Attention residue

Attention residue is the portion of your attention that remains occupied by a previous task after you’ve switched to a new one. The term comes from researcher Sophie Leroy (2009), whose experiments showed that when people move from Task A to Task B, performance on B measurably suffers because part of the mind is still processing A — especially when A was left unfinished or without closure.

It’s the mechanism behind the familiar experience of answering “one quick message” mid-report and then typing through syrup for twenty minutes: the switch felt free, but it wasn’t.

Residue accumulates across a day of fragmented work, which is why afternoons often feel cognitively bankrupt. The levers that shrink it: fewer and batched switches, a sixty-second closure ritual when leaving a task (note where you stopped and the exact next step), and capturing mid-focus intrusions in one line instead of following them.