Even repeated every hour for ten minutes, these short breaks can do nothing against the mental fatigue that seizes office workers. This is the sentence formulated by a Lithuanian team. Only the lunch break allows us to recover our cognitive functions from the level of the morning.
Hervé Poirier, editor-in-chief of the scientific magazine Epsiloon,explains to us today that breaks during the working day are useless.
franceinfo: Are you telling us that apart from the lunch break, we are always so tired after the coffee breaks of the day? For what ?
Herve Poirier: Everyone who works in an office in front of a computer is convinced of this: it feels good to take a short break, have a coffee, browse social networks, or just get some fresh air. We think of something else, and we say to ourselves that we will, afterwards, resume work with more freshness, energy, attention.
Lithuanian psychologists did the test. They asked 18 healthy young men to simulate a 7-hour workday in an office, taking 10-minute breaks every 50 minutes. And they made them go through a whole battery of cognitive exercises, involving attention, concentration, learning and memory, while doing blood tests, and scrutinizing their autonomic nervous system, responsible for regulating heart rate, breathing, blood pressure.
Well, contrary to popular belief, breaks don’t change anything: response time and cognitive functions decline irreparably throughout the day. It takes a rest of 4.5 hours to see the effects of mental fatigue disappear.
So you advise us not to take a break during the whole day?
No, this study does not show that short breaks have a negative effect. Just that they don’t have the expected positive effect. We exaggerate the benefits of these moments when we cut off our attention, when we think of something else. For researchers, things are simpler: the decline in cognitive performance after several hours of work is linked to simple energy constraints. Our brain needs, first and foremost, a constant supply of glucose and oxygen, to maintain optimal cognitive performance.
So the lunch break should have an impact?
Yes. And it’s even the only break that, during the experiment, proved to be effective against mental fatigue. After eating, working memory recovers to its morning level, presumably because blood sugar levels rise. It doesn’t hurt to have a little coffee, browse the Internet, or get some fresh air. But we get the wrong idea of how our neurons work: they don’t need breaks so much, they mostly need fuel.