What do psychologists investigate with a visual cliff?

subliminal messages

motion parallax

depth perception

none of the above

c. Depth Perception - The visual cliff apparatus comprises of a sheet of Plexiglas covering a cloth with a checkerboard pattern. On one side the cloth is placed immediately beneath the Plexiglas, and on the other, there is a drop of about 4 feet below. The Plexiglas supports the weight of the child. So this is a 'visual cliff' rather than a real fall. Using this apparatus, psychologists examine depth perceptions among babies.