Separation relative to length determines the organization of two lines into a unit.
The probability that two lines will form a perceptual unit, in the sense of reversing together under conditions of depth ambiguity, decreases as their separation is increased. In these studies, the critical separation for perceptual grouping is shown to be neither the retinal nor distal separation, but the ratio of separation to line length.
D003867:Depth Perception; D004193:Discrimination Learning; D004215:Distance Perception; D005556:Form Perception; D006801:Humans; D009949:Orientation; D012858:Size Perception