The Role of Shape in Comparing Objects: How Perceptual Similarity May Affect Visual Metaphor Processing

Comparing objects is a process necessary to cognitive tasks involving categorization. Shape is considered one of the primary vehicles for object categorization. We hypothesize that similarity in shape facilitates finding conceptual correspondences between objects, both for objects stemming from the same and from different conceptual categories. In the latter case, the comparison process requires the construction of an ad hoc category, which is also required when interpreting visual metaphors. We used three experimental tasks to investigate the role of shape in comparing objects: a similarity judgment task, a similarity rating task, and a production task. The results of our experiments support the hypothesis that an essential component of visual metaphor processing—comparing objects stemming from disparate conceptual domains—is positively affected by similarity in the objects' shape.