... heebie jeebies, anyone ?
The 'Uncanny Valley' is not a physical place, but a confusing emotional state entered by people who see on-screen overly-humanlike computer generated or animated characters in life-threatening situations.
When creatures possessed of ‘human features’, (such as the taking fish ‘Nemo’ or the computer-generated figures in 'The Polar Express') become disturbingly real, audiences over-identify with their plight during action scenes.
The term was coined by Japanese roboticist Masahiro Mori, who noticed that the more human-like a creature behaves, the more positive feelings are generated in the human viewer.
Yet there arrives a point when it all becomes a bit too lifelike, and the responses take an uncomfortable nosedive into what is known as ‘The Uncanny Valley’.
The reason for the discomfort is that your brain believes it is seeing a human figure and focuses only on the minor differences, and not the remarkable similarities. If you take away those differences, you have 'The Uncanny Valley'.
The phenomenon also extends to clowns, zombies and corpses of any kind. "The Uncanny Valley is a bad place to be", an animator was quoted as saying in The L.A Times last year during a piece on audiences getting the ‘heebie jeebies’ over on-screen characters.