Jieun Cho¹ (), Sang Chul Chong^1,2; ¹Graduate Program in Cognitive Science, Yonsei University, ²Department of Psychology, Yonsei University

The perceptual experience relies on the immediate past. The influence of the past is ambivalent, either making the current input appear more distinguished from or similar to recent inputs. Allegedly, the cause of this influence is the belief that the world remains stable and that visual inputs close in space and time are correlated. Since eye and body movements can induce changes in backgrounds and/or object locations, the belief can operate differently depending on spatiotemporal changes in visual environments. The present study investigated whether and how the spatiotemporal structure embedded in a series of background images influences people’s change detection judgments for objects presented in the background images. Participants saw a sequence of background images and were asked to judge whether two objects that were overlaid on the first and the last frame of a trial were the same (Experiment 1: Gabor patch orientation, Experiment 2: facial identity). We used pictures of real-world routes that were taken at regular intervals to compose a sequence of images and manipulated the spatiotemporal property of backgrounds. In the Straight condition, the background was the rapid sequence of six images depicting a straight sidewalk, serving as the condition where the spatiotemporal continuity among the adjacent scenes is the highest. In the Turn condition, the images included the corner of sidewalks where a pedestrian should turn. Lastly in the Jumbled condition, the straight and turn images were presented in a randomly shuffled sequence. Results showed that participants adopted the most conservative change detection criterion in the Jumbled condition and were least conservative in the Straight condition. There was no sensitivity difference across the conditions. These results suggest that a small change in objects is more frequently judged as a change when we perceive its background changes continuously and predictably.

Acknowledgements: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2022R1A6A3A13073653).