In search of an optical `brain'

'A five-year-old child can recognize faces, but a super Cray can't even recognize a handwritten character,' remarked Demetri Psaltis, associate professor of electrical engineering at the California Institute of Technology in Pasadena. Yet a human being is lousy at algebra compared with a computer. What is it about a digital electronic computer that makes it so awkward for certain tasks versus the natural neural network of the brain?'