New research has found that humans possess at least two unique networks in their cerebral cortex that are not seen in rhesus monkeys. The rhesus monkeys, though, do have one network that seems to be unique to them that humans do not have. The researchers theorize that these networks were probably ‘added’ sometime in the last few million years. The discoveries were made by analyzing the functional brain scans of humans and of rhesus monkeys, and comparing the two during different activities.