Consciousness: only half brain needed (General)

by David Turell , Sunday, November 24, 2019, 05:00 (1825 days ago) @ David Turell

A new study on six folks wit h half the brain removed in childhood to stop severe epilepsy:

https://www.livescience.com/hemisphere-removed-brain-plasticity.html?utm_source=Sellige...

"One of the best ways to understand this plasticity is to study patients who had parts of their brains removed. For the new study, a group of researchers at the California Institute of Technology analyzed the brains of six adults in their 20s and 30s who had hemispherectomies when they were between 3 months old and 11 years old to reduce epileptic seizures.

"The team found that, among patients with only one brain hemisphere, brain regions involved in the same network (such as vision) worked together just as well as those in healthy patients who had their entire brains intact.

"What's more, the authors found that connectivity — and thus communication — between parts of different networks are actually stronger in patients who had a hemisphere removed. In this way, it seems the brain is able to compensate for the loss of brain structure, the authors said.Many of these patients were high functioning, with intact language skills. "When I put them in the scanner we made small talk, just like the hundreds of other individuals I have scanned," lead author Dorit Kliemann, a postdoc at the California Institute of Technology, said a the statement. "You can almost forget their condition when you meet them for the first time."

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"There are many other cases in the literature that document the brain's amazing ability to adapt to an unexpected situation. For example, a young boy had a third of his right hemisphere removed, which included the part of the brain responsible for sight. But a few years after his surgery, neuroscientists found that the left side of his brain started taking on the missing left side's visual tasks, and he could still see just fine, according to a previous Live Science report.

"Another recent study found a small group of women who could smell despite missing their olfactory bulbs, the region in the front of the brain that processes information about smells. Though it's unclear how this happens, researchers think that it's possible another part of their brain took on the task of processing smells, according to another Live Science report."

Comment: this degree of adaptive plasticity comes built in. And note full consciousness with a half brain. Consciousness is not related to a whole substrate. it seems any portion of the brain will have it. Egnor has noted fully functional folks with a sliver of rind for a brain. We know substances that alter brain function alter consciousness. But a normally functioning half a brain is all that is needed. Obviously the brain does not make consciousness, which is Egnor's point.