Drawbridge example - 1995
A coloured box was placed behind the screen moved back-and-forth like a drawbridge
Infants were first habituated to the screen without the box present
After habituation, a box was placed behind the screen and the infants were shown two test events:
Possible event - the screen moved until it reached the box and stopped
Impossible event - the screen moved through the space by the box completing a 180 arc - the drawbridge appeared to pass through a box and ended up buying a flat and the box apparently disappeared.