Brainwaves. Abstract computer artwork showing the profile of a human head with brain, and spiked EEG (electroencephalogram) brainwaves. It is seen on a starfield. The red brainwaves may be depicting a thought pattern or some mental state. Brainwaves are electrical impulses produced by the activity of the brain when measured on an EEG machine. Such wave patterns alter when awake, asleep, or undergoing thought processes.