People have exhibited "normal" behaviour with extensive brain damage, like the boy in your example, and have gone gonzo-weird with (seemingly) minuscule brain trauma.
Part of why I find the Brain/Mind so fascinating.
So maybe removing the corpus callosus from a normal brain would kill it or turn it into a vegetable, but it's possible for the brain to develop viably without one? A vivid image of what should exist acts as a surrogate for reality. Pursuit of the image then prevents pursuit of the reality -- John K. Galbraith
"Malformation" is a physical characteristic, not necessarily having a functional affect.
That I know of.
This is kcurie territory and the wimp wimped out. (The wuss! :-)
It's not very expensive. And almost entirely painless.
And almost entirely painless.
operative word: almost!!
we already did, tbg, and yes it hardly hurt at all...
clutches cranium and staggers off into the night gibbering.
je je jejeje...
oops, wires crossed again.. ~"When an inner situation is not made conscious, it appears outside as fate." Karl Jung~
It seems there are processes during brain development that 'do their thing' with can give rise (emergent property?) to an attempt to full (?) and complete (?) status? It seems to be true that areas of the brain have their potential function lost by adjacent areas 'moving in' if it is unstimulated at the proper time or in the proper degree.
Yet other functions - language - develop no matter if the child is stimulated by human language or not.
Removing functions in a 'finished' adult brain can kill or put a person in a coma. But not always. I don't know if an adult has ever had their corpus collosum removed. There have been cases where it has been severed, eliminating the cross-hemisphere traffic, to ameliorate epileptic attacks. These are the basis for the Split Hemisphere studies and their well-known findings. These people are functional but not fully functional to a "normal" level.
As I said, it's a puzzlement.