Emergent Features Help Resolve Ambiguous Apparent Motion
43.416, Monday, May 13, 8:30 am - 12:30 pm, Orchid Ballroom
Anna Cragin1, Belicia Ding1, James Pomerantz1; 1Department of Psychology, Rice University
A Pickler-Ternus display is an ambiguous apparent motion stimulus in which three disks are horizontally aligned, and the left disk disappears as a disk in the far right appears. This motion can be perceived in one of two ways: (1) left disk can be perceived as flipping to the right (element), or (2) all the disks are shifting together as a group to the right (group). When intervals between frames are short (as low as 0ms), element motion is more likely to be perceived. When frame intervals are long (100ms), however, group motion is more likely to be perceived. At intermediate intervals, the display is bistable: the nature of the motion is ambiguous because there are two solutions to the correspondence problem. Previous research has shown that it is possible to change the distinguishing surface features of the disks (e.g., color, texture) to bias the perception. In this experiment, we were interested in investigating bias towards element or group motion when the disks contain images with special perceptual features (Emergent Features, e.g. parallelism, intersections). Specifically, we investigated the role of Emergent Features in solving the correspondence problem via intra-stimulus grouping (the more differences in Emergent Features there were between the two images used for the display, the better people were at solving the correspondence problem) and inter-stimulus grouping (the more Emergent Features arising from the elements within a row that group them together, the more likely it was that they were seen moving as a group). We conclude that Emergent Features are important in perceiving motion as well as stationary forms during visual search.