This is an interesting story that demonstrates the astonishing adaptability of the body. A man was found with a brain only about 25% the usual size, and yet he is fully functional and not mentally impaired. From the story in the New Scientist:
A man with an unusually tiny brain manages to live an entirely normal life despite his condition, which was caused by a fluid build-up in his skull. Scans of the 44-year-old man’s brain showed that a huge fluid-filled chamber called a ventricle took up most of the room in his skull, leaving little more than a thin sheet of actual brain tissue (see image, right).
Scientists say that the finding could challenge many presumptions about the brain:
The findings reveal “the brain is very plastic and can adapt to some brain damage occurring in the pre- and postnatal period when treated appropriately,” [Lionel Feuillet, a neurologist at the Mediterranean University in Marseille, France] says.
“What I find amazing to this day is how the brain can deal with something which you think should not be compatible with life,” comments Max Muenke, a paediatric brain defect specialist at the National Human Genome Research Institute in Bethesda, Maryland, US. “If something happens very slowly over quite some time, maybe over decades, the different parts of the brain take up functions that would normally be done by the part that is pushed to the side,” adds Muenke, who was not involved in the case.
What is that old saying, what we don’t know could fill a book?