Intelligence Factors in the Perception of Form through a Moving Slit

When a narrow slit moves over a line figure (or the equivalent stimulus is simulated by a short line segment appropriately displacing within a moving slit), observers often perceive an extended figure although the stimulus information is ambiguous. In several experiments it is shown that the perception of a figure tends to occur, provided the stimulus information is compatible with the perceptual ‘solution’ of a figure revealed by a moving aperture: the visible segment of the figure must completely fill the aperture, the surround of the aperture must appear to be opaque and extend an adequate distance on both sides, the aperture must be perceived as an opening rather than as a figure, and, if the slope of the segment is visible, it must change appropriately from moment to moment. Thus the outcome can be thought of as an intelligent, elegant solution to the problem posed by the transforming proximal stimulus.