The New Lie Detector

Presents information on a computer program which could read facial expressions developed by scientists at the Salk Institute for Biological Studies in La Jolla, California. How the program was modeled by Paul Ekman, a facial expert at the University of California; How the system works.

By Jamie Talan, published on September 01, 1999

EMOTIONS

Get that phony smile off your face, quick. Your friends may think it's genuine, but a new computer program knows better.

Scientists at the Salk Institute for Biological Studies in La Jolla, California, have taught a computer to read facial expressions--a science that humans are notoriously slow to master. "Our technology takes the human out of the loop," says Marian Stewart Bartlett, Ph.D., co-author of the study. What's more, adds Terrance Sejnowski, Ph.D., the study's senior author, the achievement "mimics humans' ability to learn by experience. Computers have now broken through this barrier."

The program is modeled on the work of Paul Ekman, a facial expert at the University of California at San Francisco, who has identified and analyzed 46 distinct expressions that we use to convey emotion. The computer analyzes videotapes of facial movement and indicates precisely which expressions are taking place: Arch the eyebrow, and you've got the start of joy. Invert the eyebrows into a V and you show sadness; now raise the corner of your lip, and voila--nostalgia. Using one minute of videotape, the computer can size up in five minutes what would take a person an hour to analyze.

Bartlett already envisions many implications for the computer, some whimsical, some more socially important. He suggests, for example, tutorial systems that read students' emotional states and shift the lesson if the kids look bored, furry toys that pick up on their owner's mood and smile or frown accordingly, a TV rating system that's more accurate than the Nielsens, or lie detectors that work more quickly and accurately than the polygraphs we currently use--not surprisingly, an angle that the CIA is now exploring.

But don't fret about people being replaced by machines: specialists trained to analyze facial expressions are still needed to translate physical cues into actual emotions. While the computer can describe just what it sees--a raised corner of a lip, crinkles around the eyes--only a flesh-and-blood expert can go the extra step to distinguish a real smile from a posed one.

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