Proceedings of the Annual Meeting of the Cognitive Science Society

Observers rapidly extract summary statistics from sets ofvisually presented items, like the mean size of a set of circles,or the mean expression of a set of faces. Their excellentability to report summary statistics stands in contrast to near-chance representation of any of the individuals. Here weasked to what extent this ‘ensemble perception’ signatureextends to a more abstract property: relations amongelements. Participants watched ten unique animations ofvisually patterned objects (hereafter, ‘shapes’) colliding witheach other and producing a new shape. Collisions conformedto ABA patterns, such that the result shape always matchedone of the collider shapes. Recognition tests showed thatparticipants accurately recalled the collisions they saw, butalso falsely accepted foils which conformed to the ABApattern but which were not in fact specifically seen (wererearrangements of the original shapes across collisions). Onthe other hand, they were much less likely to accept foilswhich did not conform to the pattern, but were equallydistinct rearrangements (e.g., AAB). This suggests thatparticipants represented the overall, common pattern betterthan the specifics of what they saw; the superior encoding ofthe summary relative to the individuals thus applies tosummaries of relations. However, in contrast to prior findingswith visual features, we did not find that recall of individualpatterns was entirely at chance. Our paradigm offers a way topursue future questions such as the pressures and motivationswhich might govern the trade-off between summarizingevidence vs. retaining individual experiences.