Between waking up early to squeeze in spin class and catching up with friends over late-night drinks, we’ve all experienced that groggy feeling of logging too few hours of sleep. It turns out that exhaustion (and your corresponding mood) isn’t just making you feel run down — it’s affecting the way your brain works, too. New research from Lumosity, an online brain training program with more than 60 million registered users, reveals that the hours you’ve slept, time of day, and your mood all have an effect on how mentally sharp you are throughout the day.
Researcher Daniel Sternberg, PhD, senior data scientist at Lumosity, analyzed how 60,000 people performed on Lumosity’s various tests of processing speed, short term and working memory, task switching, visual attention, and arithmetic and verbal fluency over the course of the year to find out what really makes your brain alert — or totally out of it.
Sleep Is King
Almost everyone’s brain performs better on cognitive tests in the morning hours.
The results may serve as motivation to turn in early tonight: With few exceptions, Lumosity users performed better on cognitive tests when they reported enjoying at least seven to eight hours of sleep the night before. And that effect may be more pronounced in real-life situations, according to Sternberg. “As you train on the same task many times, you get better and better at doing it and your performance doesn’t vary as much,” Sternberg says, noting that each study participant had played these games at least 100 times. “But it may be that when you’re encountering a novel situation, that’s probably where there are bigger differences.”
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Being in a bad mood doesn’t do you any favors, either. When users logged in to play a game, they were asked to rate their happiness on a scale consisting of five faces, ranging from smiling to frowning. Users’ scores were always better when they reported being in a “smiling” mood, according to researchers. Your state of mind may be an indicator of “life circumstances that specifically affect our ability to concentrate,” the study reports.
Score One for Night Owls?
Peak time for creativity seems to occur later in the day, possibly from 2 to 4 p.m.
Whether or not you identify as a morning or night person also has an effect on how you think, the research reveals. But here’s the catch: Almost everyone’s brain performs better on cognitive tests in the morning. The only difference was that night owls remained cognitively sharp later into the evening than early birds. “People who reported being evening people…they just were less affected at night. They maintained better performance as night went on, as opposed to people who felt they were sharper in the morning, who were declining,” Sternberg says.
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The researchers also discovered that peak time for creativity seemed to occur later in the day, possibly somewhere in the afternoon from 2 to 4 p.m. That’s because creativity, which requires thinking outside the box, may actually be easier to achieve if you’re a little less in control of your brain, Sternberg notes. “If you think you’re a morning person, maybe plan more creative activities in the afternoon.”
In the future, Sternberg says he hopes to use Lumosity in conjunction with other tracking devices to give people more precise insights about what times of day they might be able to think more creatively, or when they might be best equipped to handle multi-tasking, or stress. “We might be able to pull in this type of data and say based on data about other people, an extra hour of sleep would be great for you and make a really big difference.”
Plus, he thinks there’s a special place for using Lumosity in conjunction with fitness trackers to help people achieve peak fitness — both mentally and physically. “There’s lots of papers now showing that certain physical activity is pretty good for cognitive health and brain health,” Sternberg says. By tracking both workout habits and cognitive performance, researchers might soon be able to pinpoint exactly how your fitness affects your brain — and vice versa.