Magnetoencephalography (MEG) Mapping is a functional neuro-imaging technique for mapping brain activity by recording magnetic fields produced by electrical currents using very sensitive magnetometers. SQUIDs (superconducting quantum interference devices) are currently the most common magnetometer, while the SERF (spin exchange relaxation-free) magnetometer is being investigated for future machines. Applications of MEG include basic research into perceptual and cognitive brain processes, localizing regions affected by pathology before surgical removal, determining the function of various parts of the brain, and neuro-feedback. This can be applied in a clinical setting to find locations of abnormalities as well as in an experimental setting to measure brain activity.
Psychologists are also taking advantage of MEG neuro-imaging to better understand the relationship between brain functions and behavior. For example, a number of studies have been done comparing the MEG responses of patients with psychological troubles to control patients. There has been great success in isolating unique responses in patients with schizophrenia. MEG is also being used to correlate standard psychological responses, such as the emotional dependence of language comprehension.
Recent studies have reported successful classification of patients with multiple sclerosis, Alzheimer’s disease, schizophrenia, Sjögren’s syndrome, chronic alcoholism, facial pain and thalamocortical dysrhythmias. MEG can be used to distinguish these patients from healthy control subjects.