Haberman, JasonBrady, TimothyAlvarez, George2019-09-132015-04Haberman, Jason, Timothy F. Brady, and George A. Alvarez. "Individual Differences in Ensemble Perception Reveal Multiple, Independent Levels of Ensemble Representation." Journal of Experimental Psychology: General 144, no. 2 (2015): 432-46.1939-22220096-3445http://nrs.harvard.edu/urn-3:HUL.InstRepos:41364829Ensemble perception, including the ability to "see the average" from a group of items, operates in numerous feature domains (size, orientation, speed, facial expression, etc.). Although the ubiquity of ensemble representations is well established, the large-scale cognitive architecture of this process remains poorly defined. We address this using an individual differences approach. In a series of experiments, observers saw groups of objects and reported either a single item from the group or the average of the entire group. High-level ensemble representations (e.g., average facial expression) showed complete independence from low-level ensemble representations (e.g., average orientation). In contrast, low-level ensemble representations (e.g., orientation and color) were correlated with each other, but not with high-level ensemble representations (e.g., facial expression and person identity). These results suggest that there is not a single domain-general ensemble mechanism, and that the relationship among various ensemble representations depends on how proximal they are in representational space.en-USensemblessummary statisticsindividual differencesensemble mechanismsJournal Article2019-09-1310.1037/xge0000053