Step-by-step illustration of manual cortical surface-volume tracing protocol. Points, shown in blue, selected on the volume (left), were matched to points along the surface (right), shown in white. These points were used to delineate the borders of each region. (B, G) The rostral border of the ERC/PRC was traced first. (C, H) Tracing continues caudally, with the dorsomedial and ventrolateral borders of ERC/PRC delineated. To increase reliability, the paths are only drawn to the midpoint. (D, I) ERC/PRC borders are fully traced. (E, J) Tracing of the PPHC borders extends from the ERC/PRC dorsomedial and ventrolateral borders.