When forewarned is not forearmed: No evidence for cue-based proactive control in the spatial Stroop task

It is commonly assumed that people can use advance cues to proactively prepare for conflict from distracting stimulus features, yet empirical findings remain inconsistent. We tested the hypothesis that nonarbitrary stimulus-response (S-R) mappings are a key determinant of cue effectiveness, as vocal Stroop tasks (with nonarbitrary color-naming responses) have shown reliable cue benefits, whereas manual Stroop tasks (with arbitrary key press responses) typically have not. Across five experiments, using a spatial Stroop task with nonarbitrary S-R mappings, we consistently found no evidence that participants used predictive cues to proactively resolve conflict on incongruent trials. Despite providing optimal preparation conditions (100% valid cues, 2,000 ms preparation time), cue benefits only emerged on congruent trials when task difficulty was increased substantially (50 ms stimulus presentation, Experiment 4), likely reflecting a strategic shortcut rather than enhanced proactive control. These findings demonstrate that nonarbitrary S-R mappings are not a sufficient condition for ensuring cue-based engagement of proactive control and challenge the assumption that this form of control is a readily deployable, domain-general mechanism. (PsycInfo Database Record (c) 2026 APA, all rights reserved).