Phasic alertness can modulate executive control by enhancing global processing of visual stimuli.

Researchers have suggested that the attention system is composed of several networks that have different functions. One of these networks is responsible for achieving and maintaining an alert state (alerting system), and another for selection and conflict resolution (executive control). There is growing interest in how these attentional networks interact. The current study aims to unravel a mechanism by which the alerting system can interact with executive control. Participants were presented with a large arrow (global level) made of small arrows (local level). The arrows were pointing to the right or left so that the global and local levels could be congruent or incongruent. In separate blocks, participants were asked to attend to the global or local level. An auditory alerting cue preceded the arrow target in half of the trials. In the local task, the congruency effect was larger with the alerting cue than without it. In contrast, alerting did not modulate the congruency effect in the global task. We suggest that alerting creates a bias toward global processing and in turn, increases attention to sensory stimuli in the environment. This process can disrupt conflict resolution by allocating attention to irrelevant competing stimuli that surround the target.