Visual interactions in the path of apparent motion.

When two stationary visual objects appear in alternating sequence, they evoke the perception of a single object moving back and forth between them. This is known as stroboscopic or apparent motion and forms the basis of perceived continuity in, for example, motion pictures. When the spatiotemporal separation between the inducing objects is optimal, the subjective appearance of apparent motion is nearly indistinguishable from that of real motion. Here we report that the detection and identification of a simple visual form in the path of apparent motion is impaired by the illusory perception of an object moving through the empty space between the locations at which the inducing objects are presented. This observation may be a manifestation of perceptual completion or 'filling in' during apparent motion perception. We propose that feedback from higher to lower visual cortical areas activates an explicit neural representation of a moving object, which can then disrupt the representation of visual stimuli in the path of the movement.