Billions and Billions – Reshaping our Brains with Numbers

A number is a number is a number?

Why do so many prices end in .99 or .95? Decades of marketing research consistently show that customers perceive a number like $14.99 as significantly lower than $15.00. Think of how differently we treat the winners of athletic competition as compared to the second-place competitor, even if the margin of victory is only fractions of a second or slices of a centimeter. In an election year, the news is covered with poll results, which can sound completely different if “a majority” thinks one way, versus “51%.“

Some brains see numbers differently

My interest in how our brains manipulate numbers into meaning has fascinated me since I was a little girl with undiagnosed dyslexia and dyscalculia. My frequent spelling and math errors were branded “careless and sloppy” by my teachers. It didn’t help that every time I proofed my work I would get a different answer. I can still remember my high-school chemistry teacher’s frustration with my 100% score on his final exam: “You made two major errors, transposing the letters of two chemical compounds. However, it turns out that your two errors canceled each other out and you arrived at the correct answer.” At that time, I took this comment to mean two things. One – I was not as cut out for a career in science as I had imagined. Two – I was a very lucky person with something special going on inside my brain.

Your “normal” brain does crazy things with numbers

For those of us whose brains don’t appear to perform fascinating parlor tricks, your “normal” brain does a lot of crazy stuff too. For example, your brain may interpret a set of statistics differently when you are feeling happy versus a day when you review the same data but are feeling sad. Any personal or sociological bias that you have taught your brain will help you see what you expect to see, even if the numerical evidence is clearly stated to the contrary. If you are feeling anxious, the chemicals in your brain will influence you to be far more aware of potential threats – real or imagined. Driven by a bias for optimism, people consistently predict rosier outcomes than cold, hard facts would indicate.

How the brain processes the language and music of numbers

What exactly is happening inside the brain when we work with numbers? We’re still not quite sure, but we are beginning to zero in on how and where the processing takes place. The inferior temporal gyrus is believed to be responsible for processing numbers in the brain. This region is found on both sides of the brain, near the ear canals. When we see this area “lit up” on brain imaging scans, we may be looking at how the brain processes numerical information.

The authors of the study point out that their work provides hard evidence of parts of the brain that have been changed in response to education since mathematical comprehension must be taught. The transformation each of us makes on our brains is similar to what happens to London taxi drivers, who actually manage to make their hippocampus regions larger in response to repeated training on the geography of their great city. The region is also close to the part of the brain that is thought to process language and symbols. Since math is a language, the location offers some tantalizing suggestions.

I wonder if we will find that language and math are far more intertwined than we currently believe. Already there is strong evidence that studying music helps develop language skills. We also know that there is a correlation between studying music and math. So doesn’t it make sense that these three apparently different functions are really different manifestations of the same neural process?

Numbers getting personal

In a world driven by 1s and zeroes, numbers can sometimes get intensely personal. A high school honors student doesn’t hit the necessary SAT score and thus is denied entry to some top colleges and all the opportunities those schools promise for the rest of her life. A manager must “stack rank” all her high-performing team members, even though each of them is worthy of a raise. A couple applying for their first mortgage doesn’t have the “right ratios” to get a bank to take a chance on them, even though they are both employed and could easily handle the payments. My sister, a cancer patient, was told by a specialist that people with her particular type of cancer have a “forty percent survival rate.” That number sent a shiver from deep inside my brain down my spine to every inch of my body. The next day her doctor explained that this rate is based on an average and that her own chance of survival, given her current state of health is “more like 70%.” Would this number have been met with such a feeling of relief and hope if we hadn’t first heard the darker estimate? Does my story sound a little more poignant when I tell you that she is my “little” sister?

Neuroscience continues to piece out the answers to what makes us tick, one tiny neuron at a time, but our wonderful brains are capable of using the language of numbers to comprehend massively huge or incredibly tiny scales. While some see this as a reason to fear what is coming next, I choose to see it as a cause for great hope. After all, don’t we all feel a little less alone in the universe when we ponder the billions and billions” of stars with the potential to support life, rather than thinking of ourselves as alone in the universe?