Brodmann area 21, or BA21, is part of the temporal cortex in the human brain. The region encompasses most of the lateral temporal cortex, a region believed to play a part in auditory processing and language. Language function is left lateralized in most individuals. BA21 is superior to BA20 and inferior to BA40 and BA41. This area is also known as middle temporal area 21. It is a subdivision of the cytoarchitecturally defined temporal region of cerebral cortex. In the human it corresponds approximately to the middle temporal gyrus. It is bounded rostrally by the temporopolar area 38 (H), ventrally by the inferior temporal area 20, caudally by the occipitotemporal area 37 (H), and dorsally by the superior temporal area 22 (Brodmann-1909). [WP,unvetted]. [ http://en.wikipedia.org/wiki/Brodmann_area_21 ]