Professor Sophie Leroy of the University of Washington coined the term attention residue to describe the cognitive half-life left behind after switching tasks. Even after you physically move to a new task, a portion of your attention remains stuck on the previous one. The more complex or incomplete the previous task, the heavier the residue.

In the original paper (Leroy 2009), Dr. Leroy defines attention residue as, “the persistence of cognitive activity about a Task A even though one stopped working on Task A and currently performs a Task B.”

In other words, there is a cognitive switching cost to shifting your attention from one task to another. When your attention is shifted, there is a “residue (殘留)” that remains with the prior task and impairs your cognitive performance on the new task.

You may think your attention has fully shifted to the new task, but your brain has a lag.

Anything that is pulling your attention, stopping you from reaching states of flow

Close Open Loops

The only way to eliminate attention residue entirely is to:

• see a task through to completion, or
• have a clear, trusted plan for when it will be completed (the Zeigarnik effect in reverse) ¹

Always finish what you’ve started. Never start what you can’t finish.

Drop a task when it is only partially finished, without any good “closure”; it then either gets lost, or weighs on one’s mind and prevents one from fully thinking about something else, or has to be redone from an earlier point when one picks it up again.

There’s something magical in that last little bit, simply because so few are willing to do it. That’s where you unlock new levels to the game. And it does not take talent, just energy and courage.