Visual cliff

To investigate depth perception in human and animal species, psychologists E.J. Gibson and R.D. Walk created the visual cliff paradigm which allowed them to experimentally adjust the optical and tactical stimuli associated with a simulated cliff while protecting the subjects from injury.

They discovered that all species tested can perceive and avoid a sharp drop by the time they take up independent locomotion, be it at Day 1 in chicks, 4 weeks in rats, or 6 months in humans. Most rely on visual cues for depth perception. The rat, however, relies predominantly on tactual cues (being nocturnal) but will fall back on sound vision when needed. Next, the experimenters wanted to find out which visual cues played the decisive role in depth perception. Using dark-reared animals, they concluded motion parallax is an innate cue for depth discrimination, whereas responses to differential pattern-density may be learned later. [Gibson, E.J. & Walk, R.D. (April 1960). The "Visual Cliff". Scientific American.]

ee also

* Depth perception
* Developmental psychology

External Links

* [http://vimeo.com/77934 Visual Cliff Video]

References