Motion and tilt aftereffects occur largely in retinal, not in object coordinates

A variety of aftereffects was found to be processed non-retinotopically. Other studies failed to find non-retinotopic aftereffects. These experiments relied on paradigms involving eye movements. We have developed a paradigm, based on the Ternus–Pikler display, which tests retinotopic vs non-retinotopic processing without the involvement of eye movements. Here, we presented three disks for about 5 s. The central disk contained a tilted Gabor patch to which observers adapted (the outer disks were grey). After an ISI of 146 ms, the disks were shifted to the right creating the impression of group motion and establishing a non-retinotopic frame of reference. The center disk in the first frame now overlapped with the left most disk. When a test Gabor was presented on this left disk, a strong tilt aftereffect was found, but not when the test Gabor was presented on the center disk. Similar results were found for motion stimuli. Interestingly, invisible retinotopic motion can create a strong aftereffect even though non-retinotopic motion was perceived during adaptation masking the retinotopic motion. Hence, tilt and motion adaptation are processed retinotopically whereas form, motion, and attention were found to be non-retinotopically processed with the Ternus–Pikler paradigm.