Factors controlling the competing sensations produced by a bistable stroboscopic motion display.

Two competitive sensations which are produced by a previously described bistable stroboscopic movement display were studied in a series of five experiments. In Experiment 1 each of the movement sensations was selectively adapted, a finding which supports the hypothesis that a different visual process underlies each of the two sensations. In Experiments 2-5 the relative dominance of the two sensations was controlled by the manipulation of five physical stimulus variables-frame duration, duration of the interval between frames, luminance of the interval between frames, contrast of stimulus frames. and degree of dark adaptation. Limiting conditions for the processes mediating the two competitive sensations were elaborated, and the implications of the findings for other studies of stroboscopic movement were discussed. Key Words-apparent movement: bistable percept: perceptual organization; visual motion peraption.