Abstract
Crowding refers to the interference caused by flanking objects on recognition of a target. Researchers have extensively studied crowding with objects like letters, faces, symbols, and shapes. In other contexts, recognition ability for some of these stimulus categories is asymmetric across the left and right visual hemifields: letters are easier in the right visual field, while faces are easier in the left. We investigated whether crowding – specifically, the critical spacing for crowding – differs in the left vs. right visual fields and across three stimulus types: letters, faces, and Landolt squares (task is to judge the orientation of the gap). We first adjusted the size of each stimulus type so that each participant could achieve 99% correct recognition without crowding. In the second part of the experiment, we fixed the size at that level and then measured the critical spacing (the minimum spacing between objects required for 70% correct recognition) in the left and right visual fields at 4° eccentricity. Across all three stimulus types, we found a right visual field advantage: the mean critical spacing was lower in the right than left visual field. In sum, our results suggest that crowding negatively affects the left visual field more than the right, irrespective of the stimulus type. Future work will help reveal how crowding for different object types relates to specific neural circuits that are lateralized to the left or right cerebral hemisphere.