The machine of a new soul

ANALOGIES change. Once, it was fashionable to describe the brain as being like the hydraulic systems employed to create pleasing fountains for 17th-century aristocrats’ gardens. As technology moved on, first the telegraph network and then the telephone exchange became the metaphor of choice. Now it is the turn of the computer. But though the brain-as-computer is, indeed, only a metaphor, one group of scientists would like to stand that metaphor on its head. Instead of thinking of brains as being like computers, they wish to make computers more like brains. This way, they believe, humanity will end up not only with a better understanding of how the brain works, but also with better, smarter computers.

These visionaries describe themselves as neuromorphic engineers. Their goal, according to Karlheinz Meier, a physicist at the University of Heidelberg who is one of their leaders, is to design a computer that has some—and preferably all—of three characteristics that brains have and computers do not. These are: low power consumption (human brains use about 20 watts, whereas the supercomputers currently used to try to simulate them need megawatts); fault tolerance (losing just one transistor can wreck a microprocessor, but brains lose neurons all the time); and a lack of need to be programmed (brains learn and change spontaneously as they interact with the world, instead of following the fixed paths and branches of a predetermined algorithm).