Beauty is truly in the eyes of the beholder - as a study found that mathematicians looked at complicated formulas the way people appreciate beauty, art or music.

Lead author Semir Zeki of the paper titled The Experience of Mathematical Beauty and its Neural Correlates found that mathematicians perceive highly complex formulae as arts with the highest form of beauty. Looking at mathematical equations triggers activity in their brain similar to how ordinary people process their appreciation of beauty.

"Many have written of the experience of mathematical beauty as being comparable to that derived from the greatest art. This makes it interesting to learn whether the experience of beauty derived from such a highly intellectual and abstract source as mathematics correlates with activity in the same part of the emotional brain as that derived from more sensory, perceptually based, sources," wrote Mr Zeki.

In order to conduct the study, the team of researchers invited 15 postgraduate and postdoctoral mathematicians to participate. The participants were then asked to rate 60 mathematical formulas on a 10-point scale for beauty.

After two weeks, they repeat the process, this time inside a magnetic resonance imaging scanner.

"The experience of mathematical beauty correlates with activity in the same part of the emotional brain field A1 of the medial orbito-frontal cortex as the experience of beauty derived from other sources," the researchers discovered.

The result implied that there is a neurobiological basis to beauty "that is independent of culture and learning."

Both math and art showed that the strength of the brain activity is correlated with the intensity of the experience of beauty, the study explained.

The most beautiful formula for the mathematicians was Euler's formula, which links trigonometry with the exponential function.

The most interesting result of the study was that the activity in the brain of the mathematicians when looking at the formulas was not triggered by understanding the formula "but by the experience of beauty alone."

"This answers a critical question in the study of aesthetics which has been debated since classical times, namely, whether aesthetic experiences can be quantified."

"(This) raises issues of profound interest for the future that beauty, even in so abstract an area as mathematics, is a pointer to what is true in nature. What makes the theory of relativity so acceptable to physicists, in spite of going against the principle of simplicity, is its great mathematical beauty. By being based on beauty, future mathematical formulations may reveal something about our brain, and (also) about the extent to which our brain organisation reveals something about our universe," the study said.