[grey_whiskers]

Perhaps you did not realize that cortex is gray matter and your brain stem, medulla, spine, and peripheral nerves are myelinated white matter. The article mangled by C-E Headlines would appear to be about what pressures might drive the evolution of such a feature.

I was much more interested in the differentiation between local and global connections; and that within the brain proper. See the earlier remark about supercomputers.

Cheers!

[VadeRetro]

I was much more interested in the differentiation between local and global connections; and that within the brain proper.

White (myelinated) matter is global connectivity. Fast transmission along the very long myelinated axons. Gray matter is local networking, octopus cells with lots of dendrites and synaptic connections with neighboring cells.