Blind People Can Use Visual Areas of the Brain to Solve Math Problems

The brain is a highly adaptable organ

KimManleyOrt via Flickr

Blind people may not be able to see, but their bodies often adapt in interesting ways to help them get around—some have even figured out how to echolocate to assist in moving about. Now, new research suggests that blind people’s brains may be able to adapt regions usually used for sight to help solve math problems, Adrienne LaFrance reports for The Atlantic.

“Across all humans, numerical thinking is supported by similar areas in the brain,” Shipra Kanjlia, a graduate student in psychological and brain sciences at Johns Hopkins University, tells LaFrance. But for the most part people are taught how to solve math problems from an early age by using visuals. So does this brain usage change for people who have never "seen the number of people at a party or the number of flowers in a field?"

To tackle this question, Kanjlia tested 17 people born blind and 19 sighted people wearing blindfolds. She had each person do math problems while hooked up to an MRI. When all participants worked out the solutions, the researchers could see the standard parts of the brain light up with activity, Kate Baggaley reports for Popular Science. But when it came to the congenitally blind participants, another region lit up: part of the visual cortex.

According to the study, which was published this week in the Proceedings of the National Academy of Sciences, the harder the blind volunteers thought about the algebra problems, the stronger the visual cortex shone. Meanwhile, the same region remained dark for the sighted participants, even when blindfolded. It appeared that the brains of blind participants had repurposed the unused region to assist in number processing, Baggaley reports.

"To see that this structure can be reused for something very different is very surprising," Melissa Libertus, an assistant professor of psychology at the University of Pittsburgh who was not involved with the study, tells Jon Hamilton for NPR. "It shows us how plastic our brain is, how flexible it is."

In the past, researchers studying the brain have found that the visual cortex can be rewired to handle other sensory input, such as hearing and touch. The ability to do algebra, however, has nothing to do with the senses, suggesting that the brain can adjust the visual cortex to handle more tasks than scientists thought, Hamilton reports.

These findings don’t mean that people who are born blind are better at math, but it does indicate that the brain is very good at resource management in attending to higher functions, Hamilton reports. If it can rewire the visual cortex to tackle algebra, perhaps our grey matter could do a lot more than scientists once thought.

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