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Updated: May 6, 2026

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments
Published on: March 1, 2022
Perceptual comparisons through the mind's eye
1Department of Psychology, University of Western Ontario, N6A 5C2, London, Ontario, Canada.
Abstract:
Four experiments tested a theory of memory and cognition which assumes that verbal and nonverbal information are processed in functionally distinct LTM systems. Subjects presented with pairs of pictures or printed names of animals and objects differing in rated real-life size were instructed to choose the conceptually larger member of each pair, the one that appeared to be farther away, or the one whose name was easier to pronounce. The following results were consistent with theoretical predictions: (1) RT to choose the larger member increased as the memory size difference decreased, for comparisons between as well as within conceptual categories; (2) memory size comparisons were faster with pictures than with words, whereas the reverse occurred for pronounceability comparisons; (3) with pictures, but not with words, size comparisons were significantly slower when real-life (memory) size relations conflicted with physical size relations than when the two were congruent; and (4) the size congruency effect was reversed for relative distance judgments of pictured pairs. These results cannot be easily explained by current verbal coding or abstract (propositional) theories of LTM representations.
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