A cortical surface registration procedure related to a diagnostic or surgical procedure. In one embodiment, the procedure includes the steps of pre-operatively obtaining a first textured point cloud of the cortical surface of a targeted region of a brain of a living subject, intra-operatively obtaining optically a second textured point cloud of the cortical surface of the brain of the living subject, and aligning the first textured point cloud of the cortical surface to the second textured point cloud of the cortical surface so as to register images of the brain of the living subject to the cortical surface of the living subject.