対象の運動速度の過大視・過小視(E-09)

抄録

Speed perception from movements of motion-defined boundaries was investigated. A field of random dots (target) moved over a rectangular field of the same random dots (background). When random dots within target area had motion relative to its boundary motion (scroll) in addition to the absolute movement of the target itself (drift), speed perception of the drifting target was overestimated if its scroll direction was the same as the drift. This overestimation of speed was enhanced when background moved oppositely to the drift of target. Such enhancement is not predicted if the overestimation of speed is caused by "motion capture", where the boundary-defining motion captures the motion-defined boundary. Contribution of motion-contrast detectors seems appropriate for the cause of overestimation of speed of the motion-defined boundary.