Smartphone notifications interrupt users' concentration for about seven seconds, according to new research from the University of Lausanne. The effect is stronger for personally relevant alerts, with frequent checks amplifying the distraction. Researchers warn that these brief interruptions accumulate over hundreds of daily pings.
Researchers at the University of Lausanne in Switzerland conducted an experiment with 180 university students using a Stroop task, a test measuring information processing and focus. Colored words appeared on screens, requiring participants to identify font colors while ignoring the words' meanings. During the task, notifications popped up, mimicking real phone alerts in varying degrees of realism across three groups: one believing they were receiving genuine personal notifications, another seeing fake social media pop-ups, and a third viewing blurry, illegible ones. All groups experienced a roughly seven-second delay in processing speed, with the most pronounced slowdown for those anticipating real messages from their phones. Hippolyte Fournier, a postdoctoral fellow and lead author, explained that interruptions stem from perceptual prominence, repeated conditioning, and social importance of notifications. He added that notification volume and checking frequency correlate with greater disruption, suggesting fragmented smartphone use harms attention more than total screen time. Participants averaged 100 notifications daily, turning minor delays into significant cognitive costs during tasks like driving or studying. Co-author Fabian Ringeval noted in a LinkedIn post that frequent interactions heighten vulnerability to interruptions. Psychiatry professor Anna Lembke of Stanford observed that engagement levels, such as quick responses to alerts, predict problematic use better than hours spent on devices. In the US, 90% of people own smartphones and average over five hours daily usage, per Pew Research and Harmony Healthcare IT. The findings, set for the June issue of Computers in Human Behavior, urge reducing unnecessary notifications to boost digital well-being.
