On this page we have the amazing story of an MIT student who helped doctors find a baseball-sized tumor in his brain. Doctors performed surgery and removed the tumor. Later, the student gave a presentation to cancer researchers. A video of the presentation is included on that page.
Now I know what you are probably expecting – something like a wheelchair-bound presenter somehow managing to very slowly communicate by using some technology like that used by Stephen Hawking. But amazingly, the young man seems to show no sign whatsoever of a damaged mind. He walks and talks normally, and seems to have slick presentation skills sufficient to land him a job as a host on a morning TV show. The page tells us that this young man is now pursuing a PhD in mechanical engineering.
In the presentation, the young man tells us that the doctors removed about 12 billion neurons in his brain.
The anomaly discussed here is one of many in the medical literature in which people have lost large portions of their brains, and suffered little or relatively little damage. Now for another similar anomaly that is even more amazing. This is a case in which a human managed to function well in society as a French civil servant, even though he had almost no functional brain.
The case is discussed here. Inside a normal brain are tiny structures called lateral ventricles that hold brain fluid. In this man's case, the ventricles had swollen up like balloons, until they filled almost all of the man's brain. When the 44-year-old man was a child, doctor's had noticed the swelling, and had tried to treat it. Apparently the swelling had progressed since childhood. The man was left with what the Reuters story calls “little more than a sheet of actual brain tissue.”
In 1980 John Lorber, a British neurologist, recounted a similar case of a brain filled with fluid. “There's a young student at this university,” said Lorber, “who has an IQ of 126, has obtained a first-class honors degree in mathematics, and is socially completely normal. And yet the boy has virtually no brain.” According to Lorber, “We saw that instead of the normal 4-5 centimeter thickness of brain tissue...there was just a thin layer of mantle measuring a millimeter or so. His cranium is filled mainly with cerebrospinal fluid.” Lorber found other similar cases. Here is a link discussing his work.
According to the recent scientific paper published here, Lorber's findings have been confirmed by others:
John Lorber reported that some normal adults, apparently cured of childhood hydrocephaly, had no more than 5% of the volume of normal brain tissue. While initially disbelieved, Lorber’s observations have since been independently confirmed by clinicians in France and Brazil.
How can we explain such anomalies under the theory that the brain is the sole producer of your consciousness? One glib nonexplanation is the idea of degeneracy. The idea is that natural selection may have helpfully given us a brain that can lose most of its neurons but keep doing pretty much what it was doing before.
But no one can plausibly explain how such a thing could have evolved because of natural selection. Explaining the origin of human consciousness and man's mental traits is a nightmare enough without throwing in the additional difficulty of explaining how such functionality could have evolved in a way so that you could lose large parts of your brain (or even most of your brain) while still largely retaining your intellect.
I may note there is apparently no “degeneracy” at all in the human cardiac system. If one little artery gets blocked, you can die of a heart attack. If one little heart valve stops working, you also die. Why would evolution have given us “degeneracy” in the brain while not giving us “degeneracy” in the cardiac system?
There's a better explanation – that your human consciousness is not solely produced by the brain. Your consciousness may be an output that comes from the combined inputs of your brain and some totally mysterious “X Factor” from outside of your skull or outside of your body. That may be why human consciousness and intelligence can survive with relatively little damage when huge parts of the brain are lost. It may also be why people have reported floating above their bodies during near-death experiences.
As the scientific paper cited here states (in a challenge to materialistic orthodoxy), “the scope of explanations must not exclude extracorporeal information storage.”