BRAINS

[KEND]

BRAIN AND CONSCIOUSNESS
A civil servant missing most of his brain challenges our most basic theories of consciousness
Not much is definitively proven about consciousness, the awareness of one’s existence and surroundings, other than that its somehow linked to the brain. But theories as to how, exactly, grey matter generates consciousness are challenged when a fully-conscious man is found to be missing most of his brain.
Several years ago, a 44-year-old Frenchman went to the hospital complaining of mild weakness in his left leg. It was discovered then that his skull was filled largely by fluid, leaving just a thin perimeter of actual brain tissue.
And yet the man was a married father of two and a civil servant with an IQ of 75, below-average in his intelligence but not mentally disabled.

Doctors believe the man’s brain slowly eroded over 30 years due to a build up of fluid in the brain’s ventricles, a condition known as “hydrocephalus.” His hydrocephalus was treated with a shunt, which drains the fluid into the bloodstream, when he was an infant. But it was removed when he was 14 years old. Over the following decades, the fluid accumulated, leaving less and less space for his brain.
While this may seem medically miraculous, it also poses a major challenge for cognitive psychologists, says Axel Cleeremans of the Université Libre de Bruxelles.
“Any theory of consciousness has to be able to explain why a person like that, who’s missing 90% of his neurons, still exhibits normal behavior,” says Cleeremans. A theory of consciousness that depends on “specific neuroanatomical features” (the physical make-up of the brain) would have trouble explaining such cases.
In theory, the frontal, parietal, temporal, and occipital lobes in the brain control motion, sensibility, language, vision, audition, and emotional and cognitive functions. But those these regions were all reduced in the Frenchman. He did not, however, suffer significant mental effects, suggesting that, if an injury occurs slowly over time, the brain can adapt to survive despite major damage in these regions.
Cleeremans, who gave a lecture on the subject at this year’s Association for the Scientific Study of Consciousness conference in Buenos Aires, believes that the seeming plasticity of the brain is key to understanding how consciousness operates.
He believes that the brain learns to be conscious. As such, few specific neural features are necessary for consciousness, since areas of the brain are able to adapt and develop consciousness.
“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 says.
In the paper where he puts forward his thesis, Cleeremans argues that in order to be aware, it’s necessary not simply to know information, but to know that one knows information. In other words, unlike a thermostat that simply records temperature, conscious humans both know and care that they know. Cleeremans claims that the brain is continually and unconsciously learning to re-describe its own activity to itself, and these descriptions form the basis of conscious experience.
Ultimately, Cleeremans believes that consciousness is “the brain’s theory about itself.” And so, while the Frenchman may have had a tiny brain, it was still apparently able to generate a theory about itself and is “a striking case of how the brain learns to adapt.”

Front Psychol. 2011; 2: 86.

[Serena]

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[Steve James]

Btw, just out today.
http://medicalxpress.com/news/2016-07-c ... gions.html

Connectome map more than doubles human cortex's known regions

The age of exploration has long passed, but there is at least one area still largely uncharted: the human brain. Now, a detailed new map by researchers at Washington University School of Medicine in St. Louis lays out the landscape of the cerebral cortex—the outermost layer of the brain and the dominant structure involved in sensory perception and attention, as well as distinctly human functions such as language, tool use and abstract thinking.

With the features of a typical brain demarcated in painstaking detail, the new map will be a boon to researchers studying brain disorders such as autism, schizophrenia, dementia and epilepsy. Scientists will be able to use it to understand differences in the brains of patients with these diseases compared with adults who are healthy. It also will accelerate progress in deciphering the workings of the healthy brain and elucidating what makes us unique as a species.

The work will be published July 20 in Nature.

The researchers drew upon data and methods generated by the Human Connectome Project, a five-year, multimillion dollar study led by David Van Essen, PhD, the senior author on this paper, and involving a consortium that includes the University of Minnesota and Oxford University. The Human Connectome Project used a powerful, custom-built MRI machine to map the brains of 1,200 young adults. This study complements the Human Connectome Project by carefully delineating the brain regions so that their connections can be more accurately mapped.

The new map divides both the left and right cerebral hemispheres into 180 areas based on physical differences (such as the thickness of the cortex), functional distinctions (such as which areas respond to language stimuli), and differences in the connections of the areas. Brain cartography is not as simple as noting a "mountain" over here and a "river" over there, since much of the brain looks superficially the same. The map is more akin to a map showing state borders than topographic features; the most important divisions are invisible from the sky, but extremely important all the same.

"The brain is not like a computer that can support any operating system and run any software," said Van Essen, the Alumni Endowed Professor of Neuroscience. "Instead, the software - how the brain works - is intimately correlated with the brain's structure—its hardware, so to speak. If you want to find out what the brain can do, you have to understand how it is organized and wired."

The researchers mapped the cortex, a layer of neural tissue that encases the rest of the brain like a crumpled sheet of paper. The cortex is important for sensation, attention, memory, perception, thought, language and consciousness.

[Steve James]

A German neuroanatomist, Korbinian Brodmann, first mapped the human cortex in the first decade of the 20th century. He identified 50 regions, including areas later shown to be involved in visual, language and sensory processing.

When the new study's lead author Matthew Glasser, PhD, began studying the connections between language areas of the brain almost a century later, he quickly became frustrated with Brodmann's map and how it was typically being used in neuroimaging.

"My early work on language connectivity involved taking that 100-year-old map and trying to guess where Brodmann's areas were in relation to the pathways underneath them," said Glasser. "It quickly became obvious to me that we needed a better way to map the areas in the living brains that we were studying."

To make this map, Glasser, Van Essen, and colleagues pooled data from 210 healthy young adults of both sexes. The researchers combined measures of the thickness of the cortex and the amount of insulation around neuronal cables, with MRI scans of the resting brain and of the brain performing simple tasks, such as listening to a story.

"We ended up with 180 areas in each hemisphere, but we don't expect that to be the final number," Glasser said. "In some cases, we identified a patch of cortex that probably could be subdivided, but we couldn't confidently draw borders with our current data and techniques. In the future, researchers with better methods will subdivide that area. We focused on borders we are confident will stand the test of time."

Some of those areas are clearly involved in particular tasks, such as 55b, which lights up with activity when a person hears a story. Others contain a map of a person's field of vision, or are involved in controlling movement. Most areas probably will never be identified with a single function, because they don't do just one thing but instead coordinate information from many different signals.

In the century between Brodmann's map and Glasser and Van Essen's, many other maps of the cortex have been drawn, showing anywhere from 50 to 200 different areas. The researchers improved on previous maps by precisely aligning the brains to a common coordinate system before analysis, using an algorithm developed by colleagues at Oxford University, and incorporating the highest-quality MRI data available. The researchers also verified that their method could be applied to individuals by producing maps of the brains of a different set of 210 healthy young adults.

[Michael]

This guy exists because sometimes zombies are thirsty.