Horizontal motion behind occluder: Amodal perception and motion extrapolation
In real-world situations, many objects are often in motion and cross our visual fields. At times, their trajectories become hidden for brief periods by other objects. For example, when facing a dangerous free kick in a football match, a goalkeeper has to judge the motion of the ball while it is hidden behind a barrier of opponent players. To judge the current position of an occluded moving object is known as motion extrapolation (ME). This apparently simple sensorial-cognitive computation required the integrity of a large cortical network and involved many cognitive sub-processes. An interesting question is whether real motion and ME share some processes. In a series of psychophysical experiments, I investigated real motion and ME perception manipulating physical features of moving targets and of dynamic backgrounds in order to find similarities and differences between these two types of ‘motion’. For example, target size, contrast and motion adaptation seem to affect the perception of ME and the perception of real motion in a similar way suggesting the existence of common processes. On the other hand, presence of a moving directional backgrounds produced opposite effect. In conclusion, some evidence supports the idea that ME and real motion may have some mechanisms in common, but only in some specific experimental conditions.