There is a continuing assumption — a faith, really — that at some future moment, perhaps only a decade or two away, perhaps even nearer than that, artificial intelligence will, by means yet unknown, achieve consciousness. A window will open on the computer’s black box, and light will stream in. The universe will take a new turn, as the inanimate becomes, for a second time, animate.
George Lakoff, the linguist who cowrote Metaphors We Live By, says it ain’t going to happen. In a fascinating article by Michael Chorost, Lakoff argues not only that language, being essentially metaphorical, is inextricably bound up in our bodily existence, but that cognition and consciousness, too, flow from our experience as creatures on the earth. Recent neuroscience experiments seem to back Lakoff up. They suggest that even our most abstract thoughts involve the mental simulation of physical experiences.
In a 2011 paper in the Journal of Cognitive Neuroscience, Rutvik Desai, an associate professor of psychology at the University of South Carolina, and his colleagues presented fMRI evidence that brains do in fact simulate metaphorical sentences that use action verbs. When reading both literal and metaphorical sentences, their subjects’ brains activated areas associated with control of action. “The understanding of sensory-motor metaphors is not abstracted away from their sensory-motor origins,” the researchers concluded.
Textural metaphors, too, appear to be simulated. That is, the brain processes “She’s had a rough time” by simulating the sensation of touching something rough. Krish Sathian, a professor of neurology, rehabilitation medicine, and psychology at Emory University, says, “For textural metaphor, you would predict on the Lakoff and Johnson account that it would recruit activity- and texture-selective somatosensory cortex, and that indeed is exactly what we found.”
The evidence points to a new theory about the source of consciousness:
What’s emerging from these studies isn’t just a theory of language or of metaphor. It’s a nascent theory of consciousness. Any algorithmic system faces the problem of bootstrapping itself from computing to knowing, from bit-shuffling to caring. Igniting previously stored memories of bodily experiences seems to be one way of getting there.
That, as Chorost notes, “raises problems for artificial intelligence”:
Since computers don’t have bodies, let alone sensations, what are the implications of these findings for their becoming conscious—that is, achieving strong AI? Lakoff is uncompromising: “It kills it.” Of Ray Kurzweil’s singularity thesis, he says, “I don’t believe it for a second.” Computers can run models of neural processes, he says, but absent bodily experience, those models will never actually be conscious.
Then again, even the algorithmic thinking of computers has a physical substrate. There is no software without hardware. The problem is that computers, unlike animals, have no sensory experience of their own existence. They are, or at least appear to be, radically dualist in their operation, their software oblivious to their hardware. If a computer could think metaphorically, what kind of metaphors would it come up with? It’s hard to imagine they’d be anything recognizable to humans.
Image: “Camera Obscura Test 2” by Jon Lewis.