| To assess the role of perceptual representations in conceptual combination, three studies examined the features that subjects produce for unmodified and modified concepts. Across studies, manipulations of production mode and concept complexity were predicted to produce evidence of perceptual factors. For production mode, subjects produced features under imagery, neutral, or word association instructions. If conceptual representations are perceptual, then neutral subjects should produce the same features as imagery subjects, with both producing different features than word association subjects. Subjects' protocols were coded for individual features and feature clusters to establish a detailed content profile for each production mode. As predicted, neutral subjects produced essentially the same kinds of information as imagery subjects, indicating that neutral subjects were processing perceptual representations to produce features. For concept complexity, some subjects produced features for unmodified concepts, and others produced features for modified concepts. In Experiment 1, half the subjects received single concepts (e.g. watermelon) and half received modified concepts (e.g. half watermelon) that exposed internal features in the nouns' referents (e.g. seeds, pulp). If subjects represent these concepts perceptually, then feature visibility should affect production. As predicted, subjects produced internal features much more often when they were visible in the modified concepts than when they were occluded. Experiment 2 demonstrated this visibility effect for novel combinations (e.g. transparent computer), not just familiar ones (e.g. open computer), with internal features again being more accessible in both types of modified concepts than in single concepts (e.g. chips and circuits for computer). In Experiment 3, features spatially close to the modified feature were more accessible than features spatially distant, regardless of whether they were external or internal to the noun's referent. When the modified feature was external (e.g. shiny car), the production of external features increased and the production of internal features decreased. In contrast, when the modified feature was internal (e.g. comfortable car), internal features increased and external features decreased. The results of these three experiments indicate that perceptual representations play central roles in conceptual processing. |
