ECoG mapping will take place during participant's scheduled surgery. Before the procedure, participant will be assigned one of the two types of mapping grids. The mapping grid will be placed directly on the surface of participant's brain during surgery. Participant will not be able to feel this. The grids contain electrodes attached to a computer to record brain activity. A wireless digital glove will be used with the high-definition grid. The glove records hand movements, while the grids shows the areas of the brain that are active during the hand movements.