Small grooves on the surface of our brain could play a key role in our reasoning. A recent study reveals that their depth influences connectivity between areas essential to cognition.
Long considered as simple consequences of evolution, these structures, called tertiary furrows, now arouse the interest of neuroscientists. Their individual variations seem to be linked to differences in intellectual performance, opening tracks to understand neurodevelopmental disorders.
Sillons that shape our brain connections
Researchers at the University of California in Berkeley analyzed the brains of 43 children and adolescents. Their work, published in The Journal of Neuroscienceshow that the deepest furrows reinforce the exchanges between the cortex Lateral prefrontal and the lateral parietal cortex. These regions are involved in complex cognitive functions. The advanced hypothesis suggests that these folds physically bring brain areas closer, optimizing neural communication. This configuration would partly explain why some individuals have better reasoning capacities. The tertiary furrows, which appeared late during evolution, would thus be anatomical markers of our skills.
Scientists have used functional MRI to map cerebral activity during tasks of logic. The results indicate that each furrow has a unique connectivity signature, identifiable with 96 %precision. This specificity confirms their functional role beyond their simple structure.
Plasticity under environmental influence
Contrary to popular belief, these brain structures are not immutable. Their morphology evolves throughout life, in response to learning andenvironment. This discovery opens up encouraging perspectives: intellectual stimulation could influence the development of these furrows, and therefore our cognitive capacities.
The study reveals, however, that not all cortical folds react in the same way. Only some particular furrows, located in key reasoning areas, show a clear correlation with intellectual performance. Their precise identification could ultimately serve as an indicator to assess brain development.
Researchers highlight the key role in education in this process. Even in adulthood, the brain retains a certain malleability. These works thus confirm the importance of early stimulation, while offering new avenues to understand learning disabilities.
This plasticity also opens up questions: to what extent can you “sculpt” your brain by cognitive training? Scientists now explore this track, while recalling that furrows are only one element among others in the puzzle of intelligence.
