A team of Canadian and American researchers managed to figure out the calculations that specific neurons use to cause us to avoid approaching calamity.. (Shutterstock)

You're just walking up the cereal aisle, looking for Fruit Loops, when you hear the clatter of impending disaster.

Some teenager has pushed his mom's grocery cart directly at you.

In the visual flash that takes place before it can crash into you legs, what goes through your mind?

It's math.

At least according to a team of Canadian and American researchers, who have mapped the visual processes the brain uses to figure out if Billy's cart of doom will leave you with a bruise.

The study, by scientists at the Montreal Neurological Institute and Hospital -- known as The Neuro -- as well as the University of Maryland, managed to figure out the calculations that specific neurons use to cause us to avoid approaching calamity.

Igniting certain regions of the brain, the calculations work out needed information -- how far away the object is, is it harmlessly moving to the right or left or is it speeding up?

Specialized neurons in the brain's visual cortex, in an area known as MST, detect motion patterns, including expansion, rotation and deformation.

The computations used in the process were previously unknown, the researchers say.

They now know how individual MST neurons function.

But don't give yourself too much credit for those lightning fast math reflexes.

"Essentially, the underlining process is very similar to what a beetle, or fly or bird goes through," says Dr. Christopher Pack, of the high alert system that kicks in when danger rushes in.

A senior author of the research, and neuroscientist at The Neuro, Pack says he doubts the calculations used have changed much since the first big-fanged creature headed toward early man.

His team found a remarkably simple computation is at the core, and it comes down to multiplication problems.

Though in your mind, as you jump out of the way of the cart, you wish you could hold up just a single digit to that kid who pushed it.