Study offers new insights into how brains handle numbers

Researchers have found that small numbers are processed in the right side of the brain, while large numbers are processed in the left side of the brain, according to a study published Friday by Imperial College London.

The brain is divided into two halves, with the left side controlling the right half of the body, and vice versa. Previous studies have highlighted the general region where the brain handles numbers, an area called the fronto-parietal cortex. But scientists are in the dark about how exactly the brain unpicks and processes numbers.

Based on previous observations from stroke patients, who often suffer damage to the right side of their brains, researchers at the college have found out that large numbers and small numbers are handled on different sides of the brain.

"In our new study, in which we used healthy volunteers, we found the left side processes large numbers, and the right processes small numbers. So, for instance, if you were looking at a clock, the numbers one to six would be processed on the right side of the brain, and six to twelve would be processed on the left," said Dr. Qadeer Arshad, lead author of the study.

People tend to have one side of the brain which is more dominant than the other, and can test on themselves which side is more active during number processing, according to Arshad.

The findings of the research, published in the journal Cerebral Cortex, could in the future help to tailor rehabilitation techniques for patients who have suffered brain damage, such as stroke patients, and inform treatments for conditions such as dyscalculia, which causes difficulty in processing numbers.

"The findings offer a starting point for unravelling how the brain handles and represents numbers - so-called numerical cognition. If we understand how numbers are processed, we may be able to target treatments and rehabilitation therapies. The next stage is to examine how the brain handles large, complex calculations," said Arshad.