Introducing the brain: Primate brain pattern (Introduction)

by David Turell , Monday, March 18, 2024, 18:37 (40 days ago) @ David Turell

One fractal formula fits all primates:

https://www.newscientist.com/article/2422268-single-mathematical-model-governs-primate-...

"A single mathematical model can explain the pattern of folds seen on the brains of a range of primates, from bush babies to macaques to humans.

"Bruno Mota at the Federal University of Rio de Janeiro in Brazil and his colleagues have spent years trying to find out whether there is a mathematical description for the crumpled, fractal shape of the cerebral cortex, which is the outer layer of a brain region called the cerebrum.

“'The question seems trivial because you can just pick up an MRI image [of a brain] and say this is the shape,” says Mota. “But what if I wanted to compare my description to another [brain]?”

"They have now discovered that some aspects of the mathematics are universal across many primate species.

"The researchers focused on how the cortex structure changes at different scales. For instance, their analysis involved zooming in on the fine details of individual folds and, at the other extreme, zooming out and considering only the coarse outline of the cerebral cortex.

***

"They found that the graphs for 11 primate species lay on the same kind of line, pointing to a fundamental mathematical similarity in the way the cerebral cortex folds across a wide range of primate species.

"To check the algorithm was detecting a real biological signal specific to primates, Mota and his colleagues applied it to scans of walnuts, the surface of which are wrinkled a little like the cerebral cortex, and to bell peppers, which are smooth but have roughly similar dimensions to the primate brain. The graphs for these foodstuffs did not form the same kind of line as the primates brains did, he says.

"Raul Muresan at the Transylvanian Institute of Neuroscience in Romania says this is an “amazing addition” to our understanding of how the functions of the brain depend on scale, something that researchers previously only captured with less realistic, two-dimensional analyses. The new approach leaves out some biological details, but the universality it uncovers may point to a kind of biological efficiency that relieves the cortex of having to develop many different folding mechanisms at different scales, he says."

From the paper abstract:

"The mammalian cerebral cortex is a morphologically complex structure spanning a wide range of sizes and shapes across species. We have previously demonstrated that the cortical folding across various mammalian species follows a universal scaling law that can be derived from a simple statistical physics model. The same law also applies across healthy humans and cortical regions. Here, we show that, despite all this diversity, cortical shape can be universally and explicitly expressed as the hierarchical composition of folded structures of different sizes.

"More specifically, using a new set of theory-inspired morphological variables that capture shape and size of the cortex as functions of length scale, we show that for 11 different primate species, there is a natural cortical surface-preserving coarse-graining procedure that in all cases recapitulates a common scale-invariant morphometric trajectory. This indicates these cortices are approximations of a single archetypical fractal shape, differing solely on the range of length scales for which the approximation holds. These results suggest the existence of a universal gyrification mechanism operating on all scales, and that there is only a small number of effective degrees of freedom through which Darwinian natural selection can select cortical shapes. This new way of expressing morphology can be used to parametrize stages of cortical development and aging, and to characterize different conditions such as Zika-induced microcephaly and Alzheimer's. We hope that this systematic approach may help elucidate the processes underlying cortical gyrification in health and disease." (my bold)

Comment: note my bold. Rather than restrictions in a Darwinism approach I see a designer God using a fractal pattern in this case as He used throughout evolution. Design is more efficient if it follows patterns.