Brodmann areas are a system to divide the cerebral cortex according to cytoarchitectural organization, and are, despite controversy, still very widely used as a standardized nomenclature which is superimposed on the somewhat variable gyral and sulcal anatomy.
The classification relies on the fact that the human cortex is composed of six cellular layers, the density and architecture of which vary from region to region. These patterns are visible under the light microscope .
The Brodmann classification divides the cortex into approximately 52 areas, numbered sequentially, although some regions have been subsequently subdivided and other are only present in non-human primates.
The list below states how areas relate to functional areas and/or gyral landmarks.
- Brodmann areas 1, 2 & 3: primary somatosensory cortex (postcentral gyrus)
- Brodmann area 4: primary motor cortex (precentral gyrus)
- Brodmann area 5: somatosensory association cortex (superior parietal lobule)
- Brodmann area 6: premotor cortex and supplementary motor cortex
- Brodmann area 7: visuo-motor coordination (superior parietal lobule)
- Brodmann area 8: frontal eye fields
- Brodmann area 9: dorsolateral prefrontal cortex
- Brodmann area 10: anterior prefrontal cortex
- Brodmann area 11 & 12: orbitofrontal area (orbital gyri, gyrus rectus, rostral gyrus and part of superior frontal gyrus)
- Brodmann area 13 & 16: insular cortex
- Brodmann area 17: primary visual cortex (V1)
- Brodmann area 18: secondary visual cortex (V2)
- Brodmann area 19: associative visual cortex (V3, V4 & V5)
- Brodmann area 20: inferior temporal gyrus
- Brodmann area 21: middle temporal gyrus
- Brodmann area 22: superior temporal gyrus (including Wernicke area)
- Brodmann area 23, 24, 28 to 33: cingulate cortex
- Brodmann area 25: subgenual area
- Brodmann area 26: ectosplenial portion of the retrosplenial region of the cerebral cortex
- Brodmann area 27: piriform cortex
- Brodmann area 34: dorsal entorhinal cortex
- Brodmann area 35 & 36: perirhinal cortex & ectorhinal area
- Brodmann area 37: fusiform gyrus
- Brodmann area 38: temporal pole
- Brodmann area 39: angular gyrus
- Brodmann area 40: supramarginal gyrus
- Brodmann area 41 & 42: primary auditory cortex (Heschl gyrus)
- Brodmann area 43: primary gustatory cortex
- Brodmann area 44: part of Broca area (pars opercularis, part of the inferior frontal gyrus)
- Brodmann area 45: part of Broca area (pars triangularis, part of the inferior frontal gyrus)
- Brodmann area 46: dorsolateral prefrontal cortex
- Brodmann area 47: pars orbitalis, part of the inferior frontal gyrus
- Brodmann area 48: retrosubicular area
- Brodmann area 52: parainsular area
History and etymology
Brodmann areas are named after the German neuroanatomist Korbinian Brodmann (1868-1918) who first devised this cytoarchitectural map in 1909 .