One thing at a time
The case for doing one thing at a time
Multitasking feels productive. The research says it is quietly costing you — here is what happens in your brain when you switch, and why one thing at a time wins.
Your brain does not multitask — it switches
What we call multitasking is really fast toggling between tasks, and every toggle has a cost. According to the American Psychological Association's research on task-switching, the brief mental blocks created by shifting between tasks can eat up a surprising share of your day.
The underlying experiments show why: switching is not free. In controlled task-switching studies (Rubinstein, Meyer & Evans, 2001), each switch triggers two hidden stages — shifting your goal and re-activating the rules for the new task — and the cost grows as the tasks get more complex.
Attention residue: part of you stays behind
Even after you switch, your attention does not fully arrive. Sophie Leroy's research on attention residue (2009) found that a "residue" of the previous task lingers in your mind, leaving fewer mental resources for the thing in front of you — so the work you just left keeps taxing the work you are trying to start.
The real cost of one interruption: about 23 minutes
That figure comes from UC Irvine informatics professor Gloria Mark's work on interruptions. Her team also found that people compensate for interruptions by working faster — but at a real cost in stress, frustration, and effort (CHI, 2008). You can recover the time; you pay for it in strain.
Heavy multitaskers are not secretly better at it
It is tempting to think some people just multitask well. The original Stanford study on media multitaskers (Ophir, Nass & Wagner, 2009) found the opposite — heavy multitaskers were worse at filtering distractions and worse at switching. (In fairness, later replications were mixed, so treat this as suggestive rather than settled.)
What this means for your day
The consistent thread across the research is simple: focus is fragile, and switching is where it leaks. That is the whole idea behind Dot — instead of a list that invites you to juggle, it hands you one place to start. Not everything. Just the next thing.
Frequently asked questions
How long does it take to refocus after being interrupted?
Research by UC Irvine professor Gloria Mark found that interrupted work takes an average of 23 minutes and 15 seconds to return to, and people typically handle about two other tasks before getting back to the original one (Gallup Business Journal, 2006).
Does multitasking actually make you less productive?
Yes. The American Psychological Association reports that the brief mental blocks caused by switching between tasks can eat up as much as 40% of your productive time, based on task-switching research by psychologist David Meyer.
Why is it so hard to concentrate right after switching tasks?
Because of "attention residue." Sophie Leroy’s 2009 research shows that when you switch tasks, part of your attention stays stuck on the previous one, leaving fewer mental resources for the task in front of you.
Is single-tasking better than multitasking?
The evidence strongly favors doing one thing at a time. Switching carries measurable cognitive costs, leaves attention residue on prior tasks, and a Stanford study found heavy multitaskers were actually worse at filtering distractions.