Neuroanatomy of the Brain and its functionalities

The human brain is truly a masterpiece of creation!

The human brain is one-of-a-kind: our extraordinary cognitive ability has enabled us to invent the wheel, build the pyramids and land on the moon. Indeed, scientists have referred to the human brain as the "crowning achievement of evolution."

But what exactly is it about our brains that makes them so unique? Some of the most persuasive arguments have been that our brains have more neurons and expend more energy than would be expected for our size. Asides from this, our cerebral cortex, which is responsible for higher cognition, is disproportionately large—accounting for more than 80% of our total brain mass.

SuzanaHerculano-Houzel, a neuroscientist at Rio de Janeiro's Institute of Biomedical Science, disproved these long-held beliefs in recent years when she discovered a novel method of counting neurons—dissolving brains into a homogeneous mixture, or "brain soup." Using this technique, she found that the number of neurons relative to brain size is consistent with other primates and that the cerebral cortex, the region responsible for higher cognition, only contains about 20% of all neurons in our brain, a proportion similar to that found in other mammals. In light of these findings, she contends that the human brain is simply a linearly scaled-up primate brain that grows in size as we began to consume more calories due to the introduction of cooked food.

Other researchers have discovered that traits once thought to be unique to humans can also be found in other members of the animal kingdom. For instance, monkeys have a strong sense of justice, chimps are known for battle, while rats are altruistic and empathic. In a study published last week in Nature Communications, neuroscientist Christopher Petkov and his colleagues at Newcastle University discovered that macaques and humans share brain areas responsible for processing basic linguistic structures. [1]

Although some of the previously proposed reasons for our brain's uniqueness have been debunked, there are still numerous ways in which we differ. They have encoded in our genes as well as our ability to adapt to our surroundings. Two other studies, both recently published, add to the debate.