The term area 23b (macaque) refers to a portion of the posterior cingulate gyrus defined on the basis of cytoarchitecture and connectivity in the macaque ( Vogt-1987 ). It is one of three subdivisions of area 23 (macaque). The other two are area 23a (macaque) and area 23c (macaque). Area 23b lies in the upper half of the gyrus between area 23a and area 23c. An equivalent area exists in the human ( Vogt-1995 ). For a more recent segmentation of this area by the same authors later in their studies ( Vogt-2012 ) see area 23.