Modulation of the Simon effect in two-dimensional tasks: the effect of learning

The present work was aimed at investigating whether automatic two-dimensional spatial coding, as indexed by the Simon task, is affected by prior practice with a vertical spatial compatibility task. One group of subjects performed a two-dimensional Simon task in which the vertical Simon effect was absent. The other group practised the vertical dimension by performing a vertical spatial compatibility task before the two-dimensional Simon task. With prior practice, the vertical Simon effect was significant. These results are discussed in the framework of the factors that affect two-dimensional spatial coding