A type of brain activity linked to arousal and attention can track mind wandering. But research conflicts on whether this activity promotes or hinders mind wandering. Esther Thielking of Barnard College and colleagues explored whether having the eyes open or closed changes the relationship between this brain activity and mind wandering.

Said Thielking, “We predicted that eye state might explain these conflicts because closing the eyes strengthens [this brain activity] and reverses its relationship with sleepiness, which is itself closely tied to mind wandering.”

As reported in their JNeurosci paper, the researchers recorded brain activity in adults with their eyes open or closed as they performed a task involving paying attention to sounds or letting their minds wander.