Selecting mapping rules and responses in mixed compatibility four-choice tasks

Four-choice reaction tasks with a mixture of compatible and incompatible ma ppings were used to examine implications of the views that response selecti on occurs (a) in two stages (selection of the appropriate mapping rule, fol lowed by application of the rule) and (b) by means of a second, direct rout e when the mappings for all possible stimuli are known to be compatible. Al l experiments showed, consistent with the two-stage view, that responses we re faster and compatibility effects smaller when the mapping distinction co rresponded to the left-right or inner-outer locations for the stimulus-resp onse ensemble than when it did not. Moreover, precuing benefits tended to b e larger when the cued responses had the same mapping than when they did no t. There was an added benefit when both precued responses were compatible, rather than incompatible, consistent with the view that selection between c ompatible responses can proceed along a direct route.