"Writing the Brain": The birth of clinical electroencephalography

In 1924, Hans Berger (1873-1941), a German psychiatrist and neurophysiologist, recorded the first electroencephalogram (EEG) in a patient, providing the first method to record the brain's electrical activity in humans. Before this discovery, preclinical evidence from animal studies supported the idea of brain-generated electricity, although scientific thought leaned towards chemical models of brain function. Overcoming technical limitations, Berger successfully recorded brainwaves using a string galvanometer, identifying distinct electrical oscillations, later classified as alpha and beta waves, and laying the groundwork for understanding brain activity in response to external stimuli and cognitive states. Furthermore, Berger's recordings of abnormal electrical discharges during seizures redefined epilepsy as an electrical disorder, paving the way for modern diagnostic and therapeutic approaches. While Berger's initial vision of EEG as a "psychoscope" capable of precisely recording neurophysiological correlates of specific mental states was not achieved, it has proven indispensable as a "cerebroscope," offering profound insights into both normal and pathological brain function.