The human brain has greater energy demands than that of any other animal, especially in certain important regions, which may have been key to the evolution of our complex cognition. Knowing how energy use differs across the brain could also help us better understand and treat certain conditions, such as Alzheimer’s disease and depression.
Some mammals have bigger brains and more nerve cells, or neurons, than humans, making it unclear how we evolved a uniquely advanced ability to think critically …
Source: Humans - newscientist.com