The mean RTs as a function of block and trial type in Experiments 1 and 2.

<p>Panel <b>A</b> (Experiment 1) indicates that the stimulus interference (RT_SI-CO) is sharply reduced and almost eliminated with training in the Stroop task. In contrast, the response interference (RT_RI-SI) starts to decrease in the second block, and is stable with the following training. Interestingly, Panel <b>B</b> (Experiment 2) indicates that (1) the stimulus interference starts increasing in the second block, and is stably present across the following training and (2) the response interference is decreased in the second block, but increases in the following training in the Flanker task. <i>Note:</i> CO, SI, and RI are congruent, stimulus incongruent, and response incongruent, respectively.