Mapping of Human Cognition

The purpose of this study is to compare organization of normal brain function as detected using Functional magnetic resonance imaging (fMRI) in normal subjects as opposed to patients with epilepsy or brain tumors, to ascribe precise anatomic labels (including Brodmann Areas) and functional significance to each region involved in cognitive processes as detected by cortical stimulation mapping (CSM) in patients with implanted subdural electrodes (SDE) or depth (sEEG) electrodes, to describe the locations of these regions in Talairach space, for a population of patients without overt structural abnormalities in these regions, to generate a spatial probability map of locations of cortical regions "essential" for these processes, to compare the loci of "crucial" language, visual, motor and cognitive sites as determined by CSM with the loci determined by a battery of tasks using fMRI for each individual and to use these data in patients undergoing intracranial electro-corticographyto determine the loci of essential, involved and uninvolved brain areas, and use sophisticated mathematical analyses of these intracranial recordings to study information flow between these areas.