Prospective EEG technologists will find it difficult to gain any direct experience on a part-time basis in electroencephalography. Your first direct experience with the work will generally come during on-the-job training sessions or in the practical-experience (internship, co-op, practicum) portion of your formal training. You may, however, be able to gain some general exposure to patient-care activities by signing up for volunteer work at a local hospital. In addition, you can arrange to visit a hospital, clinic, or doctor's office where electroencephalograms are administered. In this way, you may be able to watch technologists at work or talk to them about what the work is like.

The basic principle behind electroencephalography is that electrical impulses emitted by the brain, often called brain waves, vary according to the brain's age, activity, and condition. Research has established that certain brain conditions correspond to certain brain waves. Therefore, testing brain waves can aid the neurologist (a physician specially trained in the study of the brain) in making a diagnosis of a person's illness or injury.

The EEG technologist's first task with a new patient is to take a simplified medical history. This entails asking questions and recording answers about his or her past health status and present illness. These answers provide the technologist with necessary information about the patient's condition. They also provide an opportunity to help the patient relax before the test.

The technologist then applies electrodes to the patient's head. Often, technologists must choose the best combination of instrument controls and placement of electrodes to produce the kind of recording that has been requested. In some cases, a physician will give special instructions to the technologist regarding the placement of electrodes.

Once in place, the electrodes are connected to the recording equipment. Here, a bank of sensitive electronic amplifiers transmits information to digital instruments, which record the patient’s brain waves on a computer screen.

EEG technologists are not responsible for interpreting the recordings (that is the job of the neurologist); however, they must be able to recognize abnormal brain activity and any readings that are coming from somewhere other than the brain, such as recordings of eye movement or nearby electrical equipment.

Technologists can make recording changes to better present the abnormal findings for physician interpretation. Stray readings are known as artifacts. Technologists must be able to determine what kinds of artifacts should be expected for an individual patient on the basis of his or her medical history or present illness. They should also be sensitive to these artifacts and be able to identify them if they occur.

Technologists must be able to detect faulty recordings made by human error or by equipment malfunctions. When mechanical problems occur, technologists should notify their supervisors so that trained equipment technicians can repair the machine.

Throughout the procedure, electroneurodiagnostic technologists observe the patient's behavior and make detailed notes about any aspect of the behavior that might be of use to the physician in interpreting the recordings. They also keep watch on the patient's brain, heart, and breathing functions for any signs that the patient is in any immediate danger.

During the testing, the patient may be either asleep or awake. In some cases, the physician may want recordings taken in both states. Sometimes drugs or special procedures are prescribed by the physician to simulate a specific kind of condition. Administering the drugs or procedures is often the technologist's responsibility.

EEG technologists need a basic understanding of any medical emergencies that can occur during this procedure. By being prepared, they can react properly if one of these emergencies should arise. For instance, if a patient suffers an epileptic seizure, technologists must know what to do. They must be flexible and able to handle medical crises during procedures.

EEGs are increasingly used in the operating room to monitor patients during major surgery, especially those involving surgery on arteries around the heart or head or neck. This type of procedure is called intraoperative neurophysiological neuromonitoring. EEG technologists may also handle other specialized electroencephalograms. For example, in a procedure called long-term monitoring (LTM), heart and brain activities are tracked over an extended time period by contonuous video monitoring. In evoked potential testing, a special machine is used to measure the electrical activity in the brain, spinal nerves, or sensory receptors in response to specific types of stimuli. In nerve conduction studies, technologists stimulate peripheral nerves with an electrical current and record how long it takes the nerve impulse to reach the muscle. The polysomnogram is a procedure that uses EEG and other physiologic monitors to evaluate sleep and sleep disorders.

Besides conducting various kinds of electroencephalograms, EEG technologists also maintain the machine, perform minor repairs (major repairs require trained equipment technicians), schedule appointments, and order supplies. In some cases, they may have some supervisory responsibilities; however, registered electroencephalographic technologists are usually supervisors in this setting.