Contrast perception as a visual heuristic in the formulation of referential expressions

We hypothesize that contrast perception works as a visual heuristic, such that when speakers perceive a significant degree of contrast in a visual display, they tend to produce the corresponding adjective to describe a referent. We tested this hypothesis in four language-production experiments. Experiment 1 revealed that speakers overspecify color adjectives in polychrome displays, whereas in monochrome displays they overspecified those properties that were contrastive, supporting the contrast perception hypothesis. Experiment 2 further supported our hypothesis by revealing an increase in color overspecification in monochrome displays when multicolored fillers were interspersed. Experiment 3 revealed that even atypical colors (which are overspecified more often than typical colors) are only mentioned in polychrome displays. In Experiment 4, participants named a target color faster in monochrome than in polychrome displays, suggesting that the tendency to overspecify color in polychrome displays is not a bottom-up effect, but a learned communicative strategy. These results support the view that perceptual contrast works as a visual heuristic for efficient communication.