Two key discoveries led up to the construction of the first electroencephalogram. The first being electrical impulses actually being observed for the first time in July 1875 by Richard Caton through the galvanometer, which is a type of electrical ammeter to measure electric current. The second was Ernst von Fleischl-Marxow and his studies on evoked potentials, linking nervous system activity to muscle movements. Hans Berger used these two discoveries as the foundation of what he would soon discover, the electroencephalogram. Using silver foil electrodes, capillary electrometer and galvanometer, Berger was able to capture what was the first recorded Alpha (bottom picture) and Beta (top picture) brain waves.
Image courtesy of Brainclinics.com
Impressed by the Berger and the invention of the EEG, Gray Walters who was a British scientist, set out to create the toposcope incorporating more electrodes along with cathode ray tubes. This led to color brain mapping, allowing for a researcher or neurologist to analyze relationships between mental work to brain activity.
Early Brain mapping from Gray Walter’s toposcope. (image courtesy of cerebromente.org)
Today the EEG is used a lot for detection and imaging for the brain. Still using electrodes that are connected to the scalp, the EEG will record electric brain activity and be assessed by physicians for abnormalities.
Where will the future of the EEG lead?
EEG technology has evolved since it’s early creation by Hans Berger. Technology is currently trying to implement EEG into more accurate non invasive medical tools and in the video game industry. Whether it be controlling robots or to direct a wheelchair, EEG technology is still new and is anticipated to grow exponentially.