Figure 1.

Directional Stroop task design. Congruent (C) trials (soft rabbit) required children to make a button press corresponding to the same side of the screen as the visual stimulus. Incongruent (I) trials (prickly hedgehog) required children to make a button press corresponding to the opposite side of the screen as the visual stimulus.

After demonstrating verbal mastery of the instructions, children completed two practice blocks: one of congruent trials and the other of incongruent trials. Children then completed three mixed blocks that combined congruent and incongruent trials. Short breaks occurred between blocks (indicated by dashed lines) to maintain electrode impedances. Children were reminded of the two rules following each break. Accuracy and reaction time from children’s button presses were recorded, along with EEG data. ERP data was analyzed from artifact-free correct trials during the Mixed blocks only.