Major Fiber Pathways Underneath the Insular Limiting Sulci. The sylvian fissure was split and the central core is seen in a lateral view. A circular cut was made along the insular limiting sulci, passing through the major fiber pathways of the cerebral isthmus and opening the lateral ventricle. The values shown in the illustration are the mean values (in millimeters) of our measurements of the distances from the anterior and posterior aspects of these major fiber pathways to the reference point of the insular limiting sulci under which they are located; the measurements along the anterior limiting sulcus were made from the frontal limen point, the measurements along the superior limiting sulcus were made from the anterior insular point, and measurements along the inferior limiting sulcus were made from the temporal limen point. The black stars indicate the positions of these points. The positions of the landmarks used for the central core subdivision into quadrants are also reported in Tables 2 and 3. The reference point of the inferior limiting sulcus is the temporal limen point, and the distance measurements posterior to this point were marked as positive values. The anterior limit of the amygdala was found anterior to this reference point, so we used a negative value to indicate that its location was before the reference point (zero). (Image courtesy of E de Oliveira)