What is attention residue? Definition and research

What does attention residue mean?

Attention residue is the cognitive phenomenon where thoughts about a task you have not finished keep intruding while you work on something else. The term appears in research by Sophie Leroy and Theresa Glomb, who used it to describe why switching from one task to another can leave you performing below your ability, even after you have physically stopped working on the first task¹.

The key insight is that attention does not switch cleanly. When you move from an unfinished task to an interrupting task, part of your mind stays with the first task. That leftover mental activity is the residue. It competes with the interrupting task for your limited attention, making it harder to think clearly and do your best work.

Where does the term come from?

The concept comes from research by Sophie Leroy, a professor of management and organisation, working with colleague Theresa Glomb. Their work examined what happens to attention when people are interrupted mid-task and then have to perform a different task¹.

Their research found that people who left a task incomplete showed attention residue and lower performance on the interrupting task. Their minds kept returning to the unfinished work, even when they were not consciously trying to think about it¹.

The term is sometimes used loosely online to mean "multitasking is bad." But the original research is more specific. Attention residue is not about doing two things at once. It is about the lingering pull of an unfinished task after you have switched to something else.

What did the research actually find?

A 2018 study by Leroy and Glomb examined attention residue in the context of interruptions, using four separate studies¹. The researchers looked at what happens when someone is interrupted mid-task and then has to perform a different task.

The study found that people who anticipated resuming their interrupted work under time pressure struggled most to focus on the interrupting task. That anticipation led to attention residue and lower performance on the interrupting task¹.

This matters because most real-world interruptions are not clean breaks. You stop answering an email to join a meeting, but you know you will return to the email afterwards. The anticipation of a time-pressured return is what the research links to attention residue and reduced performance¹.

Does attention residue affect performance?

Yes. The research showed that attention residue has measurable consequences for how well you perform on the interrupting task¹.

When people anticipate resuming their interrupted work under time pressure, they find it difficult to switch their attention to the interrupting task. This leads to attention residue and low performance on that interrupting task¹.

The practical implication is that how you leave a task matters as much as how you start the next one. Anticipating a time-pressured return to unfinished work sets you up to underperform on whatever you do next, even if you are not aware of it¹.

How can you reduce attention residue?

The same research identified a simple intervention that reduces residue and protects performance: a "ready-to-resume" plan¹. Before switching away from an unfinished task, you take a brief moment to reflect on and plan your return to it.

This is not a long planning session. It is a short, deliberate reflection: what was I working on, what is the next step, and when will I come back to it. The study found that this brief planning step reduced attention residue, and performance on the interrupting task did not suffer¹.

A sensible starting point is to write one sentence before you switch: "When I return, I will start with X." That single action creates a ready-to-resume plan, which the research links to reduced attention residue¹.

Practical ways to apply this

The research points to a few habits that fit naturally into a working day:

• Write a resume note. For anything longer than a quick task, jot down where you stopped and your next action before moving on.
• Protect the first few minutes. Give yourself a short settling period when you start a new task, rather than expecting instant focus.
• Reduce visible reminders of unfinished work. From the Unleashed Environment Bank: keep one task visible on screen at a time, and keep your desk clear of non-essential items. Visual clutter competes for the same attention you need for the task in front of you.

Attention residue is not a flaw in your brain. It is a predictable response to leaving things unfinished. The fix is not to try harder to focus, but to make a ready-to-resume plan before switching¹.

For more on how task switching affects focus, see our piece on multitasking vs single-tasking research. If you struggle to focus for more than a few minutes, this guide explores what else might be going on.