A common visual metric for approximate number and density.

摘要: There is considerable interest in how humans estimate the number of objects a scene context an extensive literature on we density (i.e., spacing) objects. Here, show that our sense and are intertwined. Presented with two patches, observers found it more difficult to spot differences either or numerosity when those patches were mismatched overall size, their errors consistent larger appearing both denser numerous. We propose estimated using relative response mechanisms tuned low high spatial frequencies (SFs), because energy at SFs largely determined by objects, whereas SF depends area occupied elements. This measure biased stimulus size same way as human observers, estimating scaled can explain all results. model simple, biologically plausible common metric for perceptual density.