The interaction between alerting and executive control: Dissociating phasic arousal and temporal expectancy

In recent years, studies have revealed an interaction between two systems of attention-alerting and executive control. Specifically, warning cues increase the influence of cognitive conflict under certain conditions. One of the problems of interpreting this effect is that warning cues can trigger two processes simultaneously-a high arousal state and strategic temporal expectancy. The goal of the present study was to clarify which process underlies the increased congruency effects following a warning event. In two experiments, the influence of warning cues on flanker congruency was examined while controlling for the effects of temporal expectancy and arousal. Experiment 1 revealed a strong effect of warning cues on congruency, even when the warning cues were not temporally predictive. This effect was evident at two short cue-to-target intervals of 100 and 500 ms, but not following a 900-ms interval. Experiment 2 revealed that this effect was not altered even when the warning cues predicted with high certainty that the target would appear at long cue-to-target intervals (e.g., 900 ms). We suggest that the interaction between alerting and executive control reflects the involvement of a subcortical mechanism responsible for increasing arousal.