It is often said that the early bird catches the worm. A popular saying that is contradicted by a study published in the journal BMJ Public Health. It is learned that people who wake up at dawn are not as intellectually alert as those who struggle to get out of bed in the morning. A research team from theImperial College London-based researcher came to this surprising conclusion after studying data from more than 26,000 people who took part in intelligence, reasoning and memory tests. The participants described themselves as early risers or night owls, depending on when they felt most alert and productive.
Good cognitive performance
The researchers used all of this information to determine the extent to which the durationdurationthe quality and sleep habits of the volunteers impacted their cognitive performance. They also took into account various factors related to general health and stylestyle of life, such as age, gender, tobacco consumption andalcoholalcoholor the presence of chronic diseases (heart disease, diabetes, etc.)).
It turned out that the “night owls” scored 13.5% higher than the early risers. The so-called “intermediate” subjects, i.e. those who could be active in both the morning and the evening, scored higher than the morning people. However, they performed worse than the night owls. It is important to note that this does not mean that all early risers have poorer cognitive performance. Our results reflect a general trend in which night owls have better cognitive performance. “, said Dr. Raha West, lead author of the study, in a statement.
Sleep neither too little nor too long
Overall, Dr. West and his colleagues have found that sleep duration is important for brain function. Getting seven to nine hours of sleep a night can improve brain function. mattermatter of reasoning and memorization, as well as its speedspeed processing information. Conversely, sleeping less than 7 hours or more than 9 hours has a deleterious effect on cognitive performance. It is important to remember that you need to get enough sleep, not too much and not too little. This is essential for your brain to stay healthy and function optimally. “, Dr. West explains in the same press release.
This study adds to a growing body of scientific work that shows that we are not all equal when it comes to the clock. We do not all reach our peak performance at the same time of day, some being more alert in the morning than in the evening, and vice versa. Differences linked to the internal clock, this molecular gear that synchronizes our body to a 24-hour rhythm. But chronotype (being a morning person or an evening person) is not everything. Sleep considerably influences our cognitive functions, given that it allows the body to recover on the physicalphysical and psychological.
To keep our brain healthy, it is therefore better to be vigilant about the quality of our sleep. And above all, respect our biological rhythm. A birdbird at night will not be at pinnacle in shape in the morning, unlike an early riser. But they will perform much better in the late afternoon, while at that time, morning subjects will suffer more from the impact of the pressurepressure of sleep accumulated during the day.
Article by Jean-Luc GoudetJean-Luc Goudetpublished on January 31, 2008
For some, waking up at dawn is an ordeal, while for others it is natural. We already suspected differences geneticsgenetics to be the cause of this inequality, but researchers have gone further, by uncovering mechanisms at work inside human cells in culture.
Like most animals, humans are wired for circadian rhythmcircadian rhythmthat is to say 24 hours… well almost. Our internal clocksinternal clocks are never on time and, besides, circadian is a francisation of Latin circa diemmeaning about a day… In some people, the clock runs fast, in others it runs slow, and the body regularly resets the clocks by referring to the variations in lightlight but also, in humans, to lifestyle habits.
In this respect, humans are distinguished from other animals by particularly marked individual differences. They have even been given a name: each of us is characterized by a certain chronotypewhich describes our behavior in relation to the circadian rhythm, from early riser to night owl. These individual variations are genetic and were previously thought to be explained by the delay or advance of our clock, what we call the perioda little more or a little less than 24 hours depending on the person.
This personal circadian rhythm is not just a matter of habit. Nature made us animals diurnaldiurnal and this cycle significantly alters a large number of biological functions, from intellectual abilities to digestiondigestion through renal activity or secretions ofenzymesenzymes. This variation can be seen in the use of GenoaGenoa by cells: for about 10% of them, their expression (i.e. their reading and the transcriptiontranscription in proteinsproteins) varies according to a circadian rhythm.
A complex clock
Achim Kramer and his team at the Charité Faculty of Medicine (Berlin) have been studying this subject for several years and have just published in the Pnas (Proceedings of the National Academy of Sciences) the results of a study on volunteers. These researchers tracked differences in biological activity in skin cells, taken by biopsybiopsy.
The twenty people in the experiment were divided into 11 early risers and 9 night owls. Once the cells were collected (from fibroblastsfibroblasts), the team monitored the expression of several genes, using luciferase, an enzyme that makes luciferin (a protein) fluorescent. The gene for this enzyme was introduced by genetic engineeringgenetic engineering next to one of the genes (Bmal1) known to have circadian activity.
Cells from different cultures were synchronized using a hormonehormonedexamethasone. The activity of the Bmal1 gene could then be monitored by simply measuring the light emitted by fluorescence (a laboratory trick widely used in genetics and which recently impressed journalists from many mainstream media outlets, astonished to see fluorescent pigs in a Chinese laboratory).
The analysis that followed is quite subtle and uses a mathematical model. But the result is easy to understand: the differences between early risers and night owls are not only due, as was thought, to differences between the periods of each person’s clock. There must also be other sources of individual variations in the very activity of the cells. In short, we do not have one clock but several and the picture is much more complex than we imagined. The only certainty is that our chronotype is indeed inscribed deep in our cells. This is, moreover, the feeling of the night owl torn from his reverie by the ringing of the alarm clock…
