Despite advances in computer modelling and research on humans, we still understand very little about the human brain and we are unable to treat many neurological conditions and injuries effectively because of this. Human brains work in very similar ways to most primates and it is possible to create lesions in primate brains which mimic the effects of certain human conditions. If we accept that it is ethical to test on primates rather than humans, such research could be done using primates. Through understanding the effects of brain lesions, we may be able to develop treatments and therapies that would benefit humans.