The size-brightness correspondence: evidence for crosstalk among aligned conceptual feature dimensions

The same core set of cross-sensory correspondences connecting stimulus features across different sensory channels are observed, regardless of the modality of the stimulus with which the correspondences are probed. This observation suggests that correspondences involve modality-independent representations of aligned conceptual feature dimensions and predicts a size-brightness correspondence in which smaller is aligned with brighter. This suggestion accommodates cross-sensory congruity effects where contrasting feature values are specified verbally rather than perceptually (e.g., where the words WHITE and BLACK interact with the classification of high- and low-pitch sounds). Experiment 1 brings these two issues together in assessing a conceptual basis for correspondences. The names of bright/white and dark/black substances were presented in a speeded brightness classification task, in which the two alternative response keys differed in size. A size-brightness congruity effect was confirmed, with substance names classified more quickly when the relative size of the response key needing to be pressed was congruent with the brightness of the named substance (e.g., when yoghurt was classified as a bright substance by pressing the smaller of two keys). Experiment 2 assesses the proposed conceptual basis for this congruity effect by requiring the same named substances to be classified according to their edibility (with all of the bright/dark substances having been selected for their edibility/inedibility, respectively). The predicted absence of a size-brightness congruity effect, along with other aspects of the results, supports the proposed conceptual basis for correspondences and speaks against accounts in which modality-specific perceptuomotor representations are entirely responsible for correspondence-induced congruity effects.