Abstract
People have systematic associations between colors and concepts formed through experiences. Several factors influence how people learn and generalize color-concept associations, including co-occurrence frequencies in the input and color typicality (Schoenlein & Schloss, VSS-2019). Rathore et al. (2019) proposed the category extrapolation hypothesis to account for how people form color-concept associations for colors not seen in the input: color-concept associations for an observed color (e.g., a purple) extrapolate to all other colors within the observed color’s category (e.g., all purples). This hypothesis implies learned color-concept associations for novel concepts will mimic structure defined by color-category boundaries. Associations between a concept and observed color should spread to other colors within its category, and then quickly decrease upon crossing the category boundary (e.g., purple to blue category boundary). We tested this hypothesis in two experiments. Both experiments included three tasks: (1) co-occurrence exposure for novel concepts (Filk, Slub), (2) color-concept association judgments, and (3) color-category membership judgments. In Experiment 1 we compared two models predicting the extent to which color-concept associations for observed colors during category learning generalized to a series of unobserved colors straddling category boundaries. The “ΔE only” model included color distance from the observed color (ΔE). The “ΔE+category” model included ΔE plus a measure of color-category membership. Supporting the category extrapolation hypothesis, ΔE+category fit the data better than ΔE only (model comparison accounting for different parameter counts: p<.001), and color category was a significant predictor (p=.034). Generalization in color-concept associations dropped upon crossing the category boundary, which cannot be explained by color distance alone. In Experiment 2, individual differences in color-category boundaries predicted individual differences in generalization patterns (purples: r=.65; yellows: r=.46). This work provides the first evidence that category boundary structure shapes color-concept associations for novel concepts, emphasizing the importance of cognitive and perceptual factors when forming associations.