The "and" wasn't the point. I don't see much in the literature regarding retardation of abstract thought due to the formation of myelin. Quite the opposite.

The "and" wasn't the point. I don't see much in the literature regarding retardation of abstract thought due to the formation of myelin. Quite the opposite. https://en.m.wikipedia.org/wiki/Myelin https://en.m.wikipedia.org/wiki/Myelin "Myelin is a fatty white substance that surrounds the axon of some nerve cells, forming an electrically insulating layer. It is essential for the proper functioning of the nervous system." Further "Myelination continues through the adolescent stage of life." And finally "The main purpose of a myelin layer (or sheath) is to increase the speed at which impulses propagate along the myelinated fiber" I'd say myelin is a pretty good thing. Pat Wolfe, in "Brain Matters: Translating Research into Classroom", goes on... https://books.google.nl/books?id=BzccMxS56LAC&pg=PA79&lpg=PA79&dq=myelin+sheaths+abstract+thought&source=bl&ots=ukonDf81F8&sig=pAaLg1yKJpq4WWLbb9nylE3uCdg&hl=en&sa=X&ved=0ahUKEwjj04zozqHPAhWFthQKHXScBwQQ6AEIGzAA https://books.google.nl/books?id=BzccMxS56LAC&pg=PA79&lpg=PA... "Neurons in the frontal lobe receive a myelin sheath late in development, as evidenced by the increased ability of children to engage in higher-level and more abstract thinking." I'm really stretching to understand how to interpret the conjunctive here