Inverting the Simon effect by intention: Determinants of direction and extent of effects of irrelevant spatial information

Summary. The Simon effect indicates that choice reac-tions can be performed more quickly if the response corre-sponds spatially to the stimulus- even when stimulus location is irrelevant to the task. Two experiments tested an intentional approach to the Simon effect that assigns a critical role to the cognitively represented action goal (i. e., the intended action effect). It was assumed that the direc-tion of the Simon effect depends on stimulus-goal corre-spondence, that is, that responses are faster with spatial correspondence of stimulus and intended action effect. Ex-periment 1 confirmed that the direction of the Simon effect was determined by spatial correspondence of stimulus and intended action effect, the latter having been manipulated by different instructions. Experiment 2 indicated that ef-fects of correspondences unrelated to the action goal (i. e., stimulus to hand location or to anatomical mapping of the hand), contributed additively to the resulting Simon effect. It is discussed how current approaches to the Simon effect can be elaborated to account for these results