Bernhard Hassenstein

In 1981 Bernhard Hassenstein was asked to contribute a chapter to a book celebrating the 70th birthday of Klaus Piper, owner of the Munich-based publisher "Piper Verlag". He thought about a topic that could be both enjoyable and academic. He came up with "Five variations about my migraine" (read the original German essay).

Bernhard Hassenstein signed his chapter to a book devoted to the 70th birthday of the publisher Klaus Piper.

Each variation of his migraine story starts with the year in which it occurred. Beginning with an attack during an exam in school (1934), he later discovered tea as a trigger of his attacks (1946). He wrote a poem about this to make any rejection of a cup of tea−which was at that time quite offending−less rude.

In 1956 he mistook a swollen eyelid as a typical perceptual completion of a migraine scotoma.

The episode from 1960 is about the above mentioned Johann Hoffmann, who determined the flicker rate of the visual aura in the range of the alpha rhythms in the electroencephalogram, i.e., about 10Hz.

In his last episode (1979) Hassenstein describes very precise measurements of the position of his migraine aura within the visual field. He estimates from the perimetric drawings the magnification from the visual field onto the underlying neural substrate.

The full version of Hassensteins "Five
variations about my migraine" has not been translated from
German. Here is the original German text:

Bernhard Hassenstein is a renowned German behavioral biologist. His carrier began as a 21-year-old biology student when he became a soldier during World War II. There, he met a young physicist, Werner Reichardt. "In the craziness of wartime, they promised each other that, if they survived, they would do something great together: start the first institute of physics and biology" (Borst, 2000). And indeed, after Hassenstein had finished his doctoral thesis in the laboratory of Erich von Holst in Wilhelmshaven on the optomotor turning behavior of the beetle Chlorophanus they meet again.

© 2006 Deutsches Museum Bonn

In an elegant experiment, Hassenstein used as a behavioral measure the optomotor response of a beetle (red arrow) . The beetle was glued under a rod so it could not move relative to the surround. Instead it 'walked'−and thereby express its behavior at decision points−by rotating a 'spangenglobus', i.e., a Y-maze globe under its feet.

In 1958, after Karl Friedrich Bonhoeffer had died, a Research Group for Cybernetics was established at the MPI for Biology in Tübingen and it was led by Reichardt and Hassenstein. Their research led to the development of a model for motion detection that became known as the 'Reichardt detector' omitting half the original team. Curiously, this research inspires current migraine projects about the illusion of movement in visual aura (see here).

Already in 1960, Hassenstein left the Cybernetics group to become full professor and head of the Zoology department at the University of Freiburg (as successor to Otto Koehler). In Freiburg Hassenstein was told about a simple frequency matching experiment to determine the flicker rate of visual migraine aura. But this was not the first time he heart about the migraine aura. Hassenstein suffered himself since the age of 12 from migraine with aura. Therefore, these experiments made a deep impression on him. They were done by the late Professor Johann Hoffmann (known from the Hoffmann's reflex) directly after World War I, when there was no money to perform more sophisticated medical research. Having heard about Hoffmann experiments, Hassenstein suddenly realized that he owns the privilege to view during a migraine attack with visual aura his brain at work.

Measurement from migraine aura observed in 1980. The graph shows the eccentricity of migraine phosphenes.

In 2004, at age 82, Hassenstein wrote to one of the co-editors of this site, Markus Dahlem, that if he had to publish the essay today it would consist of two more variations upon this topic.

References

Piper K. Für Klaus Piper zum siebzigsten Geburtstag. Piper Verlag, Munich 1981.
Borst A. Models of motion detection, Nature Neuroscience 2000; 3: 1168.

Cybernetics:
Norbert Wiener
Otto-Joachim
Grüsser
Marvin Minsky

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