On the surface of the brain is an area that controls all the voluntary movements of our muscles.

There, all parts of the body are represented according to their sensitivity.

Since the middle of the last century, neurobiologists have developed a schematic representation of this area, it is the homunculus – or “little man” in Latin.

This homunculus is nothing other than a sort of humanoid with a disproportionate body, the size of each of the parts of its body corresponding to the space devoted to it in this area, called the primary motor cortex.

A study published in the journal Nature reshuffles the cards of this representation “by suggesting that the primary motor cortex could in fact be involved in the coordination of complex movements mobilizing several muscles, the physiology of our body, the planning of actions or even critical thinking”, writes the British scientific journal in an article for the general public.

“This study is very interesting and very important,” says Michael Graziano, a neurologist at Princeton University in New Jersey (USA), who was not involved in the study.

For the scientist, it becomes clear that the primary motor cortex is not just “a simple list of muscles that descend from the brain and control the toes to the tongue”.

To come to the conclusion that the primary motor cortex plays a bigger role than previously believed, the researchers used functional magnetic resonance imaging (fMRI).

They thus discovered in the primary motor cortex “three areas strongly connected to each other as well as to other parts of the brain responsible for planning actions, tasks such as the regulation of blood pressure or pain” , details Nature.

fMRIs were also performed on infants and, surprisingly, the researchers found that the latter “had not yet developed this particular network, unlike children aged 11 months and 9 years”, explains the scientific journal.

“A discovery which confirms that this newly described network could coordinate complex actions since infants are unable to have precise control of their movements”, indicates Nico Dosenbach, neurologist at Washington University in Saint-Louis (United States) , who led the study.

These findings could change and make existing therapies more accurate for addressing primary motor cortex disorders caused by injury or stroke.

Please find this study bellow: