The development of medical applications for magnetoencephalography may soon lead to an exciting breakthrough in neurology. The analysis of magnetic activity in the brain, magnetoencephalography remains primarily a research tool for now. Its only current medical application involves identifying the locations of epileptic seizures, which focuses on specific parts of the brain. But Dr. Apostolos Georgopoulos of the University of Minnesota began to wonder if the magnetic activity of the brain as a whole might contain useful diagnostic information. When he studied the responses of healthy brains as subjects stared at a point of light, Dr. Georgopoulos indeed found a characteristic magnetic pattern. This, however, would only be useful if that pattern could be distinguished from those of people suffering from neurological diseases. A statistical trick known as discriminant function analysis, conducted on magnetic scans of people with afflictions such as Alzheimer's and schizophrenia, revealed just such a distinction. The next and most critical step will determining whether the same clarity of diagnosis applies to individuals with mild cognitive impairments. About half of elderly patients with mild symptoms go on to develop Alzheimer's. Similarly, about half of teenagers who show signs of schizophrenia continue on to a full-fledged diagnosis. While it is currently impossible to tell which patients will fall into which group, earlier diagnosis of these and other illnesses could substantially help those at risk.