In 2007, a man in his mid-40s walked into a clinic in France complaining of a pain in his leg.
Since he’d had similar complaints as a child that had turned out to be linked to cerebrospinal fluid leeching into his brain ventricles, doctors decided to do a scan to see if that could be the culprit again.
They were stunned to find that not only was his brain full of fluid, but the ventricles were so swollen that they had replaced virtually everything in his brain except for a thin layer of neurons.
The man suffered no other ill effects. He was working full time, helping to support his wife and two children, and functioning, it would seem, with far fewer working brain regions that was previously thought possible to retain consciousness.
Image Credit: The Lancet
For example, scientists believe the thalamus relays sensory signals to the cerebral cortex, which neuroscientists previously would have said was indispensable for consciousness.
Research on coma patients with major damage in that area has led to that conclusion, as well as scientist’s ability to “switch off” consciousness by stimulating that brain region in epileptic patients. Similar beliefs have arisen about the brain region known as the claustrum, after like experiments and manipulation. The two areas communicate extensively.
Many in the field have linked consciousness to the brain’s structure, while others have long thought it was due simply to how neurons communicate – but this one case seems to lend support to the latter (less widely accepted) theory.
A recent study examined the patterns of neural activity that take place when we’re forming thoughts and found that neurons rarely use the most direct route of communication. Instead, they go through many different connections and channels before producing that highly complex impulse.
Image Credit: The Lancet
This is the same idea that lies at the core of the “Radical Plasticity Theory,” which says that consciousness arises as a result of the brain slowly “learning” how to become self aware.
Basically, we still don’t know for sure what makes us us, and what leads to and qualifies as human consciousness. This case does cause researchers to pose some interesting new questions, though, and every good scientists knows you can hardly ask for more than that.
Source: https://twistedsifter.com/2022/05/what-we-can-learn-about-human-consciousness-from-a-man-missing-most-of-his-brain/
