The term corpus callosum (Witelson) refers to an alternative segmentation of the corpus callosum as defined by dissection. Measurements are based on division of the midsagittal plane of the human corpus callosum into seven parts. The parts are defined by dividing the corpus callosum into halves, thirds, and the posterior one-fifth. Referred to by the author as ‘Regions 1-7’, they are the rostrum of the corpus callosum, genu of the corpus callosum, rostral body of the corpus callosum, anterior midbody of the corpus callosum, posterior midbody of the corpus callosum, isthmus of the corpus callosum and splenium of the corpus callosum ( Witelson-1989 ). Although Witelson applied this segmentation to the human corpus callosum, later studies have applied the method to different species, such as the chimpanzee ( Dunham-2006 ) and the capuchin ( Phillips-2007 ).