Expert article: the cognitive cost of interruptions
Expert author: Prof. Gloria Mark
Source: Mark G, Gudith D, Klocke U. The cost of interrupted work: more speed and stress. CHI Proceedings (2008). DOI: 10.1145/1357054.1357072.
Key finding
After interruptions, people tend to work faster but with higher stress, frustration, and perceived workload. Speed recovery is not equivalent to cognitive recovery.
Why fatigue accumulates
Every context switch taxes working memory. End-of-day exhaustion often comes from attention switching density, not only workload volume.
90-minute deep work protocol
Block 1 - 45 min: single objective, no notifications.
Break 10 min: movement + slow breathing.
Block 2 - 35 min: finish + summarize next action.
UX micro-copy
"Focus is not a personality trait. It is an environment architecture."
Protected attention increases output quality and reduces cognitive wear.
