A fullscreen squarewave grating, which moves left- or rightwards. You can configure the speed and spatial frequency. The lateral borders have a contrast taper to reduce luminance artifacts for low spatial frequencies.
Caveats
For artifact-free motion a fast computer with a screen not larger than necessary is advisable.
At high speeds or high spatial frequencies beware of aliasing, depending on your frame rate. Don’t hesitate to contact me for any questions.
Some Details
This stimulus was developed in co-operation with Hadas Kalish to assess acuity in fish populations. First developed for the following publication:
Mac OS X application: MovingGrating1.3.app.zip • MovingGrating1.2.app.zip If you receive a message “… from an unknown developer…”, that happens because I did not “sign” the application, which only developers with a paid plan can do. Since this application is free, I cannot afford to pay developers’ fees. After un-zipping, simply right-click “MovingGrating 1.3.app”, select “open”, and confirm. From then on the application opens without warning.
Windows application: MovingGrating1.3.exe.zip • MovingGrating1.2.exe.zip If you receive a message “… unverified developer … ” or similar, the reason is the same as in the above description. Bypass the warning, and deselect the appropriate tick box to avoid that warning from then on.
Change history
2016-06-11
Updated publications list
2015-05-11
1.3
Added the comment, explaining the warning message on recent operating systems. Enlarged buttons to avoid clipping, minor code efficiency improvement
2009-12-08
1.2
Improved GUI. This was used in Stiebel-Kalish et al. 2012.
2009-08-06
1.1
new algorithm for motion update, now no longer depends on frame rate