Comparing retinotopic and spatiotopic tilt aftereffects

At the bottom of this page is a looping movie that allows you to test spatiotopic tilt aftereffects and compare them to retinotopic aftereffects and to aftereffects at neither retinotopic nor spatiotopic locations.

We have a published paper showing the absence of spatiotopic motion aftereffects using very different paradigm.
Knapen, T., Rolfs, M., Wexler, M., & Cavanagh, P. (2010). The reference frame of the tilt aftereffect. Journal of Vision, 10(1:8), 1-13. download pdf file

There are 4 seconds of adaptation, followed by a  half second blank to allow eye movements then a 1/3 second test and another half second blank to allow you to get back to where you were.

There are 7 fixation markers (numbered 1 through 7). By combining different adapta and test fixations you can examine the aftereffects at several different locations.

For example. Fixate at 4 during adaptation then wherever you move next, the aftereffect you see at 4 is the spatiotopic aftereffect. If you move to 6, the retinotopic aftereffect is at 6 and the spatiotopic at 4. If you move to 5 the spatiotopic is at 4 and the aftereffect, if any at 6 is neither spatiotopic nor retinotopic but it has the same eccentricity as test 4 (the spatiotopic case).

Try different combinations and report back.

Some instructions. The thin horizontal bars are fixation tracks during adaptation. Move your eyes left and right along these tracks to avoid afterimages.

If you haven't moved your eyes back and forth enough, the retinotopic afterimage has some contrast effects at the retinal location wherever you place it (the test bars may appear broken in the middle as a result). Keep at it, moving your eyes more until after the first 5 to 10 viewings you should get over the afterimage. Real experiments drift or flicker that adpat to avoid afterimages.

The aftereffects may be subtle so it may take several cycles before you are willing to go much beyond "tilted left of vertical" or "tilted right of vertical". Try to end up with a magnitude judgment that you can compare from one test location to the other.

If you build up adaptation at one location, say, 4, you can test many aftereffect locations with successive tests. However, if you want to switch adaptation locations, say, from 4 to 5, you need to take a break to let the first adaptation fade away.