Task rule-congruency and Simon-like effects in switching between spatial tasks

In task switching, a response indicated as correct by both task rules is executed more quickly than one for which the rules disagree. This rule-congruency, so far demonstrated unequivocally only in nonspatial tasks, shows that the currently irrelevant task set is kept active. However, in spatial task- switching, rule- congruency could potentially reflect a preexperimental tendency that contributes to a Simon-like effect. In the present study, participants switched between RIGHT-LEFT and UP-DOWN tasks with either a standard key arrangement (e. g., upper key = UP) or a mapping- reversed arrangement (e. g., up = DOWN), which reverses the direction of the potential Simon- like effect but leaves potential rule- congruency effects unchanged. Mapping- reversal did not modulate any other effect, including rule- congruency, and therefore indicated rule- congruency unequivocally. Finally, implications concerning generality versus domain specificity of control processes in task switching are discussed.