Sleeping Late Can Make Your Mind Sharper | Science

Are you more of an “owl,” a late-night worker, or an early riser with the chickens to enjoy your day? You may think it’s a preference, a habit, or simply your lifestyle, but this “style” is your “chronotype.”

Your chronotype can affect your overall cognitive abilities, suggests a study published Thursday (11/07) in the BMJ Public Health journal. The research found that evening people generally have higher cognitive scores than day people.

The study, which was conducted in the United Kingdom, conducted several cognitive tests and analyzed data from more than 26,000 people.

The aim was to discover how different aspects of sleep, including duration, patterns and quality, affect mental stimulation and overall cognitive ability.

What the “owl” study discovered

The research confirmed what we’ve always heard: that getting between 7 and 9 hours of sleep a night is ideal for brain function. The study also found that a person’s chronotype affects their scores on cognitive tests.

“Adults who are naturally more active at night tend to perform better on cognitive tests than their morning counterparts,” said lead study author Raha West of Imperial College London in the United Kingdom in a press release.

“Rather than being just personal preferences, these chronotypes can influence our cognitive function.”

But that doesn’t mean all morning people have worse cognitive performance. “The results reflect a general trend where most people tend toward better cognition in the afternoon,” West said.

Plus, our chronotype isn’t fixed—you can adapt, and getting a good night’s sleep can also improve your cognitive performance.

Sleep patterns science

Chronotypes are not permanent, but can change throughout our lives.

“Children tend to sleep in the morning, teenagers and young adults switch to sleep in the afternoon, and older adults often go back to sleep in the morning,” said Vivi Wang, a sleep expert at Eötvös Loránd University in Budapest, Hungary.

But Wang says there is clear evidence that our preferences for sleep and activity times are constant, even when we change time zones.

“A combination of genetic, hormonal, environmental and lifestyle factors determine whether a person is more active in the morning or evening, and these factors interact to shape an individual’s chronotype,” says Wang, who was not involved in the new study.

Chronotypes are partly linked to differences in our circadian rhythms, the body’s biological clock, which performs essential functions such as sleep and metabolism.

Genes involved in a person’s circadian rhythm include genes called CLOCK, PER and CRY. They have a strong influence on chronotype. These “influence whether a person is a morning person or an afternoon person,” Wang explained to DW.

But you can train yourself to be a morning, average, or evening type.

“We showed that college students can improve their chronotype by about two hours in two years,” says Ignacio Estefan, a sleep specialist at the University of Montevideo in Uruguay. Estefan was not involved in the current study.

Studying all night reduces performance on academic tests.

Stephen investigated the relationship between chronotypes and grades. He found that students’ test performance in the afternoon and morning depended on what time of day they were tested.

“We found that evening students perform worse academically than morning students if they take tests in the morning rather than the afternoon,” Stephan explained to DW, adding that his research contributes to a body of evidence showing that school start times have a significant impact on children’s academic performance.

Some experts believe that better aligning study hours with students’ biological rhythms would increase their chances later in life.

Ultimately, Stephan concludes, cognitive and test performance depend on good sleep quality. Studies tend to show that people who sleep longer perform better on tests.

This could be explained by the importance of sleep for learning and good cognitive performance, says Estefan. His research has found that staying up all night to review material at the last minute has a negative impact on test scores.

“About 15 percent of the students in our study didn’t sleep before the test and performed worse,” says Stephan.

So how can we get a good night’s sleep? Wang recommends: “Maintain a regular sleep schedule, have a dark, quiet sleep environment, try to relax, avoid caffeine or stimulants after dark, and minimize exposure to light at night, especially before bed.”

video: Rare syndrome that makes sleep life-threatening