How could incomplete tasks affect focus and attention?

Incomplete or unresolved tasks may interfere with focus and attention through a phenomenon known as the Zeigarnik effect. Unresolved tasks or problems tend to bubble up from the subconscious to the conscious landscape as intrusive thoughts, undermining the ability to direct or maintain focus and attention on a desired target.

The Zeigarnik effect was discovered by Russian psychologist Bluma Zeigarnik when by chance, she left her purse in a restaurant after a night out to dinner with colleagues. When she tracked down the waiter to ask him to help him find her purse, the waiter had no recollection of her. Zeigarnik was intrigued, since minutes before the waiter had flawlessly taken and served the orders of her large dinner party entirely by memory, without writing a single note. When Zeigarnik asked the waiter how he could have forgotten her so quickly, he answered that he had no memory of patrons after they settled the bill.^[1] Intrigued, Zeigarnik returned to her lab to study this phenomenon, making the observation that unresolved tasks have a tendency to insistently ‘ping’ the conscious mind until they are completed.^[2] The insistent pinging diminishes focus and attention until the task is resolved.