Motion Parallax in the Visual Cliff Situation

Abstract

Walk's (1965) assumption that motion parallax is “the critical cue” for depth discrimination by newly hatched chicks was assessed by the use of 3-dimensional striped patterns on each side of the centerboard. The 3-dimensional patterns served two purposes: (1) to test an hypothesis that chicks would show no significant preference for the “shallow” side if motion parallax cues were presented independent of the solid appearance furnished by 2-dimensional surfaces and (2) to permit direct manipulation of the stimulus basis for motion parallax. Ss were 250 chicks, 6 to 24 hr. old. Results provide evidence that stimuli for motion parallax, devoid of the solid appearance of 2-dimensional surfaces, are sufficient cues for depth discrimination by chicks.