Suzana Herculano-Houzel: What is so special about the human brain?
Suzana Herculano-Houzel summarizes two decades of her research work focused on answering the question How do we explain the extraordinary cognitive abilities of human beings, including:
How she verified that human beings on average have ~86 billion neurons.
Brains of different animals are not made the same way. In particular, in a rodent (such as a rats and hamsters) the number of neurons is not proportional to the size of the brain, whereas in primates (such as chimps and humans), the number of neurons is proportional to the size of the brain.
Energy consumption of a brain is linear in the number of neurons.
How the brain size had been growing slowly but couldn't grow faster because of unavailability of energy. And how everything changed when we learnt how to cook!