Fixate the center of the cross. If the grey square appears stationary
or almost stationary, you are experiencing paradoxical rest (Gerbino
& Bruno,1998). In fact, the square is rotating at the same angular
speed as the cross. Paradoxical rest may be explained by noting that strong
motion signals are available for the square only at the t-junctions formed
with the cross. But these are occlusion terminators, not true object terminators.
Thus, as in the
occluded terminators demonstration,
these signals should be disregarded if motion integration takes the global
structure of the stimulus into account. |