A visual cliff involves an apparent, but not actual, drop from one surface to another.
The floor below has the same pattern as the opaque surface.
This apparatus creates thevisual illusionof a cliff while protecting the subject from injury.
Barbara Peacock / The Image Bank / Getty Images
History of the Visual Cliff
so that investigate depth perception, psychologists E.J.
Earlier research revealed infants will respond to various depth cues even before they are able to crawl.
Depth cues allow people to detect depth in a visual scene.
These can include bothmonocular cuessuch as relative size and overlap, or binocular cues such as retinal disparity.
The same material is laid on the floor below the glass, creating the visual illusion of a cliff.
This allowed researchers to test infant perception while preserving the safety of their young subjects.
This realization only comes later when the child begins to crawl and gains real experience with taking tumbles.
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