Morning Larks vs. Night Owls: A Circadian Alertness Advantage?

People who are larks function better in the morning. Night owls are more alert in the evening. But which “chronotype” enables people to function better over the length of a day?

A new study in Science takes a look. It involved 16 early morning risers and 15 night owls. They performed alertness tests in a brain scanner after following their normal sleep schedule.

Newsweek and Science report that both groups performed well when they took the test 1.5 hours after waking. But the night owls pulled ahead when both groups were tested after being awake for 10.5 hours. They were more alert and had faster reaction times. Overall their performance improved by about 6 percent.

So do night owls have a natural alertness advantage over morning larks? Not necessarily.

Health News points out that an advantage in the lab may not translate to the workplace. A person who is a “morning type” will be alert during the hours of a normal workday. But “evening types” may struggle to align their natural sleep-wake pattern with their work schedule.

Drowsy Driving & Rumble Strips

You’re sleepy, but you’re intent on making it to your destination on time. So you keep driving.

You fight to keep your eyes open. Suddenly you’re startled by a loud noise as your car begins to shake.

Your eyes pop open as you realize that your car was drifting off the road. You just encountered a rumble strip.

The first shoulder rumble strips appeared on New Jersey's Garden State Parkway in 1955. They are used to prevent run-off-road crashes.

The Federal Highway Administration reports that this type of crash causes one-third of all traffic fatalities. The main cause? Drivers are too sleepy.

But are rumble strips an effective solution for drowsy driving? A recent study examined how rumble strips affect sleepy drivers.

Thirty-five shift workers operated a driving simulator in the morning after a full night shift. Measures of sleepiness such as eye closure duration increased as they drove.

After hitting a rumble strip their alertness increased in most parameters. But the alerting effect was very brief. Signs of sleepiness returned after five minutes.

So a rumble strip may briefly wake you up. But it won’t keep you from drowsy driving.

What should you do if you feel drowsy when you’re behind the wheel? Let another passenger take over the driving duties.

Or pull off the road at a rest stop. Have a drink that contains caffeine and then take a brief nap. Put your alertness – and your safety – first.