How long does it take to refocus after an interruption?

There is no dependable number, despite how often one is quoted. It varies with the task, the interruption and whether the previous work was left at a clean stopping point — which is the variable you can actually control.

Does closing a task really help?

Leroy’s work suggests that being able to form a concrete plan for finishing reduces the carry-over, even when the task is not finished. In practice, writing down the next action costs seconds and gets much of the benefit.

Attention Residue: Why Switching Costs More Than You Think

Attention residue: The portion of attention that remains on a previous task after switching to a new one, degrading performance on the new task.

Where the idea comes from

The term comes from Sophie Leroy, whose 2009 paper "Why is it so hard to do my work?" showed that people moving between tasks performed worse on the new one when the previous task was left unfinished — and that being able to form a plan for finishing it reduced the effect.

How it shows up

Reading the same paragraph three times after a message arrives
Coming out of a meeting still arguing with it half an hour later
Feeling busy all day with little you can point to
Needing a run-up after every interruption, however small

What actually helps

Write the next action for the task you are leaving before you leave it — a plan closes the loop the mind keeps open
Batch interruptions rather than absorbing them one at a time
Protect one block a day where switching is not possible at all
Stop mid-sentence deliberately, so the residue points at something specific rather than something vague

Where the popular version overreaches

The widely quoted "it takes 23 minutes to refocus" figure comes from a small observational study of office workers and has been repeated far past what it can support. Attention residue is real; the precise number attached to it in most articles is not a reliable constant.

Common questions

How long does it take to refocus after an interruption?: There is no dependable number, despite how often one is quoted. It varies with the task, the interruption and whether the previous work was left at a clean stopping point — which is the variable you can actually control.
Does closing a task really help?: Leroy’s work suggests that being able to form a concrete plan for finishing reduces the carry-over, even when the task is not finished. In practice, writing down the next action costs seconds and gets much of the benefit.

Sources

Leroy (2009), Organizational Behavior and Human Decision Processes

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