Abstract
As objects in the environment move, a major challenge for the visual system is to keep track of each individual object. One suggested solution is to tag each object in an object file that could continually update information about its current characteristics. In a series of experiments, we show that the construction of object files is robustly coupled to their reference frames. Based on apparent motion, we developed a psychophysical method where two frames were shown in sequence, with the first frame centered on the fixation and the second frame on the upper left, upper right, lower left, or lower right corner. Two preview letters were presented on the first frame (one on the left and one on the right of the fixation), followed by a target letter on the second frame (target letter right above or below the fixation). Subjects were asked to indicate whether the target letter was one of the two preview letters. Critically, when the target letter was one of the preview letters, it shared the same relative location either as the same preview letter (e.g. both on the left side of each frame) or as the different preview letter. Despite that the target letter was equidistant from the two preview letters, we found that sharing the same frame-location as the same preview letter improved performance. This demonstrates that the construction of object files of the two preview letters was reference frame specific. We further found that this effect 1) was preserved when no competition was involved (e.g. when only one preview letter was presented), 2) occurred in a perceptual discrimination task with no memory demand (e.g. when the preview letters were task irrelevant and uninformative), and 3) held even when the preview letters were visually equally similar to the target letter (e.g. b-B, p-B).
Meeting abstract presented at VSS 2012