“We discovered that brain connectivity — namely the efficiency of information transfer through the neural network — does not depend on either the size or structure of any specific brain,” says Prof. Assaf. “In other words, the brains of all mammals, from tiny mice through humans to large bulls and dolphins, exhibit equal connectivity, and information travels with the same efficiency within them. We also found that the brain preserves this balance via a special compensation mechanism: when connectivity between the hemispheres is high, connectivity within each hemisphere is relatively low, and vice versa.”…
“Brain connectivity is a central feature, critical to the functioning of the brain,” Prof. Assaf explains. “Many scientists have assumed that connectivity in the human brain is significantly higher compared to other animals, as a possible explanation for the superior functioning of the ‘human animal.'” On the other hand, according to Prof. Yovel, “We know that key features are conserved throughout the evolutionary process. Thus, for example, all mammals have four limbs. In this project we wished to explore the possibility that brain connectivity may be a key feature of this kind — maintained in all mammals regardless of their size or brain structure. To this end we used advanced research tools.” …
Prof. Yovel describes another interesting discovery. “We found that variations in connectivity compensation characterize not only different species but also different individuals within the same species,” he says. “In other words, the brains of some rats, bats, or humans exhibit higher interhemispheric connectivity at the expense of connectivity within the hemispheres, and the other way around — compared to others of the same species. It would be fascinating to hypothesize how different types of brain connectivity may affect various cognitive functions or human capabilities such as sports, music or math. Such questions will be addressed in our future research.”
“Our study revealed a universal law: Conservation of Brain Connectivity,” Prof. Assaf concludes. “This law denotes that the efficiency of information transfer in the brain’s neural network is equal in all mammals, including humans. We also discovered a compensation mechanism which balances the connectivity in every mammalian brain. This mechanism ensures that high connectivity in a specific area of the brain, possibly manifested through some special talent (e.g. sports or music) is always countered by relatively low connectivity in another part of the brain. In future projects we will investigate how the brain compensates for the enhanced connectivity associated with specific capabilities and learning processes.”
American Friends of Tel Aviv University, “MRI scans of the brains of 130 mammals, including humans, indicate equal connectivity” at ScienceDaily
Paper. (paywall)
So what makes humans unique isn’t brain connectivity.