text: Leonardo da Vinci, a famous artist, painted The Mona Lisa, but new technology computer software can recognize emotion, according to Prof. Thomas Huang, of the Beckham Institute for Advanced Science at the University of Illinois. The 3D computer model can construct all 44 major muscles in the humans body, but it must move like human muscles. The movent of one or more muscles during this process is called an "action unit". According to Dr. Huang, "facial expressions for each emotion are universal", even though some individuals often show varying degrees of expression.