MODULE 1

GERMANY AND HELMHOLTZ

Experimental psychology emerged in the nineteenth century as an innovation reflecting German science of the times. This new psychology was more than just a new subject matter; it was the product of new methods. Many German philosophers and scientists participated in this new movement. Men such as Helmholtz, Fechner, Wundt, Ebbinghaus, Stumpf and others devised dramatic new ways to explore prosaic ideas. We should note, however, that new methods in themselves are not necessarily good. Some persons advocate innovative approaches on the mistaken belief that innovation in itself produces lasting dramatic changes. Progress does result from innovation, to be sure; but innovation in itself does not necessarily produce progress. Innovation may be a necessary condition of progress but it is not always a sufficient condition.

Philosophers had continued during the eighteenth and nineteenth centuries to explore and define consciousness. One of the issues was whether Kant was right, that some aspects of the mind were a priori givens, that the ten categories of understanding and the two intuitions of time and space were innate. If Kant was right, then newborn infants and animals should perceive depth immediately upon opening their eyes. They should behave differently in deep as compared with shallow environments.

This issue, of whether space and time were learned or innate, was hotly debated in the later part of the nineteenth century. The debate carried on into the twentieth century. The British empiricists (Locke, Berkeley, Hume) and their followers (Condillac, Herbart, Lotze, and Wundt) maintained that space perception was empirical or genetic. (The term genetic did not mean innate, but rather evolving or developing).

For many, the problem of space seemed to depend upon the concept of time. The distance between two points had always been defined as the difference in time for travel. The time to travel one route rather than another defined the space. The same principal holds true for visual perception. The eye takes a longer time to follow a larger contour than to follow a smaller one. Further, it takes more time to examine a complicated pattern than a simple pattern. Ribot suggests that time is the crucial variable; time is the key to all the other senses. Ribot, paraphrasing Bain, says that length of a space is based on the notion of the length in time and that this is true for distance, direction, and form (Ribot, 1886, p. 108).

If depth perception is learned and not inherited, then one must clearly specify the exact nature of those factors which are learned. It must be clear which sensations are present at age six years but not present at age two hours. If depth is learned, then some new factor must be added to the mind which creates this additional dimension of sensation. Wundt was a follower of J. S. Mill, and suggested that depth perception was a synthesis or a kind of mental chemistry. Depth perception resulted from the fusion of two elements -- l) movement and 2) local signs. As in chemistry, the mixing of hydrogen and oxygen produces water, so in Wundtian psychology the mental mixing of movement and local signs produced depth perception (Ribot, 1886, p. 101). Ribot claimed that tactile sensations of space resulted from the mixing of three elements -- movement, resistance, and weight.

This nature-nurture debate in the nineteenth century became even more general, and included the question of whether mind itself was innate, i.e. -- whether the quality of mind, not the contents of the mind, was innate or learned. The issue revolved around whether man was a special creation and different from other animals, as Mueller and the vitalists believed, or a natural phenomenon and thereby molded by the common laws of nature, as Helmholtz and others proposed. Darwin demonstrated that man emerged in a remarkable way as a product of his genetic past. Certain behaviors such as instincts or emotions were transmitted from one generation to another and up the phylogenetic scale from one species to another. On the other hand, man was also a product of his environment, shaped by continual adaptation and adjustment in the attempt to survive.

After Darwin, then, the issue shifted from nature-nurture to structure-function. The original search by Wundt for the contents of the mind and the manner of their combinations into complex forms of perception changed to a search for the process and function of the mind through adaptation and adjustment. Ebbinghaus was therefore to investigate how learning and memory were necessary in adjustment; Freud explored how the mind might lead to maladjustment; and the American functionalists turned everything inside out in an attempt to study adaptation as the single and paramount phenomenon.

Regardless of issues, philosophers began to seek objective evidence -- either structures and contents, as the Scottish faculty psychologists had suggested, or that the mind possessed processes and modes of shaping and organizing the world. More than armchair philosophizing was required. German philosophers and physiologists of the nineteenth century attempted to apply physiological methods of experimentation to philosophical questions of the times. The German penchant for experimentation, observation, and technology bore heavily upon philosophical questions unanswered for centuries.

Questions regarding the nature and function of the mind had long been debated but never subjected to empirical investigation until a hundred years ago. From the time of classical Greece in 350 B.C., through the middle ages and then the controversy among British empiricists and German philosophers during the seventeenth, eighteenth, and nineteenth centuries, deductive argument was the basis for theories of the mind. That these questions were subjected to empirical examination is thus a singular event. And the event took place primarily in German universities. The origin and early development of contemporary psychology as a German phenomenon is understandable when one looks at German culture and education of the times.

We first examine the German culture which provided the climate for the new science of psychology. Then we look at Helmholtz, Fechner, and Wundt, who contributed to the founding of that science.

GERMANY EMERGES

The importance of Germany as the source of much of psychology will become evident later when we examine major theoretical systems. Along with experimental methods, Germany has been the root of Gestalt, psychoanalytic, and phenomenological psychology -- the major theoretical backgrounds of psychology with the exception of behaviorism. The applied fields of psychology (testing, educational, industrial, and others) are primarily Anglo-American inventions.

The emergence in Germany of experimental research psychology can be better understood within the context of German culture, particularly the drive for unification, the extensive educational system, and the competition with England for basic knowledge.

Psychology emerged in Germany at the same time that Germany itself was emerging from a collection of small states. A German Confederation of Prussia, Austria, and a vast system of German city-states was formed at the time of the Congress of Vienna in 1815, to provide a check against further advances by France and possible invasion by Russia. After the Prussian War in 1866, however, the Confederation was replaced, under the direction of Prussia's Bismarck, by a new North German confederation of 22 German states north of the Main River, which gradually became more powerful, and ywas potent until the end of the first world war. Following the Franco-Prussian war in 1871, the southern German states, Munich, Stuttgart, and other German cities declared in favor of the North German stateg. The German Empire, under William I as Emperor, was thus formed.

Competition with England.

Germany stood supreme as a prime example of western science and culture during the latter part of the nineteenth century. Its education was more advanced. But its technology was more behind.

In England, however, technological advances were clearly a part of English pride. Although there was no compulsory public education in England until 1870, and education was reserved primarily for the leisure classes who could afford time and money on sedentary and impractical matters, the compelling needs for technological advances within England would not wait. And on the basis of these practical demands, English technology thrived.

The British Empire was one of mankind's greatest. It covered the four corners of the known world. Vast amounts of effort and skill were required for the maintainence and development of these lands. Missionaries were sent out as educators and as aids to the natives. Specialists, accompanying the missionaries, studied and developed the new lands. Philologists learned strange new languages to better communicate with the natives. Naturalists studied the flora and fauna. Geologists analyzed rock and earth formations to better develop land, construct buildings, and perform engineering feats. Chemists studied natural resources and new raw materials. Surveyors plotted new parcels of land. These skilled researchers and technicians assisted in building up the empire and succeeded, thereby, in returning to English culture vast amounts of new knowledge about newly discovered geographical regions and unexplored frontiers of nature. Much of this knowledge was specific and descriptive, however, and had practical, technological uses, rather than being knowledge for knowledge's sake.

At mid-century, England proudly displayed its technological prowess to the rest of Europe through its Great Exhibition of 1851. Prince Albert, Victoria's consort, had devised the exhibition as an ingenious way to display this new technology to the civilized world. He proposed to mount an international exposition and to invite the leading countries of the world. A sparkling new glass dome building, an engineering masterpiece in itself, was specially designed and efficiently constructed in Kensington to house the exhibits. England's show clearly demonstrated that an industrial revolution, technological explosion, and cultural advancement could occur in the absence of basic knowledge, scientific principles, research laboratories, or graduate schools.

Germany was stunned. How was it possible to borrow or beg the knowledge which lay behind the accomplishments of this great exhibition? England was unwilling, and understandably so, to share those vast amounts of information which she had accumulated. Willing or not, there was really no immediate information available. There were only skills, developed over long periods of time. Generalized knowledge, such as one finds produced in the great universities, was limited. Of the research laboratories, there were none.

How, then, was Germany to catch up? The only really intelligent course of action was to invest heavily in basic research, ideas, and experiments. This she did. The ensuing competition between Germany and England in the latter part of the nineteenth century parallels similar competition between Russia and the United States during the middle part of the twentieth century, when the United States launched extensive educational programs and basic research to maintain preeminence in scientific fields against the advancing Russian space technology.

German Education.

More than any other country, Germany has supported public education. This provided, naturally, a receptive climate for the development of graduate education and research activity. In the nineteenth century, energetic and attractive educational programs in the basic sciences -- physics, chemistry, physiology, and mathematics-- were expanded. Germany had long supported a compulsory educational program before it was ever introduced in England.

The encouragement for advanced graduate training came from the fact that there were a large number of universities in Germany established in the papal or city states between the fifteenth and eighteenth centuries. In 1876 there were more than a dozen universities numbering hundreds of students. See a contemporary map of Germany The universities at Berlin and Leibzig combined, had over 6,000 students and 1,350 teachers. Since numerous schools were located on limited amounts of land, the small distances among these schools facilitated the exchange of both students and faculty, to the mutual advantage of both. Transfer from one school to the next was relatively easy and German students could study with eminent scholars of similar interests. The large number of German schools provided active competition and a healthy climate for scientific programs. Local funds and national pride supported the burgeoning academic programs which brough

t world recognition to a few schools in particular and to most of German higher education in general.

England introduced compulsory education somewhat later than Germany. Her public schools and colleges were fewer in number and catered to the elite. In fact, there were only two colleges of any note -- Oxford and Cambridge -- and science was not introduced into the former until a relatively recent date. Because of the long tradition of each school and the strong ties of loyalty which they possessed, there was little movement among the schools, and the curriculum tended to remain static.

In the German schools, large research laboratories were attached to the graduate schools and directed by eminent faculty members. Graduate students assisted. In addition to research activities, graduate assistants prepared laboratory demonstrations for the undergraduate lectures. Here, then, was a melding of a dual educational program. Undergraduate students listened to large lectures and observed practical demonstrations of the professor's ideas prepared by graduate students. A more practical example of academic participation and educational sharing cannot be found. Fifty years later, American psychologists provided empirical support to what Germany was practicing-- namely, that one learns best by activity and participation.

Although all of this educational activity did not make German education supreme, it did attract attention and scholars flocked from around the world to study with the European greats at the university centers along the Rhine, the Necker, and the Main. German scientists turned the laboratories and the lecture halls into showplaces. The demonstration lecture sometimes became an end in itself. Liebig, the founder of organic chemistry (or at least founder of the first chemistry laboratory), placed over his laboratory door in Liessen a sign which read, "God has ordained all things by measure, number, and weight." Another laboratory, built at Berlin, was called the "temple of physics And at Leipzig, the lecture hall was called the "physiological theatre." These terms are not totally inappropriate; laboratory does mean, after all, "sanctuary."

In many German universities the lectures were informative, colorful, and dramatic events. the adjacent laboratories to the lecture hall contained elaborate contrivances and gadgets where assistants spent long hours preparing visual aids. Sometimes the professor would need to be prompted in his demonstration by one of the assistants. The intricacies of the procedures must have been something to behold. Large wall charts could be dispensed from every conceivable angle and displayed gigantic drawings of intricate detail. There one might find immense models of the eyes and ears; there also were lenses, mirrors, and various brass instruments on the lecture table. Animals of every description, used to demonstrate some physiological principle like the circulation of blood from the heart through the arteries, were wheeled into the lecture room and prepared in front of the students. At one point, a horse, brought into the classroom, was sacrificed there on the spot in order to demonstrate the functioning of heart action!

In many German universities the lectures were informative, colorful, and dramatic events. the adjacent laboratories to the lecture hall contained elaborate contrivances and gadgets where assistants spent long hours preparing visual aids. Sometimes the professor would need to be prompted in his demonstration by one of the assistants. The intricacies of the procedures must have been something to behold. Large wall charts could be dispensed from every conceivable angle and displayed gigantic drawings of intricate detail. There one might find immense models of the eyes and ears; there also were lenses, mirrors, and various brass instruments on the lecture table. Animals of every description, used to demonstrate some physiological principle like the circulation of blood from the heart through the arteries, were wheeled into the lecture room and prepared in front of the students. At one point, a horse, brought into the classroom, was sacrificed there on the spot in order to demonstrate the functioning of heart action!

By comparison, the laboratories in the United States were memorably sterile. They contained only the simplest kinds of equipment. This is best illustrated by an anecdote about the great American naturalist, Louis Agassiz, who was the inspiration for if not the mentor of most of the early American scientists. With few material advantages but vast reserves of personal insight and energy, he founded a geological laboratory on Penikese Island in the southern part of Buzzards Bay in Massachusetts, just north of Cuttyhunk Island not far fro Martha's Vineyard. There was pitiful little apparatus in Agassiz's laboratory, save a blackboard and chalk. When the school opened, Agassiz said to his students, and one wonders whether half humorously, "I do not feel like praying before you. I do not feel like asking any of you to pray, but let us spend a few moments in silent prayer (Hall, 1912, p. 250)."

In addition to their advanced technology, the German universities possessed an unusual degree of academic freedom. Almost any subject could be taught in the classroom: materialistic metaphysics, Darwinian evolutionary theory, even the infallibility of the Pope (Hall, 1912, p. 273). By contrast, however, England imposed greater restrictions both on classroom language and on criteria used in hiring and retaining faculty.

It is small wonder that scholars and researchers from all over the world sought an education at the impressive German universities, where they became acquainted with the methods and theories of distinguished scholars. When these scholars of the last quarter of the nineteenth century reappeared again in New York, Cambridge, Baltimore, and elsewhere, they transmitted the new German tradition to their admiring American colleagues. The system of scientific higher education in the United States thus arose, and has remained virtually unchanged to the present day. There were and are adjacent to faculty offices, teaching centers, and small coteries of graduate students attached to and identified with the institution and the research instructor.

HERMANN HELMHOLTZ (1821-1894): Exemplar of German Science

Background.

Helmholtz was born during a decade of monumental advancement in physiology. These advances occurred in England and in France but mostly and eventually in the German laboratories and universities noted for dramatic and important contributions to new knowledge and education. In the end Helmholtz's own contributions surpassed those of any other person.

Forty years after the death of Frederick the Great, Helmholtz was born, in 1821. He was reared in the city. As a young adult, Helmholtz was eligible for a program sponsored by the Berlin Institute which offered to train young men as surgeons in exchange for service in the Army upon completion of their medical training. Helmholtz took advantage of this opportunity to obtain free medical training and a medical degree. After the Army, Helmholtz served as professor of physiology at Konigsberg, Bonn, and finally in 1858 at Heidelberg. While at Heidelberg, Helmholtz enlisted one of his students, Wilhelm Wundt, to assist him in physiology and help tutor and examine candidates for the medical degrees. Wundt lacked some of the mathematical sophistication possessed by other students and it is speculated that Helmholtz did not retain him as a close assistant, in spite of a tenure of some seven or eight years.

Medical practice at that time was primitive. At best, it was half science; at worst, half folklore. Most physicians were skeptical of the recent advances in physiology. They looked with disdain on the brass instruments used in diagnosis. Some diagnostic techniques were even considered sacriligeous, if not unethical. G. S. Hall, said: ...old doctors shook their heads; they said auscultation (listening to the sounds produced in the body) and percussion (striking one finger with another so as to detect from the sound produced the physical state of the body beneath) were too coarsely mechanial means of investigation, disparaging to the dignity of the patient and unnecessary for a physician with a clear mental insight, while ophthalmoscopes, measurements of temperature, et., were decidedly not in good taste (Hall, 1912, p. 274).

The medical men of the nineteenth century would undoubtedly view with disdain the use today of high speed computers to collect and analyze medical information.

Helmholtz rejected a belief in the a priori nature of space and geometrical forms as advocated by Kant. Agreeing with Zollner, Helmholtz argued that one's geometry depended upon one's experiences; if one lived in a curved universe (Zollner thought everything was curved, anyhow), the prevailing notion of space would be that of curved surfaces. This was a powerful argument against Kant's belief in innate forms.

If Kant was right by saying that all sensations come in a priori space and time forms, then one must first understand both space and time. This meant that if the mind truly organizes experiences into time dimensions, then the mind must be able to detect the passage of time and to discriminate between different periods of time. If the mind organizes by time and if it judges time then the mind must be temporal. A temporal mind was not consistent with the notion of immortality -- the belief that the mind was timeless and that its influence upon the world was instantaneous, immediate, and taking no time. The immortal mind was about to be demolished by Helmholtz and nineteenth century science.

Helmholtz brought time and thereby mind to matter. He demonstrated through measurements on the sensory and motor nerves that impulses travel at a rate of between 160 to 200 feet per second. This discovery introduced a rash of studies on reaction times, association times, judgment times, and various other time measurements. Even Jung's association tests, based on clinical rather than laboratory data, were constructed on a time dimension. The Wechsler tests developed in the 1930's and still prominent today were based on time. The Babcock tests of mental efficiency showed that personality disturbances reflected differential time patterns for mental functioning. Today, the controversial work of Arthur Jensen on genetic differences in intelligence utilizes experimental studies of reaction time differences to support his thesis.

Specific Energies.

In 1826, at the University of Berlin, just fifteen miles from Helmholtz's birthplace, his mentor, Johannes Mueller had proposed the doctrine of the specific energies of nerves. This theory suggested that different sense modalities (or differences in light and sound, e.g.) could be explained as either different energies transmitted along different neural routes, or different nerves which ended in different places in the brain. In either case, psychological phenomena were tied to bodily differences. Helmholtz's discovery of the speed of neural impulses and Mueller's theory of specific nerve energies were both part of the nineteenth century thinking that the mind had at least physical correlates if not physical substance.

The immediate background for this was the discovery, while Helmholtz was still an infant, by Bell in England and Magendie in France that sensory nerve routes to and from the spinal cord were anatomically different from motor nerve routes. They concluded, therefore, that different nerves have different functions. Johannes Mueller then proposed his specific energies of nerve doctrine, a point of view which Helmholtz later adopted and extended to differences within sense modalities. Mueller, a relatively young man when he proposed his doctrine, had obtained his M.D. degree the same year that Fechner did, which was a year after Helmholtz was born, and became the leading physiologist in all of Europe.

Helmholtz was significantly influenced by Mueller's principle of the specific energies of nerves which he not only accepted but extended to explain vision and audition. Mueller said that sight and sound were experienced as different because special energies were transported by special nerves for discriminably different senses. Light differed from other sensations such as sound, touch, smell, and taste because the energies which traveled through the optic nerve were different from those which traveled through the other nerves. Stimulation of a particular nerve, by whatever means, would create a characteristic sensation. Why then was it not possible, thought Helmholtz, that the differences within a sense modality (.e.g., high and low pitched notes) could be explained by reference to differences in the nerves or the energies which the nerves carried? Mueller had come close to implying different elements, just as chemistry had struggled to find the basic physical elements (air, fire, water) in the physical world. Galileo and then Locke had a similar idea in mind when they proposed the notion of primary qualities. Mueller, Helmholtz, and then Wundt traveled the same route in their search for elements in the physiology and psychology of sensation. We know now that it is not the qualities in the nerves (for all impulses are the same) but rather where the nerves terminate in the brain.

There was a second way in which Mueller's theories were analogous to chemistry. Just as chemistry recognized the capacity of one element to become transformed into another, so Mueller thought that physiological energies could be transformed into other energies. It was almost a case of returning again to the philosopher's stone. It is possible to transform one kind of energy into another if you have the right route or the correct combination of elements.

Mueller's transformation problem may well have been the basis for Helmholtz's notion about he conservation of energy. If one form of energy is transmitted to the organism and is then transformed into something like sensation, like the experience of light or sound, and if these characteristic sensations occur only because of the transmitted energy, then a special relationship between the two kinds of energies must exist. It appears to be just one step from the idea that physical energy transforms into sensation to the notion that energy is interchangeable and that there is a "correlation of all of the physical forces of nature (Murray, 1925, p. 84)."

Reductionism and the Helmholtz School of Medicine.

Helmholtz and other students of Johannes Mueller at the University of Berlin respected the nineteenth century master of physiology. But in their eyes Mueller had one weakness -- he promoted the doctrine of vitalism. Mueller believed that there was some life giving principle, such as "vitalism", to explain physiological factors. He maintained that the cause of living matter is in the whole, while the cause for dead matter (or inanimate matter) is in each part (Drysdale, 1874) . This belief that variability is characteristic of the whole turned out to be exactly the same position adopted by the Gestaltists almost a hundred years later.

Since the physical sciences had made remarkable progress on grounds that were metaphysically neutral, Mueller's students hoped that the new physiology could make similar progress. These students formed a group called the Physical Society, known later as the Helmholtz School of Medicine. They tried very hard to divorce physiology from vitalism and to reduce the principles of physiology to those of either physics or chemistry, i.e., to explain physiological phenomenon in physical-chemical terms. (The next step, of course, taken by later psychologists, was to reduce psychology to physiology by explaining mental phenomena in physiological terms). In fact, they vowed to explain physiological phenomenon only in "physical-chemical" terms . It was this pledge, probably more than any other thing, which helped to bring about two important events -- the unity of science movement and the law of the conservation of energy.

The unity of science movement, a belief that all sciences have some generally common core, quickly gathered recruits who believed that one science could explain a second, and a second explain a third. This implied a logical link, a tight conceptual relationship, among all the sciences. Such a close interrelationship among the sciences, as assumed in the unity of science movement, does not demand or even suggest a determinism. The actual results, however, were different. The implication emerged that physical phenomena cause, create, or account for physiological or psychological events. A reductionism resulted where the explanation of phenomena in one field of science was "reduced" to concepts in another field of science. Such a shift in concepts (e.g., increased water pressure is explained by an increased movement of molecules) as a way of explaining a phenomenon implied a causative agent or a determining factor. Thus, reductionism, one kind of determinism, arose to replace vitalism, another kind of determinism.

Four persons identified with the unity of science school indirectly had considerable impact upon contemporary psychology. These men, Helmholtz, duBois-Reymond, Brucke, and Carl Ludwig, in turn influenced three main leaders of psychology -- Wundt, Freud, and Pavlov -- persons identified with psychological materialistic bias, and the subject of attack by humanistic psychology. Pavlov was a student of Carl Ludwig. Freud studied under Brucke and worked in his laboratory. Wundt was a student at the University of Berlin and was influenced by duBois-Reymond. He was also an assistant for two years under Helmholtz, director of the Physiological Laboratory at Leipzig. As an assistant to Helmholtz, Wundt tutored medical students in preparing for their medical exams. Although there was limited contact between these two men, Helmholtz's influence on Wundt was undoubtedly strong.

The impact of the Helmholtz school is obvious. Wundt christened his new psychology a "physiological psychology." One constant criticism of Wundt, Titchenor, and eventually all of experimental psychology was the tendency to be too "reductionistic," too physiological, too attentive to the physical side of man at the exclusion of the humanistic side. This same criticism is leveled against Freud and psychoanalytic psychology -- namely that it is too mechanistic, too materialistic, and too base. Only one major motivational drive in psychoanalysis accounts for psychological phenomena. Freud's psychoanalytic theory is basically reductionistic; psychological phenomena are reduced to physical principles, e.g., libidinal energies emerging from an instinctual id. Behaviorism was also influenced by this mechanistic approach. Pavlov explained conditioning and behaviorism as the product of conditioned instincts or conditioned reflexes. A physical stimulus rather than a human "instinct" was proposed as a prime mover of the organism. These three men, Wundt, Freud, and Pavlov have probably done more to effect the direction of contemporary psychology than all other psychologists put together.

Conservation of Energy.

This leads us to the second contribution of the Physical Society, emergence of the doctrine of the conservation of energy. In a sense, the original principle of transformation of energy got changed to a modern day conservation of energy. In transformation of energy, food is changed to blood which supplies tissue growth. This in turn facilitates sensation or movement. Out of this emerged Helmholtz's notion of the conservation of energy, one of the really signal contributions of the nineteenth century. This discovery was simultaneously made by Sir William Robert Grove, an English physicist, in a lecture on the correlation of physical forces at the London Institution in January, 1842, and published in 1846.

The conservation of energy doctrine stated that there is a constant amount of available energy. No new energy is created and none disappears. This doctrine, similar to the first law of thermodynamics, was also similar to Newton's third law of motion -- for every action there is an equal and opposite reaction. This conservation of energy theory was founded on a mechanical theory of heat. It had been discovered that air under pressure results in heat. In any event, Grove's book and Helmholtz's doctrine led in the nineteenth century to the popularization of such concepts as force, energy, power, action, impulse, impetus, stress, strain, and work. (McKendrick, 1899, p. 48). All of these concepts have emerged in one form or another as parts of major psychological theories.

Because of his work on vision and hearing, published in two large tomes on the subject, Helmholtz became the leading world authority on sight and sound. And his prominence in these two fields was at a time when great technological and engineering advances were being made in these areas -- e.g., the development and popularization of photography, electric lighting, and the invention of the telephone and phonograph -- all in the latter half of the nineteenth century. Helmholtz's contributions to vision and hearing continued to be the authoritative works in physiology down to and including recent years.


Color Theory.

One of the difficult explanations in vision was that of color. In this regard, Helmholtz extended Mueller's specific energies doctrine (explanation of differences between qualities) to an explanation of the variations within a sense modality. If different energies account for a difference between light and sound, then perhaps they also account for a difference within light -- e.g., between one kind and another kind of light experience, like differences in color.

To account for the experience of color, Helmholtz proposed three primary or elementary energies. This became known as the Young-Helmholtz* theory of color vision. These energies were responsive to different wave lengths of light and in turn innervated special neural endings. Newton had demonstrated that white light could be broken up into a color spectrum, and that different colors correlated with different vibrations -- red had few vibrations (or wave lengths), green more vibrations, and blue-violet a high density or high ratio of vibrations (short wave lengths). These different vibrations could be differentiated by the different receptor cells in the retina of the eye. This point of view eventually received experimental support. Different chemical compositions in three different receptors respond differentially to the different wave lengths of light. Work by Charles Michael, reported in the Scientific American (1969, p. 114), suggests that the presence of color vision in the animal depends upon the presence of at least several kinds of bipolar cells. The frog, for example, has two-color vision, green and blue, based on two kinds of cells.

There were problems, however, which Helmholtz's color theory could not adequately explain -- color blindness, color contrast, and after images. Each of these phenomena occur in spite of the fact that no apparent physical stimulus or specific energy for these phenomena are present. The color blind person generally cannot discriminate between red or green and yet is able to see yellow. Under the Helmholtz theory, stimulation of both red and green receptors produces the experience of yellow. Mixing red and green lights on the theatre stage produces the experience of yellow. The color blind person, however, who presumably lacks red and green sensitivity can sense the compound yellow. This presented a theoretical dilemma which Helmholtz could not resolve.

The Hering theory, on the other hand, more adequately explains both color blindness as well as after images (the experience of seeing a complimentary color on a neutral gray background after gazing for a while at one color). Hering proposed a six color theory in which six primary colors were arranged in three pairs of complimentaries on the color chart -- a red-green pair, a blue-yellow pair, and a black-white pair. The Hering theory states that light of a particular color will automatically saturate the cells for that color and "bleach" out the characteristic chemical. The complimentary of the pair then becomes highly sensitized and will be experienced when white light is projected on a gray background.

Audition

Helmholtz also utilized the specific energies doctrine to explain audition. His theory of hearing, a resonance Or a "place" theory, was analogous to that of a harp. He reasoned that the receptor cells in the basilar membrane of the cochlea responded with sympathetic vibrations to different frequencies of sound. The pitch of a sound depends therefore upon what part of the organ of Corti is stimulated. This theory is in contrast to the telephone theory which proposes that the pitch of a sound is determined by the frequency of electrical impulses transmitted through the nerve, and the intensity of sound is determined by the number of hairs that are stimulated, i.e., louder sounds stimulate a larger number of hairs.

Helmholtz's contributions are vast but unfamiliar to most persons. Psychologists recognize him primarily for his theoretical contributions to sensation. James Newman, in his The World of Mathematics, depicts Helmholtz as a true renaissance man, as indicated by the following description:

Herman von Helmholtz was a scientist of such prodigious power and range that the mere listing of the subjects to which he made major contributions provokes disbelief. He was trained as a physician but practical medicine was the field that least interested him. Instead he undertook investigations in, among others, physiology, physiological optics and acoustics, electricity and magnetism, thermodynamics, theoretical mechanics, hydrodynamics, meteorology, biology and psychology. (Newman, 1956, p. 642).

What is even more startling than his accomplishments is the recognition that this giant of nineteenth century science made with his own hands many pieces of scientific equipment from bits and pieces of readily available equipment. A few years after Helmholtz's death, his biographer assessed the relationship between the scientist and his laboratory and cautioned modern educators and researchers against a too heavy reliance upon laboratory gadgetry:

In these days of palatial laboratories springing up all over the world in connection with each department of science, it is well not to forget that some of the greatest results in science have been gained in humble rooms and with simple appliances. Neither the most splendid buildings, fitted with the most modern appliances, nor the endowment of research, however wisely conceived, will compensate for the absence of genius. The living spirit must be the propelling force, and whilst it is reasonable that every facility for research should be afforded, a view which is now recognized in every civilized country, and mostly by those nations that form the vanguard of progress, there still remains the fat that in Science as in Art the great investigator, like the great artist, is born, not made (McKendrick Hermann von Helmholtz, 1899, p. ?).

GERMAN PHYSIOLOGY, ENGLISH PHILOSOPHY, AND A NEW SCIENCE

Germany is important in the development of psychology because it marked the place where philosophy and physiology merged into a new science -- the science of psychology. But the philosophy was not that of traditional German nativistic-mentalisic-phenomenological philosophy. The philosophy which gave birth to modern psychology was that of British empiricism -- the belief that the mind was the product of experiences, of sensations, of input from the external world. British empiricism, through three centuries, had supported the parallel development of the sciences. It was quite natural, therefore, that in the latter half of the nineteenth century, when scientific development was reaching it's apex (with startling advances in chemistry, physics, and now even physiology), that attempts would be made to extend this thinking to the human sciences of sociology and psychology. Since Germany was preeminent in most sciences, it is not surprising that Germans tried to take the methods of physiology and combine them with the empirical notions of a mind developed from sensations.

Helmholtz, the renaissance scientist, emerges as a forerunner of this new psychology. And he stands squarely at the forefront of psychological advancement -- because he demonstrates (through measurement of the neural impulse) that the mind is "material;" and he does the monumental work on sensation, without which, there is no way for the external world to stamp itself upon the tabula rasa.


MODULE 1
PROGRESS CHECK 1

NOW TEST YOURSELF WITHOUT LOOKING AT THE READING

Check those answers which are correct (one or more) or fill in the blank spaces.

1. One explanation for why a color blind child might confuse red and green colors while at the same time be able to discriminate yellow, is that color vision is dependent upon pairs, of which red and green are one pair. This theory was proposed by:
a. Hering
b. Helmholtz
c. Mueller
d. Brucke

2. Mueller believed in both specific energies and in:
a. Vitalism
b. Mechanism
c. Holism
d. Elementism

3. Germany contributed to the development of the new psychology, by providing a climate that emphasized:
a. Elementary education
b. Scientific research
c. Innate characteristics of the mind
d. Technological advances

4. A psychological theorist who is "reductionistic" tends to explain psychological phenomenon by reference to concepts in:
a. Sociology
b. Philosophy
c. Epistemology
d. Physiology

5. The equipment used by Helmholtz in conducting his classical research was:
a. Constructed by him from fragments of other equipment
b. Imported from English scientists who were great technologists
c. Built by master German craftsmen
d. Invented primarily by Weber.

6. Helmholtz's theory of color and of hearing were based upon the specific energies of nerve doctrine proposed by ___________________________.

7. One of Helmholtz's students became a famous psychologist. Who was that?
a. Wundt
b. Kant
c. Fechner
d. Ebbinghaus

8. Helmholtz grew up in one of the great cultural centers of Europe in the nineteenth century:
a. London
b. Berlin
c. Potsdam
d. Rome

9. German scientists used which philosophy?
a. Scottish faculty
b. American functionalism
c. German phenomenology
d. British empiricism

ANSWER KEY 7 OR MORE CORRECT, GO TO MODULE 2
LESS THAN 7 - COMPLETE EXERCISE ON
NEXT PAGE


MODULE 1

EXERCISE

1. The assumption that phenomenon in one science can be explained by the terms and concepts of another science which is more molecular, is a philosophical position known as ___________________________.

2. Helmholtz's scientific empiricism was, in part, a reaction away from:
a. Kant's intuitionism
b. LaMettrie's materialism
c. Lotze's Ideal-Realisms
d. Mill's associationism

3. J. Mueller and other biologists of the early part of the nineteenth century believed that life and movement of living organisms could be explained by some special immaterial quality which kept the life processes going. Such theorists were referred to as ________________________.

4. The specific energies of nerve doctrine assumed that:
a. Every nerve carried the same electro-chemical signal.
b. Differences in sensation are attributed to differences in perception
c. Differences in sensation occur because of learning
d. Light and sound are different because the nerves are different


5. During the nineteenth century. the country which was just beginning to emerge as a world power and which had an advanced public educational program was ________________________________.

6. The Helmholtz School of Medicine:
a. Was identified with the University of Berlin
b. Reduced all biological explanations to physical chemical terms
c. Influenced Freud, Pavlov and Wundt
d. None of the above.

7. The assumption that there is no new source of energy in a system, that different forms of energy are merely transformations of one kind of energy into another kind, was proposed by Helmholtz as the doctrine of the __________________ of energy.

8. To Helmholtz, psychology was:
a. Essentially physiological
b. An exact science
c. Dependent on experimentation and mathematics
d. All of the above.

ANSWERS:

7. conservation
4. D
2. A
5. Germany
9. France
6. A,B,C
1. reductionism
3. Vitalists
8. D

NOW TAKE PROGRESS CHECK 2


MODULE 1

PROGRESS CHECK 2


1. Helmholtz maintained that concepts of space were products of experience rather than innate factors. Such a point of view is referred to as _________________.

2. Which of the following would have opposed "mentalism" and vitalism?
a. Kant
b. Fechner
c. Helmholtz
d. Wundt

3. Helmholtz's theory of hearing is:
a. Based on assumptions similar to those of his theory of vision
b. Is a derivative of J. Mueller's specific energy of nerve doctrine
c. Assumes there are different cells which code for different frequencies of sound
d. All of the above

4. The two major color theories of the nineteenth century and beyond were those proposed by ______________________ and by __________________.

5. One of the great apparent paradoxes for psychology was how the mind could be immortal and also:
a. Organize experiences into time
b. Organize experiences into space
c. Receive revelations of truth
d. Be independent of bodily processes

6. Reductionism was a kind of:
a. Scientific technique for measuring physiological changes
b. Logical process for constructing the number of available hypotheses
c. Scientific explanation
d. Psychological theory


7. Helmholtz's theory of color was that:
a. There were four primary colors
b. Each color was represented by different frequencies of light
c. Different cells in the retina of the eye were sensitive to different colors of light
d. The primary colors were red, yellow, and blue/violet.

8. German physiology combined with which philosophy to form the new psychology?
a. German
b. English
c. American
d. British

ANSWER KEY

6 OR MORE CORRECT, GO TO MODULE 2
LESS THEN 6 - Instructor conference


Unit 5 Table of Contents

Psych 601 Home Page