How sleeping after an alarm clock affects brain function
A study has shown that delaying an alarm clock by 30 minutes does not impair brain function, but instead helps you to be more awake in the morning.There is a popular belief that sleeping after an alarm clock and using the "repeat signal" button has a negative impact on both sleep quality and cognitive function during the day. Researchers from Stockholm University have found that actually being able to sleep an extra half hour in the morning can have a beneficial effect.
Researchers surveyed 1,732 adults about how they wake up in the morning. The study found that 69% of participants set multiple alarm clocks or use the repeat function at least occasionally. On average, participants slept an additional 22 minutes after the first alarm (responses ranged from a few minutes to 3 hours). Younger people and owls were more likely to "catch up" on sleep.
For a more detailed analysis, the scientists invited 31 people who regularly snooze after the alarm clock to spend a few nights in the sleep laboratory. On the first morning, they were allowed to sleep for an additional 30 minutes, and on another morning, they were roused immediately after the alarm clock rang.
Analysis showed that even though the participants' sleep was disrupted during the half-hour nap, most of them still managed to sleep for more than 20 minutes. No one was awakened from a deep sleep during the nap, and on days when participants were given a nap, they performed slightly better on cognitive tests immediately after waking up. Signs of sleep's effect on mood, sleepiness or cortisol levels were not established by the scientists.
"The results suggest that there's no reason to stop napping in the morning if you enjoy it, at least for a period of about 30 minutes. In fact, it may even help those who experience morning sleepiness to feel awake upon waking," Tina Sundelin, PhD, of Stockholm University.