections.

B. The human brain also seems to benefit from enriched, stimulating envi-ronments—the brains of university graduates were found to have up to40 percent more synaptic connections than the brains of high schooldropouts.

C. Studies show that the best protection against developing Alzheimer’sdisease is engaging in intellectually stimulating hobbies.

D. In humans, a mentally stimulating, intellectually challenging environ-ment is associated with enhanced cognitive functioning. Even in lateadulthood, remaining mentally active can help prevent or lessen mentaldecline.


APPROACHING YOUR LECTURE

Although this chapter appears at first glance tocontain an overwhelming number of technicalterms that are difficult to pro nounce and impossi-ble to spell, students often do well with this mater-ial. We think the reason students do better thanexpected is that the terms and concepts, while dif-ficult, are concrete and somewhat familiar to them.Students have had some exposure to this materialin high school biology, whereas few have had anyexposure to such topics as memory, learning, or cog-nition. Drawings work best; film clips of neurons atwork, while entertaining, do not necessarily makegood teaching devices. If you draw fairly well, drawthe neuron yourself; students will attempt to copyit and profit from the interactive learning involvedin doing so.

Begin, as the book does, with the neuron. Try toget the students to think about how the neuronrelates to their personal behavior. You might men-tion illnesses that are related to neurons or neuro-transmitters, such as Alzheimer’s, Park inson’s, andmultiple sclerosis.

Draw Figure 2.1, the neuron, on the chalk-board. First, explain the functions of the threemajor parts of the neuron: dendrites, cell body, andaxon. Then, point out the other parts of the neu-ron—the myelin sheath, nodes of Ranvier, and theaxon terminals—and explain how they function.Explain that degeneration of patches of the myelin

sheath is associated with multiple sclerosis, whichmay be why this disease affects young and middle-aged adults rather than children—since children’smyelination is not completely developed. Put it alltogether by describing the major processes involvedin communication within and between neurons.

We suggest that, at the very least, studentsshould be familiar with the resting potential, theaction potential, reuptake, and the all-or-none law.To help weaker students understand the actionpotential, create a transparency of communicationwithin the neuron (text Figure 2.4).

We are not aware of any mnemonic devices thatease the learning process, so visual aids are thebest pedagogical tools. Whenever possible, encour-age students to draw, label, and explain theprocesses to one another. Use drills, such as label-ing the parts of the neuron, defining the processes,and relating the neurotransmitters to their func-tions. Additional visual materials are suggested inthe Class Activities section.

Neurotransmitters are not as difficult to teachas the neuron. You should, however, emphasizevery early on that neurotransmitters either inhibitor excite transmission. Review for students the sev-eral possible effects of drugs on neuronal transmis-sion: (1) Some drugs mimic the neurotransmitterand produce the same effect (agonists); (2) somedrugs block the receptor sites and prevent theeffect of the neurotransmitters (antagonists); and(3) other drugs block the reuptake of the neuro-


transmitter, increasing its effects. The followingchart can be used to amplify the text material; itlists important neurotransmitters, the effects of

deficits and excesses, and substances that increaseor decrease the activity of the neurotransmitter.

SUMMARY OF IMPORTANT NEUROTRANSMITTERS

Effect of Effect of Increases DecreasesNeurotransmitter Function Deficit Excess Activity Activity

Acetylcholine Stimulates muscle Alzheimer’s Nicotine Curarecontraction; involved Nerve gas Atropinein memory, learning,and general intellectualfunctioning

Dopamine Involved in movement Parkinson’s Schizophrenia L-dopa Some anti-attention, learning, and Amphet. psychoticpleasurable sensations Cocaine drugs

Serotonin Involved in sleep, Anxiety, mood LSDmoods, and disorders, SSRIsemotional states insomnia

Norepinephrine Involved in increasing Mental Anxiety Lithium heartbeat and arousal, disorders, Cocaineas well as learning especially Amphet.and memory retrieval depression Caffeine

GABA (gamma- Helps to offset excitatory Anxiety Sleep and Alcoholaminobutyric acid) messages and regulate eating disorders Valium

daily sleep–wake cycles XanaxBarbit.

Endorphins Involved in pain Body Body may not Opiates Naloxoneperception and positive experiences give adequate Alcohol Naltrexoneemotions pain warning about

pain

The nervous system and its divisions can bestbe explained by using the transparency of textFigure 2.10 (Organization of the Nervous System).We draw the chart on the board as we explainbriefly how each system functions. We do this bycomparing and contrasting the functions of the par-allel systems.

The other topic that is difficult for students isthe brain. To some extent, the amount of difficultythey experience will be related to the amount ofmaterial you require students to master. If youplan to go into some depth, we recommend you usetransparencies, enabling students to relate theinformation to the structure’s location in the brain.

Generally, start with the brainstem and then moveon to the more complex structures. Those brainareas related to the sympathetic and parasympa-thetic nervous systems and those that affect emo-tions before the cerebral cortex becomes involvedare usually of greatest interest to students.Because the structures in the cerebral cortex areinvolved in sensory and motor functions, as well asin the thinking processes that differentiatehumans from other animals, these too may be ofinterest to students. On the next page is a summa-ry of the major brain structures, which has beenenlarged so you can use it as either a student hand-out or as a transparency.

SUMMARY OF THE MAJOR BRAIN STRUCTURES

Structure Function(The brainstem is made up of the hindbrain and the midbrain)

Hindbrain Incoming sensory messages cross over to the opposite side of thebrain; outgoing motor messages cross over to the opposite sideof the body.

• Medulla Controls vital autonomic functions, such as breathing, heartrate, and digestion.

• Pons Relays information from higher brain regions to the cerebellum.• Cerebellum Involved in the control of balance, muscle tone, coordinated

muscle movements, and the learning of motor skills.• Reticular Network of neurons at the core of the medulla and pons that formation helps regulate attention and sleep.

Midbrain Plays a role in processing auditory and visual informationbefore sending it to higher brain centers.

• Substantia Involved in motor control and dopamine production.nigra

Forebrain • Cerebral Contains centers involved in complex behaviors and cortex mental processes. Each hemisphere has four lobes:Temporal lobe Processes auditory information.Occipital lobe Processes visual information.Parietal lobe Processes bodily sensations.Frontal lobe Processes voluntary muscle movements and involved in

thinking and planning.• Corpus Communication link between the left and right cerebral callosum hemispheres.

Limbic System• Hippocampus Involved in learning and forming new memories.• Hypothalamus Regulates the autonomic nervous system, behaviors related to

survival, and the pituitary gland.• Thalamus Processes and distributes motor and sensory information going

to and from the cerebral cortex. Involved in regulating aware-ness, attention, motivation, and emotional aspects of sensations.

• Amygdala Involved in emotional responses (especially fear and rage),learning, and memory formation.


CLASS ACTIVITIES

I. Introduction: Neuroscience and Behavior

Activity: Neurophysiology and the InternetThe Internet is a good source for helping studentsto learn the material in this chapter. Some stu-dents will not venture into the Internet until forcedto do so. We recommend that you do just that,because once students get involved with theInternet, all of a sudden, education is interactiveand fun. The following exercises can be completedby students outside of class.

1. Have students research different terms—forexample, neuron, neurotransmitter, pituitarygland, hypothalamus—using one the Web’smany interesting sites. When they have locateda good site for neurophysiology, have them fol-low the various links for a set period. To com-plete the assignment, they should prepare abrief written report of the sites visited or printout a few pages of the more interesting sites.

2. Some researchers argue that glial cells actual-ly do transmit messages. Have students checkthis out on the Internet and in very recentresearch journals. Have them write a briefstatement that describes the form of the glialcells’ communication. Tell your students tosearch on the key word glial.

3. Consider having students research one of thefollowing conditions or diseases: Parkinson’s,Alzheimer’s, multiple sclerosis, pituitary orthyroid disorders, or neurotoxins, such as theone present in the Puffer fish. Ask other stu-dents to research one of the promising newtreatments for these conditions. The Parkin -son’s Web site is http://neurosurgery.mgh.harvard.edu/functional.

4. Encourage students to get updates on brainresearch from www.brain.com. This Web sitecarries Reuters Health press releases on newbrain research as well as compilations of re -search in specific areas. Topics covered in cludetraumatic brain injury, the possible role ofestrogen in treating strokes to minimize long-term damage, the role of various parts of thebrain in forming memories, and new researchon the role of genes and other causes of and riskfactors for Parkinson’s and Alzheimer’s disease.The reading level is appropriate for an educat-ed layperson.

Discussion: Ethics and the Biology of BehaviorEthical concerns related to the material in thischapter will provoke heated debate. Following areseveral of the issues discussed in the chapter.

1. Researchers have developed a number of stemcell lines. Former President George W. Bushsigned legislation that allowed researchers touse these lines for research but prohibitedthem from developing any stem cell linesbeyond these already existing ones. How doyou feel about such legislation? Would youwant unlimited development if it meant a curefor some deadly diseases? What about the pos-sibility of using stem cells to clone “designerbabies”? President Obama is expected to revisethis policy. What do you think?

2. In some severe cases of epilepsy, seizures can-not be controlled by medication. To stop theneurotransmission from one side of the brainto the other that causes seizures throughoutthe body and can eventually result in death,the corpus callosum is surgically split. At whatpoint should a decision be made to performthis surgery? Do the benefits outweigh the con-sequences?

3. In the United States, the availability of newimaging technologies has led to quicker andbetter diagnosis. However, the cost of themachinery to the clinic or hospital and the costof administration for the patient are enor-mous. Government statistics show that 40 mil-lion or more people, often the working poor,have no health insurance. Will the high costsof new technologies and new procedures exac-erbate what some argue is already a two-tieredhealth-care system? What, if anything, can bedone? As an out-of-class exercise, assign one ormore students to research the cost to patients,or their insurance companies, for the adminis-tration of the following imaging techniques:PET, MRI, and fMRI.

Web Resource: Neuropsychology CentralThis site (www.neuropsychologycentral.com/index.html) provides a wealth of information related toneuropsychology, including imaging, assessment,and links to related organizations and research lab-oratories.

Web Resource: Neuroscience for KidsDon’t let the name of this site fool you (http://faculty.washington.edu/chudler/neurok.html). Dr.Eric Chudler of the University of Washington has


created an educational Web site on the brain andnervous system that appeals to kids of every age.

ActivePsych: Video: Program 2,Neuroimaging: Assessing What’s Cool(Scientific American Frontiers, Third Edition) See the Faculty Guide that accompaniesActivePsych for a description.

Web Resource: Neurosciences on the InternetAs of fall 2009, this site (www.neuroguide.com) isbeing redesigned to serve two purposes: List thebest neuroscience resources on the Internet in onelocation, and present original neuroscience contentnot available elsewhere. In the meantime, it stilloffers some great material on neuroscience.

II. The Neuron: The Basic Unit ofCommunication

ActivePsych: Flash-based InteractiveDemonstrations: Nerve Cell DemonstrationsStudents can participate in demonstrations inwhich they will enact neural transmission of animpulse by playing the roles of either the dendrite,soma axon, or axon terminal of a nerve cell (neu-ron).

ActivePsych: Flash-based InteractiveDemonstrations: Synaptic Transmission andNeurotransmittersIn this activity, students learn about various neu-rotransmitters and their effects on a person’s abili-ty to perceive, feel, think, move, act, and react. Abrief explanation of action potential and synaptictransmission begins this activity.

Web Resource: Neural Processes TutorialsJohn Krantz of Hanover College maintains thisWeb page (http://psych.hanover.edu/Krantz/neurotut.html), which is a collection of tutorialsthat provide excellent practice for students.

A. Characteristics of the Neuron

Video: Psychology: The Human Experience:Segment 6, Neurological DisorderSee the Faculty Guide that accompanies Psychol -ogy: The Human Experience for a description.

B. Communication Within the Neuron: The All-or-None Action Potential

Activity: Using Dominoes to Illustrate theAction Potential

Students often have difficulty understanding theconcepts involved in neural transmission. WalterWagor suggests an activity using dominoes to helpexplain the neural threshold, the all-or-none prin-ciple, how the action potential “flows” along thelength of the axon, and the refractory period. Youwill need two sets of dominoes and a smooth table-top surface at least five feet long. You may wish toset up the dominoes before the students arrive forclass.

• To show how the action potential is passedalong the length of the axon, set up dominoeson end about one inch apart in a three-footrow. Then push the first domino in the line.

• To help explain the refractory period, point outto the students that no matter how hard youpush on the first domino of the fallen line,after the action potential has occurred, thedomino effect (or action potential) cannot berepeated until the dominoes are set up again.

• To help explain the all-or-none principle, setup two three-foot rows of dominoes. Barelytouch the first domino in one row. Increase thepressure until the first domino falls and thedomino effect begins. For the second row, pushhard on the first domino. This demonstratesthat a neuron does not “fire” until the neuralthreshold is reached. Once the threshold isreached, each neuron “fires” in the same way,regardless of the strength of the incomingstimulation. Pushing harder on the first domi-no does not increase the speed of transmission.

[Adapted from Wagor, W. F. (1990). Using dominoes tohelp explain the action potential. In V. P. Makosky, C.C. Sileo, L. G. Whittemore, & M. L. Skutley (Eds.),Activities handbook for the teaching of psychology (Vol.3). Washington, DC: American Psychological Associa -tion.]

Activity: Racing Neurons!This is a fun way to teach the action potential andto help students understand the anatomy of thenervous system by function and structure.

You will need a bag of any small, enticing candy(chocolate kisses, fruit chews, caramels) and sever-al sets of 11 index cards, depending on the size ofyour class. Each card in a set contains one of thelists of structures given below (along with theanswers). The students should form teams of 12,with each team standing in a line. Hand each stu-


dent except the last in the line a list and two orthree candies. Instruct the first student to read thelist (omitting, of course, the unifying theme that isthe answer) to the next student in line. When thelistening student gives the correct answer (thecommon feature of the listed structures), the stu-dent who was reading the list immediately handsto the listener the candies and that student beginsto read his or her list to the next student.

The sequence—as students answer questionsand pass the candy along—is much like the all-or-none action potential. The passing of the candy rep-resents the release of neurotransmitters when theaction potential reaches the synapse.

If your class is small (under 20 or so), have oneteam do the exercise while the rest of the classwatches. If it is a large class, you can have two ormore teams compete to see which team can gettheir “action potential” from the starting “neuron”to the terminating “neuron” most quickly.

Structures (and answers):

1. Glial cells, sensory neurons, interneurons,motor neurons (types of nervous system cells).

2. Dendrite, axon, cell body, nodes of Ranvier,myelin sheath, receptors, vesicles (parts of aneuron).

3. Depolarization, refractory period, all-or-nonelaw, sodium channels, stimulus threshold,potassium ions, –70 millivolts (action potential).

4. Axon terminals, synaptic vesicles, reuptake,neuro transmitters, excitatory message, presynaptic neuron, receptor (synaptic trans mission).

5. Acetylcholine, GABA, dopamine, serotonin,endorphin, norepinephrine, substance P (neurotransmitters).

6. Somatic, autonomic, sympathetic, parasympa-thetic (divisions of the nervous system).

7. Hypothalamus, pineal, pituitary, adrenal,pancreas, thyroid, ovaries, testes (endocrine system).

8. Melatonin, prolactin, oxytocin, thyroxin, progesterone, gonadotrophins, adrenaline (hormones).

9. Medulla, reticular formation, cerebellum,pons, midbrain, substantia nigra (brainstemstructures).

10. Thalamus, hypothalamus, hippocampus,amygdala (limbic system).

11. Frontal cortex, primary somatosensory cortex,parietal lobe, temporal lobe, primary motorcortex, occipital lobe (cerebral cortex).

C. Communication Between Neurons: Bridgingthe Gap

PsychSim 5: Neural MessagesThis activity explains the structure of the neuronand the transmission of neural messages. A simpleneuron is drawn and students actively participatein the naming of the structures and their functions.The processes of axonal and synaptic transmissionare graphically depicted, including an extremelyclear picture of polarization of the axon.

In the News: Neural Inhibition and ExcitationResearchers Make Surprise Discovery That BrainCells Can Transmit Three Signals at Once (March7, 2005, Pittsburgh, ScienceDaly.com): Findingssuggest that immature brain cells can release up tothree neurotransmitters upon activation, withopposing functions. This is a good article forreviewing neural inhibition and excitation. Mostimportant, the article challenges the earlier viewthat each neuron releases only one neurotransmit-ter.

Videos: The Brain Teaching Modules, SecondEdition: Module 17, Learning as SynapticChangeDigital Media Archive: Segment 1, NeuralCommunicationSee the Faculty Guides that accompany The BrainTeaching Modulues and Digital Media Archive fordescriptions.

ActivePsych: Video: Segment 1, NeuralCommunication: Impulse Transmission Acrossthe Synapse (Digital Media Archive, SecondEdition) See the Faculty Guide that accompaniesActivePsych for a description.

Video Tool Kit for Introductory Psychology:Neural Communication: Impulse TransmissionAcross the SynapseSee the Faculty Guide that accompanies the VideoTool Kit for Introductory Psychology for a descrip-tion.


D. Neurotransmitters and Their Effects

Video: The Mind Teaching Modules, SecondEdition: Module 5, Endorphins: The Brain’sNatural MorphineSee the Faculty Guide that accompanies The Mindvideos for a description.

Video Tool Kit for Introductory Psychology:Compulsive Gambling and the Brain'sPleasure CentersSee the Faculty Guide that accompanies the VideoTool Kit for Introductory Psychology, Volume Two,

for a description.

Lecture: Parkinson’s DiseaseAs noted in the text, the neurotransmitter dopa -mine is crucial for motor skills; it ensures thatmuscles work smoothly, are under precise control,and do not exhibit unwanted movement. InParkinson’s disease, the dopamine-producing braincells slowly degenerate, eventually robbing victimsof their ability to walk and talk. Over 1 million peo-ple in the United States suffer from Parkinson’sdisease, including ex-heavyweight championMuhammed Ali and actor Michael J. Fox, who lefthis hit TV series Spin City to fight this disease andto help raise funds for research into treatment andpossibly a cure. Early Parkinson’s is often treatedwith drugs, but side effects may pose a problem,and the drugs lose their effectiveness after a fewyears. A number of years ago, researchers beganexperimenting with human fetal brain cell trans-plants, replacing damaged dopa mine-producingneurons with dopaminergic fetal brain tissue.Although the therapy has shown great promise,two serious problems remain: ethical/ moral con-siderations and the availability of fetal tissue. InSeptember 1996, surgeons at Boston MedicalCenter attempted to remedy these problems byusing fetal pig cells in place of human fetal cells.They transplanted the fetal pig cells into the brainsof 12 Parkinson’s patients. “Half the patients haveshown marked improvement . . . the other half haveregained some control over their motor skills.” Oneof the great successes of the study is Jim Finn.

The following Web sites provide additionalinformation about Parkinson’s disease:Parkinson’s Alliance (www.parkinsonalliance.net)National Parkinson Foundation(www.parkinson.org)The Parkinson’s Disease Foundation(www.pdf.org)

[Sinha, G. (1999, October). On the road to recovery.Popular Science, 255(4), 77–81.]

Videos: The Brain Teaching Modules, SecondEdition: Module 31, Brain Transplants inParkinson’s PatientsMoving Images: Exploring PsychologyThrough Film: Program 2, NeuralCommunication: NeurotransmitterAcetylcholineSee the Faculty Guides that accompany The Brainvideos and Moving Images for descriptions.

Video Tool Kit for Introductory Psychology:Parkinson's Disease: A Case StudyTreating Parkinson's Disease: Deep BrainElectrode ImplantationSee the Faculty Guide that accompanies the VideoTool Kit for Introductory Psychology, Volume Two,for a description.

Popular Film: Iris (2001)This movie tells the true story of philosopher andnovelist Iris Murdoch and her battle withAlzheimer’s disease. Painfully realistic, the filmshows the slow and degenerative process of thisfatal disease. Have students follow Iris’s life fromher first symptoms to her final days. This is a greatmovie for discussing the devastation thatAlzheimer’s brings to everyone involved.

Popular Film: Eden (1997)Show this movie to demonstrate the debilitatingeffects of multiple sclerosis. Helen, a mother of two,develops escape methods for the grim reality of thisprogressive disease. Have students discusswhether her “out-of-body experiences” could bebeneficial or harmful to her situation.

E. How Drugs Affect Synaptic Transmission

III. The Nervous System and the EndocrineSystem: Communication Throughout theBody

A. The Central Nervous System

B. The Peripheral Nervous System

Activity: Reaction TimeThe text mentions the key role of the somatic ner-vous system in communicating information fromthe sensory nerves to the central nervous system(CNS) and from the central nervous system to themotor neurons to perform voluntary muscle move-ments. The following exercise uses reaction time toillustrate the differential speed of reactions as a


function of the source of sensory input (the closer tothe CNS, the faster the reaction). Follow thesesteps:

1. Have students form a line and hold hands.

2. Tell them to close their eyes.

3. Cue the first person in line to squeeze thehand of the person next to him or her.

4. As each student feels his hand being squeezed,he or she should squeeze the next person’shand (gently!).

5. Using a stopwatch, time how long it takes thesqueeze to go down the line. Tell the last stu-dent in line to raise his or her hand to signalcompletion.

6. Repeat this task several times until a relative-ly stable estimate is achieved.

Using the same procedure, have studentssqueeze each other’s shoulder instead of the hand.Repeat the procedure several times. The averagereaction time should be shorter because the senso-ry information has a shorter distance to travel theneural pathway. Ask students why their reactiontimes were shorter when they squeezed shouldersas opposed to hands? In “real time,” how significantis the difference in reaction time?

An alternative demonstration of reaction time,from visual input to manual response is the old dol-lar bill trick, as follows:

1. Select a student who claims to have fast reflex-es and invite him or her to stand in front of theclass with you and to copy your movements.

2. With the tip of your fingers and thumb, holdthe top of a dollar bill in your nondominanthand (left if you are right-handed, and viceversa). Place your dominant hand so that thedollar bill is midway between your thumb andfirst finger, which should be held about an inchand a half apart. When you are ready, drop thebill. You will catch it.

3. Hand a dollar bill to your volunteer and askthat person to hold the bill as you are holdingyours and to place his or her free hand as youare holding yours.

4. Tell the class that you and the volunteer aregoing to drop your respective dollar bills andtry to catch them with your dominant hands.Tell your volunteer to drop the dollar anytimehe or she is ready. Then drop your own bill. Youwill both catch your bills.

5. Have the student stand sideways to the class.Put your dollar bill away, and take the dollarbill you handed the student earlier and hold it

in front of the volunteer. Standing beside thestudent, tell him or her that the dollar bill ishis or hers if he or she catches it when youdrop it. Have the student spread his or herthumb and finger apart horizontally so thatthe thumb is on one side of the center of thedollar bill, and the forefinger on the other side.Say, “Are you ready?” Count to three silentlyand drop the bill. Unless the student grabbedthe bill before you dropped it, he or she will notbe able to grab it as it falls slowly to the floor.

6. Watch the stunned expressions on the faces ofthe students. Ask the students why the subjectwas able to catch the dollar bill when he or shedropped it. Then ask them why the studentwas not able to catch the dollar when, you, theinstructor, dropped it. In the first, the commu-nication did not involve vision. With the addi-tion of vision, the message has to travel muchfurther.

[Rozin, P., & Jonides, J. (1977). Mass reaction timemeasurement of the speed of the nerve impulse and theduration of mental processes in class. Teaching ofPsychology, 4(2), 91–94; Wertheimer, M. (1981). Chainreaction time. In L. T. Benjamin Jr., & K. D. Lowman(Eds.), Activities handbook for the teaching of psycholo-gy (Vol. 1, pp. 205–206). Washington, DC: AmericanPsychological Association.]

In the News: Nerve Therapy to TreatDepressionDevice Is Offering Hope on Depression: ItStimulates Nerve Linked to Mood (December 30,2005, Philadelphia Inquirer): This article describesa controversial therapy to treat depression calledvagus nerve stimulation, or VNS. Questionsregarding the effectiveness of the procedure areraised, and possible applications of VNS for otherdisorders are discussed.

C. The Endocrine System

Popular Film: Open Water (2004)This is a great movie to demonstrate how the fight-or-flight response and our cognitions integrate dur-ing times of stress. Forgotten at sea while scubadiving, a married couple passes through stages ofhope, fear, anger, and ultimately resignation. Besure to show the scene in which they are surround-ed by sharks. Have students discuss their pastreactions to similar threatening situations.

In the News: Hormones Build TrustTrust-Building Hormone Found (December 8, 2005,United Press International): Findings from scien-


tists at the National Institute of Mental Healthsupport the effectiveness of the hormone oxytocinin boosting trust. Brain imaging was used in thestudy, suggesting new therapies for diseasesinvolving amygdala dysfunction and social fear.


Activity: Viewing the BrainTo enhance your discussion of brain structures andfunctions, obtain a plastic, multicolored model ofthe brain that can be taken apart. Beginning withthe structures that make up the hindbrain, pointout and discuss all the major brain structures. Forexample, point to the corpus callosum and remindstudents that it connects the two hemispheres,allowing them to communicate. They will be able tosee how severing it would make this communica-tion impossible. Similarly, the reticular formationprovides a main communication link between thehindbrain and the forebrain. When they see thatthe reticular formation occurs throughout thebrain, they will be able to understand how the var-ious sections of the brain communicate rapidly withone another. If your classroom has an overhead pro-jector, show simultaneously the Summary of MajorBrain Structures, the transparency master provid-ed in Approaching Your Lecture. This transparencywill help students understand the organization ofthe brain.

ActivePsych: PowerPoint Demonstration:Name that Brain DamageThis activity links specific brain areas with theirfunctions.

PsychSim 5: Brain and BehaviorThis activity reviews the major divisions of thebrain, the structures within them, and their func-tions. The student takes a tour of the brain, discov-ering the functions of each region or area.

Video: The Brain Teaching Modules, SecondEdition: Module 1, Organization andEvaluation of Brain FunctionSee the Faculty Guide that accompanies TheBrain videos for a description.

A. The Dynamic Brain: Plasticity andNeurogenesis

Videos: Psychology: The Human Experience:Segment 5, Brain PlasticityThe Brain Teaching Modules, Second Edition:Module 7, Brain Anomaly and Plasticity:Hydrocephalus

See the Faculty Guides that accompanyPsychology: The Human Experience and The BrainTeaching Modules for descriptions.

ActivePsych: Video: Program 3, BrainPlasticity: Rewiring the Visual Cortex(Scientific American Frontiers, Third Edition)See the Faculty Guide that accompanies Active -Psych for a description.

Video Tool Kit for Introductory Psychology:Language and Brain Plasticity

Rewiring the BrainSee the Faculty Guide that accompanies the VideoTool Kit for Introductory Psychology Volumes Oneand Two for descriptions.

B. Neurogenesis

Videos: The Brain Teaching Modules, SecondEdition: Module 32, NeurorehabilitationMoving Images: Exploring PsychologyThrough Film: Program 4, BrainReorganization: Phantom Limb SensationsSee the Faculty Guides that accompany The BrainTeaching Modules and Moving Images for descrip-tions.

C. The Brainstem: Hindbrain and MidbrainStructures

D. The Forebrain

Lecture: Experimental Treatments for BrainInjuries and DegenerationThe text provides an easy-to-understand descrip-tion of brain structures and functions. Remind thestudents that like every other organ in the body,the brain needs oxygenated blood pumped from theheart in order to function. Lack of oxygen due to anobstructed artery or suffocation can cause strokesthat lead to paralysis, speech difficulties, and otherdeficits.

In 1998, Dr. Douglas Kondziolka and col-leagues at the University of Pittsburgh performedthe first trial stroke treatment using stem cells.Working with rats whose brains had been damagedin a way very similar to that caused by a stroke,Dr. Kondziolka injected laboratory-grown imma-ture nerve cells (LSB-neurons) into the damagedregions of the rats’ brains. Within one month, thetreatment reversed the brain damage.

Since 1998, more evidence has been found thatthe hippocampus has stem cells capable of matur-


ing into functioning neurons. In March 2000, Dr.Steven Goldman of Cornell University MedicalCollege extracted stem cells from the hippocam-puses of eight male patients ranging in age from 5to 63. The research team was able to culture andgrow functional neurons using these stem cells.The team successfully reinserted the mature cellsinto the brains of the research participants. Similarprocedures are now being pioneered in attempts torepair the damage caused by degenerative braindisorders such as Parkinson’s and Alzheimer’s dis-eases. Some researchers are also trying to developprocedures that would allow the new neurons to bestimulated to grow without being removed from thebrain.

Other novel methods for healing brain damagedue to injury and disease have also been tried. Forexample, Dr. Gary Steinberg of Stanford Universityand his associates have been exploring the use ofinduced hypothermia—cooling the whole bodydown by several degrees—to limit the damagecaused by stroke or injury. Patients are wrapped inspecial blankets containing networks of hoses thatare pumped full of chilled water. The temperaturein the body and brain is lowered to 88 degreesFahrenheit.

The mechanism by which hypothermia protectsneurons is not yet fully understood, but it isthought that the cool conditions limit the release ofneurotransmitters and toxins and decrease thebrain’s need for oxygen and nutrients.

More bizarre, but quite successful in somecases, is a surgical intervention that involvesremoving part of the skull, called hemicraniectomy.This procedure has been performed after closedhead injuries and strokes in order to allow thebrain to swell and to prevent the death of neuronsthat would otherwise be squeezed against theinside of the cranium. Versions of this procedurewere performed as long ago as the 1800s, but littledescriptive research is available. In 1999, Dr.William Coplin and associates began a long-term,multicenter study to systematically track theprogress of persons who receive this surgery.Several more years must pass until enough caseshave been followed for a length of time sufficientfor making a determination of how effective thisdrastic procedure may be.[Fackelmann, K. (1998). Stroke rescue. Science News,154(8), 120–122; Linton, P. (1999). Time and space healhead injuries. www. med.wayne.edu/wayne%20medi-cine/wm99/time_and_space.htm; Brain cell researchoffers hope for Alzheimer’s. (2000). Nature’s Medicine, 6,249–250, 271–277.]

Lecture: The Thalamus and Consciousness The role of the thalamus is probably underempha-sized in most introductory psychology textbooks.The thalamus is essentially a gateway into thebrain, a sensory integration and relay station; it isinvolved in regulating our level of awareness,attention, motivation, and emotional aspects ofsensations. As accurate as this description may be,it does not express the full importance of the thala-mus in producing and maintaining consciousness.

The thalamus is part of the older, more primi-tive layer of the brain; damage to it can have anynumber of profound effects, for example, causingproblems that are remarkably similar to those seenin cases of severe damage to the cerebral cortex.Experienced neurologists must perform MRIs inorder to correctly distinguish between damage tothe cerebral cortex and damage to the thalamus.For example, if the part of the thalamus that con-nects to the visual cortex (the lateral geniculatenucleus) is damaged, vision may be severelyimpaired.

It can be said that consciousness is produced atleast in part by the dialog between the thalamusand the cortex. This is because the thalamusassists the cortex in the crucial task of “binding”the many sensory messages that bombard ourbrains every second of every day. Binding, in sim-plistic terms, is the process whereby all the sepa-rate sensory messages are turned into one smoothcognitive experience. If disease, stroke, or injurydamages the thalamus, consciousness may no long -er be a smooth, comprehensible experience. Thereare a number of mental illnesses that may involvesome disruption of the thalmo-cortical dialog,which neuroscientist Rodolfo Llinás (2001) refers toas a “dance” or a “rhythm” in the communication ofthe neurons in the thalamus and cortex. Autism,schizophrenia, and dyslexia are thought to havetheir origins in a disruption in this system, alongwith other biological or genetic problems.

Lecture: Attention-Deficit HyperactivityDisorder (ADHD) and the BrainTo illustrate the practical aspects of knowing aboutbrain functioning, discuss findings regarding braincharacteristics of children with ADHD. ADHD is adisorder characterized by inattention, hyperactivi-ty, and impulsive behavior. Studies estimate thatbetween 2 and 9.5 percent of all school-age childrenworldwide have ADHD, with boys being at leastthree times as likely as girls to develop ADHD. F.Xavier Castellanos, Judith L. Rapoport, and col-leagues at the National Institute of Mental Health


(1996, 1998) have found that the right prefrontalcortex, two basal ganglia, and the vermis region ofthe cerebellum are all smaller in children withADHD than in children without ADHD. Mostresearchers now believe that ADHD is a polygenet-ic disorder involving the genes that dictate the waydopamine conveys messages from one neuron toanother. Barkley (1998) believes that these defectsmay underlie the impaired behavioral inhibitionand self-control seen in children with ADHD.Drugs such as Ritalin are often prescribed for chil-dren with ADHD. “These drugs act by inhib itingthe dopamine transporter, increasing the time thatdopamine has to bind to its receptors on other neu-rons.” Such drugs improve the behavior of 70 to 90percent of children with ADHD who are older than5 years.

[Barkley, R. A. (1998). Attention-deficit hyperactivitydisorder. Scientific American, 279(3), 66–71.]

Videos: The Mind Teaching Modules, SecondEdition: Module 7, The Frontal Lobes:Cognition and AwarenessPsychology: The Human Experience: Segment7, Brain Surgery for Neurological IllnessSee the Faculty Guides that accompany The Mindvideos and Psychology: The Human Experience fordescriptions.

Videos: The Brain Teaching Modules, SecondEdition: Module 25, The Frontal Lobes andBehavior: The Story of Phineas GageMoving Images: Exploring PsychologyThrough Film, Program 3: A ContemporaryPhineas GageSee the Faculty Guides that accompany The Brainvideos and Moving Images for descriptions.

Lecture: The Curious Case of Phineas GageHandout 2.1 describes the unusual case of PhineasGage, who, despite having a tamping rod throughhis frontal lobe, survived, although as a somewhatdifferent person.

Activity: Demonstrating the SomatosensoryCortexThe text explains that the parietal lobe is involvedin processing bodily, or somatosensory, information,including touch, temperature, and pressure. Thesomatosensory cortex receives information fromtouch receptors in different areas of the body, whichare more or less sensitive to touch. The somatosen-sory homunculus, as depicted in the text, showswhat the body would look like if the body parts

were proportional to their representation on thesomatosensory cortex.

This activity demonstrates the varying levels ofsensitivity to touch that correspond to the propor-tion of the somatosensory cortex devoted to differ-ent areas of the body. Divide the class into pairs ofstudents. Distribute two dull pencils to each pair.Students should take turns being the subject andbeing the one testing and recording the results.The subjects should close their eyes while thetesters very gently touch the two dull pencil pointsat one-half inch, one inch, or two inches apart onvarious parts of the body, including the fingers andthumbs, the lower arm, and the back. The subjects’accuracy when guessing the distance between thetwo points should be greatest for the fingers andthumbs and poorest for the back.

Activity: How the Brain Takes a BlowBlow up a heavy-duty balloon. On either side of theballoon, draw the four lobes of the brain. Thenattach a string about 10 inches long to the balloon.Find a box that the balloon will fit into with only aninch or two of clearance. Leave the front of the boxopen. Have a student hit the box from the front andobserve what happens to the balloon. See whichlobe a blow from the front affects. Students willnotice that the primary damage is to the occipitallobe. The “bounce back” will affect the frontal lobeas well. This helps explain why so much damage issustained when a heavy blow is struck to thehuman head. Strike the box in various places toillustrate the different effects of physical blows tothe head.

Videos: The Brain Teaching Modules, SecondEdition: Module 24, Aggression, Violence,and the BrainDigital Media Archive: Segment 26, Self-Stimulation in RatsSee the Faculty Guides that accompany The BrainTeaching Modules and Digital Media Archive fordescriptions.

ActivePsych: Video: Program 1, Brain andBehavior: Phineas Gage Revisited (ScientificAmerican Frontiers, Third Edition) See the Faculty Guide that accompaniesActivePsych for a description.

Video Tool Kit for Introductory Psychology:Mapping the Brain Through ElectricalStimulationPlanning, Life Goals, and the Frontal LobeSee the Faculty Guide that accompanies the Video


Tool Kit for Introductory Psychology fordescriptions.

V. Specialization in the CerebralHemispheres

Video: Scientific American Frontiers VideoCollection, Second Edition: Segment 8, OldBrain, New TricksSee the Faculty Guide that accompanies ScientificAmerican Frontiers for a description.

ActivePsych: Video: Program 4, AchievingHemispheric Balance: Improving SportsPerformance (Scientific American Frontiers,Third Edition)See the Faculty Guide that accompanies Active -Psych for a description.

ActivePsych: Flash-based InteractiveDemonstration: Hemispheric PathwaysThis activity illustrates the pathways throughwhich the hemispheres of the brain receive infor-mation and control sensory experiences and motorfunctions.

PsychSim 5: Hemispheric Specialization, andDueling Brains

Hemispheric Specialization is a graphic demon-stration of how messages reach the two sides of thebrain and of the special functions of each side—forexample, speech is controlled in the left hemi-sphere. The processing of a visual stimulus throughthe brain is the example used. Sperry’s work withsplit-brain patients is also illustrated, and theresponses of normal subjects are compared withthose of split-brain patients. For Dueling Brains,see Chapter 7.

Discussion: Left Brain/Right Brain: Which IsRight?Locate one or more “pop psychology” articles con-trasting “left-brain” people with “right-brain” peo-ple. Before you discuss hemispheric specialization,distribute copies of these articles to the studentsand have them read them before the next class. Ifstudents can talk about this material without feel-ing threatened, they can learn from one anotherabout some of the “pop” views that may be moremyth than fact (this also provides a useful applica-tion of critical thinking). Take, for example, thenotion that right-brain people are more artistic,and left-brain people are more logical. The differ-ences that have been discovered are not statistical-ly significant. Students should be reminded that

left-brain/right-brain research is correlational anddeals with percentages. For instance, even the ideathat speech is located in the left hemisphere is notentirely true. In about 10 percent of those tested,speech is located in the right hemisphere.

A. Language and the Left Hemisphere: The EarlyWork of Broca and Wernicke

Videos: Psychology: The Human Experience:Segment 16, Language Centers in the BrainThe Mind Teaching Modules, Second Edition:Module 8, Language Processing in the Brain,and Module 26: The Bilingual BrainThe Brain Teaching Modules, Second Edition:Module 6, Language and Speech: Broca’s andWernicke’s AreasSee the Faculty Guides that accompany Psychol -ogy: The Human Experience, The Brain videos, andThe Mind videos for descriptions.

B. Cutting the Corpus Callosum: The Split Brain

Videos: Scientific American Frontiers VideoCollection, Second Edition: Segment 7,Severed Corpus CallosumThe Brain Teaching Modules, Second Edition:Module 5, The Divided BrainSee the Faculty Guides that accompany ScientificAmerican Frontiers and The Brain Teaching Mod -ules for descriptions.

Video Tool Kit for Introductory Psychology:The Split Brain: Lessons on Language, Vision,and Free WillThe Split Brain: Lessons on Cognition and theCerebral HemispheresSee the Faculty Guide that accompanies the VideoTool Kit for Introductory Psychology Volumes One

and Two for descriptions.

Activity: Integrated Functioning and theCerebral Cortex

The various regions of the brain have evolved towork together and allow us to control our move-ments in a smooth and coordinated way. Chapter 2introduces us to the layout and lateralized designof the cerebral cortex. Efficient cerebral functioningresults from the dedication of cortical areas to bodyregions and from the distance between brainregions that might interfere with each other. In certain circumstances, neighboring areas of the primary motor cortex can hamper each other’sfunctioning. Ask for a volunteer to perform the fol-lowing demonstrations to illustrate this point.


Demonstration 1: Have the student sit in a chair at the front of theclassroom (a chair with no desk) and to hold out hisor her right arm, palm down. The student shouldthen make a continuous counterclockwise rubbingor “polishing” motion (as if polishing an imaginaryflat surface). When the student has a good rhyth-mic motion going, instruct him or her to also startmaking a counterclockwise circling motion with theright foot. Then, when the student has this dualmotion going smoothly, instruct him or her toreverse the foot motion to a clockwise circling.

The student will almost certainly say that thisis rather difficult. You can then point out for theclass that the neurons controlling arm and leg onthe right side, being close together inside thebrain’s precentral gyrus on the left side, worktogether cooperatively if the activities are basicallythe same. If the activities are different (conflicting),the neurons interfere with each other, just as whennext-door neighbors play two different kinds ofmusic, both at a loud volume.

Demonstration 2: After the student has rested for a bit, ask him orher to repeat the first demonstration, except thistime make the counterclockwise circling motionwith the left foot (so both the right hand and leftfoot are simultaneously moving in a counterclock-wise motion). When the student has a smoothmotion going, ask him or her to start moving theleft foot in a clockwise motion instead.

The student should report that this is some-what easier than performing the circling in oppo-site directions on the same side (as in demonstra-tion 1). The areas of the motor cortex controllingthese two limbs are on opposite sides of the brainand will not interfere with each other, even whenengaged in conflicting motor activities.

Demonstration 3: Ask the student to state his or her handedness.Then instruct the student to continue the circlingmotion of the right arm. Instead of making the footmotion, the student should look down at the floorand trace an imaginary circle with his or her nose,first in a counterclockwise direction and then in aclockwise direction.

Finally, have the student stop polishing withthe right arm and begin the counterclockwisemotion with the left arm. After a short time (30–60seconds) ask the student to compare the level of dif-ficulty in performing the “nose-circling” task whenmoving the right or left arm. Most students willreport that the nose-tracing action was more diffi-

cult when done simultaneously with the circling ofthe dominant hand.

Neuroscientists have not yet determined exact-ly why this happens. It is puzzling because theneck muscles involved in the nose-tracing activityare most likely controlled equally by both sides ofthe cerebral cortex. One plausible explanation isthat as the person performs this task the dominantside of the motor cortex (the left side in a right-handed person and either side in a left-handed per-son) takes up more cortical resources than the non-dominant side and creates more interference withthe activity of the neck muscles.[Haseltine, E. (2002, March). Nosy neighbors: Goodfences make good neurons. Discover, 88.]

Activity: Testing Hemispheric LateralizationThe following activity suggested by Eric Haseltineshould be timed to follow your classroom discussionof hemispheric lateralization. This activity, whichis easy to do even in a crowded lecture hall, allowsstudents to determine which of their eyes is thedominant one.

With both eyes open, hold up your right thumb atarm’s length under an object across the room direct-ly ahead of you. Now alternately close your left andright eyes and see if your thumb appears to jump tothe right or left with respect to the distant object. Ifyou are right-eyed, like 54 percent of the population,your thumb will jump to the right when you closeyour right eye but stay put when you close your lefteye, because your right eye contributes more to yourperception of the visual world than does your left.The opposite will occur if you are left-eyed, like 5percent of the population. If you see little or no jump-ing, you are among the 41 percent of the populationwho are neither strongly left-eyed or right-eyed.

Suggest to students that by closely observinghow people use different halves of their bodies,they can see brain specialization at work—“stringmusicians finger notes with their left hands, fieldgoal kickers usually score with their right feet, and. . . about 35 percent of eavesdroppers consistentlylisten through walls with their right ears.”[Haseltine, E. (1999). Your better half. Discover, 20(6),112.]

Activity: Right-Brain/Left-Brain QuizThe Discussion “Left Brain/Right Brain, Which IsRight?” focuses on right-brain/left-brain myth ologythat most people now accept as truth. Eitherinstead of or with that discussion you may wish togive Handout 2.2’s quiz on dichotomania, a termused by Michael Corballis (1980) and others in


describing misinformation regarding cerebral later-alization in humans. The term serves as a usefultool in stimulating thinking about these popularbrain myths. You can also use this quiz as a preludeto the following activity, which is a clever demon-stration of the true behavioral impact of cerebrallateralization.

After giving the quiz (the answers appear inHandout 2.3), you might want to show the Scien -tific American Frontiers video segment 7, SeveredCorpus Callosum, to highlight the different special-izations of the two halves of the brain. After ward,you may need to clarify some of the points made byDr. Gazzaniga. For example, Dr. Gazzaniga says ineffect “the left hemisphere is the part of the brainthat draws connections between things.” Many stu-dents are primed to think that this means that “theleft hemisphere is logical” when in fact it does notmean that at all, because some connections thathumans make are rational and supported by evi-dence and others are incorrect and spurious. Thismay lead you to revisit the Chapter 1 discussion ofcritical thinking and human fallibility in reasoningand drawing connections between events, thusreminding students of some important themes ofthe scientific method that should be reinforcedthroughout the course.

Dichotomania is a simplistic and stereotypicalway of looking at the world that does no justice tothe complexity of human cognitive processing. Non -verbal reasoning can be quite logical, as architectsand designers know quite well. Verbal processing isoften also very creative. If students resist thisnotion, simply mention poetry, prose writing, andsong lyrics. Logic and creativity are “whole-brain”processes.[Corballis, M. C. (1980). Laterality and myth. AmericanPsychologist, 35, 284–295; Hermann, N. (2002).]

Activity: Cerebral LateralizationThe specialized functions of the left and right cere-bral hemispheres continue to be debated. However,most agree that the left hemisphere plays a some-what dominant role in language comprehensionand production. As noted in the text, the left hemi-sphere of the brain is also responsible for coordi-nating the actions of the right side of the body (and,of course, vice versa). When one hemisphere mustprocess multiple sources of information simultane-ously, a person’s performance often is hindered. Thefollowing exercise is designed to illustrate theeffects of interfering with the undivided function-ing of the left hemisphere.

To conduct this demonstration, you will need(a) one wooden dowel (1/2 inch in diameter and 36

inches long) for every one to four students, (b) astopwatch, and (c) a list of 20 to 30 spelling exer-cises (for example, repeat the alphabet backward,spell “Mississippi” backward, and so on).

First, allow students to practice balancing thewooden dowel on the tip of the index finger for 5 to10 minutes, alternating right and left hands. Thestudents then undergo eight test trials, four witheach hand, in which they balance the dowel on thetip of their index finger. The trials should be:

1. Twice with the left hand in silence.

2. Twice with the right hand while performing aspelling exercise aloud.

3. Twice with the left hand while performing aspelling exercise aloud.

4. Twice with the right hand in silence.

Use a stopwatch to time the number of secondsbefore the dowel drops or touches each student’sbody. Trials should be alternated (cross-balanced)among students so that each student balances thedowel.

Trial 2 is an example of a competition task, inwhich the simultaneous activities of performing aspelling exercise and balancing a dowel with theright hand both tax the resources of the left hemi-sphere. Typically, students’ scores (in terms of num-ber of seconds balancing the dowel) will be lower inthis condition. You may examine this phenomenonby comparing mean scores among participants foreach of the four conditions.

Questions for Discussion

1. How are tasks performed in the “real world”affected when a specific cerebral hemispherehas to process information simultaneously?

2. If gender differences appear in your data, whatmight account for these differences?

3. Are women’s brains organized differently frommen’s?

[Kemble, E. D. (1987). Cerebral lateralization. In V. P.Makosky, L. G. Whittemore, & A. M. Rogers (Eds.),Activities handbook for the teaching of psychology (Vol.2, pp. 33–36). Washington, DC: American PsychologicalAssociation.]

Activity: The Interdependence of the Brainand Both Hands

The following activities can be used to demonstratethe rich dialog between the two sides of the brain.They also help students to distinguish between“handedness” and myths about “right/left brain”preference.


Ask the students to take out two sheets ofpaper and a pen or pencil. On the first sheet, havethem write down all the things that they could notdo if they suddenly lost the use of their dominanthand. They will have no problem producing alengthy list. Then have them list all the things theycould not do if they lost the use of their nondomi-nant hand. The list will be much shorter. Toincrease their appreciation for the interactive rela-tionship of their two hands, have them do one orboth of the following.

• On the second sheet of paper respond to thestatement, “If I ruled the world . . .” When theyhave been writing for a minute or so, ask themto note what their nondominant hand is doing.Most of the students will be using it to steadyor reposition the page. Ask them to continuewriting with the nondominant hand placed intheir laps. Most will realize that this is diffi-cult to do. In fact, we write 20 percent moreslowly when we are not allowed to use our non-dominant hands in this fashion. If you havestudents in the class who have had any kind ofsurgery or disability of the hand, perhaps theywill be willing to comment on this issue also.

• Bring a piece of cardboard, a spool of thread,and a sewing needle to class. Stick the needleinto the cardboard. Place it on a table or desk.Give a piece of thread to a student volunteerand instruct him or her to thread the needlewhile holding one hand behind his or her back.This task will be difficult or impossible toaccomplish. Then allow the student to pull theneedle out of the cardboard and thread it inthe usual manner (holding the needle in thenondominant hand). Of course, this will bemuch easier.

Both exercises illustrate the crucial importanceof left-right hemisphere communication. Through acombination of visual cues and the constant inter-change of neural signals that occurs via the corpuscallosum, we perform the most complex fine motortasks with relative ease. The fact that we prefer theuse of one hand does not mean that we prefer theuse of one hemisphere over the other. [Haseltine, E. (2002). One head, two hands. Discover,23(12), 96.]

Video: Psychology: The Human Experience:Segment 4, A Case Study of Brain DamageSee the Faculty Guide that accompanies Psychol -ogy: The Human Experience for a description.

VI. Enhancing Well-Being with Psychology:Pumping Neurons: Maximizing Your Brain’sPotential

Video: The Mind Teaching Modules, SecondEdition: Mod ule 18, Effects of Mental andPhysical Activity on the BrainSee the Faculty Guide that accompanies The Mindvideos for a description.

ActivePsych: Videos: Segment 2, Activity,Exercise, and the Brain (Digital MediaArchive, Second Edition) Program 12: Experience and Exercise:Generating New Brain Cells (ScientificAmerican Frontiers, Third Edition)See the Faculty Guide that accompaniesActivePsych for descriptions.

Discussion: Keeping the Brain Healthy:Exercise Your Mind

In Enhancing Well-Being with Psychology“Pumping Neurons: Maximizing Your Brain’sPotential,” the authors discuss the phenomenon of“structural plasticity.” The once widely held opinionthat the brain structure is “hard-wired” for life hasbeen seriously challenged. Researchers using ani-mal models have provided compelling evidence tosuggest that environmental factors contribute tothe structural integrity of the brain. Correlationalstudies using human subjects have presentedimpressive results suggesting that “structural plas-ticity” is also a human phenomenon. One widelyheld public misconception is that the brain (andmental ability) invariably decreases as a functionof age. However, we tend to ignore the remarkablemental agility of many “senior” citizens. Instruc -tors might wish to discuss the phenomenon ofstructural plasticity as it relates to age-relateddeclines in mental functioning. Consider the fol-lowing individuals.

1. The University of Alabama’s perennial headfootball coach Paul “Bear” Bryant was leadingteams to national championships and collegebowl games while in his 70s. Bryant wasknown as one of the most intellectually cun-ning and prescient coaches the game of foot-ball has ever seen. Apparently, Bryant’s acu-men had not diminished upon his retirement,as many professional teams offered lucrativecontracts for his services.

2. Jack LaLanne, the physical fitness guru, isnoted for his impressive feats of physical fit-


ness (such as towing a barge through SanFrancisco Bay) despite his age. What peopletend to forget is that LaLanne, despite being inhis 90s, continues to oversee the daily opera-tions of a vast conglomerate of business enter-prises. Anyone who sees LaLanne speak pub-licly would be immediately struck by his clear,cogent thinking. The man is in shape—physi-cally and mentally!

3. The late Winston Churchill, former prime min-ister of England, retained his brilliant in tellectwell into his 80s. Although he retired as primeminister at the age of 81, Churchill retainedhis seat in the House of Commons. Aside fromhis accomplishments as prime minister,Churchill authored numerous literary works,including a four-volume History of the English-Speaking Peoples, which he completed at theage of 83. Churchill also retained his keen wit.After suffering a stroke at the age of 90, hedeclared, “I am ready to meet my Maker, butwhether he is ready to meet me is anothermatter.”

Questions for Discussion

1. What personal qualities did these individualspossess that allowed them to accomplish suchimpressive feats in their later years?

2. How were these personal qualities supportedby the environment?

3. What are some activities that we can engage inthat will maximize the potential for maintain-ing our own intellectual integrity?

Discussion: Should We “Enhance” HumansThrough Neuroendocrine Treatments?Ongoing research on the nervous and endocrinesystems has led to increasing knowledge of theirfunctions. As a result, more deficiencies and dis-eases have become treatable and millions of peoplehave benefited. With these new interventions, how-ever, many ethical, social, and economic questionsarise. Should we treat only deficiencies and dis-eases? Or should we also offer treatment that will“enhance” people’s lives, even though they arealready functioning within normal limits? And, ifwe offer “enhancing” treatment, who should pay for

it? Ask students to think about where medicaltreatment leaves off and “enhancement” begins ineach of the following situations.

1. Human growth hormone is available to treatchildren with proven deficiencies, enablingmany of them to grow to “short normal” byadulthood. Few would question this use ofhuman growth hormone. But, should a boywho is the shortest child in his class but suf-fers no deficiency be given growth hormone, sothat he won’t be ridiculed and will be sociallyaccepted? Should a six-foot excellent basket-ball player be given growth hormone so that hehas the added height advantage?

2. Prozac and other similar antidepressants are selective serotonin reuptake inhibitors(SSRIs); they seem to lift depression by slow-ing the reuptake of the neurotransmitter sero-tonin, leaving more of it in the synaptic gap.By the early 1990s, far larger numbers of peo-ple were being treated with SSRIs than hadbeen treated with earlier antidepressants.Should only people who are quite depressed begiven SSRIs? Or should people who feel bluefor a while get them so that their lives areenhanced?

3. Alzheimer’s disease involves lower levels of theneurotransmitter acetylcholine. Research ersare experimenting with ways to increase thelevels of acetylcholine in the brain or to treatthe progressive memory loss and general dete-rioration of intellectual functioning. A treat-ment may be found that not only helpsAlzheimer’s patients with their memories butalso enhances the memories of people whohave no diseases. Should people who desire toenhance their memories receive such a drug?Or should only people with a biologicallycaused memory loss receive the drug? And whoshould pay for “memory enhancement” drugs?

Remind students that “the future will continueto provide agents that do not just treat illness butalso hold out the promise of enhancing normalfunctioning.”[Konner, M. J. (1999, January/February). One pillmakes you larger: The ethics of enhancement. AmericanProspect, 55–60.]


Handout 2.1

The Curious Case of Phineas Gage

On September 13, 1848, a freak accident occurred—an event that was to become a landmark in ourunderstanding of the brain’s role in behavior.Phineas Gage, 25 years old, was the foreman of arailroad crew that was blasting rock nearCavendish, Vermont. The crew would drill a hole inthe rock, fill it with gunpowder, and cover the gun-powder with a layer of sand. Then, using a fine-pointed, 3 1/2-foot-long iron rod, Gage would packthe sand and gunpowder down into the hole. Thesand kept sparks from igniting the gunpowderwhen Gage tamped it down with the iron rod.

On this particular day, Gage and a crew mem-ber were momentarily distracted while filling thehole. When Gage turned back to his task, hethought his assistant had already poured the sandinto the hole, but this was not the case. Gage thrustthe iron rod into the hole. A spark caused by therod’s scraping the rock ignited the gunpowder.

The iron rod blew out like a javelin, strikingGage just below his left eye. The rod went com-pletely through his skull, tore through a hole in thetop of his head, and landed some 50 feet away. Thecrew stared in horror at Gage lying on the ground,thinking that Gage must surely be dead.

But after a few minutes, Gage began to speak.His crew, astonished that he was still alive, rushedGage to the town of Cavendish. The town’s doctors,John Harlow and Edward Williams, helped Gagewalk up three flights of stairs to an attic room,where they cleaned his wounds (Harlow, 1848).

Miraculously, Phineas Gage survived. In manyrespects, his recovery was nearly complete. Move -ment, speech, memory, and the ability to learn newinformation were not impaired. Gage appeared tobe as intelligent as he had been before the accident.

But the accident produced a profound changein Gage’s personality. The previously friendly, competent, responsible foreman became stubborn,ill-tempered, profane, and unreasonable. He alsobecame incapable of carrying out plans and couldno longer hold down a job. As Dr. Harlow (1868)later wrote, “His mind was radically changed, sodecidedly that his friends and acquaintances saidhe was ‘no longer Gage.’”

Gage survived for more than 12 years followingthe accident. After Gage’s death in 1861, Harlowpersuaded Gage’s family to have the body exhumedso that the skull could be recovered and kept as amedical record. The tamping iron, which had beenburied with Gage, was also recovered.

In 1868, Harlow presented a paper to theMassachusetts Medical Society detailing the acci-

dent. He suggested that the changes in Gage’sbehavior and cognitive functioning were the resultof damage to Gage’s frontal lobes. In effect, Harlowproposed that the frontal lobes were involved insocial and emotional behavior, reasoning, the abili-ty to think and plan, and decision making.

At the time, Harlow’s ideas about the frontallobes were dismissed. Why? One reason was thatHarlow had not performed an autopsy. Withoutanatomical evidence, critics discounted Harlow’sideas. Claims for specialization were viewed withgreat skepticism by scientists because of the rejec-tion of the pseudoscientific claims of phrenology(Fancher, 1996). Harlow’s ideas were too close toGall’s notion of “faculties” that could be determinedfrom the bumps on a skull (Damasio & others,1994).

Harlow’s suspicions were finally confirmedalmost 125 years after Gage’s death. In 1994, Drs.Hanna and Antonio Damasio, of the Department ofNeurology at the University of Iowa, reexaminedPhineas Gage’s skull. Using X-rays and sophisti-cated computerized brain-modeling techniques,they created a three-dimensional model of theinjury to Gage’s brain (see photograph). In effect,the Damasios simulated the autopsy that wasnever performed on Phineas Gage.

The Damasios found that the specific braindamage sustained by Gage and the subsequentbehavioral changes fit the same pattern found inother individuals with similar frontal lobe damage(Damasio & others, 1994). Damage to this area ofthe frontal lobes is associated with an impaired


A Model of Gage’s Injury Computer-simulatedreconstruction of Gage’s skull by Damasio and her col-leagues (1994) suggests that Gage’s left and rightfrontal lobes were both damaged.

ability to make rational decisions in personal andsocial matters and also compromises the processingof emotions (Robin & Holyoak, 1995).

Although Harlow’s ideas about the role of thefrontal lobe in behavior and emotions was initiallyrejected, over a hundred years later the Damasiosconfirmed the accuracy of Harlow’s proposal. AsHanna Damasio and her colleagues (1994) wrote,“The mysteries of frontal lobe functioning are slow-ly being solved, and it is only fair to establish, on amore substantial footing, the roles that Gage andHarlow played in the solution.”

[Harlow, J. M. (1848, December 13). Passage of an ironrod through the head. Boston Medical and Surgical

Journal, 39(20), 389–393; Harlow, J. M. (1868). Recoveryfrom the passage of an iron bar through the head.Publications of the Massachusetts Medical Society, 2,327–347; Fancher, R. E. (1996). Pioneers of psychology(3rd ed.). New York: Norton; Damasio, H., Grabowski, T.S., Frank, R., Galaburda, Albert M., & Damasio, A. R.(1994, May 20). The return of Phineas Gage: Clues aboutthe brain from the skull of a famous patient. Science, 264,1102–1105; Robin, N., & Holyoak, K. J. (1995). Relationalcomplexity and the functions of the prefrontal cortex. InM. S. Gazzaniga (Ed.), The cognitive neurosciences.Cambridge, MA: MIT Press.]

Copyright © 2006 Worth Publishers.


Handout 2.2

Dichotomania Quiz

Think about each of the following skills, qualities, and activities and its designated base in one ofthe hemispheres of the brain. Please note that this refers to where the function or skill is predomi-nantly located.

Using your knowledge of the brain, indicate whether the location is “supported” by research evi-dence or simply a commonly accepted “myth.”

Right Hemisphere:

Face recognition SUPPORTED MYTH

Mystical experience SUPPORTED MYTH

Nonverbal processing SUPPORTED MYTH

Creativity SUPPORTED MYTH

Spatial processing SUPPORTED MYTH

Left Hemisphere:

Logic SUPPORTED MYTH

Language processing SUPPORTED MYTH

Speech production SUPPORTED MYTH

Sequential processing SUPPORTED MYTH

Right-handedness SUPPORTED MYTH


Handout 2.3

Answers to Dichotomania Quiz

The correct answers are in bold.

Right Hemisphere:

Face recognition SUPPORTED MYTH

Mystical experience SUPPORTED MYTH

Nonverbal processing SUPPORTED MYTH

Creativity SUPPORTED MYTH

Spatial processing SUPPORTED MYTH

Left Hemisphere:

Logic SUPPORTED MYTH

Language processing SUPPORTED MYTH

Speech production SUPPORTED MYTH

Sequential processing SUPPORTED MYTH

Right-handedness SUPPORTED MYTH


Biological Basis for Behavior Resources

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