Hysteresis in the Perception of Objects and Scenes
36.415, Sunday, May 12, 2:45 - 6:45 pm, Orchid Ballroom
Sonia Poltoratski1, Frank Tong1; 1Department of Psychology, Vanderbilt University
Recently, we have considered how categorization occurs when observers dynamically view objects and scenes (Poltoratski & Tong, VSS 2012). We developed a set of 16s movies that smoothly transitioned between a single closely viewed object and the entire scene. We found that when observers made online reports of whether they perceived these movies as either predominantly object or predominantly scene, their responses were contingent on the direction in which the movie was shown. We found this hysteresis-like effect to be consistent across manipulations of the stimulus; herein, we sought to characterize its resilience to manipulations of observer criterion and motivation. In Experiment 1, we introduced a semantic manipulation that required observers to report either time as object or time as scene for each movie, rather than reporting both concurrently. This allowed us to identify periods of uncertainty, which could occur if the stimulus is not unequivocally perceived as an object or a scene. Even when accounting for uncertainty, a significant effect of hysteresis was still present (2.26s). In Experiment 2, we tested whether observers could avoid hysteresis when encouraged to do so, providing a monetary bonus for responding consistently across presentations of each movie and cumulative feedback between experimental blocks. In the first block, a typical hysteresis difference was found (3.53s). By the fifth block, participants reported using an alternative strategy to improve the consistency between their responses and ignoring the original object/scene task. We conclude that the hysteresis mechanism persists even with high motivation to respond consistently (in Block 1), but that observers can gradually learn to respond consistently by relying on alternative cognitive strategies to avoid their predisposition for hysteresis. With these two experiments, we show that the hysteresis effect for gradual transitions between objects and scenes is robust to manipulations of observer criterion and motivation.