Perceptual Similarity and Conceptual Structure

Abstract

This chapter discusses perceptual similarity and conceptual structure. The relevance of perceptual similarity for conceptual structure stems from the role of real world experience on feature weights. One kind of knowledge that pushes feature weights around and stretches the similarity space is implicit knowledge about relations among perceptual features. Perceptual features do not vary orthogonally in the world. They come in causally related clusters; birds with webbed feet tend to have bills and objects with dog-like feet tend to have dog-like heads. Evidence from laboratory experiments indicates that both adults and older infants are sensitive to such correlations. This empirical evidence indicates that experience with correlations causes increased attention to the combinations of features that enter into correlations. Perceptual and conceptual similarity are not the same things. Conceptual similarity does not reduce to perceptual similarity. The chapter discusses how perceptual and conceptual similarities are different and describes the causal dependencies between the two.