Science desk – A French man lives daily life without 90 per cent of his brain absent. This fact has challenged scientists to rethink their understanding about consciousness. Even after decades of research, our understanding about human consciousness-being aware of one’s existence- is still very thin. We know that it lies somewhere in the brain but it has become extremely difficult for scientists after discovering a man with 90 per cent of his brain gone.

The 44 year old French man went to the doctor complaining mild weakness in his left leg. After being diagnosed, it was revealed that his skull was mostly filled with fluid, leaving just a thin outer layer of brain tissue.

His internal part of brain has absolutely eroded away. Doctors think the majority of the man’s brain was slowly destroyed over the course of 30 years by the build-up of fluid in the brain, a condition known as hydrocephalus. He was diagnosed with it as an infant and treated with a stent, but it was removed when he was 14 years old, and since then, the majority of his brain seems to have been eroded. With an IQ of 75, the man was able to perform daily routines, which includes working as a civil servant. He is also married with two children. His identity is kept confidential, according to a science journal.

An image of a healthy brain

In the past, researchers have suggested that consciousness might be linked to various specific brain regions – such as the claustrum, a thin sheet of neurons running between major brain regions, or the visual cortex. The French man should not be conscious with the majority of his brain missing, if those hypotheses were correct.

Axel Cleeremans, a cognitive psychologist from the University Libre de Bruxelles in Belgium, has come up with a hypothesis based on the brain learning consciousness over and over again, rather than being born with it. Which means its location can be flexible and learnt by different brain regions. “Consciousness is the brain’s non-conceptual theory about itself, gained through experience – that is learning, interacting with itself, the world, and with other people,” he explains.

He calls his hypothesis the ‘radical plasticity thesis’, and it fits very well with the French man who is living with only 10 per cent of his brain tissue and recent research that suggests the adult brain is more adaptable than we previously thought – and capable of taking on new roles in case of injury.

According to Cleeremans, though the man’s remaining brain was only tiny, the neurons left over were able to still generate a theory about themselves, which means the man remained conscious of his actions.

We are discovering more and more each day just how flexible and adaptable our brains really are. Just this week, scientists were able to trigger brain cells to start growing again in order to restore vision in blind mice. But it’s a striking reminder of what our brains can learn to achieve, even when they’re incredibly damaged, and provides hope that we might one day learn how to reverse some of the illnesses that cause neuro-degeneration.

newsnextbd.com/rk/n