What’s 75+12? And what about 13-7?Never mind the answers. More importantly, which way did you move your eyes when you were doing the problems?
Scientists in France used a computer program to record brain activity when participants were looking left or right, and then again when they were given addition or subtraction problems to solve.
It turns out that adding numbers triggered the same patterns of brain activity as looking right. Subtracting numbers activates the same brain patterns as looking left.
Why? Well, it’s got to do with spatial relationships between numbers. Addition is like moving to the right on a number line in your head. Subtraction is like moving to the left. It’s not necessarily conscious, but it’s there.
This may have to do with the human brain 'recycling' more primitive brain structures to handle cultural innovations like reading and mathematics. So brain functions once devoted only to visualising spaces are now also involved in performing simple mental math.
So when you solve sums, you’re using the same brain wiring your thousand-times-great-grandma might have used to plan the best route to escape from a woolly mammoth stampede. Cool!
