What Difference Reveals About Similarity
Article first published online: 11 MAY 2012
Copyright © 2012 Cognitive Science Society, Inc.
Volume 36, Issue 6, pages 1019–1050, August 2012
How to Cite
Sagi, E., Gentner, D. and Lovett, A. (2012), What Difference Reveals About Similarity. Cognitive Science, 36: 1019–1050. doi: 10.1111/j.1551-6709.2012.01250.x
- Issue published online: 27 JUL 2012
- Article first published online: 11 MAY 2012
- Received 31 December 2010; received in revised form 11 September 2011; accepted 12 September 2011
- Structural alignment;
- Perceptual comparison;
- Same-different judgments;
- Alignable differences
Detecting that two images are different is faster for highly dissimilar images than for highly similar images. Paradoxically, we showed that the reverse occurs when people are asked to describe how two images differ—that is, to state a difference between two images. Following structure-mapping theory, we propose that this disassociation arises from the multistage nature of the comparison process. Detecting that two images are different can be done in the initial (local-matching) stage, but only for pairs with low overlap; thus, “different” responses are faster for low-similarity than for high-similarity pairs. In contrast, identifying a specific difference generally requires a full structural alignment of the two images, and this alignment process is faster for high-similarity pairs. We described four experiments that demonstrate this dissociation and show that the results can be simulated using the Structure-Mapping Engine. These results pose a significant challenge for nonstructural accounts of similarity comparison and suggest that structural alignment processes play a significant role in visual comparison.