The term area PGi refers to a cortical structure located in the posterior half of inferior parietal cortex, a region that is much expanded in humans relative to macaques and chimpanzees. It is bounded dorsally by area PGs, rostrally, ventrally and caudally (right) by areas of the temporo-parieto-occipital junction. On the left it is bounded caudally by area PGs. Defined by multiple criteria, it is a major node in the default network. It is fMRI activated in FACE-AVG, LANGUAGE STORY, and STORY-MATH tasks. Other authors have referred to the same topological area as PGa, 39, PG, or 90 ( Glasser-2016 ).