Depth from Motion

This is a rambling, 14 minute series of explorations of depth from motion-defined stimuli, with voiceover — more of a podcast that was a video letter to a colleague. The point of the demonstrations is to show that shapes defined by motion can be fused to produce depth. So a square with leftward moving dots within it but on background of motion to the right in one eye will fuse with a similar square from the other eye to produce an impression of depth. The key point is that the random dot motion is uncorrelated in the two eyes and yet does not veto the fusion. All that is matched is the motion-defined shape. There are some limits though, the two motions must be in similar directions to fuse.

At the end of the video, some cross-modal versions of illusions and of apparent motion are presented to compare to the constraints seen for depth.

WARNING — the entire series requires free fusing a left and right image, not something everyone can do. So if you can, get ready to cross your eyes (or diverge) as soon as the movie begins. The first few minutes use a particularly difficult stimulus to fuse, apologies. These are followed by an easier version.

Depth from uncorrelated motion
when video starts, free fuse please, then you should see three outline squares, the middle one is the one to watch, it will have depth