it tells us from other primates .
while other brain parts keep track of how well , or not , our decisions are working for us , the new structure is more outward - looking , and mulls over what we might have done instead .
but it is surprising how many similarities there can be , and how a couple of differences can mean our behaviour is so far removed from them , " said matthew rushworth , a professor of cognitive neuroscience , who led the study at oxford university . "
scientists spotted the region , named the lateral frontal pole , after scanning the brains of healthy humans in two different ways .
the size and shape of a large brussels sprout , the ball of neural tissue seems to be crucial for the kind of flexible thought that allows us to consider switching to a more promising course of action .
there are a few brain areas that monitor how good our choices are , and that is a very sensible thing to have .
but this region monitors how good the choices are that we did n't take .
 
we know there are differences between humans and monkeys .