Authors and Affiliations 4

22 We have a remarkable ability to accurately estimate average featural information across 23 groups of objects, such as their average size or orientation. It has been suggested that, unlike 24 individual object processing, this process of feature averaging occurs automatically and 25 relatively early in the course of perceptual processing, without the need for objects to be 26 processed to the same extent as is required for individual object identification. Here, we 27 probed the processing stages involved in feature averaging by examining whether feature 28 averaging is resistant to object substitution masking (OSM). Participants estimated the 29 average size (Experiment 1) or average orientation (Experiment 2) of groups of briefly 30 presented objects. Masking a subset of the objects using OSM reduced the extent to which 31 these objects contributed to estimates of both average size and average orientation. Contrary 32 to previous findings, these results suggest that feature averaging benefits from late stages of 33 processing, subsequent to the initial registration of featural information. 34 35