EEG (electroencephalogram)
From Kook Science
An electroencephalogram (EEG) is a device that uses electrodes to measure electrical activity of the skin to which the electrodes are attached, typically being placed on the scalp, this method being used as a non-invasive means of evaluating the underlying electrical activity of the surface layer of the brain. The first EEG was credited to Hans Berger and Berger's work was developed on by W. Grey Walter.