It resembles the strung-out entrails of a computer: five circuit boards, connected by an intestinal tangle of wires. A lens peers out at Kwabena Boahen, the creator of the device, from one of the boards, and on a screen nearby the blocky pixels of his face nod and gesture.

Though the chips mounted on these circuit boards are the same sort used to build everything from iPods to supercomputers, that's where the similarity ends. This machine can't run a word processor or let you email, but it can do things most desktop computers find virtually impossible to do in real time: it can see.

That's not to say it is conscious, of course, but what it can do is organise raw optical stimuli into a useful representation of the thing it's "looking" at, and identify the outlines of different objects in its field of view. Instead of mindlessly number-crunching like ...