DYNAMIC NEUROIMAGING OF BRAIN-FUNCTION

To fully characterize the brain processes underlying sensorimotor and cognitive function, the spatial distribution of active regions, their interconnections, and the temporal patterns of activity within and bet ween these interconnected regions must be measured. We describe method s for imaging brain sources from surface-recorded EEG and magnetoencep halographic data, called electromagnetic source imaging (EMSI), EMSI p rovides brain source locations within the common framework of magnetic resonance (MR) images of brain anatomy. This allows integration of da ta from other functional brain imaging methods, like positron emission tomography and functional MR imaging, which can improve the accuracy of EMSI localization. EMSI also provides submillisecond temporal resol ution of the dynamic processes within brain systems. Examples are give n of applications to visual perceptual and attentional studies.