Mathematicians have long likened the experience of mathematical beauty to that of visual and musical beauty. Now scientists in England and Scotland have determined that despite the abstract nature of mathematics, mathematical beauty is linked to activity in the same region of the brain as beauty from sensory sources.

The researchers asked 15 mathematicians to view a series of 60 mathematical equations and rate each one on a scale of −5 (ugliest) to +5 (most beautiful). Then they scanned the subjects' brains with functional MRI as they looked at the equations again. Follow-up surveys revealed that understanding the math was necessary but not sufficient for a participant to see beauty in an equation—some equations were well understood but did not strike the mathematicians as beautiful. The distinction allowed the researchers to factor out the brain activity associated with understanding and home in on the area responsible for the feeling of beauty: the medial orbitofrontal cortex, an area thought to integrate sensory experience, emotion and decision making. Previous studies have shown that this area is highly active when subjects see or hear something—for instance, art or music—that they perceive as beautiful.

Beauty is a tricky concept for scientists to study because of its subjective and personal nature. Study author Semir Zeki, a neuroscientist at University College London, suggests that by considering beauty mathematicians may be touching on a deep connection between the human brain and the natural world. Because “we have evolved in this universe,” Zeki posits, “the experience of beauty may be a pointer to truth about the universe.” Many mathematicians say they strive for beauty the way a composer or a painter would. Zeki points out that this approach has sometimes led to incredible insights: “Relegating beauty to the study of art and leaving it out of science is no longer tenable.”