'Night Owls' Shouldn't Be Made to Work Mornings as Their Brains Are Wired Differently, Scientists Warn

The brains of people who feel most spritely in the morning are wired differently to so-called "night owls," warn scientists who have urged employers to rethink the standard working day.

Forcing an owl to live like a so-called "morning lark" can negatively affect their brain function, productivity and health, the authors of a study published in the journal Sleep said.

Ideally, employers would consider their workers' body clocks when setting shift patterns to ensure workers are not only healthy but productive, the researchers said. Working 9 a.m. to 5 p.m. "may be detrimental for an individual whose biological preference is for a late sleep-wake cycle," the authors wrote.

The researchers investigated how a person's inclination towards being a morning lark or a night owl—what scientists call their circadian phenotype or chronotype—affected functional connectivity or how their brains regions link together.

Their study involved 38 participants who were asked to wear sensors tracking their rest and activity cycles for 13 to 16 days. The saliva of participants was collected in the morning, afternoon and evening, and tested for levels of hormones melatonin and cortisol. Participants were set tasks to test their reaction times, completed questionnaires detailing their lifestyles and sleepiness, and underwent MRI scans.

The results showed night owls struggled with slower reaction times in the morning and sleepiness during the hours of the normal working day, which could affect their productivity. Larks fared better in the morning tasks, and owls at around 8 p.m. But larks didn't suffer later in the day. More research is now needed to understand the cause of these patterns.

The researchers believe differences in the functional connectivity of the part of the brain known as the default mode network, which plays an important role in cognitive functions and consciousnesses, may explain why late types can feel less productive and sleepy while larks are at their best.

Dr. Elise Facer-Childs, who lead the research while she was at University of Birmingham's Centre for Human Brain Health, U.K., commented in a statement: "A huge number of people struggle to deliver their best performance during work or school hours they are not naturally suited to. There is a critical need to increase our understanding of these issues in order to minimize health risks in society, as well as maximize productivity."

Facer-Childs, currently at the Monash Institute for Cognitive and Clinical Neurosciences in Melbourne, Australia, continued: "This mismatch between a person's biological time and social time—which most of us have experienced in the form of jet lag—is a common issue for night owls trying to follow a normal working day. Our study is the first to show a potential intrinsic neuronal mechanism behind why 'night owls' may face cognitive disadvantages when being forced to fit into these constraints.

"A typical day might last from 9 a.m. to 5 p.m., but for a night owl, this could result in diminished performance during the morning, lower brain connectivity in regions linked to consciousness and increased daytime sleepiness. If, as a society, we could be more flexible about how we manage time we could go a long way towards maximizing productivity and minimizing health risks."

Co-author Dr. Andrew Bagshaw, from the University of Birmingham, told Newsweek: "Although there are previous studies into the behavioural differences between chronotypes, very little is understood about how the timing of sleep impacts on the brain.

"Adequate sleep is crucial for optimal brain function, and one of the main reasons we sleep at all is because of the brain. We need more research that specifically investigates how the brain networks that are needed for cognition and good mental health are impacted by differences in sleep patterns between individuals. Our work is a first step in this direction."

Last year, the authors of a separate study concluded night owls should be able to shift their schedules to protect their health.

The findings published in the journal Chronobiology International found being a night owl was linked to a higher risk of dying and higher rates of conditions such as diabetes, as well as psychological disorders and neurological conditions.

Jessica Alexander, a spokesperson for the Sleep Council, an organization that promotes healthy sleep habits, told Newsweek at the time: "The world we live in (in Western, industrialized societies at least) is more geared up to early birds than to night owls, who are often trying to fit into the external world while at the same time carrying on sleeping—and being awake— as dictated by their internal body clocks. Result: sleep deficit, big time!"

This article has been updated with comment from Dr. Andrew Bagshaw.