Depth perception in the rat (Rattus Norvegicus): prepotency of three-dimensional over two-dimensional surfaces.

The descent behavior to two- and three-dimensional surfaces in a depth situation was measured and compared for 45-50 days-old hooded rats. When depth differences between surfaces were controlled, significantly more descents were made to three-dimensional than to the two-dimensional surface. The results suggest that a three-dimensional surface--more representative of an animal's natural terrain--provides a more informative environment for motion parallax than does a two-dimensional one.