Our Ability to Talk and Write Are Independent Of Each Other

by Natalie Shoemaker

Writing is a recent innovation in the history of human evolution. So, how then is it that our brains have incorporated a skill of this type? Is it based on speaking?

Lead researcher Brenda Rapp, along with her team, wanted to find out just that. They write in their paper that it's possible “written language is dependent on evolutionarily older skills, such as spoken language; another is that dedicated substrates develop with expertise.” But researchers found in their studies that people can have damage to the speaking part of the brain that leaves writing unaffected and visa versa.

The researchers used five individuals with aphasia in their experiments. Four of them had experienced difficulties writing sentences with the proper suffixes, but no issues speaking the same sentence, while the remaining one had the opposite problem.

The researchers showed the five participants a series of images, and asked them to describe the action depicted by telling and writing what they saw. They would get a participant saying, "The boy is walking," but writing, "the boy is walked." These results help support Rapp's idea that there are “two quasi-independent language systems in the brain” that are responsible for high-level sentence construction.

Rapp said in a press release:

"We found that the brain is not just a 'dumb' machine that knows about letters and their order, but that it is 'smart' and sophisticated and knows about word parts and how they fit together. When you damage the brain, you might damage certain morphemes but not others in writing but not speaking, or vice versa."

What's more, the discoveries from this study could help aid in education and rehabilitation to help people who struggle with the written language.

Read more at EurekAlert!

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