 Subjects enrolled in this study will be selected from patients requiring neurosurgical intervention in the form of craniectomy or craniotomy and, therefore, will not be exposed to an invasive procedure solely for the placement of subdural recording electrodes. During the standard craniectomycraniotomy procedure, the dura is opened to expose allowing the placement of the subdural recording strips with minimal modification to the standard surgical procedure. After the subdural strips are placed, the leads will be tunneled away from the brain so that they exit away from the brain, minimizing infection risk. This approach has the added benefit that when the study period is over, the tunneled leads can be removed at the bedside. 