Abstract
When viewing the concentric circles, which consist of oblique components, the observers see illusory rotation of those circles by changing the viewing distance. If several additional elements were superimposed on the concentric circles, they will see the illusory rotation not only for the circles, but also for the superimposed dots (Ichikawa et al, 2006, Perception, 35, 933-946). This illusory rotation of the superimposed dots is caused by "motion capture". We examined how motion signal with different directions in terms of apparent motion, as well as illusory motion signal from the oblique components, affects the motion capture. A CRT display presented dots with the inner and outer circles (14.3 and 17.2 deg in diameter) each that consisted of 72 oblique lines, which were tilted radially by 30 deg. We prepared four conditions. In the size change condition, the stimulus changed its size from 17.2 to 6.9 deg. In the rotation condition, the inner and outer circles rotated to opposite direction by 10.0 and 6.0 deg, respectively. In the rotation with size-change condition, the inner and outer circles, which consisted of 72 radial lines, rotated to opposite direction by 10.0 and 6.0 deg, respectively, and changed its size from 17.2 to 6.9 deg. In the rotation with translation condition, the inner and outer circles rotated to opposite direction by 10.0 and 6.0 deg, respectively, and the whole stimulus translated horizontally by 6.4 deg. Observers tended to perceive motion capture for the dots in the size change, rotation with size-change, and rotation with translation conditions. However, in the rotation condition, they tended to perceive induced motion for the dots. These results suggest that the existences of the common fate factor for the stimulus elements determine how to allocate and integrate the motion signal in each element in the stimulus to generate motion capture.
Meeting abstract presented at VSS 2016