FOR centuries, artists, historians and tourists have been fascinated by Mona Lisa’s enigmatic smile. Now it seems that the power of Leonardo da Vinci’s masterpiece comes in part from an unlikely source: random noise in our visual systems.
Christopher Tyler and Leonid Kontsevich at the Smith-Kettlewell Eye Research Institute in San Francisco manipulated a digital image of the painting by introducing random visual noise – the equivalent of the snow seen on a badly tuned TV set – and asked 12 observers how they rated the resulting expression on a four-point scale from sad to happy.
As would be expected, noise that…
