The Neural Code and Dynamics of the Reading Network.

Comparative Analysis of Structural and Functional Characteristics of Brain Regions Measured by Functional Imaging AND Electrophysiology and Hemispheric Laterality Predicted by Structural Connectivity and Fronto-basal-ganglia Circuits for Selective Stopping and Braking and Diffusion Imaging for Seizure Focus Localization AND Representation and Binding of Spatial and Temporal Episodic Memories in Human Hippocampus AND Sparsity and Spectral-Temporal Decomposition in Real-Time Network Modulation for Intractable Epilepsy AND Neural Basis of Human Spatial Navigation AND Mapping Brain Regions of Mood

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.

In either the MRI suite, or the Epilepsy Monitoring Unit, or the operating room, epilepsy and tumor subjects are asked to perform a variety of language-based tasks as neural recordings are made from and/or neural stimulations are delivered to various language areas of the brain.

Inclusion Criteria: patients with medically refractory epilepsy who are scheduled to undergo or have previously undergone placement of sub-dural electrodes (including depth electrodes) to localize the site of seizure onset and to map the locations of critical language and motor regions patients with epilepsy, brain tumors or cortically based vascular malformations (cavernous malformations or arterio-venous malformations) with lesions that are/were proximate to crucial brain regions, and who are scheduled to undergo or have previously undergone intra-op mapping of motor, visual or language function, or a Wada test, or maybe part of an awake craniotomy. proficiency in English Exclusion Criteria: Gross structural abnormalities (large hamartomata, tumors, large vascular malformations, very large diffuse malformations of cortical development) that may have impacted upon the location of critical brain areas. Unable to participate in testing due to impaired cognition or mental retardation. Cardiac pacemakers, intracranial aneurysm clips, or other potentially mobile implanted metallic devices Patients with claustrophobia who cannot undergo an MRI scan without sedation