Abstract

Correspondence matching is the process by which the visual system matches the attributes of objects (luminance, color, shape, contrast, etc.) at different places and at different times to determine the path of the objects in apparent (stroboscopic) motion. We present a class of stimulus which allows the existence of simultaneous motion paths carried by a multiplicity of attributes. Each attribute can be matched independently of the others to elicit unambiguous (unidirectional) or ambiguous (multidirectional) motion perception. When two or more attributes are matched, we can either match them along the same direction (concurrent matching) or along different ones (competitive matching). This flexibility in manipulating the stimuli makes it possible to (a) isolate specific motion mechanisms in the absence of stimulation of any other mechanisms, (b) assess the summation index for motion strength when two or more attributes are matched concurrently, and (c) directly assess the relative strength of pairs of attributes by using competitive matchings to determine which of them prevails in determining the perceived direction of motion. These stimuli have been employed in psychophysical experiments to assess the relative strength of several attributes (color, orientation, luminance, spatial frequency, binocular disparity, and polarity) in eliciting motion.

© 1988 Optical Society of America