Proceedings of the Annual Meeting of the Cognitive Science Society

Non-numerical magnitudes such as cumulative area, element size, and density influence the perception of number. How-ever, it is unclear whether interactions between number and non-numerical magnitudes reflect independent representationsthat interface vis--vis other systems (e.g., language) or, conversely, reflect holistic perception of number and other mag-nitudes. In the present work, we found converging evidence that number and cumulative area are perceptually integraldimensions. Whether assessed explicitly (Experiment 1) or implicitly (Experiment 2), perceived similarity for dot arraysthat varied parametrically in number and area was best modeled by Euclidean, as opposed to city-block, distance. Criti-cally, we also found that the integrality of number and area is comparable to other integral dimensions (Exp. 1: bright-ness/saturation; Exp. 2: radial frequency components), but different from separable dimensions (Exp. 1: shape/color; Exp.2: thickness/curvature). In summary, these findings suggest that non-symbolic number perception is holistic, such that theprocessing of non-numerical magnitudes is obligatory.