An anonymous reader writes: Connoisseurs catch imitation artworks by spotting minuscule differences in brushstroke patterns. Now, mathematicians have taught a computer to do the same thing — and they've done it by mimicking the way the human visual system works. Our brains have evolved to represent the world we see in the most efficient way possible. The researchers used an algorithm that works the way a creature would if it had evolved only looking at authentic Bruegel drawings. Then, when the algorithm was used to represent imitations, it was less efficient, revealing the fakery. So far, the researchers have used the algorithm only to identify known fakes, but they plan on using it on art of uncertain origins soon.