 A person could learn to raise or lower blood pressure, quiet muscle spasms, or soothe an irritable bowel. Neurofeedback is simply the application of this same principle to the electrical waves produced by the brain as recorded on an EEG, an electrocephalograph. With subtlety and skill, it is helping thousands of children and adults learn to regulate their own nervous systems, a not insignificant matter. For the CNS, the central nervous system determines just how one functions in life.