Medial and lateral lines are drawn starting at the “inflection point” of curvature where the condyles are tallest, which is just proximal to the sulcus terminalis.

(A) The right vlFC ROI. Dorsally it included the inferior frontal sulcus and, more posteriorly, it included PMv; anteriorly it was bound by the paracingulate sulcus and ventrally by the lateral ...

A boundary called the central sulcus separates the two lobes. The parietal lobe also sits above the temporal lobe, with the Sylvian fissure, or lateral sulcus, separating the two.

Three-dimensional variability in cortical sulci between the patient and control groups. C, central sulcus; L, lateral sulcus. Courtesy of Jennifer G. Levitt, University of California, Los Angeles.