Neuroscientists have come up with a new model of how the brain works, which says that the connections between brain regions are more important than the regions themselves. This new point of view helps us figure out why and how our brains are different. The findings will be published in a November 4th special issue of Science by the research team.

The right hemisphere is for creativity and the left is for logic. It’s an urban myth that comes from an old way of thinking about how our brain works, which says that different parts of the brain have different jobs. Many textbooks still present this outdated “modular” model of the brain.

But neuroscientists Stephanie Forkel at Radboud University and Michel Thiebaut de Schotten at the University of Bordeaux say we should look at how the brain works in a different way. Brain functions don’t just happen in one part of the brain. Instead, they come about when different parts of the brain talk to each other.

Forkel says, Take “language as an example.”

“Here, the result is greater than just the sum of the parts. To communicate, you need to very quickly understand what is said within a given context and consider the emotional intentions that depend on whom you talk to. 

“If the brain worked in a modular fashion, it would not allow us to have all these different language computations in such a short time frame.”

Neuroscientists claim that connections influence the anatomy and function of the brain by amplifying or attenuating brain signals. The way that brain regions are connected and how they function when doing cognitive activities are closely related. Brain connections can be used to anticipate where a function will occur in the brain. 

Forkel: “If you look at a children’s brain before they acquire literacy, you see that the white matter, which consists of nerve pathways, is already connected to the ‘classical’ reading area.”

The modular brain model cannot explain individual variability.

“Everyone has a different brain, which isn’t anything like the textbook brain we all know. That’s something I realised when I worked on postmortem brains. Neuroimaging research, most of the time, makes all the brains of participants fit a standard brain, leading to a loss of insight into the variability between people. That’s a big topic in neuroscience at the moment,” adds Stephanie Forkel.

With the new network approach, scientists can model how our brains have changed over time, for example. 

“If you look at the white matter, we see that older parts in our brain (the ‘reptile’ brain) are more or less the same. Parts that are more recently evolved are more variable between us. This puts brain evolution in a new framework.”

Also, the new way of studying how the brain works could have a big effect on clinical treatments. 

“There are patients with brain lesions without any symptoms or symptoms that you wouldn’t expect. In a study, we looked at how the lesions affected the whole brain network, and we could show that we could use the network pattern to predict which symptoms patients had or which symptoms they would develop one year later.”

The research team says that in order to bring the work up to date with this new model, researchers will need to set up professional networks that bring together different fields of neuroscientific research. This will push the limits of what we know now and lead to new ways of imaging the brain, personalized anatomical models, and a big impact in the clinic.

Source: 10.1126/science.abq2591