Hermann Von Helmholtz on Neural Impulses, Perception and Audition

Hermann Von Helmholtz on Neural Impulses, Perception and Audition

Psychology and physiology are built on the foundations of Hermann Von Helmholtz and many other scientists. In essence, these foundations became stepping stones for the essential theories that help create the history surrounding these fields. The gap between psychology and physiology was made smaller by Helmholtz, as he discovered theories concerning neural impulses, perception and audition. Helmholtz contributed to the field of physics with his theory, the law of conservation of energy. Helmholtz also provided findings to the area of vision and helped to clarify the theories of color vision.

Hermann Von Helmholtz was born in 1821 in Postdam, Germany. He excelled in academics early in his educational career. At the age of 17, Helmholtz enrolled into medical school in Berlin. Due to financial burdens, he was not able to attend the university he preferred; however he still finished his program in medical school in four short years. While in Berlin, Helmoltz found the time to informally study alongside Johannes Muller. One issue that Helmholtz, Muller and his students focused on was vitalism versus materialism. Helmholtz was a materialist who believed that reality has physical properties that can be broken down to physical or chemical matters; He and Muller were on opposite ends of the spectrum on this issue. Helmholtz made additional friends at school named Ernst Brucke, Emil du Bois Reymond, and Karl Ludwig, who were also students of Muller. These men joined Helmholtz in becoming science field leaders and also aided in building psychology’s history. In 1847, Helmholtz’s paper concerning the law of conservation of energy, which made a lasting contribution to the field of physics, was published. A couple of years later, Helmholtz accepted a job at the University of Konigsberg with the help of his fellow scholars Brucke and du Bois Reymond. This was a historical move for Helmholtz, because the University of Konigsberg became the birthplace for some of his most influential studies and findings. Helmholtz moved back and forth between the University of Bonn and the University of Heidelberg throughout his career. Helmholtz returned to Berlin in 1871, where he finished up his career as a professor of physics.

During the 1850’s many scientists began researching the operations of a nerve fiber and its relation to electricity, also known as, neural impulses. Emil du Bois Reymond is credited with discovering the relationship between nerves and electricity. When demonstrated, he found that electricity will travel through the nerve and cause a connected muscle to twitch. As discussed before, there was a strong debate concerning vitalism and materialism at this time for many scientists. The issue of measuring neural impulses became a platform for vitalists and materialists to prove that their beliefs were, in fact, accurate compared to the others. Muller, a known vitalist, found du Bois Reymond’s findings to be a result that could not be measured. According to C. James Goodwin (2008), “Authorities such as Muller believed that the nerve impulse might be instantaneous or, at the very least, that it occurred too rapidly to be measured” (p.71). Du Bois Reymond continued his research and “suggested that the impulse was propagated along the nerve by an electrochemical process that would be slower than a pure electrical transmission.” (Goodwin, 2008, p.71) These findings gave Helmholtz the motivation he needed to take part in the history of neural impulses, by looking into the actual speed of a neural impulse. An induction coil was used to send a surge of electricity through a nerve on his test subjects, frogs. As stated by Helmholtz later edited by Wayne Dennis (1948), “I have found that there is a measurable period of time which during the effect of a stimulus consisting of a momentary electrical current applied to the iliac plexus of a frog is transmitted to the calf muscles at the entrance of the crural nerve” (p. 197). Helmholtz proved that there was in fact a measurable speed to be assessed. To conclude further, he investigated the rate of transmission by testing the electrically charged nerves from many distances. According to Goodwin (2008), “Helmholtz discovered the calculation for the rate of transmission as: rate =distance/time” (p. 71). His study showed that physical parts have direct reactions with nerves, further proving his belief in materialism.

Helmholtz then went onto his next experiment where he was able to discover his theory of resonance. According to John Gray M’Kendrick (1899), “Streams of air were directed across the mouths through flattened gutta-percha tubes. The bottles were tuned to b and b’ an interval of an octave and tones of sound to discover the use of resonators” (p.145). Of course the magnitude of this experiment was much more extensive, but this was the beginning to the theory of resonance. What Helmholtz ultimately discovered was, “different frequencies of sound were detected by receptors located in different places along the basilar membrane of the cochlea” (Goodwin, 2008, p.73) Along with contributions to audition, Helmholtz also helped clarify the research on color vison by developing the trichomatic theory. According to Goodwin (2008), the trichomatic theory “concluded that the eye must contain three different kinds of color receptors” (p.72). The primary color receptors that Helmholtz found were red, green and blue. His work was an extension to the color vision work that Thomas Young previously presented in the nineteenth century. Helmholtz also invented the ophthalmoscope which is used by eye doctors.

The discoveries that Helmholtz made concerning vision and audition led him to understand that our vision and hearing senses are imperfect but work in remarkable ways. This issue was to be called the problem of perception. “On the one hand, it appears that the human system for seeing and for hearing are remarkably capable. On the other hand, the structures designed to deliver these senses seem to be terrible flawed” (Goodwin, 2008, p. 74). Helmholtz looked into this problem to understand how our flawed senses work for us and not against us when it comes to perception. Helmholtz explained through his research that we use our flawed senses to our benefit through unconscious inference. According to Goodwin (2008), “Helmholtz would say that because we know through experience that people don’t grow or shrink as they approach or recede, we conclude logically (i.e. unconsciously infer) that the person must be getting closer” (p.74) This inference is used throughout our lives and becomes a learned effect, therefore becomes an unconscious act.

Helmholtz was an influential scientist to the fields of psychology and physics. Not only did he leave behind a list of indispensable theories, he also opened doors for future scientists to discover and add more to his findings. Helmholtz understood that, although the path to his findings may have been complicated, he knew other scientists could take his work and expand essential results that would benefit the field of psychology.

Work Cited
Goodwin, C. J. (2008). A History of Modern Psychology. Hoboken, NJ: John Wiley and Sons, Inc.

Helmholtz, H. V. On the Rate of Transmission of the Nerve Impulse, 1850. Retrieved from http://search.proquest.com.manowar.tamucc.edu/docview/614186051.

M’Kendrick, J. G. Helmholtz in Bonn and Heidelberg—Sensations of Tone Continued. Retrieved from http://search.proquest.com.manowar.tamucc.edu/docview/867782486.