I still tend to move my fingers, almost subconsciously, when doing arithmetic. Well, that might not be so strange, according to research published in the May 8th issue of the journal Science. The report says that math and movement through space use some of the same brain circuitry.

Researchers in France scanned the neural activity in the brains of people who were moving their eyes right or left. Then study participants were asked to do arithmetic in their heads. And the brain scan data correctly showed whether the person was adding or subtracting. Because adding used the same brain circuits as when eyes moved right. And subtraction matched up with the neurons firing when eyes moved left.

Researchers say this finding shows that the development of math is too recent and advanced to have a brain region devoted solely to it. So we reuse systems that we already have. The study authors note that “throughout the history of mathematics, concepts of number and space have been tightly intertwined.” Now we know that the connection even occurs in our brains. So I don’t feel too bad about still counting on my fingers.

—Cynthia Grabe