Distractor preview moderates the alerting-congruency interaction in Stroop and flanker tasks.

Responses to targets are often slower when distractors are incongruent rather than congruent with the required response. Past research indicates that alerting cues can magnify this congruency effect, such that responses are faster when the target is cued, but distractors have a greater negative influence. This alerting-congruency interaction is reliably found in the arrow-version of Eriksen's flanker task but not in the Stroop task, leading some to suggest that the interaction only occurs with stimuli that have pre-existing directional associations. The current experiments test the possibility that the alerting-congruency interaction depends on the timing of distractor processing, rather than directional associations, by varying whether the distractor appears before the target or simultaneously with the target. In Experiment 1 (N = 158) using Stroop stimuli, and Experiment 2 (N = 157) using the arrow-version of the Eriksen flanker task, results replicate past findings: no alerting-congruency interaction in the Stroop task and a robust interaction in the arrow-flanker task when distractors and targets appear simultaneously. Importantly, previewing the distractor reverses both of these patterns. Delta plots showing congruency effects across the reaction-time distribution support the conclusion that the timing of distractor activation may be critical. Discussion focuses on implications for theories of the alerting-congruency interaction. OPEN PRACTICES STATEMENT: Subject-level data for all experiments are publicly available at https://osf.io/uxebp/?view_only=0db3638a66454684aee9fc41550a3a48 . The studies reported in this article were not preregistered.