Does the contribution of stimulus-hand correspondence to the auditory Simon effect increase with practice?

In two-choice reaction tasks for which stimulus location is irrelevant, crossing the hands typically does not alter the benefit for corresponding stimulus and response locations (the Simon effect), which implies location coding of responses. However, for auditory tasks in which a consistent mapping between responding hand and tone pitch is maintained, the Simon effect may become smaller for crossed than uncrossed hands with practice, suggesting increased reliance on anatomical coding. Two experiments tested this possibility. In Exp. 1, the Simon effect tended to be smaller with crossed than uncrossed hands in the second half of 1,600 trials but not in the first half. Experiment 2 showed that this result was not due to reinstructing subjects mid-experiment about the consistent mapping of stimuli to hands. Although the Simon effect was apparent with crossed hands throughout both experiments, it tended to be slightly smaller than the effect obtained with uncrossed hands.