Advances in neuromagnetic topography and source localization.

The development of ultra-low noise instrumentation for neuromagnetic mapping has yielded significant progress in the study of brain function and pathology. New multi-channel systems, belonging to an "intermediate" generation, are already in use, or are going to become operative in the near future. These systems permit simultaneous field mapping over a relatively large area of the scalp, and allow source localization on the basis of a single trial, although they still do not permit topographic mapping over the whole scalp. Significant improvements are being made also in realistic modeling of the human head and brain, with the aim at increasing the accuracy of source localization. Finally, a few examples of recent studies on normal brain function and application of the technique in the clinical field will be illustrated.