Sustained attentional state is a floodlight not a spotlight

Maintaining attention to a task is essential for accomplishing it. However, attentional state fluctuates moment to moment and task-irrelevant information may compete for processing. What are the consequences of attentional fluctuations for what we remember? Do fluctuations in sustained attention vary the spotlight of selective attention, prioritizing task-relevant at the expense of task-irrelevant information? Or, are increases in sustained attentional state akin to a floodlight, enhancing processing of all information, regardless of task-relevance? In an online sample of 215 adults, participants were presented simultaneous streams of images and sounds and instructed to make responses based on only one modality. Afterwards, recognition memory for both images and sounds was tested. Across individuals, we found no evidence of a tradeoff between memory for task-relevant and task-irrelevant items. Within individuals, successful memory for a task-relevant item predicted successful memory for its task-irrelevant pair. Thus, the spotlight metaphor of attention does not extend to the dynamics of sustained attention. Rather, fluctuations in attention are more akin to a floodlight, affecting processing of all task information, regardless of relevance.