Hermann von Helmholtz (1821 – 1894) – A pioneer of Psychology

Many scientists see Hermann von Helmholtz (1821 – 1894) as one of their prime fathers. He has enduringly inspired Physiology, Medicine and Physics amongst others. Less well known is the fact that he also participated in the development of Psychology with an orientation towards the natural sciences. This is not only due to Wilhelm Wundt (1832–1920) being his assistant at the University of Heidelberg for several years.Hermann von Helmholtz demonstrated especially great achievements in the field of sensory physiology and the related psychology of perception. In 1850 he invented the ophthalmoscope, which allowed him the view of an animate retina for the first time in human history. With this instrument he provided a tool for Ophthalamologists to be able to diagnose indispositions of the retina. The question how humans perceive colours was answered by him through a further development of the colour theory of Thomas Young (1773–1829). Helmholtz could show that every possible colour can be combined out of the three primary colours, which are red, green and blue. Thus, he assumed three receptor types for the human eye, which have a specific sensibility for the three primary colours and which create the impression of colour through their shared activity.By also examining the ear as sensory organ in detail, Helmholtz could physically detect the sound – amplifying effect of the eardrum and the auditory ossicle. Furthermore, he developed the resonance – theory of the perception of pitch in the inner ear. This theory postulates that specific frequencies are displayed on definite locations of the cochlea of the inner ear (place theory of pitch perception). Until today the finding of the described place theory of pitch perception is seen as correct, although the by v. Helmholtz assumed mechanism of resonance was replaced by the travelling wave theory by Georg v. Békésy. One of Helmholtz’s works published in 1850 was from extraordinary meaning for Psychology. This work deals with the measurement of the speed of nerve – transmission. Before Helmholtz carried out these measurements it was assumed that the speed of nerve – transmission complies with the velocity of light and therefore, is not measurable. Von Helmholtz could show in his experiments that this assumption is incorrect and that nerves transmit information much slower than assumed and thus, the transmission is measurable. This insight accounts for the great importance of reaction time experiments in Psychology. The exhibition outlines the biography of the significant scientist Hermann von Helmholtz as well as the fields of hearing and seeing. Numerous exhibits from the collection of the centre with direct or indirect link to Helmholtz can be viewed.

Armin Stock