Unpublished Manuscript Running Head: Distraction and Idle Resources Target-Distractor Phase and Selective Attention: Idle Resources do the Devil’s Work?

Four experiments tested the hypothesis that exclusion of irrelevant stimuli is more effective when attentional resources are engaged in processing task-relevant stimuli than when they are idle. Subjects (university students) attended to a series of target words while attempting to ignore distractor words and then recalled the targets. Distractors were presented either in phase with targets (when attentional resources are presumably occupied with target processing) or out of phase (when resources are relatively idle). When distractors occurred in the same modality as targets (auditory in Experiment 1, visual in Experiment 2), recall accuracy was lower with out-of-phase distractors, consistent with the hypothesis. However, when distractors occurred in a different modality than targets (auditory distractors with visual targets in Experiment 3, vice versa in Experiment 4), there was no difference between the phase conditions, although both were inferior to the no-distractor control condition. The interaction between phase and modality is consistent with largely modality-specific processing resources