Smug early birds take note: Night owls actually have more mental stamina than those who awaken at the crack of dawn, according to new research.

"It's the late risers who have the advantage, and can outperform the early birds," said Philippe Peigneux, a professor of clinical neuropsychology at the Free University of Brussels in Belgium, who along with co-author Christina Schmidt published the counterintuitive findings in the latest issue of the journal Science .

Using magnetic resonance imaging, the pair conducted an experiment that measured alertness and ability to concentrate in 30 subjects who were naturally "extreme" early or late risers. The early risers got up between 5 a.m. and 6 a.m., and the late risers at noon.

Story continues below advertisement

Maintaining their natural schedules, the volunteers spent two consecutive nights in sleep labs. After 10 hours of being awake, the early birds showed reduced activity in brain areas linked to attention span, compared with the night owls. The early risers also felt sleepier and tended to perform tasks more slowly, compared with the night owls, when their level of alertness was measured.

"The results suggest that night owls generally outlast early birds in the length of time they can be awake without becoming mentally fatigued," the study concluded.

Dan Reynish, host and producer of radio show Saskatchewan Weekend , rises most days at 3:30 a.m. The Regina radio personality never uses the snooze button on his alarm clock and enjoys getting his day started ahead of his co-workers.

But he admits that his energy dwindles some afternoons.

"There are definitely times where I find if I'm not doing something or I'm sitting down. … I find myself slowing down a bit," he said.

Thierry Busset, pastry chef at CinCin, an upscale Italian restaurant in Vancouver, wakes up most days around noon. He said he always feels well rested and enjoys working late into the night when the restaurant is empty and his mind is clear.

"I'm lucky because I need very little sleep, and I wake up ready to go," he said.

Story continues below advertisement

Yet there are no "late-riser" special discounts or idioms such as "the night owl catches the worm." That's because of societal pressures, says Prof. Peigneux, co-author of the study. Those who hit their stride at midnight are often required to then get up early for work or school. They may appear to be lazy or unmotivated - but are really just sleep-deprived.

"If you allow them to live on their preferred schedule, then they can outperform the morning types," he said.

The study measured the part of the brain that is home to the circadian master clock that operates according to a day-night cycle. Sleep pressure dampens the circadian signal, and activity in this area decreases the longer the person is awake. The night owls were more resistant to sleep pressure.

Genetics dictate whether someone is a morning person, Prof. Peigneux said, adding that most people are "neutral." But 15 per cent of the population is an "extreme" early morning or late riser; and another 15 per cent are "moderately evening or morning types."