Perception of visual apparent movement and topographic analysis of related evoked potentials.

Most of the studies in long-range apparent movement have been concerned with the psychophysical properties in central vision. However, apparent movement in peripheral vision is not clearly understood. This study focuses on the properties of the perception of apparent movement between central and peripheral vision. The results show that judgements of apparent movement in central vision indicate high performance at less than 4 degrees of spatial separation, and that judgements in peripheral vision indicate high performance at greater than 4 degrees. Evoked potentials associated with long-range apparent movement were also measured, and topographic maps were constructed to evaluate the active areas corresponding to visual apparent movement. The topographic maps show that the central regions are activated above 300 msec after the onset of the second apparent-movement stimulation. The results suggest that visual apparent movement occurs in the visual association area, or at higher levels in the central nervous system.