Stimulus – response sets with multiple dimensional overlap: Asymmetric effects are influenced by the degree of overlap

Performance in choice reaction tasks was examined by investigating stimulus – response mappings that overlapped on multiple dimensions (Kornblum, Hasbroucq, & Osman, 1990). The purpose of the investigation was to determine whether the relationship between the dimensions was symmetric or asymmetric. In two experiments, city names (London, Bristol, Washington, Dallas) were presented as stimuli and response labels employing a variant of the Hedge and Marsh (1975) task. In Experiment 1, responses were based on whether the cities were American or English. Analyses of performance revealed evidence of both Simon and reverse Simon effects. In Experiment 2, participants responded on the basis of whether or not the same cities were capitals. Simon effects but no reverse Simon effects were found, revealing asymmetric effects. A third experiment demonstrated that the cities were more likely to be grouped as belonging to a country by comparison with a grouping in terms of capitals. The asymmetric effects observed support the view that processing was influenced by the degree of dimensional overlap.