The effects of displacement size and frame duration on the motion-incoherence aftereffect

After motion adaptation, the perception of global movement direction in partially coherent random-dot kinematograms (RDKs) is temporarily impaired if the predominant direction of dots in the test stimulus matches that of the adaptation stimulus. The dependence of this motion-incoherence aftereffect on stimulus characteristics (displacement size and frame duration) of the RDKs used to produce and measure it were examined. In addition, the speed selectivity of the aftereffect was investigated. The results indicate that the motion-incoherence aftereffect depends on frame duration, not displacement size, and that it is coarsely velocity selective.