EEG typically takes about 60 minutes. Sleep disorders may require more extensive testing at longer durations. A technician will place an elastic cap fitted with electrodes on your head. The technician will then clean the surface of each arm and behind the ears, and put gel into the cap’s holes. The electrodes are connected with wires to an instrument that will amplify and record the brainwave activity on a computer.
During most of the test, you will be in a relaxed position with your eyes closed. At various times during the test, the technician may ask you to open and close your eyes, breathe deeply (hyperventilate) for a few minutes, or look at a flashing light.
It is customary to video record the EEG procedure to capture your body motions simultaneously with the brain waves, which can help the doctor diagnose and treat your condition.