Fig. 1.

Two trials from our modified flanker task. In this example yellow is the informative color. The top trial demonstrates the response preparation cue. The left hand in yellow indicates that a left hand response will be required to the following flanker. The bottom trial demonstrates the null cue. The null cue provides no information about the nature of the following flanker or the response that will be required. All stimuli were surrounded by a white border and participants were instructed to restrict their gaze within it; the inter-trial interval was indicated by a color change of the surrounding border from white to green.