A motion aftereffect for long-range troboscopic apparent motion

The existence of a directional motion aftereffect (MAE) for long-range (LR) stroboscopic apparent motion (SAM) was examined with the use of a directionally ambiguous test stimulus. The spatial and temporal parameters were such that the LR, rather than the short-range, mechanism was likely to be implicated. MAEs were found for SAM, which were in the same direction, but somewhat weaker than those for a comparable stimulus in real motion. The MAEs for SAM were present only when good apparent motion was perceived, and could be shown also when only the unstimulated area between the two stroboscopic flashes was tested. The LR mechanism was further implicated, since the MAEs were also obtained under dichoptic adaptation conditions. It is concluded that the LR-motion mechanism does show a usual MAE under proper testing conditions.