brain plasticity: blind use optical cortex for language (Introduction)

by David Turell , Monday, September 18, 2017, 23:40 (2624 days ago) @ David Turell

New research shows this:

https://www.newscientist.com/article/2147696-blind-people-repurpose-the-brains-visual-a...

"People who are blind use parts of their brain that normally handle for vision to process language, as well as sounds – highlighting the brain’s extraordinary ability to requisition unused real estate for new functions.

"Neurons in the part of the brain normally responsible for vision synchronise their activity to the sounds of speech in blind people, says Olivier Collignon at the Catholic University of Louvain (UCL) in Belgium. “It’s a strong argument that the organisation of the language system… is not constrained by our genetic blueprint alone,” he says.

"The finding builds on previous research showing that the parts of the brain responsible for vision can learn to process other kinds of information, including touch and sound, in people who are blind.

***

"While they were being scanned, groups of sighted and blind volunteers were played three clips from an audio book. One recording was clear and easy to understand; another was distorted but still intelligible; and the third was modified so as to be completely incomprehensible.

"Both groups showed activity in the brain’s auditory cortex, a region that processes sounds, while listening to the clips. But the volunteers who were blind showed activity in the visual cortex, too.

"While they were being scanned, groups of sighted and blind volunteers were played three clips from an audio book. One recording was clear and easy to understand; another was distorted but still intelligible; and the third was modified so as to be completely incomprehensible.

"Both groups showed activity in the brain’s auditory cortex, a region that processes sounds, while listening to the clips. But the volunteers who were blind showed activity in the visual cortex, too.

"The blind volunteers also appeared to have neurons in their visual cortex that fired in sync with speech in the recording – but only when the clip was intelligible. This suggests that these cells are vital for understanding language, says Collignon.

"The visual cortex contains the relevant architecture, he says, to go from sound processing to language comprehension.

“'The new finding is perhaps not surprising, but it is groundbreaking,” says Daniel-Robert Chebat at the Israeli Ariel University in the West Bank. “It shows that these parts of the brain are not only recruited [to receive new kinds of input], but can adapt and modulate their response.”

"The discovery highlights how malleable our brains are, says Collignon, but he thinks there may be a limit to this. It’s unlikely that any part of the brain can eventually learn any function, he says. Instead, there may be a set of rules, laid down in our genes, which brain regions can follow."

Comment: This is further evidence of how the human brain can modify its functional areas. It allows a highly complex organ to adapt to almost any function presented to it. The brain enlarged and developed this capacity over an eight million year period, rather speedily for evolution. It development looks designed and driven.