Biography of Hans Berger
Hans Berger was born in Neuses, near Coburg in Thüringen, the son of the physician Paul Friedrich Berger and Anna Rückert. One of his grandfathers was Friedrich Rückert (1788-1866), professor of Oriental languages and a much-quoted poet, whose work is still alive.
Berger graduated from the Gymnasium in Coburg and then entered the University of Jena. After one semester in astronomy he transferred to medicine. In 1897 he received his doctorate and became assistant to Otto Ludwig Binswanger (1852-1929) at the university's psychiatric clinic. In 1900 he was called, with Korbinian Brodmann (1868-1918) as assistant to Binswanger at the Grossherzogliche Sächsische Landes-Irren-Heilanstalt in Jena.
Hans Berger was habilitated in Jena in 1901 and was appointed ausserordentlicher professor in 1906, 1912 physician-in-chief at the clinic, and in 1919 became director of the clinic and succeeded Binswanger in the chair of psychiatry and neurology. He was rector of the university 1927-1928, and prorector 1935 to 1938, when he was emerited. His appointment at Jena was the beginning of an illustrious scientific career.
The central theme in Berger's Work was the search for the correlation between objective activity of the brain and subjective psychic phenomena. In his work on blood circulation in the brain (1901) he described his efforts to gain insight into this correlation through plethysmographic registration of the brain pulsations. He investigated the influence of the heartbeat, respiration, vasomotor functions, and position of the head and body on brain pulsations, which were measured through an opening, made by trephination, in the skull.
After series of disappointing experiments measuring the blood circulation and temperature of the brain during the first two decades of the century, Berger following his return from World War I devoted himself mainly to the measurement of the brain's electrical activity. In 1902 he had taken measurements of electrical activity above skull defects with the Lippman capillary electrometer (Gabriel Lippman, 1845-1921), and later with the Edelmann galvanometer. In 1910, however, Berger mentioned in his journal that the results of these measurements were not satisfactory. Therefore, until 1925 he followed two methods of research: stimulation of the motor cortex through a defect in the skull, measuring the time between stimulus and contralateral motor reaction, and registration of the spontaneous potential difference of the brain surface.
After 1925 Berger no longer used the stimulation method. He specialized, with ever increasing skill, in registering the spontaneous fluctuations in electrical potential that could be recorded through the skull from the cortex. In his first publication on electroencephalography (1929), he called July 6, 1924 the date of discovery of the human electroencephalogram, which he called ”Elektroenkephalogramm.” He did this not only in normal subjects but also in the brain-injured, thereby laying the foundation for the application of the technique to clinical technology. In the following year, using a Siemens double-coil galvanometer, he found a decrease in activity on sensory stimulation – thus duplicating the results obtained by Beck and Pravdich-Neminski in animals and he also found the counterpart of two of Pravdich-Neminski’s categories of waves, the alpha and beta ranges.
In developing electroencephalography, Berger was fully aware that Richard Caton (1842-1926), a Liverpool surgeon, had succeeded in 1875 in measuring electrical potentials on the exposed cortex of experimental animals (rabbit and monkey), and that he was thus the discoverer of the electrical activity of the brain. Berger also knew about the further successes along this line achieved by the Polish physiologist Adolf Beck (1863-1939) in 1891, and of the findings of Russian workers. In 1912 a paper by the Russian physiologist Pravdich-Neminski (1879-1952) for the first time illustrated a photographic record of the electrical activity of the brain. He called it an ”electrocerebrogram.” Pravdich-Neminski’s electrocerebrogram was made on dogs with the skull intact by means of the string galvanometer (Willem Einthoven, 1860-1927. Having suffered many setbacks in his experiments, Berger’s reaction to this demonstration was that he should work harder.
Berger's experiments were carried on in his spare time and in utter secrecy. Never did he mention what he was doing, nor would he ever admit anyone to the laboratory located in a small building on the grounds of the clinic in which he worked. As a diversionary measure he would give public discourses on telepathy, in which he was a firm believer, offering hypotheses of wave propagation to explain it. Increasing inflexibility in his attitude towards his assistants went hand in hand with his increasing isolation, so that people began to shun him.
Berger’s paper announcing that variations in voltage could be recorded through the intact cranium appeared in 1929, five years after he had conceived the idea. The others that followed were also epoch-making.
Recognition came late to Hans Berger, but in 1937 he was invited to preside with Adrian at the symposium on electrical activity in the nervous system at the Congress of Psychology in Paris. They hailed Berger as the most distinguished of all the visitors. Tears came to his eyes as he said: ”In Germany I am not so famous.” Plans were made to have him visit the United States to inspect laboratories where electrical studies on the brain were in progress and to lecture on his work. He began to polish his English and wrote: ”I will come as soon as the international situation permits.” He retired in 1938.
Edgar Douglas Adrian, 1st Baron Adrian (1889-1977) and Sir Bryan Harold Cabot Matthews (1906) drew attention to his work in 1934.
As a front-row witness of the rise of Hitler and World War II, and forced by old age merely to wait and watch, he decided in a fit of melancholia – to which he was subject – that he had seen enough and on June 1, 1941, ended his life. He had entered the hospital on the medical service, and hanged himself.
His associates described him as punctual, strict, demanding, and reserved. Both for work and for leisure the synchrony of his days was phased to the exact minute.