Magnetoencephalography (MEG) is a non-invasive technique for investigating mental faculties activity. It allows this measurement of continuing brain activity using a millisecond-by-millisecond basis, and it shows where from the brain activity is produced. Applications of MEG include research into perceptual as well as cognitive brain procedures, localizing regions suffering from pathology before surgical removal, determining the function of parts of the brain, and neurofeedback.