The electrical excitability of the brain: toward the emergence of an experiment

In 1870, Eduard Hitzig and Gustav Fritsch performed experiments on dogs by which they were able to produce movement through electrical stimulation of specific parts of the cerebral cortex. Contemporaries regarded the experiment as a milestone in the controversially discussed issue of cerebral localization of functions even though this experiment came as a surprise to the community of experimental physiologists who had rejected localization for several decades after the antiphrenological work of the physiologist Pierre Flourens. In this article, I will argue that the context in which this experiment emerged was not so much the French localization debate of the 1860s but rather practical demands in clinical medicine, notably in electrotherapy. At the time of the experiment, Hitzig worked as a medical practitioner in Berlin and was interested in an anatomical and physiological explanation of the specific symptoms of one of his patients. The unpredictable outcome of this interest was the discovery of the electrical excitability of the cortex. Whereas experimental physiologists dominated the discussion on cerebral localization in Germany before 1870, the situation shifted after the publication of Fritsch and Hitzig's paper. Concrete medical necessities forced the discussion about localization and it was mainly due to the authority of clinical physicians that the localization of mental qualities in the brain became a cornerstone of brain research.