Evolution and humans: big brain size or use (Evolution)

by David Turell @, Thursday, May 25, 2017, 18:53 (395 days ago) @ David Turell

A study of illiterate 30-year-old Indian women has shown they can learn to read quickly and the brain rewires itself in the process, since evolution has not prepared the brain for reading. although there is the preexisting speech area (Boca's):

https://www.newscientist.com/article/2132589-learning-to-read-and-write-rewires-adult-b...

"Skeide and his colleagues wanted to study how culture changes the brain, so focused on reading and writing. These cultural inventions have appeared only recently in our evolutionary history, so we haven’t had a chance to evolve specific genes for such skills.

"The team recruited 30 Hindi-speaking adults from two villages near the north Indian city of Lucknow, with an average age of about 31 years. Twenty one people from this group were taught to read and write the Devanagari script, which is used in Hindi and other Indian languages, over six months. Nine people weren’t taught anything. All of the volunteers had their brains scanned before and after the six-month period.

"By the end of the study, the team saw significant changes in the brains of the people who had learned to read and write. These individuals showed an increase in brain activity in the cortex, the outermost layer of the brain, which is involved in learning.

"Learning to read also seemed to change brain regions that aren’t typically involved in reading, writing or learning. Two regions deep in the brain, in particular, appeared more active after training – portions of the thalamus and the brainstem.

"These two regions are known to coordinate information from our senses and our movement, among other things. Both areas made stronger connections to the part of the brain that processes vision after learning to read. The most dramatic changes were seen in those people who progressed the most in their reading and writing skills.

"The brainstem and thalamus are also known to control attention, so this may also be enhanced by learning to read and write.

“'This clearly shows that reading, which involves important cognitive processes, also involves the development of important sensorimotor skills, namely the need to finely control eye movements to scan the text lines and to [move the eyes] onto most informative parts of text,” , says Gianluca Baldassarre of the Institute for Cognitive Sciences and Technologies in Rome, Italy.

"Such changes are probably happening in children as they learn to read and write, potentially faster and more widely, but no such studies have been done in children, says team member Falk Huettig of the Max Planck Institute for Psycholinguistics in Nijmegen, Netherlands."

Comments from another site: http://www.dailymail.co.uk/sciencetech/article-4538816/Learning-read-adulthoood-transfo...

"'While it is quite difficult for us to learn a new language, it appears to be much easier for us to learn to read.

"'The adult brain proves to be astonishingly flexible.'
Specifically, researchers found that the exterior of the brain - known as the cortex, which is able to adapt quickly to new challenges - was not the main area where transformation occurred.

"Instead, researchers found that reorganisation took place deep inside the brain, particularly in the brainstem and thalamus,

***

"'We observed that the so-called colliculi superiores, a part of the brainstem, and the pulvinar, located in the thalamus, adapt the timing of their activity patterns to those of the visual cortex,'"

Comment: this is direct evidence that brain size and complexity contains abilities that can be learned by recruiting different areas of the brain, helped by actual brain plasticity, that stands at the ready to do the work. It is obvious from this study that size and complexity come first and learned use is second, just as I hypothesize in the hominin brain development I've discussed. This study clearly shows brain size and complexity first, then learned use.


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