Behavior therapy/models human Behavior

Veronica27

psychology-six-perspectives_n3.pdf

Home >Psychology homework help >Behavior therapy/models human Behavior

SAGE Books

Psychology: Six Perspectives

Biological Psychology

By: Dodge Fernald

Book Title: Psychology: Six Perspectives

Chapter Title: "Biological Psychology"

Pub. Date: 2008

Access Date: November 3, 2022

Publishing Company: SAGE Publications, Inc.

City: Thousand Oaks

Print ISBN: 9781412938679

Online ISBN: 9781452224862

DOI: https://dx.doi.org/10.4135/9781452224862.n3

Print pages: 49-88

This PDF has been generated from SAGE Knowledge. Please note that the pagination of the online

version will vary from the pagination of the print book.

javascript:void(0);

https://dx.doi.org/10.4135/9781452224862.n3

Biological Psychology

Biological psychology

• Origins of Biological Psychology ◦ Wundt and Physiology ◦ Changing Views of the Brain ◦ Basic Research Methods

• The Nervous System ◦ Interlocking Systems ◦ Structure of Neurons ◦ Neurotransmitters and Drugs

• Organization of the Brain ◦ Maintaining Internal Conditions ◦ Responding to External Events ◦ The Limbic Connection

• The Cerebral Cortex ◦ Primary and Association Areas ◦ Concept of Localization

• Modern Biomedical Therapy ◦ Assessment and Diagnosis ◦ Guidelines for Treatment

• Commentary and Critique

Biological psychology is a useful starting point in the study of behavior. All human and animal activities emerge from underlying biological mechanisms. Focusing on the nervous system, especially the brain, biological psychology examines the ways the organs of the body influence behavior and experience.

In the 17th century, René Descartes greatly advanced the dawn of biological psychology through his inquiry into natural philosophy, meaning a systematic study of nature, especially animal physiology, which was pursued chiefly through dissections. In this way he studied animals and human beings in terms of a machine metaphor. In animals, the mechanical parts were simpler and were activated by a special fluid, which Descartes called animal spirits. In human beings, some mysterious, immaterial substance played a loftier role, for human mental life seemed to be separate from bodily activity. In one way or another, the machine metaphor of the body endured until the contemporary focus on the brain prevailed.

After further comments on the origins of biological psychology, this chapter turns to modern views of the nervous system, organization of the brain, and details of the cerebral cortex. It closes with a discussion of mental disorders and biomedical therapy, followed by a commentary and critique of the biological perspective.

With modern biomedical therapy still emerging in the late 19th century, the Bellevue Sanatorium in Konstanz, Switzerland, developed an enviable reputation for the treatment of brain disorders, now called mental disorders. It resisted the usual therapeutic practices of that day, such as early Hydrotherapy, which was used to shock people out of their illnesses. Suddenly sprayed with a strong stream of frigid water, patients sometimes fainted or experienced even more negative outcomes (Guttmann, 2001).

The Bellevue Sanatorium operated instead on the controversial principle of nonrestraint. In particular, it placed great importance on providing social opportunities for the patients, who came from wealthy families all over Europe. They needed normal human relationships. The Sanatorium encouraged them to mix with the director's family, staff, and visitors, as well as with other patients.

The records of the Bellevue Sanatorium for July 1882 include case 548, which describes the background and mental condition of a young woman named Bertha Pappenheim, born February 27, 1859. According to the report, she entered treatment with a moderately severe hereditary handicap. Her brother and a cousin once prepared a family tree, identifying ancestors who had become mentally ill. They were concerned about genetic

SAGE Books

Page 2 of 27 SAGE Books - Psychology: Six Perspectives

abnormalities caused by marriage between close relatives (Guttmann, 2001). Bertha's mental condition was diagnosed as hysteria, a common disorder at that time. But she also suffered involuntary, painful contractions of the facial muscles and an addiction to morphine (Hirschmüller, 1989).

In emphasizing the biological basis of Bertha's condition, this case report adopted an approach to the study of behavior, which is still common today. Some causative factors in mental disorders do lie in the human body. But the evidence for a biological basis varies from one disorder to another, remaining complex and controversial even today.

Origins of Biological Psychology

By several standards the oldest of the modern perspectives, biological psychology aims to understand how the mechanisms of the human body make possible our various behaviors and experience. According to this view, the route to psychology goes through anatomy and physiology, especially neurology. Modern biological psychology encompasses the widest possible range of these relationships, and it stands among the most current of all psychological perspectives, steadily advancing its research frontiers. Pursued by scientists with diverse backgrounds, it is sometimes viewed as a broad sub-field in psychology, rather than an integrated perspective.

Interest in bodily functions appeared in Wilhelm Wundt's laboratory, and it is of course as old as humanity. However, no one person can be credited with the founding of biological psychology. Wundt serves here as a founder chiefly on the basis of his primacy in the field and training in medicine. But working as a medical doctor did not satisfy his research interests. So he came to psychology from physiology and conducted early investigations on sensory and other bodily processes. His interests shifted later to the study of consciousness.

Wundt and Physiology

Life began in a dismal fashion for Wilhelm Wundt (1832–1920). He experienced little parental love, no close friends, and few playground activities. At age 13, even his teachers openly criticized him. Then he changed schools. In this new environment, he developed a keen interest in reading and began, with much satisfaction, a long life of learning (Boring, 1957).

According to historians, Wundt's early social deprivation and subsequent academic recognition contributed greatly to his prodigious capacity for scholarship. Humorless, tireless, and clearly talented, Wundt not only founded a laboratory but also created a substantial library of books and articles he wrote himself. In his first publication, on the sodium chloride content of his own urine, he noted the change in salt concentration after placing himself on a special diet. Only age 21 at the time, this study began his unrelenting authorship.

He guided his most renowned work, Principles of Physiological Psychology, into two volumes and eventually six editions. For decades, this book provided the framework for the emerging interest in experimental psychology. It has been called the most important book in the history of modern psychology (Boring, 1957). Later he contributed ten volumes on social and cultural psychology. He also founded a journal, Psychological Studies; the first journal in experimental psychology, it presented the results of his laboratory research. Altogether, his bibliography included 491 entries, averaging about 110 pages each, representing a total of 53,735 pages, including all pages of each revised edition. On this basis, Wundt wrote an average of 2.2 pages per day for his entire career of 67 years (Boring, 1957).

Through his writing, research, and teaching, Wundt greatly influenced many graduate students. After they passed through his laboratory and courses, they returned to their homes, many in the United States, and spread the new doctrine of psychology.

As a distinctive perspective, biological psychology was slow to gather momentum. Introspection and other early efforts, including cultural psychology, intervened. But we can give Wundt credit for being the first psychologist, founding the first laboratory, inaugurating the first research journal, writing the first textbook, and preparing the first graduate students (Boring, 1957). And we can credit him with studying the full range of

SAGE Books

Page 3 of 27 SAGE Books - Psychology: Six Perspectives

topics from biology to culture.

His massive Physiological Psychology emerged from two traditions. Beginning with the structural elements of the nervous system, it discussed the pathways of neural conduction, the central nervous system, divisions of the brain, and functions of the cerebral hemispheres (Wundt, 1874/1904). In his day, physiology referred to experimental or laboratory procedures as well as the study of bodily functions. Thus, the book included methods for experimental psychology. It emphasized that physiological and psychological processes, which were usually separated for purposes of efficiency in teaching and research, occur together in a living human being. Insofar as possible, they must be studied together as a complex but nevertheless unitary entity.

In summary, Physiological Psychology became a crossroads book. In it, Wundt moved from physiology to psychology; the field of psychology, in turn, moved away from philosophy toward science.

In this context Wundt noted with some interest the early work of a contemporary Spanish neurologist, Santiago Ramón y Cajal; this work supported his ideas about the structure of the nervous system. At that time, many scientists regarded this new view skeptically, as no more than a hypothesis or theory.

In fact, for thousands of years our nervous system was believed to be one intact, continuous network, an endless matrix of piping that carried messages into every corner of the human body. This view became known as network theory, or reticular theory, for reticular in Latin means resembling a net. According to network theory, all nerve cells were continuously fused in the brain; they were all interconnected.

Instead, Ramón y Cajal advocated neuron theory, which states that the nervous system consists of countless individual nerve cells that never actually touch one another. Individual nerve cells are the fundamental units for the transmission of information in the body. Our nervous system is thus not a mass of physically connected cells but rather an exquisitely intricate organization of separated cells. Observing the enormous diversity in human abilities, he decided that no single network could account for such flexibility in behavior.

With his early microscope and staining methods, Ramón y Cajal hit on a promising approach to confirm his view. Because the human adult brain was too densely packed to observe the speculated spaces among its components, he decided to study lower animals in their earliest stages of development, even before birth. Their less-developed brains might be more accessible than mature brains, providing information on nerve growth and the formation of nerve pathways. Working with extraordinary intensity, he examined embryonic chicken brains. In that way, he confirmed the predicted spaces and thereby overthrew network theory (Cannon, 1989).

The delicacy of these cells, and the tiny spaces between them, which somehow must be transcended, greatly impressed Ramón y Cajal—so much so that he called their speculated connection a “protoplasmic kiss.” The protoplasm was viewed as a semi-fluid substance essential to life functions; the kiss suggested that adjacent cells somehow made gentle contact through a “lip lock,” exchanging that substance with one another (Ramón y Cajal, 1989). We now know that adjacent cells are structurally independent and are functionally connected by electrochemical activities.

Almost single-handedly, he unraveled the basic elements of the great raveled knot, as the human brain is sometimes called. Neuron theory no longer remained a theory. The individual nerve cell, or neuron, became recognized as the basic unit of the nervous system. Among these billions of nervous mechanisms, investigators might find the physical bases of human thought and therefore the answers to many questions about the biological bases of psychology.

Changing Views of the Brain

Centuries ago, scientists believed that the brain functioned only as a whole. All parts were alike. They responded together and completely or not at all—a capacity called the principle of mass action. Furthermore, all parts responded in essentially the same way, a function known as equipotentiality. In short, the brain was viewed as one uniform mass. The highly specialized parts that we know today were not recognized at all.

SAGE Books

Page 4 of 27 SAGE Books - Psychology: Six Perspectives

In the latter part of the 19th century, the idea of mass action became replaced by its seemingly more sophisticated opposite. According to phrenology, a person's psychological capacities could be identified in terms of 40 or so highly specific contours or bumps in specific areas of the head—memory emerged from one bump, agreeableness from another, and aggression, reasoning, language, love of infants, and many more from other locations. Enormous interest arose over this long-awaited, apparently successful way of assessing mental functions and personality. The chief concept, complete localization, meant that each ability was located solely and fully in just one brain site. But phrenology and its theory of complete localization soon fell out of favor. Experiments with animals showed no relationship between the loss of certain “bumps” and loss of the alleged mental capacity.

Today we regard the human brain very differently indeed, totally unlike what the concepts of mass action and complete localization would imply. Biological psychology today studies the human brain in terms of specialized parts, or systems, and also for their exquisitely complex relationships, both increasingly understood in the context of modularity doctrine. A prominent concept in modern biological psychology, modularity doctrine states that for any complex mental or physical activity, units of relatively independent, specialized brain structures become involved in an integrated fashion, with different units in different parts of the brain responding in separate but coordinated ways.

A module is a self-contained unit, or it is constructed of self-contained units. Either way, modularity doctrine points to brain systems operating for the most part independently of other brain systems or units. But some units are more autonomous than others, owing to weaker connections with their surroundings. Also, they vary in their integration—the degree to which they are internally coherent. In other words, modules differ in both the integration among their internal components and the strength of their connections with external mechanisms (Schlosser & Wagner, 2004). Information available to a particular module may or may not be available to other modules (Flombaum, Santos, & Hauser, 2002).

On these bases, biological psychologists speak of modular design, meaning that some global response, such as viewing a scene, can be achieved by subsystems designed first to react in relatively independent ways to specific information and then to implement that information as part of an aggregate, integrated whole. For a particular scene, individual modules might include color perception, recognition of faces, analysis of space, and language comprehension. Each module would be insensitive to some aspects of the scene but not to others. And some modules could be embedded in others, providing a hierarchical arrangement in the overall response to the visual image (Hirschfeld & Gelman, 1994; Schlosser & Wagner, 2004).

One metaphor for modularity doctrine is an orchestra. Playing in an independent but coordinated fashion, the groups of various instruments produce a complex, integrated outcome. Another metaphor is an ecological system, such as a rain forest, composed of many interdependent parts—plants, insects, decaying trees, birds, and brooks—each influencing the activities of other parts in important, subtle ways. In short, the brain operates not as a whole and not in isolated parts but through exquisitely complex integrations of simultaneously functioning units.

Moreover, the brain constantly reorganizes itself as a function of experience, a condition called brain plasticity. These changes in structure involve the generation of new brain circuits and the modification of existing circuits. Alteration in the brain's physical structure is then reflected in the ways it operates. In fact, the capacity to develop new neurons, called neurogenesis, has been found not only in birds and nonhuman primates but also recently in certain areas of middle-aged human brains. In particular, studies have shown neurogenesis in the hippocampus (Gage, 2003). If it is to be found anywhere, its presence here is least surprising, for this brain structure is critically important in learning and memory of new information, as noted later. In this respect, the human brain is not a static mass of nervous tissue. Regulated by inborn molecules known as growth factors, and highly sensitive to experience, it undergoes constant modifications on diverse bases.

Influential environmental factors operate throughout the life span, even into senescence. Among the most negative factors, traumatic injury, psychoactive drugs, lead poisoning, and disease can produce profound and irrevocable disruptions. In contrast, a healthy lifestyle achieved through dietary regimens, regular programs of exercise, and challenging mental activities can exert long-term, favorable influences on brain development (Kolb, Gibb, & Robinson, 2003).

SAGE Books

Page 5 of 27 SAGE Books - Psychology: Six Perspectives

Basic Research Methods

Biological psychology expands its knowledge chiefly through experimental methods, supported by clinical case studies. In laboratory experiments with animals, the investigator alters some body part, usually the nervous system, and observes any change in behavior. Or the investigator alters the subjects' living environment and notes any change in the structure or function of the body.

A classic laboratory experiment with animals illustrates this model. Investigators studied rats bred for brightness or dullness, placing half of each group in a restricted environment and the other half in an enriched environment, beginning at 25 days of age. The restricted cages included only a food box and water pan. The same-sized enriched cages also included treadmills, tunnels, swings, seesaws, mirrors, and marbles, in addition to poles with bars for climbing. After 40 days in these environments, all rats were tested in a field maze, which is commonly used for assessing mental ability in animals. The results showed a large difference in ability between the two strains. The bright rats and dull rats from the enriched environments performed much better than both groups of rats from the restricted environments. At both levels of heredity, early experience made a substantial difference in the rats' behavior (Cooper & Zubek, 1958; Greenough & Chang, 1989).

A classic quasi-experimental design demonstrates this approach with human beings. Young children were unintentionally exposed to one of two different environments, enriched or deprived. The former included unexpected, abundant stimulation and child-caretaker interaction; the latter involved the absence of these activities in an early, understaffed orphanage. After approximately two years, the children from these different environments showed clear differences in mental functioning. The enriched group showed an average IQ gain of more than 20 points; the deprived group showed a comparable loss. Marked differences in personal adjustment were observed as well, even in later life, again in favor of the enriched environment (Skeels, 1966; Skeels & Dye, 1939).

In case studies, often with ill or injured people, clinical treatments provide information on the malfunctioning body parts (Rosenzweig, Leiman, & Breedlove, 1996). The procedure involves a comparison of the behavior of the individual before and after the injury.

Phineas P. Gage, 25 years old, had been a healthy, intelligent, respected construction foreman. Working on a railroad in Vermont in 1848, a dynamite explosion sent a pointed, 13-pound, 4-foot iron bar completely through his head. Gage miraculously regained consciousness, then talked and walked around, and later rode in a horse-drawn cart to his hotel. The significance of this case extends well beyond Gage's physical recovery, an outcome meriting attention in the history of biology. Showing no obvious deficits in physical behavior, intelligence, or memory, he became a changed man nevertheless, a result of special significance for biological psychology. No longer respectful of others, he often swore at them instead, becoming obstinate, poorly controlled, and even wildly emotional at times. A person who knew him previously described him as “No longer Gage” (Harlow, 1869).

A full 20 years after Gage's accident, a physician studied his preserved skull and tamping iron and decided that his change in emotional control was caused by damage to the frontal region of his brain. Ten years later, a physiologist speculated more precisely, attributing Gage's misbehavior to damage in the left frontal area of the brain. And in our times, a team of investigators used neuro-imaging techniques with the skull, tamping iron, and its probable trajectory to confirm that Gage suffered damage to the frontal lobes, thereby disrupting his capacity for processing emotional reactions and making rational decisions (Damasio, Grabowski, Frank, Galaburda, & Damasio, 1994).

Despite his emotional outbursts, Phineas Gage's reaction did not demonstrate the role of the frontal cortex in emotional behavior. Rather, it demonstrated that the frontal lobes play a role in rational thought and decision making, thereby exercising control over emotional behavior.

Today, experimental investigations and case studies remain the primary research pathways in biological psychology, but the measurement procedures have improved enormously, entailing little danger for the participants while providing considerable information for the investigators. These devices, collectively called

SAGE Books

Page 6 of 27 SAGE Books - Psychology: Six Perspectives

brain imaging techniques, produce photographic-like images of the brain's structure or function. Some, like the PET and MRI, do so by monitoring blood flow; others, such as the EEG, do so by measuring spontaneous electrical activity of the brain.

In the PET scan, using positron emission tomography, the participant lies with her head in a PET scanner, a framework that includes detectors surrounding the person's head. Then she receives a tiny dosage of a positron-emitting tracer injected into the bloodstream. This tracer enables the PET scanner to assess the blood flow, which signals neural activity.

In an MRI scan, using magnetic resonance imaging, the participant places her head into a strong magnetic field, revealing brain images through electromagnetic radiation. The MRI can provide images of brain structure or, indirectly, of brain functions. A functional MRI, or fMRI, actually provides images of blood oxygenation that are associated with various levels of neural activities in specific brain regions (Coleman, 2001). A much older technique, the EEG, or electroencephalogram, is instead a graphic display of the electrical activity of the brain, sometimes called brain waves, obtained through electrodes attached to the scalp.

In one study, investigators employed the PET scan to examine normal and abnormal brains in living human beings, using a procedure similar to that of the cardiologist who asks a patient to perform various physical exercises, thereby inducing electronically detectable changes in heart functions. These investigators asked each participant to engage in various mental tasks, producing electronically detectable changes in brain functioning. When a participant simply gazed around the room, the PET images showed activities in the visual cortex. When the person listened to speech, the images indicated activity in the left hemisphere but not the right, and vice versa when the individual listened to music. With speech and music together, both hemispheres became active simultaneously. All these responses had been predicted on the basis of prior knowledge. Thus, the PET scan confirmed our understanding of brain regions and normal mental activities without surgery or any other invasive method.

When using a PET scan to assess abnormal brain functions, the investigators proceeded on the assumption that all brain diseases arise from or create biochemical changes in the brain. And they found that the images of abnormal brains revealed specific areas of disturbance in far greater detail than prior techniques, aiding in earlier and more accurate diagnoses of abnormality (Phelps & Mazziotta, 1985).

The Nervous System

Far more than other body parts, the nervous system underlies the riddles of human behavior. As the body's primary communication network, consisting of all organs composed of nerve tissue, the nervous system exerts the most fundamental command over the activities of human beings. In fact, it perhaps should not be called the nervous system, for it consists of several intricately connected systems.

Twentieth-century research advanced our knowledge on several fronts. Investigators first calculated the speed of a nerve impulse, known today to be almost 300 miles per hour along some neurons. Then they discovered that this neural message travels across the synaptic gaps between neurons via chemicals called neurotransmitters. Since the identification of acetylcholine, the search for other neurotransmitters has been steady and productive. Other investigators explored the nature of the nerve impulse, which occurs when positively charged ions penetrate the cell membrane, creating a change in electrical potential that travels along the neuron.

Interlocking Systems

Within our vast array of nerve tissue, the integrating and coordinating center is the central nervous system, composed of the brain and spinal cord. It is the chief message center. It prepares, receives, and transmits neural messages throughout the body, thereby controlling its activities. In particular, it receives information from the peripheral nervous system, which includes essentially all nerve tissue outside the brain or spinal cord. The peripheral nervous system collects information from the outside world and also from inside the

SAGE Books

Page 7 of 27 SAGE Books - Psychology: Six Perspectives

body. It is basically a transmission system with two major components.

One part, the somatic nervous system, connects with the sense organs for receiving incoming messages and with the voluntary muscles for sending outgoing messages. In other words, it relays to the central nervous system information from the eyes, ears, and skin, and it relays from the central nervous system information for the muscles that move the body. It transmits incoming and outgoing information.

The other major part, the autonomic nervous system, connects largely with involuntary organs, such as the heart, lungs, stomach, and various glands, including the adrenal glands. It includes two divisions that increase or decrease the activities of these organs, depending on the individual's interpretation of the circumstances. In perceived emergencies, the sympathetic division becomes ascendant, mobilizing the body for action—a fight-or-flight reaction. It accelerates the heart rate, increases the flow of adrenaline, and so forth, as the individual becomes emotionally aroused. The parasympathetic division regulates the body in more routine circumstances, conserving rather than expending energy. Heart rates and respiration become normal; digestion commences; and saliva returns to the mouth. The person functions in a more normal manner.

Structure of Neurons

The discovery of neurons, emphasizing that humans have billions of individual nerve cells, had profound implications for understanding the human nervous system. Scientists tried to imagine billions of independent nerve cells somehow making connections with one another. Eventually they discovered functional connections, the activities between and among neurons. These connections occur at a synapse, a tiny space among adjacent nerve cells where a neural message may or may not pass to countless other cells. The activities in each of these billions of spaces have the capacity to transmit or inhibit messages to countless other neurons, making possible the enormous flexibility of human behavior—from finely coordinated finger movements to unparalleled thought processes. In fact, the process called learning, so fundamental in human beings, is based on the capacity of neurons to grow and thereby to create new synapses, new connections among countless other neurons.

If the human brain were one solid mass, like a mound of jelly, we could not originate or transmit the messages behind these activities. We would move in a slow, restricted, repetitive way—or not at all. Our behavior would be extremely limited.

Neuron theory underlies vast areas of biological psychology. The synaptic spaces between cells are so well established and so central to biological studies that this idea is no longer debated and no longer a theory. The individual nerve cell, or neuron, is a functionally separate, structural unit in the nervous system, maintaining contact with other such units but not physically connected to them. What we popularly call a nerve or nerve fiber is, technically speaking, an extension of the neuron.

Neurologists recognize three major parts of the neuron. The central portion, the cell body, is the focal point of the neuron, containing the nucleus. Other nerve tissue is organized around this fundamental component. Two types of thread-like fibers extend from the cell body. The shorter fiber, a dendrite, has many branches, all of which carry nerve impulses toward the cell body. The longer fiber, an axon, transmits impulses away from the cell body to dendrites or cell bodies of other neurons. Nerve impulses in axons proceed in one direction only—from dendrite to cell body to axon—which is sometimes called the law of forward conduction and was first demonstrated by Santiago Ramón y Cajal (Figure 3.1).

SAGE Books

Page 8 of 27 SAGE Books - Psychology: Six Perspectives

Figure 3.1 A Neuron and Synapse. The neuron's major parts include its dendrites, cell body, and axon. The arrow indicates the direction of the nerve impulse. At the synapse, neurotransmitter substances play a central role in the flexibility of human behavior, stimulating extensive neurochemical activities among the fibers of adjacent neurons

Moreover, all impulses in axons appear at one level of intensity. This condition, called the all-or-none law, means that the nerve responds completely or it simply does not respond. There is no intermediate level of reaction. A doorbell rings or does not ring. A weak press does not produce a weak ring. Why then are some injuries more painful than others? How does someone detect the strength of a stimulus? One answer lies with the number of activated neurons in sensory systems. A stronger or more frequent stimulus causes more neurons to fire, increasing the pain. Or it increases the rate of firing. But it does not influence the speed, direction, or strength of the impulse causing the pain.

A painful condition around the mouth, nose, and face is often associated with the trigeminal nerve. Sudden, sharp aches and twitches occur in this region in a disorder called trigeminal neuralgia. These involuntary movements are habitual and spasmodic; each movement is known as a tic and appears as a visible muscle contraction. When admitted to the Bellevue Sanatorium, Bertha Pappenheim experienced tics of this sort.

After a few weeks, Bertha's tics grew worse. By seven o'clock in the evening, animated spasms appeared in the whole left side of her face, especially the jaw. Experiencing no relief, she required more morphine, which extended her addiction (Hirschmüller, 1989).

Tics, and all other responses, are aroused by messages in the nervous system, often originating in the brain. Each message, or nerve impulse, involves a brief burst of electrochemical energy traveling along the nerve fiber, much the way a spark travels along an ignited firecracker fuse. Initiated by an adequate stimulus, this shift in energy occurs through an exchange of electrical charges passing in and out of the porous covering of the nerve.

In its resting state, the nerve transmits no message. When the fiber is stimulated, positively charged sodium ions flow inward for an instant, passing through the cell membrane, causing positively charged potassium ions to flow outward. Within nanoseconds, tiny ionic pumps restore the normal balance in that part of the nerve.

SAGE Books

Page 9 of 27 SAGE Books - Psychology: Six Perspectives

But this change in voltage initiates a change in the adjacent fiber, and so forth, in successive parts, until this exchange of energy has traveled the full length of the fiber. This exchange of energy in the nerve, known as the nerve impulse, is formally called the action potential, emphasizing the change in the polarization of the nerve.

The individual's response to this message is determined by numerous factors. Among them, two are prominent: the sense organ responsible for the initial stimulation—visual, auditory, or otherwise—and the destination of the nerve fiber in the central nervous system.

Three kinds of neurons convey the message. One type, the sensory neuron, transmits the nerve impulse from sense organs to the central nervous system, resulting in the experience of pain, vision, hearing, or some other sense, depending on the area of the brain that has been stimulated. Sensory neurons carry information about our world and ourselves. They inform us. Another type, the motor neuron, transmits impulses from the central nervous system to muscles and glands, producing voluntary and involuntary responses. Motor neurons enable us to do something about the information received from sensory and other neurons. These reactions may be involuntary, as in a tic or reflex, or voluntary, such as rubbing the painful spot or requesting medication for pain.

A third type, the interneuron, makes connections with sensory and motor neurons and especially with countless other interneurons. Found only in the central nervous system, interneurons often appear with branches, which facilitate these innumerable connections. Thousands of times more prevalent than the other types, interneurons range in number up to many, many billions (Rosenzweig, Leiman, & Breedlove, 1996). Information processing in the human brain takes place primarily among interneurons. They play a vital role in the diverse, marvelously coordinated activities in human thought and behavior.

Neurotransmitters and Drugs

At the center of this flexibility lies the synapse, functionally connecting the neurons. On reaching this space, the nerve impulse releases the chemical bases of nerve transmission from tiny sacs. Each sac contains a chemical substance called a neurotransmitter, which travels instantaneously across the synaptic space, exciting or inhibiting adjacent neurons, depending on its fit with the molecular structure of the receiving neurons.

In other words, the nerve impulse does not jump across synaptic space like a spark. Instead, a neurochemical message travels through the fluid-filled synapse.

In some cases, the molecular structure of the particular neurotransmitter matches a receptor site on the receiving neuron, increasing its potential to initiate a nerve impulse, depending on the reactions at other receptor sites. This outcome is called an excitatory reaction because it arouses a nerve impulse. In other instances, a neurotransmitter may fit the receptor site, and there is no initiation of a nerve impulse. This outcome is called an inhibitory reaction because the neurotransmitter stimulates chemical activity that reduces the propensity of that neuron to arouse a nerve impulse. Still other neurotransmitters become irrelevant, not fitting any site at all. This whole process has been called lock-and-key transmission, for the key, the neurotransmitter, must fit the lock, the receptor site, in order to become effective. If it fits, it may open the door, an excitatory reaction, or firmly lock it, an inhibitory reaction.

Some neurotransmitters, rather than being discharged into a specific synaptic space, become discharged into a series of synapses. In addition, they have the capacity to amplify or diminish the capacities of a number of specific neurotransmitters. For both reasons, these modulating neurotransmitters are known as neuromodulators; they modify the effects of other neurotransmitters.

This activity takes place among countless neurons simultaneously and almost instantaneously, producing a flood of neurotransmitters into the synapses. For a person to function normally, a delicate balance must be sustained between the diverse excitatory and more prevalent inhibitory reactions. These tiny neurotransmitters, each characterized by its particular chemical makeup, operating in literally billions of synapses, make possible the immense versatility of human behavior.

SAGE Books

Page 10 of 27 SAGE Books - Psychology: Six Perspectives

But what happens to the neurotransmitters after they have served their purpose in synaptic space? How do they leave? In one process, called the reuptake process, the neurotransmitter is drawn back into the sending, or presynaptic, neuron from which it was discharged. In another, a deactivation process, the neurotransmitter becomes neutralized by cleanup chemicals in the synaptic space.

The number of different neurotransmitters currently remains undetermined, but estimates range upward to 100 or more. Among the most common are glutamate and GABA. Compared with other neurotransmitters, glutamate exerts the most widespread influence; it has the potential to stimulate an excitatory reaction in synapses all over the nervous system. In contrast, GABA, an acronym for gamma amino butyric acid, exerts a pervasive inhibitory influence, though less extensive than glutamate because it is limited to the brain.

Acetylcholine, whether excitatory or inhibitory, plays a prominent role in learning, memory, and muscular activity. Its release into the synapse initiates a muscle contraction. Its deficit in the central nervous system is associated with Alzheimer's disease, involving memory loss and disorientation. Its deficit also produces paralysis, as demonstrated by a drug known as curare, which obstructs acelytcholine receptor sites, preventing those neurotransmitters from influencing the muscles. When a healthy young man received small amounts of curare, he became completely paralyzed. During the growing paralysis, he spoke as long as possible and then communicated through prearranged muscle movements. After administration of a counteracting drug, he reported that he had remained fully conscious and experienced normal thought processes throughout the paralysis, suggesting that the curare operated on the acetylcholine receptor sites (Smith, Brown, Toman, & Goodman, 1947).

A bedtime snack can stimulate production of serotonin, associated with the usually pleasurable activities of eating and sleeping, as well as general arousal. Low levels of serotonin have been linked to aggression and depression; when medication and psychotherapy relieve those conditions, the presence of serotonin is also restored. Also associated with pleasurable activities and psychiatric conditions, dopamine influences emotional arousal, rather than general arousal. Special sensitivity to their normal levels of dopamine may appear in people with schizophrenia. Blocking dopamine at the synapses with the administration of psychotherapeutic drugs has proven useful in treating such disorders. In contrast, Parkinson's disease is associated with a dopamine deficiency, resulting in slowness and loss of muscular control. These different responses to the same neurotransmitter in different amounts illustrate the delicate balance among and within these chemical substances.

Finally, endorphins are widely recognized for acting as anesthetics or opiates that naturally occur in the body. The term comes from the words endogenous, meaning within, and morphine, a pain killer. Endorphins become anesthetics by blocking neural impulses for pain much as morphine reduces pain and increases a sense of well-being. As neuromodulators, endorphins operate in a more general way than the traditional neurotransmitters.

The neurotransmitters and neuromodulators together demonstrate that brain chemistry can have both specific and broad functions. In addition, their reactions can vary with different locations in the nervous system. In these ways they exert an enormous influence on the behavior and experience of any human being.

With its billions of separate neurons, their tiny functional connections, and minute chemical messengers, the human nervous system also remains highly susceptible to disorders. As evident with Bertha Pappenheim, conditions can go awry. In her case, endorphins did not suppress pain in the trigeminal nerve, and morphine had become addictive.

But painful tics were not her sole problem. Bertha occasionally experienced serious memory lapses, and she remained depressed for long periods, sobbing over the recent death of her father. She also complained about being in the hospital. Almost daily, she insisted on returning to her home in Vienna to live with her mother.

Returning to Vienna? To live with her mother? Mourning her late father? Suffering from mental disorder?

If Bertha Pappenheim sounds like Anna, the resemblance is not chance. Bertha was Anna, and her condition had worsened. After treating Anna—er, Bertha—Breuer later published the case for the benefit of colleagues,

SAGE Books

Page 11 of 27 SAGE Books - Psychology: Six Perspectives

referring to her as Anna O., a name still widely recognized throughout psychology. For this pseudonym, he used the letters of the alphabet immediately preceding her initials. B.P. became A.O. Then he selected Anna, which sounds somewhat like Bertha (Jensen, 1970; Pollock, 1984).

Breuer waited 13 years to publish the disguised case in a professional journal, an unusually long time even for introducing a novel therapy. But when he terminated the case, he had nothing to report publicly. The talking cure showed no permanent value at that early point, and he went on to other interests (Hirschmüller, 1989). In fact, he might have refrained from publishing the case at all had not a colleague urged him to do so.

In an earlier, confidential report of 22 handwritten pages to Bellevue Hospital at the time of Bertha's admission, Breuer included extensive details, especially on her tics, which he viewed as strictly a medical issue, not a psychological problem. Thus, he did not include them in the published report of Anna O.

For Bertha's tics, the Bellevue Sanatorium continued to prescribe doses of morphine, numbing the pain. But then she experienced a drug-induced state, which is any uncontrollable, often unpredictable, change in consciousness produced by chemical substances. She developed a physical dependence on this drug, called an addiction, which included painful withdrawal symptoms when the drug was no longer used.

Morphine quickly becomes addictive. By injection, Breuer had administered large amounts, doses of 0.05 to 0.20 grams daily. The hospital thus pursued both goals: to eliminate the tics and to remove the addiction.

Drugs, natural or manufactured, operate in two broad categories, agonist and antagonist. An agonist drug exerts essentially the same effect as the neurotransmitter. It binds to the receptor sites, exciting or inhibiting a reaction, much like a neurotransmitter at that site. An antagonist suppresses the influence of an agonist, sometimes by acting at different receptor sites and sometimes by binding to the same receptor sites without inducing excitation or inhibition. The drug nalaxone, a narcotic antagonist, binds to receptor sites that otherwise would be occupied by morphine, thereby preventing the usual effects of morphine (Coleman, 2001).

The hospital staff did not understand how morphine diminishes pain. As an agonist, with a molecular structure much like endorphins, it increases endorphin-like transmission at the receptor. Without the drug, endorphins alone make the transmission. Especially in large amounts, morphine greatly augments pain-killing capacities at those receptor sites.

Breuer also administered chloral hydrate to help Bertha sleep, using doses up to 5 grams daily, many times what might be used today. It produced another addiction. In an effort to wean her, the hospital withheld the drug for four nights, creating serious withdrawal symptoms in Bertha, including delirium tremens (Hirschmüller, 1989).

But at totally unpredictable moments, she surprised everyone with her joyful spirits. She even posed for a photo taken by a professional photographer in Konstanz. It showed a healthy-looking, sporting young woman ready to go horseback riding.

Organization of the Brain

Even when Bertha simply posed for a photograph, neural messages excited countless circuits throughout her nervous system. Other messages became activated when she planned a career in nursing and rode horseback in the Konstanz woods. These complex transmissions were coordinated by the brain, which serves as the basic integrating mechanism in the human body. In recognition of the brain's central role, behavioral neuroscience has emerged alongside biological psychology, concentrating on the relations between brain functions and behavior. It examines the ways in which the brain influences behavior or, more abstractly, the ways in which the brain, a biological structure, creates the mind, a psychological concept.

Only recently in human history have we viewed the brain as underlying our thoughts, feelings, and behavior. Aristotle assigned this fundamental role to the heart, a much noisier and livelier central organ. The brain, by comparison, appears as an inert mass, crudely described as three pounds of moist rubber, a head of cauliflower, or a deeply wrinkled boxing glove. Unlike the heart and all other bodily mechanisms, it is

SAGE Books

Page 12 of 27 SAGE Books - Psychology: Six Perspectives

conscious of itself, and it can understand itself in various ways, one of which involves a self-description in terms of evolution.

Progressing from the upper end of the spinal cord to the very top of the brain, three divisions presumably reflect the evolution of the brain. The lowest portion of the brain, closest to the spinal cord, is called the hindbrain because, for an animal on four feet, it is toward the rear. In an evolutionary sense, it is the oldest part of the brain. The hindbrain mediates basic biological functions, such as breathing, digestion, blood circulation, and reflexes. We share the hindbrain with many other animals, including the most primitive aquatic creatures. One major part, the cerebellum, called the “little brain” because of its size and location, maintains posture and coordinates sequential movements, making-well practiced habits smooth and precise, as in running, writing, talking, and riding horseback. Adjacent parts play a central role in the regulation of heart rate, breathing, and blood pressure, and perhaps certain cognitive processes as well.

A small area above the hindbrain, the midbrain, processes information for the upper brain regions, especially visual and auditory information. And it shares with the hindbrain a group of cells called the reticular formation, one part of which serves broadly to induce sleeping, waking, and other levels of arousal. The painful withdrawal from her addiction kept Bertha awake long into the night. When she finally fell asleep, the reticular formation contributed significantly to this quiescent state.

Bertha's thoughts about a career were produced chiefly in the third area, the large forebrain, so called because it is situated at the front in four-footed animals. At the top of the human skull, it is responsible for the higher mental processes: our thinking, remembering, perceiving, language, problem solving, and all sorts of experiencing. This portion of the brain makes human beings unique among the species, capable of thoughts and feelings not found in other creatures.

Located in the center of the forebrain, the thalamus serves as the main relay center, receiving neural messages from the eyes, ears, and other sense organs and relaying them to higher brain regions where they are interpreted, informing us about ourselves and the world around us. The term thalamus means “inner room.” Its central location serves well for these activities, playing a major role in human awareness.

These three evolutionary regions provide a rough index of the location of brain organs in relation to their function. The most biological lie at the lowest level, in the hindbrain, also called the reptilian brain. The most psychological occur at the top, in the forebrain, sometimes known as the primate brain. Linking and transfer functions occur in the much smaller midbrain, referred to as the mammalian brain despite its diminished importance in many mammals.

Biological psychology investigates the neural activities within and among these structures. They are specialized to perform one of three basic functions: to obtain information from the environment; to act on the environment; or to transmit information within the body, between input and output, a function of many brain structures.

The following discussion focuses on the forebrain, again in a three-level hierarchy. But here the sequence begins at the lowest level, then moves to the highest, and finishes with a connection between them, providing a conceptual overview of the most complex structure known to human beings.

Maintaining Internal Conditions

In the mid-20th century, partly by chance, investigators discovered some puzzling properties associated with the hypothalamus. In fact, these studies could be considered inaugural moments for biological psychology, for they represented some of the earliest efforts to study specific organs lying deep within the living brain.

The prefix hypo means “less” or “lower than.” The hypothalamus in human beings lies just below the centrally located thalamus. Using needle electrodes implanted in rats, early investigators delivered electrical stimulation to the lateral hypothalamus, at the side of this tiny organ, and they found that it sustained eating, even in animals that were presumably already satiated. And when this area was damaged, the animals ceased eating before their normal needs were met. Despite the availability of food, they became emaciated.

SAGE Books

Page 13 of 27 SAGE Books - Psychology: Six Perspectives

But electrical stimulation of the ventromedial nucleus, an area in the lower center of the hypothalamus, produced a very different outcome. Experimental rats immediately ceased eating, even those previously on a food-deprivation schedule. Damage to this hypothalamic region produced marked overeating, resulting in rats three times their normal size. The injured animals simply did not stop eating. Apparently they did not know when they had consumed sufficient food.

Initial interpretations of these findings pointed to the intricate role of the hypothalamus in hunger and eating. However, it alone is not solely responsible for either behavior, nor is any other organ, but it is involved in both reactions. The lateral area prompts eating; if destroyed, eating ceases. The more central region signals the time to cease eating; if destroyed, the stop signal does not occur (Anand & Brobeck, 1951; Mayer, 1956; Miller, Bailey, & Stevenson, 1950). But a major nerve pathway influences such responses, for it passes through the hypothalamus (LeDoux, 2002).

Today we view the tiny hypothalamus more complexly as playing a big role in maintaining a healthy body by influencing motivation and emotion and monitoring and regulating our biological drives, including hunger, feeding, fatigue, sexual behavior, and related survival and reproductive activities. Detecting changes in body chemistry and temperature, the hypothalamus has been called the “inner brain” and the “brain's brain,” out of respect for its capacity to regulate and maintain appropriate conditions within our bodies, enabling us to respond effectively to the external world (Greenberg, 2004). People who are extremely hungry, tired, weak, hot, or ill are not prepared to carry out their missions in everyday life. The little hypothalamus ensures a healthy readiness to behave effectively.

The hypothalamus maintains this extensive control partly through its direct connections with organs in the autonomic nervous system. In addition, it retains an influence over the endocrine system, the body's second major communications network, which is composed largely of glands that secrete chemical substances directly into the bloodstream. These substances, called hormones, are carried to various parts of the body, ensuring chemical activities essential for body growth and maintenance. Defects in hormone secretion can have extensive consequences, ranging from sharply stunted physical growth to sudden personality disorders. Malfunction of one element of this system may produce widespread changes in a person's feelings and behavior.

Specifically, the hypothalamus exerts this control through its connections with the pituitary gland, the “master gland” in the endocrine system, which in turn regulates the other endocrine glands, involving bodily growth, energy, and even personality. Also known metaphorically as the brain's drugstore, the hypothalamus performs a pervasive maintenance function throughout the body (Greenberg, 2004).

Responding to External Events

In contrast to the tiny, deeply embedded hypothalamus, the large cerebral cortex appears at the very top of the human brain as the brain's covering. A cortex is a covering or bark. The term cerebral indicates the largest part of the brain, the entire upper portion, both left and right. The cerebral cortex covers the whole upper portion of the brain and thereby mediates our sensory and motor contact with the outer world. These functions were first demonstrated convincingly in the latter part of the 19th century.

In the 1860s, two German physiologists resisted the view that the brain operated only as one excitable mass. Prompted by phrenology and more scientific research, they pointed out that the brain's surface had not been examined systematically and that hemorrhages from surgery decreased its responsiveness. With more careful methods, Gustav Fritsch and Eduard Hitzig decided they might be able to show that the brain functions in specialized ways. As a wartime surgeon, Hitzig had noticed that cleaning and dressing soldiers' head wounds sometimes produced a twitching in various muscles. These case studies of human beings laid the groundwork for experimental research with animals.

After some preliminary tests on the cortex of a rabbit, they turned to the Hitzig kitchen table on which they conducted more precise experiments with a dog, using a weak electric current applied directly to the surface of the dog's brain, just as other investigators had done earlier. That current barely evoked a tingling sensation on the human tongue but when applied in a systematic fashion, it worked well. Fritsch and Hitzig found that

SAGE Books

Page 14 of 27 SAGE Books - Psychology: Six Perspectives

stimulation at one point on the cortex produced movement in the dog's neck. Stimulation in another region induced leg movements. At still another point, facial movements occurred. Other stimulations brought forth muscle contractions in the back, stomach, and tail (Fritsch & Hitzig, 1870).

The investigators had demonstrated that the human brain was not one excitable mass. Stimulation of certain parts of the brain induced certain body movements. Other investigators advanced this knowledge and within a few years identified most areas of the cortex associated with muscle movements, also called motor control. Study of the sensory areas followed. Sensory studies were initially more difficult owing to the absence of observable movements, but human participants undergoing brain surgery gave reports, facilitating these investigations. Collectively these procedures, called cortical mapping, revealed which areas of the cortex mediated which sensory experiences, such as vision and hearing, and which regions mediated the movements of certain body parts.

We know today that sights, sounds, and experiences of touch are mediated primarily in specific areas toward the rear of the cerebral cortex, just as our responses to such stimuli are organized and initiated toward the front and middle areas. In juxtaposition to the hypothalamus, the cerebral cortex is our “outer brain.” The hypothalamus plays a major but not exclusive role in regulating our internal environment; the cerebral cortex becomes vital in managing our responsiveness to the external environment, a complex capacity considered in further detail shortly.

The Limbic Connection

So human beings have brain mechanisms for regulating the body's automatic responses to its internal needs. They also have the apparatus for responding appropriately to external conditions. What more is needed? In fact, the brain requires some linkage between the two—organs to connect our responsiveness to the inner and outer environments. When the deeply embedded hypothalamus signals the need for food or rest, for example, the outlying cortex must make successful contact with environmental events that will satisfy these needs (Greenberg, 2004). The system providing this linkage must be a subcortical structure, lying below the cortex, which covers the top of the brain.

The limbic system becomes important here, but it is poorly named. The adjective limbic indicates a border, a dividing line, often between two territories. But this system is more like a bridge than a border. A scattered group of brain structures, including the bilateral amygdala and hippocampus, the limbic system plays a connecting role in brain functions, especially in the context of emotion and memory. In highly simplified terms, it connects the inner brain of the hypothalamus and outer brain of the cerebral cortex. More generally, it bridges the gap between the deeper subcortical regions and the upper brain areas.

As a limbic structure, the amygdala closes the gap partly through its evaluation of emotional experiences, which it does quickly but often inaccurately. In one series of studies, rats learned to fear a sound that had been followed repeatedly by an electric shock. After they acquired this fear, they were denied information about its origins through removal of the cerebral cortex. But they continued to be afraid anyway, even after no longer knowing the prior circumstances. Based on studies of brain anatomy, the investigator pointed out that the amygdala provides a quick but crude appraisal of a potentially dangerous situation, apparently as an adaptive reaction before a more thorough, protracted interpretation is made by the cerebral cortex (LeDoux, 1995, 2002).

Imagine walking in the woods and hearing a growling bear. This stimulus initiates messages that go directly to the amygdala, and you start to run. Your first reaction would be fear, owing to the immediate interpretation of that event as something dangerous. By a longer route in the brain, this strange sound also initiates messages that travel through the cerebral cortex. The slightly delayed interpretation in these areas reveals the stimulus as merely branches brushing against one another in the wind. You smile and begin walking again. As Shakespeare said:

Or in the night, imagining some fear,

How easy is a bush supposed a bear.

SAGE Books

Page 15 of 27 SAGE Books - Psychology: Six Perspectives

(A Midsummer Night's Dream)

Both reactions, limbic and cerebral, can be viewed in the context of evolutionary theory and individual survival. The limbic arousal alerts us promptly to possible danger; the cerebral reaction provides a more thorough representation, enabling us to respond more appropriately.

Another major limbic structure, the hippocampus, plays a role in the formation of memory. Without it we simply cannot create new memories, failing even to recognize someone encountered just minutes earlier, which poses an insurmountable handicap in everyday life.

The role of the hippocampus appeared dramatically and regrettably in the plight of H.M. who, as a young man, obtained surgical relief from constant epileptic seizures. However, the procedure left him with a large deficit in the hippocampal area, after which he could only remember events prior to the surgery. His recall of childhood experiences remains basically undiminished, although he can form no new memories. He has a normal consciousness, but once an event leaves his immediate awareness, he typically cannot recall it. He cannot make new friends because he forgets people after they leave his presence. Over and over, he tells the same jokes, reads the same books, and forgets what he had just experienced. Living in this stressful condition for 50 years, H.M. has offered himself for intensive studies by psychologists (Milner, Corkin, & Teuber, 1968; Postle & Corkin, 1998). They have generated invaluable information on the contributions of the hippocampus to our capacity for memory, although it is not a primary repository of memories.

Much debate still surrounds the functions and even the components of the limbic system. For example, the thalamus and hypothalamus are sometimes included in and sometimes excluded from descriptions of the limbic system. There is, however, considerable certainty that emotional experience involves all of these brain structures, as well as the cerebral cortex and frontal lobes. One inescapable fact about the human brain is its intricate coordination among diverse parts (Figure 3.2).

SAGE Books

Page 16 of 27 SAGE Books - Psychology: Six Perspectives

Figure 3.2 Brain Structures and Fear Reactions. Shown in cross-section from the front, the brain is largely bilateral, including the almond-shaped amygdala and the hippocampus, resembling the tail of a seahorse. The dotted line indicates the shorter route from the thalamus to the amygdala, providing a quick response to fear. The dashed line represents the longer thalamic route to the cerebral cortex, providing a delayed but more thorough assessment

All human activity arises from exciting, inhibiting, and reverberating circuits in interconnected areas of the brain. Most synaptic events in the brain are inhibiting, not exciting, even in emotion. Without extensive inhibition, human beings would become inundated by random, redundant, competing neural messages. Brain activities would become chaotic, as in epilepsy, when a cascade of neural impulses in a large region produces dizziness, fits, and loss of consciousness.

Tics are a milder, more confined form of this disorder. They reflect a failure of inhibition in a restricted, specific brain area.

Appearing only around the mouth and lower face, Bertha's tics reflected an inhibition failure in those areas of the cerebral cortex. With limited knowledge of tics and limited means of treating them, the physicians at the Bellevue Sanatorium did what they could to ease Bertha's pain. They administered more morphine. But the cost was not worth the benefit. Morphine did not make her comfortable, and because of her increased addiction, withdrawal produced further pain.

She left the hospital anyway after four months of treatment. For case 548, the register at the Sanatorium read: “Condition improved. Discharged” (Hirschmüller, 1989). At her mother's insistence, she went to live with her Homburger cousins in Karlsruhe. There she wrote to Dr. Robert Binswanger, director of the Sanatorium: “As for my health … I can tell you nothing which is new or favorable. … However, I am glad that I can attend the nursing course which started last Friday” (Pappenheim, 1882).

Bertha never finished that course, but it left its mark, inspiring her with its volunteer opportunities in orphanages, schools for the poor, and soup kitchens. One cousin, Anna Ettlinger, inspired Bertha in a different

SAGE Books

Page 17 of 27 SAGE Books - Psychology: Six Perspectives

direction. She had published her recollections and translated foreign prose. After Bertha responded by telling some of her fairy tales from Vienna, Anna advised her to abandon nursing and begin a literary life.

The Cerebral Cortex

All these mental activities—writing letters, taking courses, and telling fairy tales—are centered in the cerebral cortex, the much-folded layer of gray tissue covering the forebrain and responsible for many neural connections. In addition to its role in incoming messages and outgoing responses, noted already, this part of the brain is critically involved in mental processes. It serves as our “thinking cap.”

As a cap, the cerebral cortex is thin yet large and new yet wrinkled, and these seemingly inconsistent characteristics require some explanation. Only a few millimeters thick, this outer covering represents more of the brain than might be expected or can be observed without pulling the cap apart. The reason lies with its wrinkles, many quite deep. They allow this large surface to fit into a relatively small space, our skull, much as a paper bag can be crumpled up and squeezed into a cup. These wrinkles, or crevices, known as convolutions, are less pronounced or absent in animals. Much of this tissue is called neocortex, for in an evolutionary sense it is a recent brain development, not shared with many animals. It covers older parts of the cortex.

The two cerebral hemispheres appear essentially alike, and in most activities they operate in a coordinated fashion. Functionally, however, they show important differences called hemispheric specialization, meaning that one hemisphere or the other is dominant in a certain activity. They are connected by the corpus callosum, a large mass of nerve tissue lying above the limbic system. Serving as a bridge, the corpus callosum transmits information between the hemispheres, thereby facilitating coordination of activities throughout the body. This condition of asymmetry is common in all paired body parts.

The left hemisphere tends to be dominant in language and numbers, the right in synthesizing and using spatial information (Hellige, 1990). For these reasons, people sometimes speak today of being left-brained or right-brained. But these expressions create a distortion, suggesting far greater reliance on one hemisphere or the other than occurs in our reliance on one hand or the other. Despite their specializations, the normal cerebral hemispheres are closely integrated, continuously exchanging information they receive from our many pairs of symmetrically arranged organs.

Primary and Association Areas

In terms of input and output, much of the cortex can be roughly considered as either sensory or motor areas. The sensory areas provide information. Through these regions, located toward the back of the cortex, we learn about our environment. We hear the sound of an airplane. The motor areas enable us to respond to that stimulation. Through these regions, located toward the front of the cortex, we do things about our environment. We look up in the sky.

Each of these regions, sensory and motor, is divided into primary areas and association areas. Here the term primary means first in either receiving or sending signals. Thus, the primary sensory areas receive information from the sense organs, transmitted via the thalamus. The primary visual area, at the back of the head, processes information for seeing. The primary auditory area, at the sides of the head, near the ears, receives information for hearing. And the primary somatosensory area, at the top of the brain, slightly toward the rear, responds to information about touch, temperature, and other experiences of the skin. The latter term comes from soma, meaning “body,” and sensory, meaning “feeling.” Loosely, it refers to touch or skin sensitivity. In addition to vision, hearing, and touch, there are to a lesser degree also primary areas for taste and smell.

These primary areas are often called primary projection areas because they roughly correspond to the regions of the body that they mediate. Thus, adjacent neurons in the retina project their messages onto adjacent cells in the visual cortex. Adjacent regions in the skin project their signals onto adjacent areas of the somatosensory cortex, and so forth. The size of the cortical area does not correspond to the size of the relevant body part, but it reflects the sensitivity of that body area. Thus, the highly sensitive lips and fingers

SAGE Books

Page 18 of 27 SAGE Books - Psychology: Six Perspectives

occupy more cortical areas than the less sensitive hips and trunk.

The primary motor areas influence body movements, sending information to the muscles and glands via the spinal cord; they initiate walking, talking, and countless other activities. These motor areas are located at the top of the head, slightly toward the front, just forward of the somatosensory areas. As with primary sensory areas, their relationships to the body are contralateral, meaning that each hemisphere stimulates or receives messages from the opposite side of the body, a condition found in most nervous systems. And here the body parts are represented in proportion to their flexibility of movement. Again, the tongue, lips, fingers, and other mobile parts occupy large regions; the less moveable torso occupies a much smaller brain region, despite its larger size.

The remaining regions of the cortex are not primary areas. Variously called nonprimary or association areas, they retain the effects of prior experiences and thereby play diverse integrating roles, coordinating incoming and outgoing messages for the primary sensory and motor areas and engaging in vast, currently unspecified activities. In short, these cortical regions integrate past experience with new messages. Thus, they provide additional meaning in a given situation. Rarely do adult human beings experience pure, unassociated stimulation. Combining new information with stored information, association areas contribute significantly to higher-level mental processes—perception, memory, and thinking.

Even in routine tasks, such as writing a letter, association areas play a fundamental role. “I hear such good news of my dear mama and my brother,” Bertha wrote again from Karlsruhe to Dr. Binswanger, “that it would be irrational of me to be homesick.” Reading these words aroused visual impulses that traveled to the primary visual areas and eventually to the association areas where they aroused diverse associations about Dr. Binswanger, his sanatorium, and so forth. Simultaneously, other association areas organized messages for writing more words, coordinated this information, and provided feedback about these activities, which was eventually integrated in the primary motor areas. One defining characteristic of human beings, in comparison with other creatures, is the far greater ratio of brain tissue devoted to association areas of all sorts.

Concept of Localization

Until the 15th century, many investigators understood the human brain differently. As noted earlier, they viewed it like a sponge or muscle, all of its regions similar in structure and operating together in much the same way, as a whole. For any given function, different parts of the cortex were considered equally important. Four centuries later, phrenology made a contrary claim, stating that specific mental functions emerged from bulges in specific areas of the brain. But research eventually refuted this doctrine of complete localization, derisively called “bumpology.”

Today we recognize certain brain areas, some called primary, as playing indispensable roles in certain functions, and yet they are complemented by extensive association areas and other brain structures. This viewpoint suggests again modularity doctrine, stating that human behavior emerges through largely independent networks of diverse brain structures, or modules, involved in an integrated fashion, with different units contributing in different ways. Some of these units have local functions, others play a more general role, and many of their connections arouse brain regions yet to be understood. Modularity doctrine emphasizes the extraordinary interactions among diverse brain structures and functions.

Given this interdependence among parts of the cerebral cortex, localization occurs only in a relative sense. The concept of brain localization now means that some areas are especially adapted for specific functions, but it does not mean they are solely responsible for them. For example, some areas of the temporal lobes, near the sides of the head, are primary and essential in speech. Without them there is no speech. But even with them, speech also requires responsiveness to the stimuli for speaking, received through sensory channels. It requires associative processes for decisions about what to say. It requires access to memory for the particular words. It requires motor responses to utter them and kinesthetic feedback about which ones we are saying. The temporal areas are necessary for speech, but they are not sufficient. This same condition holds for all other complex mental functions, whether or not they are associated with primary areas.

Thus, the localization of memory, a higher-order cognitive function, consists of numerous lower-order, more

SAGE Books

Page 19 of 27 SAGE Books - Psychology: Six Perspectives

specific functions in different brain regions, each contributing to what we call memory: the amygdala in attention and emotional memory, basal ganglia in the acquisition of skills, the cerebellum in conditioning, the cortex in associative memory, and the hippocampus in forming long-term memories. Similar statements can be made for the way the brain manages emotion, problem solving, and other activities. This view of dispersed localization and modularity doctrine has emerged slowly through successive investigations, building on one another and supported today by immense contributions from brain-imaging techniques, including the PET scan, MRI, and others.

As a group, these techniques serve the scientist, who is seeking new information, and the practitioner, who is meeting the personal needs of human beings. Not long ago, the useful options were almost nonexistent. Brain science was confined to autopsies of deceased brains, expanded in Bertha's era to injured and surgically altered brains, and today it includes the study of healthy, living brains, a huge advancement. And the therapeutic treatment of mind-brain disorders also has progressed dramatically, chiefly since the advent of medications in the middle of the 20th century. Practitioners at the time of Bertha's illness possessed only crude methods of drug therapy, evident when she wrote to Dr. Binswanger: “You will realize that to live with a needle always at the ready is not a situation to be envied.” Indeed, some of Bertha's symptoms perhaps arose from drug intoxication.

But things have changed. The hospital today would employ much improved medications. Bertha might expect a discharge within a couple of weeks.

Modern Biomedical Therapy

In biomedical therapy, the aim is to alleviate psychological problems by altering an individual's physical condition. At the outset the therapist might hospitalize Bertha for diagnostic purposes but would not consider any initial treatment except drugs, perhaps accompanied by psychotherapy. This treatment would be guided by a close monitoring of her condition and vastly greater knowledge of medications than was available to the earnest but ignorant Breuer. With current insurance practices, she would be discharged promptly.

Modern biomedical therapy is known by various names, including psychopharmacology and pharmacotherapy, owing to the predominance of drug treatments, as opposed to electroconvulsive shock therapy and psychosurgery. Modern drug therapy can be astonishingly effective in relieving even severe symptoms. In fact, drug treatments are so widespread today that many are managed by physicians who are not specialists in psychiatry (Kramer, 2000). In treating a disease about which he had little special knowledge and no training, Breuer would not be so far afield today.

Ideally, the drugs would relieve Bertha's symptoms, enabling her to profit later from some other, less intrusive therapy (Martorano, 1984). This aim is crucial, though not always possible. If the treatment relied solely on medication, Bertha would run the risk of becoming dependent on the drugs. She might never examine whatever psychological issues may lie at the origins of her symptoms, apart from any hereditary disposition. Drug therapy, if required, ideally includes some form of expressive therapy.

Several cautions arise in drug therapy. First, therapists and the public have been bombarded with compelling claims and dramatic reports of their effectiveness in the mass media. As a result, drugs have been overprescribed. Second, drug treatment avoids a lengthy hospitalization—the positive side. But this prompt discharge leaves many former patients without adequate assistance, and they discontinue treatment—the negative side. In this regrettable cycle, the revolving-door outcome, half the psychiatric patients move back and forth, into and out of the hospital—or they remain homeless.

Assessment and Diagnosis

The potency of therapeutic drugs and the ease with which they can be misused have prompted the development of extensive methods for assessing their outcomes. The knowledge gained from these tests is then made available to the individual therapist in the form of a database.

SAGE Books

Page 20 of 27 SAGE Books - Psychology: Six Perspectives

In the most powerful assessment method, the randomized double-blind technique, prospective patients are assigned on a chance basis to an experimental or control group. The experimental patients receive the real drug, the control patients a placebo, a nonmedical concoction merely simulating the treatment. The technique is called a double blind because neither the experimenter nor the participants know who has been assigned to which group. A third party makes these random assignments, keeps confidential records, and does not participate in judging the outcomes of the tests.

Even as recently as 30 years ago, psychopharmacology was deemed an art, as practitioners struggled to find the appropriate medications for diverse patients. But our knowledge of drugs and ways of evaluating them have grown at an unprecedented rate. Today, with far greater sophistication, drug therapy is a more precise enterprise, practiced not only by physicians but also psychologists with pharmacological training (Kramer, 2000; Nies & Spielberg, 1996). But owing to the unpredictable human element in all patients, it inevitably involves trial-and-error procedures, even in diagnostic efforts.

The Bellevue Sanatorium agreed with Breuer's diagnosis: Bertha suffered from hysteria. Today her diverse symptoms would have produced multiple diagnoses, including depression and some of the following conditions: somatization disorder, dissociative disorder, and borderline psychotic disorder.

As noted earlier, depression is marked by sad or irritable moods, poor concentration, feelings of worthlessness, and little pleasure in life. By today's standards, it is perhaps the most encompassing single diagnosis for Bertha.

When diverse parts of the body, or soma, become painful or malfunction without any medical explanation, the condition is called a somatization disorder. It became another feature of Breuer's diagnosis of hysteria. In addition, she might have been diagnosed with dissociative disorder—a sudden, extreme memory loss with no obvious cause. Finally, a psychotic disorder includes delusions, hallucinations, and other disorganized behavior, all of which Bertha displayed.

These disorders, described today in the Diagnostic and Statistical Manual of Mental Disorders—IV, raise the question about causes of mental illness. In everyday terms, two sets of causative factors can be identified. Some predisposing factors may be present well before the outbreak of the disorder, making it more likely. The early deaths of Bertha's two sisters, family discrimination against her, parental overprotectiveness, a possible hereditary tendency, and cultural restrictions in her education all can be viewed as predisposing factors. Then some specific event immediately preceding the illness becomes the precipitating factor, the most obvious instigator. Bertha's debilitating effort to nurse her ill father may be regarded as the precipitating factor. Expressed as the vulnerability-stress model of mental illness, predisposing factors make the person vulnerable; then a precipitating factor adds additional, intolerable stress, resulting in the disorder.

Despite her miserable circumstances, Bertha also has been suspected of feigning her symptoms, and perhaps some were of this nature (Borch-Jacobsen, 1996). But to be diagnosed as malingering, the patient must feign illness for some personal gain: to collect insurance benefits, evade the law, leave work, or simply to find a bed for the night (American Psychiatric Association, 1994). Bertha gained no such outcomes. She avoided nursing her father and certainly caught Breuer's attention for a while, but her symptoms continued and even increased after both these relationships ceased. To forego the daily pleasures of eating, drinking, talking, sleeping regularly, and even moving about in her environment, and to endure instead incarceration and the threat of treatments with electricity, drugs, and cold baths, as well as surgery, Bertha surely was experiencing a psychological problem of some sort. Amid these stressful, restrictive circumstances, the idea of pervasive malingering gains little significant support.

Moreover, diagnosing mental disorder across cultures and centuries becomes a dubious goal. Symptoms from one time or place cannot be readily interpreted from a different perspective. Legal, institutional, and economic conditions influence diagnoses; even fads may play a role. Seeking a correct diagnosis for someone living years ago in a foreign country is almost impossible. Fortunately, biomedical treatment can be implemented even without a clear diagnosis.

SAGE Books

Page 21 of 27 SAGE Books - Psychology: Six Perspectives

Guidelines for Treatment

Using information from published research, the therapist considers the anticipated effects of administering certain drugs to a particular patient, taking into account the patient's symptoms, age, history, health, genetic background, and a host of other factors (Nies & Spielberg, 1996). Organizing the patient's symptoms into clusters, the therapist begins with the most promising drug for the diagnostic category of the first cluster. If the patient shows improvement, then that tentative diagnosis gains some support. If that drug proves ineffective, the diagnosis remains “uncertain,” and the next most-promising drug is employed. This systematic approach is possible because there is a predictable period between the beginning of treatment and the patient's response to a particular drug (Martorano, 1984). That period may range from a few moments to some weeks, depending on the characteristics of the drug.

Many therapeutic drugs fall into one of three broad categories: antianxiety, antidepressant, or antipsychotic. For Bertha's symptoms, the initial prescription might be a minor tranquilizer, an antianxiety drug designed to diminish tension and sleeplessness. This drug alone probably would not provide a full recovery. It would reduce her symptoms by increasing the action of an inhibiting neurotransmitter. By stimulating a suppressant neurotransmitter, the drug would cause the brain synapses to produce tranquilizing effects, enabling her to participate more effectively in everyday activities, perhaps including other modes of therapy.

The probable side effects would include drowsiness and slightly disrupted thinking. A side effect is an unintended, usually unwanted, outcome of any therapy, such as increased heart rate, fatigue, or dizziness. Many side effects might be called bad effects. One drug might cause a mildly nauseous condition; another might prompt vomiting; still another might induce dizziness, fatigue, mood changes, or even more disruptive conditions.

If the patient benefited from this medication, her progress would be monitored as a single drug user or multi-drug user. As a rule, the single-drug user does not disrupt the treatment. Multi-drug users are more difficult patients, for they consume whatever other drugs may be available for sedative or euphoric effects, complicating the treatment process. Combinations of drugs can create unpredictable outcomes. Bertha's addictive response to morphine in the Bellevue Sanatorium would be a cautionary signal for potential drug abuse (Martorano, 1984).

After using an antianxiety drug for some time, a person may begin to show adaptation or tolerance, which is a decline in response because the person's body has become accustomed to the stimulus—in this case the therapeutic drug. If adaptation occurs, the drug must be administered in larger and larger doses to obtain the desired outcome, thereby increasing the side effects. The therapist must consider these issues in the later stages of drug therapy.

If Bertha's symptoms instead seemed to cluster around depression, the medication would have been directed to this problem. Following the systematic guidelines, the first question here is whether the depression is reactive or endogenous. As suggested already, a reactive depression is a normal but acute response to a traumatic occurrence, such as divorce, bankruptcy, or the death of a parent. A precipitating factor seems clear. The endogenous depression has a broader basis and longer history and is not so obviously triggered by a traumatic event. Its more complex origins have earlier roots.

If Bertha's depression appeared to be reactive—essentially a response to arduous nursing and her father's death—the therapist would undertreat it, prescribing small doses of a mild medication that enabled Bertha to obtain a much-needed rest. With an obvious endogenous depression, she would be administered a standard antidepressant drug, aimed at stimulating interest in the world. It would do so by increasing the presence of serotonin and certain other neurotransmitters in the synaptic spaces.

Bertha suffered from a traumatic event, but endogenous depression would become the focus of this treatment. This condition had been building for several years—an accumulation of anger, frustration, and feelings of not being truly loved emerging from the obviously preferential treatment given her brother Wilhelm. The therapist would have several choices of medication for endogenous depression, but the lag time for effectiveness might be several days or weeks.

SAGE Books

Page 22 of 27 SAGE Books - Psychology: Six Perspectives

In a broader sense, her diverse symptoms might suggest a psychotic disorder. In fact, Breuer at one point referred to the symptoms of psychosis, noting her hallucinations about black snakes and death's heads. If she were administered an antipsychotic drug, used to eliminate hallucinations and disturbed thinking, alleviation of those symptoms would suggest an underlying psychosis, requiring a closely monitored medication.

Many of the most effective antipsychotic drugs diminish the bizarre symptoms by blocking the presence of dopamine in brain synapses. A prominent neurotransmitter, dopamine appears to play a key role in certain psychotic disorders (Davis, Kahn, & Ko, 1991). But antipsychotic drugs can produce highly disagreeable side effects. In addition, they may fail to alleviate many deficits in schizophrenia: diminished speech, thought, and motivation.

But Bertha experienced a combination of symptoms, and here the guidelines become less systematic. If the antidepressant drug did not prove effective, the therapist would be confronted with several questions. Should a larger dosage be administered? Should a different drug be used? Does she need an antidepressant plus another medication for the other symptoms? Fortunately, drugs today contain combined ingredients, eliminating the lag time that would occur in successive treatments with different medications. Moreover, some medications can treat more than one condition.

Considering Bertha's diverse symptoms, a modern therapist certainly would administer a set of drugs. But multiple medications raise another pair of problems: patient compliance and drug interactions. Always an issue, patient compliance becomes increasingly difficult with multiple medications that may require different doses and different schedules. The treatment plan may become so intricate that the patient does not adhere to it, making the therapy worthless (Kramer, 2000). The second problem, drug interactions, occurs when medications consumed by the same patient alter the effect of one another. The combination produces an increased or decreased effect or a totally unexpected outcome, not predicted on the basis of any one drug alone. For example, two drugs may not produce significant side effects when only one or the other is used. When a patient consumes both in the same medically effective time frame, the drugs may generate a marked skin rash, tremor, or other undesirable conditions. Drug therapy requires caution, for it may be prescribed with too little regard for side effects, interaction effects, and long-term consequences. These detrimental outcomes can be cumulative.

Moreover, drugs do not necessarily solve the problem. Often, they simply remove the major symptoms. For this reason, drug therapy is used in conjunction with other treatments, commonly dialogues with a counselor or therapist, along with healthful programs of exercise, nutrition, and rest. In this combined therapy, using two or more treatment methods, each serves a different purpose. The medication provides stability; the dialogues provide an opportunity for exploring possible underlying problems. These patient-therapist dialogues are known as psychotherapy, which loosely includes almost any nonmedical conversation aimed at providing assistance. This combined therapy has been found beneficial with some disorders, but not with others.

Modern drug therapy, when used alone, raises still another caution—the absence of sustained contact with a caring therapist. Breuer's regular presence was essential to Bertha and highly unusual. Modern drug treatment tends to be brief and impersonal. A treatment session may last no more than 15 minutes, time enough for the therapist to check some physiological signs and ask a few questions about symptoms and side effects (Martorano, 1984). Even if the therapist demonstrates concern, the patient may feel overlooked and subsequently may fail to comply with the treatment plan. Without a strong patient-therapist alliance, any treatment may become ineffective or ignored by the patient.

Modern medications can provide fast, initial relief. If they had been available, they would have suppressed some of Bertha's symptoms. But they would not have solved all her problems or even enabled her to begin a complementary psychotherapy—because none existed at the time. She became a pioneer in that regard, showing the way through her “chimney sweeping.”

Instead, biomedical therapy served Bertha poorly. Without any knowledge of neurons and neurotransmitters, Breuer and others who administered the drugs could not even imagine the blocking and flooding they created in the synaptic connections. Used to diminish her pain or put her to sleep, they sustained her addiction, and they produced powerful withdrawal symptoms. For the overdoses he administered, Breuer today certainly

SAGE Books

Page 23 of 27 SAGE Books - Psychology: Six Perspectives

would become liable in a malpractice suit.

But he should be judged by the standards of his day. He used what was available and acceptable at the time. Since then, biological psychology has discovered many new ways of answering old questions—and pursuing the further questions those answers raise. And future investigators will do so too. That is the nature of science. Each generation stands on the shoulders of its predecessors.

Commentary and Critique

Knowledge of brain-behavior relationships takes a vital place in our efforts to understand human behavior and to improve the conditions of life. Biological psychology has made impressive progress toward these goals. But like most of our human-made world, all perspectives and research methods involve assets and drawbacks. In closing this chapter, and those on the other perspectives, it becomes essential to recognize the major limitations of each perspective.

All the perspectives seek findings that are accurate and comprehensive, but they cannot have both at once in any large measure. To ensure accuracy, some address relatively narrow questions or small units of behavior. Sacrificing some degree of certainty in favor of greater breadth, others concentrate on more diffuse questions or larger units of behavior. This dilemma about precision and breadth—the size of the phenomenon to be studied—extends throughout science.

Given that all biological systems are composed of separate but related organs, and that each system is connected to other systems with their own organs, investigators in biological psychology can study the body as a whole or focus on its separate parts. No one investigation can possibly address every aspect of any research question. A choice must be made. And in biological psychology, one choice, called reductionism, has become more popular than the other, variously known as nonreductionism or holism.

The premise in reductionism is that complex phenomena are best understood by examining their basic parts. The focus is on elementary properties, meaning the most basic, irreducible parts of something. The study of a complex whole is reduced to separate studies of elementary properties because investigating a smaller sphere offers less chance for error than addressing a larger one. The parts are not necessarily simple, but they are more limited than the whole. Scientists commonly tend toward reductionism, investigating narrowly defined topics and hypotheses, gaining precision in exchange for more comprehensive investigations.

In fact, science employs reductionism in two ways: within the same field and to another field. When a question is reduced within the same field, this reductionism might be called narrowness, for it reduces the range of inquiry. In this sense, all perspectives become reductionistic; none can take all factors into account.

Biological psychology illustrates this form of reductionism, investigating narrowly defined hypotheses about the behavioral details of anatomy and physiology. Investigations of the body that do not include a behavioral or experiential element fall outside the boundaries of biological psychology. The other psychological perspectives narrow the scope of inquiry differently. Psychoanalysis focuses on unconscious processes, and behaviorism studies environmental factors. Humanistic and cognitive psychology restrict inquiry largely to mental life in one form or another, and evolutionary psychology examines the implications of our common genetic background.

So much for reductionism as a form of narrowness within the field. It occurs everywhere in varying degrees. And it has been essential to progress in modern science.

Reductionism also occurs when a question is examined in the more fundamental units of a lower-level science, which is its most common meaning. Among all the psychological perspectives, biological psychology, for obvious reasons, most frequently employs this form of reductionism. Here the study of aggression, personality, sexuality, or another psychological phenomenon is reduced to brain physiology, or further reduced to brain chemistry or, once again, to genetics or protein synthesis. This process—moving from behavior, to brain physiology, to brain chemistry, genetics, and so forth—is much like taking a photograph and enlarging it again and again, each time bringing some small part of the picture into sharper and sharper focus (Holzman,

SAGE Books

Page 24 of 27 SAGE Books - Psychology: Six Perspectives

2000). A particular detail becomes increasingly available and thereby can be measured with greater accuracy. But the overall image fades. The periphery of the scene becomes blurry or lost completely.

Reductionism to a lower level does not mean that the question no longer exists at the upper level. It remains, but a narrow part of that question is examined in a more basic form. The question also can be “expanded” back into its original form and studied at that higher level. Especially in biological research, questions often become reduced, not expanded, with the aim of achieving greater precision (Figure 3.3).

Figure 3.3 Reductionism in Behavioral Studies. The fields of inquiry might be extended downward to chemistry and physics or upward toward sociology. They depict a continuum of reductionism, not a series of discrete steps. As illustrated, investigations of memory, for example, occur at various levels of analysis. The open arrowheads indicate the lesser tendency for upward movement, away from reductionism and toward holism (Wahlsten, 2000)

But this reductionistic strategy, however compelling, should not lead psychology away from its fundamental goal of understanding human behavior amid the events of everyday life. This larger goal remains. For example, psychoanalysis aims for a grand view of humanity, addressing such broad questions as lifestyle, the unconscious, identity, and sense of self. Like the humanistic perspective, it generally studies the individual interacting in an everyday setting, not in a controlled laboratory environment. This broader aim goes a long way toward capturing the public interest—and poses problems for rigorous science.

Reductionism has played a massive, indispensable role in the advancement of science. As any field matures, it moves not only toward specialization but also toward reductionism, which offers precision and control. But reductionism alone, especially to a more basic science, does not necessarily provide adequate explanations of complex phenomena. Water is composed of two basic elements, hydrogen and oxygen, the former capable of burning, the latter essential for burning. But these basic elements are combined in such a way that water possesses neither characteristic. Similarly, an understanding of the electricity in the circuits of the computer does not explain the machine's problem-solving capacities.

SAGE Books

Page 25 of 27 SAGE Books - Psychology: Six Perspectives

The success of biological psychology's narrowly focused studies of living brains is beyond question. But the extent to which psychological phenomena can be described in neurological terms remains uncertain. At some point the psychological event disappears when examined only in terms of its biological underpinnings.

The reductionist fallacy states that phenomena are not always best understood in terms of their smaller, more basic parts. A more complete understanding of the human personality, consciousness, and other psychological characteristics will require something else too. Traditional reductionism does not eliminate the need for insights from other methods and other perspectives at other levels of inquiry (Cacioppo, Berntsen, & Crites, 1996).

Nevertheless, psychologists universally acknowledge the essential contributions from reductionism, especially in understanding the human nervous system. These restricted, precise investigations have formed an indispensable pathway to our ever-increasing knowledge of human behavior and experience.

Summary

Origins of Biological Psychology

In the human body, the nervous system serves as the basic communications network, receiving incoming information, mediating that information, and generating outgoing responses. Modularity doctrine states that any complex behavior requires the integrated contributions of various specific brain mechanisms, or modules. As the second communications network, the endocrine system plays a role in body maintenance, growth, and energy.

Key Terms: biological psychology, network theory, neuron theory, neuron, principle of mass action, phrenology, modularity doctrine, brain plasticity, brain imaging techniques

The Nervous System

The human nervous system provides flexibility of behavior through its billions of neurons in the brain, which are especially numerous relative to the size of the body, and through its billions of synapses, which are the spaces between neurons. In these synapses, neurotransmitter substances excite or inhibit connections with countless adjacent neurons, conducting impulses into, away from, and within the central nervous system, thereby enabling human beings to engage in a wide range of reactions.

Key Terms: nervous system, central nervous system, peripheral nervous system, somatic nervous system, autonomic nervous system, synapse, cell body, dendrite, axon, all-or-none law, action potential, sensory neuron, motor neuron, interneuron, neurotransmitter, drug-induced state, addiction

Organization of the Brain

The human brain can be viewed in three evolutionary parts: the hindbrain, mediating basic biological functions; the small midbrain, serving linkage functions; and the large forebrain, dominating in thought, memory, language, and other higher-level processes. The forebrain, in turn, can be considered in three levels: at the lower level, the hypothalamus, which plays a vital role in body maintenance; at the upper level, the cerebral cortex, which maintains contact with the environment; and in between them, the limbic system, which serves as a bridge and plays a vital role in emotion and memory.

Key Terms: cerebellum, reticular formation, thalamus, hypothalamus, endocrine system, hormones, cerebral cortex, limbic system, amygdala, hippocampus

The Cerebral Cortex

The gray outer covering of the brain, called the cerebral cortex, becomes critical in human mental processes. Its primary sensory areas and primary motor areas play fundamental roles in receiving information and responding to it, respectively. Its association areas serve an integrative function, combining the effects of

SAGE Books

Page 26 of 27 SAGE Books - Psychology: Six Perspectives

earlier experiences already stored in the brain with incoming and outgoing information. Modularity doctrine emphasizes that any complex human activity requires an intricate, simultaneous coordination of different brain units, or modules, in various parts of the brain.

Key Terms: hemispheric specialization, corpus callosum, primary sensory areas, primary motor areas, association areas, brain localization

Modern Biomedical Therapy

Drug therapy, the most common biomedical treatment today, follows a set of systematic yet trial-and-error guidelines for identifying the most appropriate medication for a certain individual with a specific set of problems. The aim is to stabilize the patient and, ideally, to eliminate the need for medication, partly by encouraging patients to engage in additional therapeutic efforts, such as expressive therapy and programs of exercise, nutrition, and relaxation.

Key Terms: biomedical therapy, antianxiety drug, side effect, adaptation, antidepressant drug, antipsychotic drug

Commentary and Critique

Investigators employ reductionism in research by narrowing the range of inquiry and by examining a question in terms of the units of a lower-level science. According to this critique of biological psychology, understanding the operation of the billions of neurons in the human brain will not by itself explain the intricacies of human experience from one moment to another. Nevertheless, reductionism has been essential in the advancement of biological psychology.

Key Terms: reductionism, elementary properties, reductionist fallacy

Critical Thinking

In order to advance our knowledge of the nervous system, you have been invited to participate in research requiring the sacrifice of part of your brain. You are not suicidal. Indicate your reasons for offering one of these structures: the thalamus or corpus callosum or limbic system. Then state your rationale for keeping the others. Explain the concept of modularity doctrine in brain function by using a metaphor. Think about an orchestra presenting a concert, and then offer a different metaphor. Consider research on depression. Outline a likely reductionistic sequence beginning with culture and proceeding to the synapse. Then describe the reductionist fallacy.

• biological psychology • brain • drugs • nervous system • central nervous system • neurons • hypothalamus • neurotransmitters • psychology • reductionism

http://dx.doi.org/10.4135/9781452224862.n3

SAGE Books

Page 27 of 27 SAGE Books - Psychology: Six Perspectives

https://dx.doi.org/10.4135/9781452224862.n3

SAGE Books
Psychology: Six Perspectives

Biological Psychology

Biological Psychology
Origins of Biological Psychology
Wundt and Physiology
Changing Views of the Brain
Basic Research Methods
The Nervous System
Interlocking Systems
Structure of Neurons
Figure 3.1 A Neuron and Synapse. The neuron's major parts include its dendrites, cell body, and axon. The arrow indicates the direction of the nerve impulse. At the synapse, neurotransmitter substances play a central role in the flexibility of human behavior, stimulating extensive neurochemical activities among the fibers of adjacent neurons
Neurotransmitters and Drugs
Organization of the Brain
Maintaining Internal Conditions
Responding to External Events
The Limbic Connection
Figure 3.2 Brain Structures and Fear Reactions. Shown in cross-section from the front, the brain is largely bilateral, including the almond-shaped amygdala and the hippocampus, resembling the tail of a seahorse. The dotted line indicates the shorter route from the thalamus to the amygdala, providing a quick response to fear. The dashed line represents the longer thalamic route to the cerebral cortex, providing a delayed but more thorough assessment
The Cerebral Cortex
Primary and Association Areas
Concept of Localization
Modern Biomedical Therapy
Assessment and Diagnosis
Guidelines for Treatment
Commentary and Critique
Figure 3.3 Reductionism in Behavioral Studies. The fields of inquiry might be extended downward to chemistry and physics or upward toward sociology. They depict a continuum of reductionism, not a series of discrete steps. As illustrated, investigations of memory, for example, occur at various levels of analysis. The open arrowheads indicate the lesser tendency for upward movement, away from reductionism and toward holism (Wahlsten, 2000)
Summary
Critical Thinking