Schematic of experimental tasks. Participants performed an incompatible or compatible stimulus-response mapping task on each trial. The mappings are shown in the upper right of the figure. A centrally located task cue (neutral, incompatible, or compatible) appeared between 4.4 and 8.8 sec prior to stimulus onset. These trial-types are identified in the figure. The words, neutral, compatible, and incompatible did not appear onscreen during the experiment.