Aftereffect of perceived motion trajectories.

If our visual system has a distinct computational process for motion trajectories, such a process may minimize redundancy and emphasize variation in object trajectories by adapting to the current statistics. Our experiments show that after adaptation to multiple objects traveling along trajectories with a common tilt, the trajectory of an object was perceived as tilting on the repulsive side. This trajectory aftereffect occurred irrespective of whether the tilt of the adapting stimulus was physical or an illusion from motion-induced position shifts and did not differ in size across the physical and illusory conditions. Moreover, when the perceived and physical tilts competed during adaptation, the trajectory aftereffect depended on the perceived tilt. The trajectory aftereffect transferred between hemifields and was not explained by motion-insensitive orientation adaptation or attention. These findings provide evidence for a trajectory-specific adaptable process that depends on higher-order representations after the integration of position and motion signals.