title: Testing the role of vertical symmetry in letter matching.
abstract: A series of experiments tested a recent suggestion that vertical symmetry of a stimulus display can serve as a visual diagnostic for responding "same" in a letter-matching task. The data of chief interest were same reaction times to vertically symmetric (e.g., AA) and asymmetric (e.g., LL) displays, each composed of two side-by-side uppercase letters. Overall, the data argue against subjects' use of vertical symmetry as a diagnostic in dealing with letter pairs. The results were interpreted within the context of recent work on symmetry. In particular, it was suggested that the importance of structural diagnostics in a matching task may be inversely related to the codability of the stimulus elements being compared.
mesh_terms: D000293:Adolescent; D000328:Adult; D004192:Discrimination, Psychological; D005556:Form Perception; D006801:Humans; D009949:Orientation; D011214:Practice, Psychological; D011930:Reaction Time; D012718:Set, Psychology; D014796:Visual Perception