The term area 13m refers to one of four subdivisions of area 13 in the orbital gyri of the human cerebral cortex. Defined on the basis of multiple stains, it is a narrow, largely granular area located rostral to the junction of the olfactory tract with the cerebral cortex. It is bounded medially by area 13b rostrally and area 13a at the caudal end. It is bounded laterally by area 13l and rostrally by area 11m. For the relations of this segmentation and terminology to others, see Ongur-2003. Its equivalent in the macaque is area 13m (macaque). As primarily granular prefrontal cortex, it has no equivalent in the rat ( Wallis-2012 ).