Scaling up the simian primate cortex: A conserved pattern of expansion across brain sizes

The primate cerebral cortex shares a common plan of organization, but larger brains are not simply scaled-up versions of smaller brains—some cortical areas are disproportionately large in large brains, in comparison with small brains. We describe the use of computational methods to investigate how the size and location of different cortical areas changed in simian evolution. The results revealed a conserved pattern of expansion, likely to reflect the application of a shared developmental program to brains of different sizes. We also discuss how understanding evolutionary change is important for interpretation of human brain function and pathology.