When the brain is at rest, humans and monkeys do not think alike – edition du soir Ouest-France

When the brain is at rest, humans and monkeys do not think alike - edition du soir Ouest-France

Interview with Margot Ferreira

A new scientific study published in the April 12, 2022 issue of Cell Reports focuses on cognitive differences between humans and other animals at rest. Mark Tenain conducted the study. He returns to what can explain man’s “superior abilities.”

What distinguishes humans from animals? The question has attracted experts. Mark Denine, a CNRS researcher at the Neurodegenerative Disease Laboratory, and his team are studying brain connections. Different animals. For the first time, they have proven that one of the networks that exists in humans is not the same as in other animals. This network, called the “default mode network”, operates when the brain is at rest. This difference, among other things, can explain different behaviors in terms of information processing. Descriptions.

Mark Tennin, What is the “default mode network” in humans?

There are different parts of our brain. With nuclear magnetic resonance imaging (MRI) technology, it is possible to detect which areas are being activated simultaneously. When multiple components are implemented, we assume that it is a network, a synchronously functioning system. We have a lot of networks Brain : Networks involved in vision, walking, decision making … and each of these networks uses a different part of the brain. About ten years ago, when researchers said we did nothing – for example when we were asleep or in the waiting room – there were still areas that worked together, the network. This network is called the “Default Mode Network”.

What is he responsible for?

When we do nothing, we are in the logic of mind wandering and daydreaming. The network is then activated for many things such as thinking about itself or planning for the future. But he waits for information from the outside and evaluates its relevance to find out whether or not to start a process. For example, if we start daydreaming in the doctor’s waiting room, a lot of things around us can happen without our attention. But when the doctor’s door opens, our attention immediately goes to that information. And it’s the default network that allows us to click, to realize that something important is happening.

The human brain is made up of different parts that work in a network. (Description: Getty Images / iStockphoto)

How does this brain network differ in animals?

Initially, when we tried to compare this default network, we wanted to show that it is similar to many animal networks. We realized that was not the case. In the human default network, many parts are connected in a single network. In animals, this network is “transmitted” into at least two networks.

Differences were also found in relation to the intermediate prefrontal cortex. This is an area located in the front Brain Important for information handling. In the human default network, it is connected in an important way with the posterior cingulate cortex. In other animals, however, the intermediate prefrontal cortex was not attached. As animals have less ability to handle information coming from all parts of the brain.

This level difference is obvious, you can see it clearly in the culture, in the ability to project yourself into the future … and one of the important elements that can explain it is that the default network is very different.

What kind of animals are you interested in?

The research was conducted on small animals such as humans, macaques, marmosets and murine mouse lemurs. Macaulay is an Old World monkey. This is a type of monkey that originated in Africa. Marmosets are the new world apes that originated in the United States. There was an early split between the evolution of macaques and the evolution of marmosets. Also the rat lemon is an animal that is further removed from the monkeys. They are not primates, but Prosimians. The idea was that the primates should be much wider.

The researchers looked at the brains of different branches of the animal. (Description: Clement Carin)

How long did your research last?

The development of mouse lemur technology began five or six years ago. We realized that the networks of mouse lemurs were different from those of humans. So this was a starting point, which we released two years ago. From there, we looked at the integration between humans and other animals. It took two more years.

What about large animals like gorillas and chimpanzees?

In France, chimpanzees or gorillas are not allowed to study. There are tracks, but we are not 100% sure. They are believed to have a default network Is slightly closer to man Than other monkeys. So it’s about big apes, maybe not just humans.

Scientific studies of MRI on large animals are not recognized in France. (Photo: Edward Eswall / Reuters Archive)

What do your results show about the difference between humans and other animals?

The brain is organized differently. So if there is a different system, we assume that the function of the brain is different between species. This may explain the different and perhaps higher cognitive abilities of humans compared to other animals. This is one of the possible explanations. Now we can compare with the rest animals.

Clement Carin, the researcher on this study, is now wondering how dogs’ brains work. Are there different networks than apes and humans? It is very interesting to understand how the brains of other organisms work.

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