Backscroll illusion is the apparent motion perceived in backgrounds of movie images that present locomotive objects such as people, animals and vehicles. In the attached movie, a human figure presents a walking gait against a counterphase grating. Although the grating has physical motion energies equally in the left and right directions, it appears to drift in a direction opposite to that of the gait.
Backscroll illusion in far peripheral vision Kiyoshi Fujimoto & Akihiro Yagi Journal of Vision. 2007. 7(8):16, 1–7
Backscroll illusion: apparent motion in the background of locomotive objects Kiyoshi Fujimoto & Takao Sato Vision Research. 2006. 46:14-25