LIMITS OF THE HUMAN BRAIN

The human brain is an incredible machine, but it may have reached the limit of its abilities. Evolution could cause our brains to grow a bit more, though bigger may not necessarily be better.

Human beings have bad sight, bad hearing and a bad sense of smell. We’re not particularly strong either. So how did we become the planet’s dominant species? “It’s only because of our brain,” says Heinrich Reichert from the biocenter at Basel University. “Other than that we are pretty ill-equipped animals.”

Neuroscientists believe our brain is the best out there. Human brains aren’t all that different from the brains of other species. They’re just better. “It’s the same system, only much more powerful,” says Reichert. “It’s like comparing a super-computer to a PC.

Proportionally to the size of our bodies, our brains are big. But that in itself isn’t necessarily an advantage. Elephants have huge brains. Compared to humans, their neurons are bigger as well. But so are the distances separating those neurons, meaning it takes longer for signals to transmit between them.

“What’s striking in the human brain is its density,” according to Micah Murray from the center of biomedical imagery at the Lausanne University teaching hospital. “Primates’ neurons are more compact than those of rodents, for example. If [rodents] had as many nerve cells as we do, their brains would weigh about 45 kgs. And if you compare our brain with that of a chimp, it has more folds. That allows a bigger surface of grey matter and gives more possibilities for connections between neurons.”

Murray believes that our unmatched ability for abstraction, thought complexity, language and learning skills as well as the capacity to project ourselves in the future is what makes our brains exceptional.