La Giocanda's Mysterious Half-Smile

Leonardo Da Vinci's masterpiece, The Mona Lisa or La Giocanda, is still a subject of intrigue and an object of experimentation by researchers and art historians.

In a fun demonstration of technology rather than a serious scientific experiment,Dutch researchers scanned a reproduction of Leonardo da Vinci's masterpiece and subjected it to cutting-edge "emotion recognition'' software, developed in collaboration with the University of Illinois.

The result showed the painting's famous subject was 83 percent happy, 9 percent disgusted, 6 percent fearful and 2 percent angry. She was less than 1 percent neutral, and not at all surprised.