No Escape: Your Brain Is Constantly Doing Math, Study Finds

There are some people who are capable of random on-the-spot calculations (like figuring out a 15 percent tip), which might impress other math-poor-minds while not being all that impressive. Then of course there are the people who are unnervingly excellent at math, who can seem alien to those who stopped doing crude calculations after puberty. Fortunately, your brain is more powerful than you think: A new study finds that you're constantly, subconsciously performing complex math equations in order to understand the world around you.

The study, "A Probability Distribution over Latent Causes, in the Orbitofrontal Cortex," was conducted by the Princeton Neuroscience Institute at Princeton University. Researchers created a "virtual safari" experiment in which different groups of fictional animals were assigned to different safari zones, called the blue, yellow, pink, and green sectors respectively. Each of these sectors was distinguished by "a different color, background image, background music, and location on a map," the study reads. Thirty-two subjects were shown these zones, along with the five different kind of animals that inhabited each one. According to the study, "every animal appeared in every sector, but with different likelihoods."

While being scanned by an fMRI machine, subjects had to guess which sector they were in based on an animal they were being shown—unknowingly engaging in a complex probability calculation. This is something everyone does all day every day, whether you're trying to figure out if that unmarked black car is the Uber you ordered, or waiting your turn to order fries at McDonald's.

In an interview with Broadly, head researcher Stephanie Chan explained that participants in the study had a high accuracy rate in performing this task; Chan says that the fMRI results show that an area of the brain called the orbitofrontal cortex was active during the experiment, and it was doing all kinds of math that the subjects weren't even aware of.

"This information seemed to be computed in a close-to-mathematically-optimal way," Chan says. According to Chan, as well as her colleague and co-author Yael Niv, who also spoke with Broadly for this story, the orbitofrontal cortex is a "mysterious" chunk of the brain located right behind your eyes. Scientists know that it is responsible for "higher learning," as well as your "overall personality and behavior," but little else is known about it.

"Our brain does subconscious calculations all the time that would be very difficult to do consciously," Chan explains. "Even 'simple' things like vision or recognizing faces require complex calculations that engineers are only now starting to do relatively well compared to humans." There are all kinds of situational details that our brains observe but that are "hidden" to us, and the way that our brain understands them can shape our experience of the world, Chan says.

When I informed a colleague about this study's findings—that our brains are performing subconscious calculations about hidden situations all the time—she confidently replied, "Not my brain," because math isn't something she can do. But whether she likes it or not, my coworker's brain is doing those computations constantly. Furthermore, though they don't have the data to show this, Chan and Niv both predict that people of either strong or poor mathematical ability are probably equally proficient at subconscious brain math.

"I believe that 'doing math' consciously is something that is relatively separate from these subconscious computations about situations, and so I would not expect to see correlations between math abilities and inference of situation," Chan says, pointing out that actually "doing math" is a recent human development, and secret brain math "is something that our species has done for eons."

"The brain is a vast computing machine with approximately ten billion neurons, each an independent computing unit, working in parallel all the time," says Niv, explaining that the brain is capable of a lot more than just figuring out how much weed you get for $20. "As we pick up a cup of water, for instance, the brain is making complex calculations about what is the likely weight of the cup given how much liquid we see in it, how slippery it may be, and how hard its surface is to determine how strong our grip should be." For instance, Niv says, you don't want to "grip a paper cup with the same force we would have used for a mug."

"We are not aware of these calculations, but they happen all the time. In fact, our brain is much better at these difficult calculations than at performing long multiplication," she explains.