Determinants of the benefit for consistent spatial mappings in dual-task performance of three-choice tasks

Performance of pairs of three-choice tasks shows a consistency benefit for which reaction times are shorter when the stimulus-response mappings for each task are consistent (both corresponding or both mirrored) than when they are inconsistent. In the present study, we examined whether this consistency benefit is reduced at long stimulus onset asynchronies, as it is for pairs of two-choice tasks, or is relatively unaffected, as it is for pairs of four-choice tasks. The consistency benefit was evident for both corresponding and mirrored mappings, at all intervals. For consistent mirrored mappings, the benefit was found for the side stimulus positions (for which responses are crossed) but not for the center position, whereas for consistent corresponding mappings, a benefit was evident for the center position as well. The results for both mappings are in agreement with an emergent mapping-choice account. The consistent corresponding mapping also benefits from subjects' ability to apply a respond-corresponding rule across tasks. An emergent perceptual-feature process that contributes to the consistency benefit for two-choice tasks does not seem to play a role in tasks with three or more choices.