1. A method for brain stimulation targeting based on brain connectivity, the method comprising: using an MRI system, acquiring a preoperative image of a brain; using image analysis software, defining a region of interest (ROI) of a brain in the preoperative image of the brain, the ROI including a plurality of voxels; using image analysis software, determining a probability of connectivity for each voxel in the plurality of voxels within the ROI with respect to each of a plurality of predefined target regions, wherein the determining of the probability of connectivity is conducted using diffusion tractography; and using image analysis software, segmenting the ROI to produce a connectivity map of the ROI with respect to a desired predefined target region in the plurality of predefined target regions, wherein the segmenting of the ROI is based on with which of the plurality of predefined target regions each voxel in the plurality of voxels within the ROI has the highest probability of connectivity, and the connectivity map provides an optimal location in the brain for directing stimulation with respect to the desired predefined target region in the plurality of predefined target regions.