2024-07-18 00:59:34
Some people don’t go to bed at night, others jump out of bed feeling refreshed in the morning. Are there differences in the brain performance of the two chronotypes?
In chronobiology, a distinction is made between owls and larks. Owls are night owls, they have a hard time getting into bed in the evening and getting out of it again in the morning. Larks, on the other hand, are morning people. They like to get up early, but they also get tired earlier in the evening.
Researchers at Imperial College London have now investigated whether the cognitive abilities and performance of night owls and early risers differ. To do this, they evaluated the data of more than 26,000 people who had completed tests on intelligence, thinking ability, reaction time and memory. They compared the results with the test subjects’ statements on their own sleep duration and bedtime. The study participants themselves assessed whether they saw themselves as night owls or morning owls, i.e. whether they felt fitter and more productive in the morning or in the evening.
The surprising result: night owls and also “middle sleepers” who belong to neither chronotype performed significantly better in the tests than early risers. The latter consistently showed the lowest values.
The press release states: “Evening sleepers or owls scored about 13.5 percent higher than morning sleepers in one group and 7.5 percent higher than morning sleepers in another group. Middle sleepers – a mix of the two – also fared better, scoring about 10.6 and 6.3 percent higher than morning sleepers in the two groups, respectively.”
In their analysis, the researchers also took into account other health and lifestyle factors such as age, gender, smoking and alcohol consumption, as well as the presence of chronic diseases such as heart disease and diabetes. However, the result remained constant.
One of the study authors, Dr. Raha West, explains: “Our study found that adults who are naturally more active in the evening (what we call ‘evening people’) tend to perform better on cognitive tests than ‘morning people’. These chronotypes are not just personal preferences, but could also influence our cognitive functions.”
However, the researchers make it clear: a morning person cannot simply be converted into an evening person; the individual biorhythm is too complex for that.
But the scientists also discovered something else: seven to nine hours of sleep per night is optimal for brain and cognitive functions such as memory performance, thinking ability and the speed of information processing. In contrast, sleep of less than seven hours or more than nine hours had a clearly detrimental effect.