Yanina E. Tena Garcia¹ (), Bianca R. Baltaretu¹, Katja Fiehler¹; ¹Experimental Psychology, Justus Liebig University Giessen, Giessen, Germany

Spatial information about object positions can be encoded individually or as an ensemble. Previous studies have shown that the temporal resolution of processing differs for individual and ensemble information, notably for simple stimuli under simplistic conditions. Here, we aimed to investigate whether scene context influences the encoding of individual and ensemble object positions across time for naturalistic environments. Participants viewed six objects (fruits and humanmade) in front of either a naturalistic kitchen scene (Scene) or a texturized background (Texture Control), at one of three encoding times (100, 800, or 3200 ms) in the Encoding phase. During the Response phase, they indicated via mouse click the remembered location of a specified object (Individual) or the average location of the six presented objects (Ensemble) on the corresponding, empty scenes. We found better performance in positional judgments for the Texture Control than the Scene at the shortest encoding time. While there was no systematic influence of scene context on Individual or Ensemble encoding, there was an overall increase in accuracy for both conditions with more encoding time. When analyzing eye movements in the Encoding phase, we found an interaction of encoding condition and encoding time for fixation frequency (more fixations for Individual than Ensemble encoding at longer encoding times). In addition, there were more frequent fixations on individual objects for Individual encoding, whereas fixations were more likely to occur between objects for Ensemble encoding. Overall, our findings suggest that individual and ensemble object position encoding for naturalistic environments is independent of scene context.

Acknowledgements: German Research Foundation (DFG) Fi1567/6-1 “The Active Observer”