Brain complexity: learning new tasks (Introduction)

by David Turell , Saturday, November 18, 2017, 01:17 (2563 days ago) @ David Turell

A new paper on expanding with new skills and then shrinking as the brain reorganizes its newly developed region:

https://www.livescience.com/60967-brain-cells-learning-pruning.html?utm_source=ls-newsl...

"Every time you learn a skill, new cells burst to life in your brain. Then, one after another, those cells die off as your brain figures out which ones it really needs.

"In a new opinion paper, published online Nov. 14 in the journal Trends in Cognitive Sciences, researchers proposed that this swelling and shrinking of the brain is a Darwinian process.

"An initial burst of new cells helps the brain deal with new information, according to the paper. Then, the brain works out which of these new cells work best and which are unnecessary, killing off the extras in a survival-of-the-fittest contest. That cull leaves behind only the cells the brain needs to most efficiently maintain what it has learned, the paper said.

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"Researchers have long known that brains change in response to learning. A classic 2003 study, for example, observed major volume differences between the brains of professional and amateur musicians. But the new study is the first time researchers have watched that growth in action over a fairly long timescale, Wenger said, and offered a hypothesis as to how it works.

"Wenger and her colleagues had 15 right-handed study subjects learn, over the course of seven weeks, to write with their left hands. The researchers subjected the enterprising learners to magnetic resonance imaging (MRI) brain scans over the study period. The gray matter in the subjects' motor cortices (regions of the brain involved in muscle movement) grew by an additional 2 to 3 percent before shrinking back to its original size, the researchers found.

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"Some mix of neurons and synapses — as well as various other cells that help the brain function — bursts into being as the brain learns. And then some of those cells disappear.

That's all the researchers know so far, though it's enough for them to develop their still-somewhat-rough model of expansion and renormalization. In order to deeply understand exactly how the process works, and what kind of cells are being selected for, the researchers need to study the process at a much finer level of detail, they said in the paper. They need to see which cells are appearing and which are disappearing."

Comment: If this process exists now I am sure it was present in the first hominins and carried through all the steps until H. Sapiens appeared 300,000 years ago. It was not invented along the way. And it probably is present in apes and monkeys to a lesser degree and developed further as our ancestors branched off.