1. The EEG (electroencephalograph) measures Brainwaves of different frequencies within the brain

2. The electroencephalograph was primitive in the early 1930s, having only one channel.

3. Brainwave - (neurophysiology) rapid fluctuations of voltage between parts of the cerebral cortex that are detectable with an electroencephalograph brain wave , cortical potential neurophysiology - the branch of neuroscience that studies the physiology of the nervous system