Transitions and buffer time: the gaps between tasks

Switching from one task to another is slower and more error-prone than staying on one, and part of your attention can stay behind on the task you left. Many articles say this cost is much larger with ADHD. The laboratory evidence for that is weaker than the claim.

What the evidence says

Switching costs everyone. In laboratory studies with simple tasks, responses right after a switch slow down and errors increase. Time to prepare reduces the cost but does not remove it ¹. The cost grows with more complex rules and shrinks when a cue tells you what is coming next ².

Unfinished work follows you. To move fully to a new task, people need to stop thinking about the previous one; the attention that stays behind is called attention residue ³. Taking a minute to plan how to resume the interrupted work reduced the residue and helped people focus on the task that had interrupted them ⁴.

An upcoming appointment shrinks the time before it. In an online study, people who imagined a friend arriving in an hour counted about 50 free minutes, but felt they had only about 40 ⁵. In another study by the same team, using people’s real schedules, those with an appointment within the hour were more likely to pick a 30-minute task over a longer, better-paid one ⁶.

What we don’t know

Whether transitions are specifically harder with ADHD is not settled. A meta-analysis of 83 studies found that people with ADHD did worse on executive function tasks in general, with medium-sized effects that did not apply to everyone ⁷. In a study of adults, those with ADHD switched between simple tasks about as well as the comparison group, and were slower only when the switch also required changing the scope of attention ⁸.

So the common experience of transitions being hard may be real without being a switching problem as laboratories measure it. It could be about stopping something rewarding, about time, or about what is left unfinished.

Things to try

These come from general-population research.

• Write one line before you leave a task: where you stopped and what you will do first when you return ⁴.
• Know what is next. A cue about the next task reduced the cost of switching ².
• Leave the gap loose. In a laboratory study of 158 students, when the five minutes before the next commitment were framed as “exactly five minutes”, people got less done than when it was “about five minutes” ⁹.
• Group appointments together so that they do not each shrink the time around them. That is the recommendation of the researchers who found the effect ⁶.
• Take breaks earlier in the day. In a five-day study of 95 employees, earlier breaks and doing something they liked during a break were associated with better recovery ¹⁰.