What Happens in the Brains of Blind People Who Do Math

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Photo: Jeffrey Coolidge/Getty Images

The brain, neuroscientists have long known, has a pretty remarkable ability to rewire and adapt itself on the fly — one of the most notable things about it is its plasticity. But just because researchers know that it has this capability doesn’t mean they’ve come anywhere close to fully understanding it. That’s why a new recent study that involved blind people doing math is so fascinating.

For the study, published in the Proceedings of the National Academy of Sciences, a John Hopkins team led by Shipra Kanjlia, a researcher there, asked 17 blind people and 19 sighted ones to do some algebra problems that were read aloud to them. “So they would hear something like: 12 minus 3 equals x, and 4 minus 2 equals x,” Marina Bedny, one of the co-authors, told NPR’s Jon Hamilton. “And they’d have to say whether x had the same value in those two equations.” The researchers then used fMRI technology to record the participants’ brain activity as they worked through the problems.

For the blind participants but not the sighted ones, areas of the visual cortex lit up during the computation. “That really suggests that yes, blind individuals appear to be doing math with their visual cortex,” Bedny told NPR. That is, the brain seems to have “realized” — that’s obviously too intentional a word — that that region wasn’t being used for processing visual stimuli, and rewired it to help with other tasks.

Hamilton writes that this finding falls in line with “[e]arlier research [that] found that visual cortex could be rewired to process information from other senses, like hearing and touch,” and that in the long run “[d]rugs or even mental exercises” might leverage the brain’s plasticity to help out people dealing with injuries, cognitive deficits, or whatever else. It’s hard not to be excited about the future of brain science when fascinating results like this one keep popping out, one after another.

What Happens in the Brains of Blind People Who Do Math