Hans Berger (1873-1941): the German psychiatrist who recorded the first electrical brain signal in humans 100 years ago.

In 1924, at the University Hospital of Jena, Hans Berger first recorded an electrical brain signal in humans. This discovery revolutionized clinical neuroscience and neurotechnology, as it contributed to both electrophysiology and the development of the electroencephalogram (EEG). The manuscript provides a historical overview of Hans Berger's seminal contributions, highlighting the importance of his early recordings, the motivations that drove him, and the scientific problems he had to initiate and solve, in a historical context of profoundly changing circumstances. He also faced low acceptance of his works initially, and only belatedly did they become accepted by the scientific community. Berger was known to be a humble but tenacious person who believed in his convictions to the core, and this strength of will is an example of passion for students and scholars of neuroscience.