Using evoked potential, normal and abnormal function of the retina and optic tract, auditory pathways, skin sensitivity and arbitrary muscle control.
You will have to sit in a darkened room. In front of you is a screen with a white and black pattern similar to a checkerboard. Additionally you see a light dot which is usually found in the middle or, if checked closely, at the edges. During the entire procedure, you should be looking at the dot, no matter where the black and white pattern moves. The procedure requires you have to a small metal plate attached to the back and middle of your head. Through these electrodes, like during an EEG, retinal activity and optic tracts can be monitored.
The procedure takes place either while sitting or laying down. You will receive earphones out of which you will hear a crackling sound first from the right side, then the left. Because each side should be tested individually, the ear not being tested will be blocked by continuous static. Small metal plates will be placed behind each ear and on the middle of the head. Brain waves will be measured by electrodes which begin in and run through the auditory canal.
During the procedure, you must lie down and relax. The sensory nerves are activated through short, weak electronic stimulus. Your muscles will contract minimally. Stimulus will occur behind the left and right ankle as well as both wrists in order to exam the pathways of the arms and legs. Small metal plates or very thin, sterilized acupuncture needles will be places on the right and left sides of the head, on the forehead, or in questions areas in the neck and shoulder.
The nerves from the brain to various muscles are examined using light, magnetic stimulation. During the examination you will lie on a lounge chair. Superficial electrodes are places over the muscles being examined. If your tongue or cheeks are being investigated, the electrodes are embedded in in a device which will then be placed on the tongue or the cheeks. Electronic stimulation activates the nerve cells. You will hear a clicking sound as the machine loads and experience short, light muscle contractions.