The Hidden Beginnings of EEG Research

Hans Berger’s search for telepathy and electric signals of the mind

• Hans Berger recorded the first human EEG while searching for physical signs of mental processes.
• His work initially faced skepticism, but later gained international recognition.
• EEG has since become a key tool in neuroscience, used for everything from studying the brain's inner workings to diagnosing illness.

In 1893, a young Prussian army officer fell off his horse and narrowly avoided being run over by an artillery cart. On the same day, his sister, who was at home many miles away, had a feeling that something terrible had happened to her brother. She insisted on sending a telegram to check he was well.

Was her premunition caused by telepathy? The young officer in question, a 19-year-old named Hans Berger, certainly thought so. So much so that he abandoned his plans to become an astronomer and dedicated his career to searching for a link between mental processes and the physical world. Needless to say, his research in neurology and psychiatry would not provide the proof of thought transmission that he had hoped for. But what he discovered instead was impactful enough to turn the world of brain research upside down.

Scrawny lines from a self-constructed device

But first, this brush with death changed the course of Hans Berger’s life. Influenced by his lucky escape, he studied medicine and soon after started working at the University of Jena’s psychiatric clinic, where he eventually became a professor and the clinic’s director. This promotion was crucial as it allowed him to devote the rest of his career to the search for physical correlates of mental processes, largely undisturbed.

Convinced that meticulous measurements of cerebral processes would help gain evidence of telepathy, Berger designed his own device for recording the electrical activity of the human brain. Even in those days, his hypotheses were considered occult, so he conducted his experiments in utter secrecy in a laboratory in a basement of the clinics – on himself, his children, and his patients. Working in increasing isolation, facing a flurry of technical obstacles, and plagued by harsh self-criticism, it took him years to achieve his big breakthrough: the first electroencephalogram (EEG) from a human brain.

In the scrawly lines that his device recorded, Berger discovered rhythmic patterns of electric activity, known today as brain waves or neural oscillations. He immediately recognized the potential of his discovery and asked questions that would shape brain research for decades to come: What functions do the strangely uniform patterns of electric activity have? How do they change when we think, look, act, or sleep? Can EEG be used to diagnose diseases like epilepsy?

Skepticism turns to recognition

Of course, Berger’s groundbreaking achievement did not happen in a vacuum. He was familiar with the work of the British surgeon Richard Caton, who had succeeded in measuring electricity from the brains of rabbits and monkeys as early as 1875. Berger was also aware that the Polish physiologist Adolf Beck had observed changes in brain activity of rabbits and dogs in response to light, and that the Ukrainian physiologist Vladimir Pravdich-Neminsky had obtained electrical recordings from the surfaces of intact dog skulls.

What set Bergers work apart, though, was not only that his EEG recordings were the first to be made in humans. His observations also stood out because he conducted numerous control experiments with meticulous attention to detail, perhaps anticipating that his discovery would be greeted with doubt and skepticism. Initial reactions to Berger’s first EEG publication were indeed very reserved. It was not until five years later that British scientists Edgar Adrian and Bryan Matthews replicated Berger’s experiments – in an attempt to refute his findings. They were surprised to discover the same clear rhythms of electrical activity in conscious subjects that Berger had described.

This increased Berger's international fame and drew more and more researchers to the puzzling phenomenon of brain waves. Even today, neuroscientists are trying to further unravel their mysteries: How do brain waves guide selective attention? How do they serve to move and maintain posture? And what roles do they play in mental illness, its diagnosis and treatment?

The story that began with a horse, a soldier and a telegram is far from over.