Proceedings of the Annual Meeting of the Cognitive Science Society

Numerosity is informative for living organisms. It cantransmit, among many things, amount of food available,heading direction of the troop, which group could win aterritorial dispute, the decision of were to build a beehive.Given its ecological importance, we test the hypothesisthat numerosity captures visual selection. In five exper-iments we confirmed that an irrelevant visual stimulusthat was numerically large slowed down participants indetecting a task-relevant visual target (Exp. 1 and 2). Thiscapture was not driven by sensory variables that could cor-relate with numerosity: cumulative area (Exp. 3) and ele-ment size (Exp. 4). We also confirmed that the underlyingnumerosity representations were analogue, not set-based(Exp. 5). In a crowded visual scene numerosity is a rele-vant cue for visual selection, but represented only in ap-proximate/coarse fashion.