People born without sight appear to solve math problems using visual areas of the brain.
A functional MRI study of 17 people blind since birth found that areas of visual cortex became active when the participants were asked to solve algebra problems, a team from Johns Hopkins reports in the Proceedings of the National Academy of Sciences.
"And as the equations get harder and harder, activity in these areas goes up in a blind person," says Marina Bedny, an author of the study and an assistant professor in the department of psychological and brain sciences at Johns Hopkins University.
In 19 sighted people doing the same problems, visual areas of the brain showed no increase in activity.
"That really suggests that yes, blind individuals appear to be doing math with their visual cortex," Bedny says.