title: The moon illusion: a test of the vestibular hypothesis under monocular viewing conditions.
abstract: The results of earlier monocular experiments on the moon illusion have been either negative or confounded. To test the role of vestibular function, 24 subjects made forced-choice distance comparisons between stimuli mounted in translucent tubes. The stimulus tube for standard distance could be positioned in three viewing angles (45 degrees up, horizontal, and 45 degrees down). A comparison tube adjustable for distance was mounted horizontally. There was a greater perception of depth in the downward looking condition. The relatively weak effects are discussed in terms of a two-hypothesis explanation of the real-life moon illusion and the poor cues for depth perception in monocular viewing.
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D003463:Cues; D003867:Depth Perception / Q000502:physiology; D004215:Distance Perception / Q000502:physiology; D005260:Female; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008297:Male; D008954:Models, Biological; D009799:Ocular Physiological Phenomena; D009903:Optical Illusions / Q000502:physiology*; D012737:Sex Factors; D012858:Size Perception / Q000502:physiology*; D014722:Vestibule, Labyrinth / Q000502:physiology*