Transcription
In 2007, a strange headline shocked the world. The mysterious case of the white-collar worker without a brain.
On the outside, a normal 44-year-old man, employed, married with two children, and an IQ of 75.
And on the inside, a gaping fluid-filled cavity where a brain would normally be. And he's not the only one. Stories like this keep making headlines.
People living otherwise regular lives, but underneath the surface, nothing. How do these stories challenge our understanding of how the mind works?
And how would you feel if you found out you had no brain? The case of the missing brain is rare, but not unique. Outside of the headlines, there have been many studies examining these instances of people missing most of their brains.
Often, these people go into hospital for other reasons, and only then does a scan reveal that they just have a thin layer of cortex, the rest of their skull filled with fluid. In these cases, it's a surprise that these people have been going about their lives fairly normally all while lacking so much brain matter.
Even rats with hollowed-out brains have been shown to perform well at various tasks. Importantly, if you're born with no cortex, things look pretty bleak. Infants born with hydrocephalus rarely survive longer than a year. But these cases of having barely any brain reveal something quite extraordinary.
If you were born with just a tenth of your liver, you'd have a serious issue. But somehow, the brain can handle it. We know what brains are supposed to look like, and these brains just don't look right.
Our nervous system, the brain, the spinal cord, and the brainstem float around in cerebrospinal fluid. Our brain should have a few ventricles, but not ventricles that big. A normal adult skull has a bit of fluid in the center and around the edges. The rest is brain matter.
But the skulls of these individuals are mostly filled with fluid, with just a little bit of brain matter at the outskirts. It's like the central ventricles have overflown completely, which is actually something that can happen in adulthood, a condition known as hydrocephalus, and it's bad news.
The skull fills with excess fluid, which impairs behavioral, cognitive, and motor functions. And to prevent serious damage, shunts have to be installed to drain the excess fluid.
But in these cases, if the initial brain to fluid ratio is different, somehow it works just fine. It's just a different arrangement.