How could lack of planning affect focus and attention?

Over the years, researchers have continued to study the Zeigarnik effect to figure out how it works. In 2011, Masicampo and Baumeister performed a series of experiments that suggested lack of planning, rather than lack of task completion per se, is the source of the intrusive, pinging reminders associated with the Zeigarnik effect.

For one study, Masicampo and Baumeister asked college students to think about how they were going to prepare for a pending exam. Half of the participants were asked to make clear study plans, detailing the time, place, and location that they were going to study. The other half of the participants, the control group, did not make any specific plans. None of the participants actually studied — instead they were asked to perform some unrelated tasks. Compared to the control group, the planning group had much higher levels of focus and attention while performing their tasks, while the control group struggled with focus and attention.^[1] Based on these observations, the researchers proposed that coming up with a specific plan relieves the subconscious mind of the requirement for incessant pings or reminders to the conscious mind about unresolved tasks.^[1] This suggests that forming a plan to complete an unresolved task in the future may be sufficient to overcome the Zeigarnik effect, relieving the associated drag on focus and attention.^[2]