From Scientific American online magazine, June 2011:
"Santiago Ramón y Cajal, the Spanish Nobel-winning biologist who mapped the neural anatomy of insects in the decades before World War I, likened the minute circuitry of their vision-processing neurons to an exquisite pocket watch. He likened that of mammals, by comparison, to a hollow-chested grandfather clock. Indeed, it is humbling to think that a honeybee, with its milligram-size brain, can perform tasks such as navigating mazes and landscapes on a par with mammals. A honeybee may be limited by having comparatively few neurons, but it surely seems to squeeze everything it can out of them.
At the other extreme, an elephant, with its five-million-fold larger brain, suffers the inefficiencies of a sprawling Mesopotamian empire. Signals take more than 100 times longer to travel between opposite sides of its brain—and also from its brain to its foot, forcing the beast to rely less on reflexes, to move more slowly, and to squander precious brain resources on planning each step.
- Human intelligence may be close to its evolutionary limit. Various lines of research suggest that most of the tweaks that could make us smarter would hit limits set by the laws of physics.
- Brain size, for instance, helps up to a point but carries diminishing returns: brains become energy-hungry and slow. Better “wiring” across the brain also would consume energy and take up a disproportionate amount of space.
- Making wires thinner would hit thermodynamic limitations similar to those that affect transistors in computer chips: communication would get noisy.
- Humans, however, might still achieve higher intelligence collectively. And technology, from writing to the Internet, enables us to expand our mind outside the confines of our body."
How Simple Photos Could Be Used as a Test for a Conscious Machine [Contest]
Join Scientific American's contest to show why conscious humans best unconscious computers and win a recently authored book by renowned neuroscientist Christof Koch
Monday, June 13, 2011 | 14
The mystery of human consciousness appears routinely as one of the greatest science problems of all time. One way to get a grip on this seemingly ineffable property would be to build a conscious machine. It may be many years before that happens. But the overriding question, when someone does try, will be: how will we know whether that machine is really conscious—and not merely faking it?
Probing a machine for consciousness need not require an elaborate mathematical construct. In fact, it might derive from something as simple as a street photo snapped with a cell phone camera, or you could use photo editing software to devise an image that just about any human would recognize is irrational or nonsensical, but that even today’s smartest computers might pass over as reasonable.
The authors define consciousness here as an ability to understand whether a photograph depicts an image that makes sense based on knowledge of the world that most people share—general knowledge that no present-day computer is capable of storing and processing in the way people do. A person, for instance, knows that a keyboard belongs in front of a computer screen, whereas a potted plant in that spot does not.
A computer might be able to win at Jeopardy, but it doesn’t have the basic common sense to understand that something is just plain wrong with the off-kilter juxtaposition of an iMac paired with a geranium. Koch and Tononi describe similar examples in their article, "A Test for Consciousness," available to readers free of charge. Even a six-year old, for instance, can pinpoint the fundamental improbability of an ice skater on the rug in the living room, a transparent cow or a cat chasing a dog. Yet a computer doesn’t "know” these things about the world.
These absurd yet simple images devised by the authors to illustrate this distinction between conscious human and unconscious computer led us to the idea of a contest in which readers could contribute their own examples of pictures that might fool a machine. Entries of digital images that display illogical imagery similar to what is described above can be submitted to ScientificAmerican.com for judging by Koch and Tononi and Scientific American editors (see the rules below). Koch and Tononi are the judges because unfortunately a real machine that could be used to carry out such a contest does not yet exist.
