Forget what you learned in school — the brain might not work in 'regions' after all

• You may have been taught that brains are organized in neat regions with a specific purpose.

What you think you know about "regions" of the brain may be wrong.

School biology lessons and countless psychology theories draw on the supposedly distinct functions of areas like the frontal cortex and hippocampus, each with their role to play.

But these distinctions may play a much smaller role than previously believed, according to a scientific analysis published in the peer-reviewed journal Science on Thursday.

Not so neat after all

Scanning techniques developed in recent decades have shown that injuries don't always match up with the classical map of the brain, said Stephanie Forkel, one of three authors of the analysis.

Forkel is a neuroscientist at the Donders Institute of Radboud University in the Netherlands.

"I work a lot with stroke patients who lose the ability to use language," she said. "I realized that there is this mismatch. You can have a lesion and not have the symptoms or have a lesion somewhere else, but have the symptom. So that didn't match the textbooks."

The analysis, which reviewed previously published research using these new imaging techniques, suggests that maps of the brain may be too restrictive.

White matter ruling how we think and feel

Brains are made up of two types of material: white matter and gray matter. The gray stuff is where the actual thinking was thought to take place, with the white matter playing a role of connector.

The new model from Forkel and her colleagues changes that, giving white matter a much bigger role.

Per the new analysis, gray matter still processes the information. But it's how the white matter connects the information in the brain that defines how we think and act and feel.

Think of it like a football team. The gray matter of the brain is like a bunch of football players, each of which have their own skills and weaknesses.

But it doesn't matter how much skill a player has. It's how the coach puts the team together that wins the game.

"We are now thinking that it is the association between the brain regions that is doing the stuff and we have some solid arguments in this favor," said Michel Thiebaut de Schotten, another author of the analysis.

Thiebaut de Schotten is a professor of neurosciences at the French National Centre for Scientific Research.

One example of how white matter connects unexpected regions of the brain is the incredible injury of a railway worker 150 years ago.

In 1848 Phineas Gage, then 25, was packing down explosives in a boulder with an iron rod when the gunpowder went off, shooting the rod right through his skull.

Gage miraculously survived. But his behavior changed forever. The once-agreeable Gage became short-tempered and irritable, unable to keep down a job.

Thiebaut de Schotten's research suggests it came down to white matter.

"The connections that were interrupted in Phineas Gage between the bit of frontal cortex and the amygdala actually explained very well the change of behavior," he said.

"He was not able to inhibit his emotion as well as he used to. And that is because the cables between the two regions have been interrupted."

One argument to support this idea, Thiebaut de Schotten said, was a 2009 study looking at brain scans of psychopaths. That study found that the same connections that were damaged in Gage's white matter were less pronounced in people with psychopathy, he said.

For Forkel, it makes complete sense that our complex behaviors, like language, are spread out all across our brain.

"Language is so complex, we don't think about it because we just use it every day," she says. "You need to talk and you need to understand. And ideally those two centers are connected and talk to each other.

"But when you think about it, language is so much more, it is humor, intonation, emotional effect."

White matter may organize the regions

It's also possible that it is the white matter that directs which region does what in the gray matter, rather than the other way around.

Just like a football player can learn another position on the pitch, areas outside of dedicated regions can easily learn to pick up information.

In a 2000 study, scientists rewired the brain of young ferrets to test this theory. They connected the white matter that receives signals from the eyes and plugged it into the gray matter that is usually thought to be responsible for hearing.

The ferret's brain was able to adapt and learn to see using the auditory region of the gray matter, Thiebaut de Schotten said.

Not everybody agrees with this view of the brain

Putting all this together, Forkel and Thiebaut de Schotten suggest that the regions of the brain are much less important than what connects them.

Forkel and Thiebaut de Schotten both acknowledge that their view of how the brain work isn't shared by all of their colleagues.

Scientists have been entrenched in this idea that gray matter is king for a very long time, and a lot of research rests on the idea, they said.

This analysis suggests that these studies will have to be rethought to look at the brain as a whole. But Thiebaut de Schotten is undeterred.

"I do research — controversy is always welcome," he said.