Introducing the brain: rethinking brain organization (Introduction)

by David Turell , Tuesday, August 24, 2021, 19:22 (1185 days ago) @ David Turell

There are general areas of specific function, but generally the brain works a whole:

https://www.quantamagazine.org/mental-phenomena-dont-map-into-the-brain-as-expected-202...

"Neuroscientists are the cartographers of the brain’s diverse domains and territories — the features and activities that define them, the roads and highways that connect them, and the boundaries that delineate them. Toward the front of the brain, just behind the forehead, is the prefrontal cortex, celebrated as the seat of judgment. Behind it lies the motor cortex, responsible for planning and coordinating movement. To the sides: the temporal lobes, crucial for memory and the processing of emotion. Above them, the somatosensory cortex; behind them, the visual cortex.

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"But a brain map with neat borders is not just oversimplified — it’s misleading. “Scientists for over 100 years have searched fruitlessly for brain boundaries between thinking, feeling, deciding, remembering, moving and other everyday experiences,” Barrett said. A host of recent neurological studies further confirm that these mental categories “are poor guides for understanding how brains are structured or how they work.”

"Neuroscientists generally agree about how the physical tissue of the brain is organized: into particular regions, networks, cell types. But when it comes to relating those to the task the brain might be performing — perception, memory, attention, emotion or action — “things get a lot more dodgy,” said David Poeppel, a neuroscientist at New York University.

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"But they also found unsettling evidence that those categories and the neural networks that support them don’t work as expected. It’s not just that the architecture of the brain disrespects the boundaries between the established mental categories. It’s that there’s so much overlap that a single brain network “has more aliases than Sherlock Holmes,” Barrett said.

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"But he and other scientists believe the recent findings also highlight a deeper conceptual problem in neuroscience. “We divide the real estate of the brain according to our preconceived ideas, assuming — wrongly, as far as I’m concerned — that those preconceived ideas have boundaries, and the same boundaries exist in brain function,” Buzsáki said.

"In 2019, Russell Poldrack, a neuroscientist at Stanford University, and his colleagues set out to test how appropriate the recognized categories for mental function are. They gathered a massive amount of behavioral data — obtained from experiments designed to test different aspects of cognitive control, including working memory, response inhibition and learning — and ran it through a machine learning classifier. The resulting classifications defied expectations, mixing up traditional categories of brain results and sorting them into new groups that seemed to “move together in terms of some much more generic constructs,” Poldrack said — constructs for which we don’t yet have labels, and which might not relate directly to our conscious experience.

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"But teasing apart the significance of different brain areas is further complicated by the discovery that the involvement of neural systems in particular functions isn’t simply all or nothing. Sometimes it’s contingent on the details of what’s being processed."

Comment: We see the brain is not a computer. As a living organ the neurons of a specific area can recruit any and all of the brain as required when the neurons recognize the current task at hand. That has to be seen as superb design. The article is very long and filled with examples of current discoveries.