Important+People

Hermann von Helmholtz (August 31, 1821 – September 8, 1894)

Hermann von Helmholtz was a German physiologist who mastered in medicine and physics. He is well known for his research in the nervous system, along with research of sensation and perception. Helmholtz has also made many great contributions to physiology by his inventions in the optical department along with his study in the field of sensation by research in the theory of music. Helmholtz is well known for, Treatise On Physiological Optics, which is dived into three Volumes. He is also highly recognized for his important paper, //Über die Erhaltung der Kraft,// which studied concept of conservation energy.

Growing up Helmholtz was fairly poor and when it came time for college, Helmholtz wanted to study science but due to his financial situation his father encouraged him to study medicine where he would use his medical skills to aid the government. In 1898, Helmholtz attended Friedrich Wilhelm Institute and four years later, graduated with his M.D. Soon after receiving his M.D., he began military duty for Prussian army practicing surgery.

After several years of active duty for the army, Helmholtz was released and in 1849 that Helmholtz began his teaching in physiology at the University of Konigsberg later on moving to Heidelberg, where a lot of his important work was done.

Throughout Helmholtz career as a Physiology he studied the human eye and in 1851 heinvented a device to help examine the retina called the ophthalmoscope, which is still used today, by modern eye specialists. Helmholtz also invented the Ophthalmometer, which was used for the measurement of the curve of the eye. The ophthalmometer became very helpful to the study of color blindness.

Helmholtz also went on in the study of sound in the human ear. He studied the effect of pitch and tone, along with the ear distinguished the two. In 1852, Helmholtz was determined to find the unanswered question of the measurement of speed, within a nerve impulse. He conducted an experiment on a frog by stimulating its nerve s and found the velocity to be just about one-tenth the speed of sound, within the nervous system.

After much of his work completed in sensory physiology Helmholtz moved on to continue on in the study of physical science. Through his study of physical science, he became greatly known for the concept of conservation of energy. Julius Mayer originally introduced this concept, of conservation energy. However, Helmholtz obtained his own research and perfected the concept making it much more clearer through his explanation. Helmholtz concluded. Energy is either used or released as heat; it cannot be created nor lost.

Helmholtz continued to carry out his studies but his life shortly came to an end. In 1894 Helmholtz fainted after a lecture he held in the United States causing him to fall and suffered a concussion. Sadly, Helmholtz was never able to fully recover. He passed way several months later due to the complications. Helmholtz's work is still used today by many and has helped further the study of science.


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 * Old Opthalmoscope ||


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 * New Opthalamoscope ||


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 * Old Opthalmometer ||


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 * New Opthalamometer ||



Wilhelm Maximilian Wundt

** ( ** August, 16, 1832 – August, 31, 1920) Wilhelm Maximilian Wundt was born on August 16, 1832, in Neckarau, Germany. Although, Wundt is well known for his work as an experimental psychologist he did have some contributions to the field of physiology sensation and perception. Wundt attended the University of Heidelberg as a lecturer in physiology. Through out his years at Heidelberg, Wundt worked with Hermann Helmholtz, as his lab assistant later published the Beiträge zur Theorie der Sinneswahrnehmung, early in his teaching career at Heidelberg (1858–1862). Beiträge zur Theorie der Sinneswahrnehmung, contained his theories of sense perception, and was actually considered as the first treatment of psychology in scientific experimentation, also Vorlesungen über die Menschen- und Tierseele (1863).

Wundt also went on to become the first, in history, to teach a course about scientific psychology. Wundt’s most important work for psychology was Grundzüge der physiologischen Psychologie (1874), in which he uses his method of introspection by studying experiences of the conscious mind. "In Wundt's 1893 edition of Physiological Psychology, he published the 'tridimensional theory of feeling': feelings were classified as pleasant or unpleasant, tense or relaxed, excited or depressed. A given feeling might be at the same time a combination of one of each of the categories." This website same also states, ("Wilhelm Wundt ," 2012)- "the task of determining a person's mental age was reminiscent of one of the psychophysical methods developed by Wundt to determine the level of a person's sensitivity to faint stimuli or to small physical differences in stimuli."

Although Wilhelm Maximilian Wundt did more work as an experimental psychologist, Wundt challenged psychology to be broken down with his experiments that helped raised many questions; Questions that also needed the help of physiology to be properly answered. He brought much attention to the human mind and the process of how it works with our own personal experiences in life. The study of perceptual processes and cognitive psychology can be credited to Wundt; Wundt opened the window to experimental psychology. He inspired Emil Kraepelin, a student of his, in psychopathology. His work also stimulated C. G. Jung’s development of the association test that was used in Zurich by his associates. “ Wundt supervised 186 doctoral dissertations in various disciplines and taught over 24,000 students.”- ("Wilhelm wundt ," 2008).



Ernst Heinrich Weber

(June 24, 1975- January 26, 1878)

Ernst Heinrich Weber was a German physiologist and anatomist, and his most important contribution to the physiology of sensation and perception is his work on the sense of touch. He discovered the smallest perceivable difference between two similar stimuli within the sense of touch (Ernst, 2012). He was one of the first scientists to use experiments to study how physical stimuli affect the human body. His research was also helpful to future research when it was discovered that human skin contained nerve endings, for example, the nerve endings of human fingertips (Faq, 2012).

His education began when he became of professor at the University of Leipzig in 1818, where he stayed for most of his life, until 1871. He worked with the sense of touch and stimuli containing different weights, pressures, and temperatures. He is also noted with discovering that there is a threshold of touch, and a stimulus must reach or pass this threshold in order to be perceived. He also determined the difference in threshold needed to perceive a noticeable change when it comes to humans. This is referred to as the concept of "just-noticeable difference" (Faq, 2012). Not only did he discover the "just-noticeable difference" for the sense of touch, he also is noted for finding the differences for the other senses as well. Lastly, he is noted to of discovered the maximum thresholds for all of the senses, which is very important knowledge of our day. This refers to the largest threshold that any of the human senses can possible endure (Ernst, 2012).

Weber's work has been noted as the rock from which experimental psychology is based on. He is also the influence of “Weber’s Law,” created by Gustav Fechner, who took Weber’s idea of the minimum amount of stimulus intensity that is required to notice a change in sensation, and converted it into a mathematical formula (Heeger, 2006).





Johannes Peter Müller  (July 14, 1801- April 28, 1858)

Johannes Müller was a German physiologist with some of the largest contributions to physiology of perception and sensation, from his research of human and animal vision, to human facial expression, his work on the individual sense organs and how they respond to certain stimuli, and also, the anatomy and problems with perceptual development (Johannes, 2012).

Müller’s biography begins when he studied at the University of Bonn, where he was able to lecture on physiology, and eventually became a professor with the viewpoint that empirical evidence along with practical thinking were the keys to philosophy. It was during this time that he grabbed the attention of scholars with his work in vision of animals and humans. Müller published a monograph titled “Our Imaginary Apparitions,” where he wrote about the ideas of internal stimuli caused by excitement from our imaginations leading to external apparitions that are not real, i.e., ghosts (Johannes, 2012).

Müller’s work also had an impact on the current “theory of knowledge” of his time period. One of his most important achievements was the discovery of the sensory organs and how external stimuli have a different effect on each of them. Müller also is famous for his work with anatomy, studying how nerves travel to the brain and through the nervous system. He is noted for promoting the “doctrine of specific nerve energies,” which explained that perceptions rely on nerve energies reaching the brain, which also depend on which nerves are stimulated. He discovered the Müllerian duct, which forms the female internal sex organs, and worked with sound in the middle ear (Goldstein, 2010).