[FOUNTAIN]A robotic response

The 19th-century French neurologist Guillaume Duchenne found that a genuine smile uses a different set of face muscles than a fake smile. A genuine smile makes crinkles around the eyes, whereas a fake one doesn’t. The muscle called the orbicularis oculi was found to control the key function. In honor of Mr. Duchenne’s research, psychologists have begun to call a genuine smile a “Duchenne smile,” wrote Steven Johnson in his “Mind Wide Open: Your Brain and the Neuroscience of Everyday Life.”
Psychologist Silvan Tomkins rejected the conventional theory that “facial expressions are the products of cultures.” He said, “The face is like the penis.” He believed facial expressions have a will and desire of their own, like the penis.
Paul Ekman, a student of Mr. Tomkins, traveled around the world and took pictures of various facial expressions of different people. By classifying the photos, he deciphered 43 muscular movements in the face. He categorized these into action units, numbering them from one to 43.
“Just with two muscles, one can produce 300 combinations of facial expressions,” Ekman says. “If you add in a third, you get more than 4,000. If we took it up to five muscles, one can identify more than 10,000 visible facial configurations.”
Mr. Ekman selected about 3,000 more meaningful facial expressions and compiled the facial action coding system, or FACS.
The Ekman system has been used for productions of computer animations such as “Toy Story” and “Shrek.” The naturalness of the facial expression of characters can be attributed to his system.
Sometimes, a facial expression can create emotion inversely. Ekman’s formula to generate sadness and anguish is simple. Lower the eyebrows, which is action unit 4, raise the upper lid, action unit 5, narrow the eyelids, action unit 7, and press the lips together, action unit 24. The heartbeat will go up and hands will get hot.
EveR-1, the recently developed world’s second android, can simulate facial expressions. Though more or less awkward, EveR-1 can express joy, anger, sorrow and happiness. Fifteen tiny motors have embedded in its face to enable muscular movements.
Professor Baeg Moon-hong, who led the development, said the team concentrated more on the facial expressions than its functions.
Without any understanding of this complicated science, our ancestors solved the secret of facial expressions a long time ago. “You get older for every rage, and you get younger for every smile.”

by Yi Jung-jae

The writer is a deputy business news editor at the JoongAng Ilbo.