The machine will respond in a certain way when your brain is sending the "correct" signals. You might use your brain waves to make a robot or spaceship icon move about on the screen, or play a game like "Pac-man." Your brain experiences this as a reward for staying within the proper wavelengths, and it will begin to do so more often, and for longer periods, until the changes become longer lasting.
How does this help with migraines? Well, these debilitating headaches may originate from improper signals in the brain, and they are sometimes brought on by stress. In fact, people who feel they have little control over their lives are more likely to get migraines. Neurofeedback allows you to overcome your migraines and helps you to have more control over your life by changing the way your brain functions. In fact, in some studies, 80% of the people who used neurofeedback therapy saw no recurrences of their migraine headaches. These results were achieved without the use of heavy medications with their sometimes unpleasant side effects.