New study by Concordia grad student looks at the effects of recovery naps
A study on sleep could offer new insight into the benefits of recovery naps. Alex Nguyen, a Concordia Master of Science candidate, conducted a research project to find out more about what happens to our brains after sleep deprivation and during recovery naps.
Nguyen compared the cognitive performance and brain connectivity of participants after a full night of sleep, and after a night of total sleep deprivation. The novelty of his research lies in the fact that he continued to monitor the participants after a night of total sleep deprivation—he monitored them during and after a 60-minute recovery nap. He used functional Magnetic Resonance Imaging (fMRI) and ElectroEncephaloGraphy (EEG) to measure brain activity.
“What we’re doing new here is we’re going to have them take that nap,” said Nguyen. He explained other studies did not evaluate cognitive performance and brain activity during and after a short period of recovery sleep.
Another novelty in Nguyen’s study was his simultaneous use of EEG and fMRI to obtain the results. “Usually people only do one or the other,” he said, adding that combining the measures of both will provide more comprehensive results. “EEG is really good at temporal resolution, meaning it’s good at capturing when things happen, and fMRI is really good at taking spatial resolution, meaning where it happens,” he said.
Nguyen is currently working on analyzing the results of his research from summer 2018. So far, “it shows that with just one hour of nap, you can find improvement in your performance,” said Nguyen.
A total of 20 people completed Nguyen’s full study process. Each participant spent three nights at the PERFORM Centre, where Nguyen and other students conducted their research on sleep. The first night served as a habituation night to “let you get used to the environment,” said Nguyen. “It’s not always that you sleep in a new environment with an EEG cap on.”
The participants returned for a second night; half of them started with a normal, full night of sleep, and the other half started with a night of sleep deprivation. The former wore an EEG cap while they slept, a cap with electrodes that monitor the neurological connections in the brain. In the morning, they did an fMRI screening with the EEG cap on and completed a series of tasks that tested their working memory, vigilance, attention levels, and resting state.
During the night of sleep deprivation, the participants stayed awake with volunteers who made sure they didn’t fall asleep. In the morning, participants went in the fMRI scanner with the EEG cap and completed the same tasks. Then, they stayed in the fMRI scanner to take a 60-minute nap. Upon waking up, they performed these tasks again. This allowed Nguyen to observe what goes on inside the brain during this second test and to compare their performance before and after the nap.
However, cognitive performance after the recovery nap is not as good as after a normal night; the nap helps reduce the extent to which brain performance is diminished after sleep deprivation. “We might think it’s not that important, like, ‘Oh I’m going to pull an all-nighter to ace this exam.’ But in the end, maybe pulling an all-nighter, based on these results, you’re going to see you’re not going to perform as well.”
Nguyen thinks that the malfunction of network connectivity inside the brain after sleep deprivation might cause task performance to deteriorate. “When they’re sleep deprived, it actually becomes a chaos,” said Nguyen. “Networks that should be talking to each other are no longer talking to each other, and networks that shouldn’t be talking to each other are now talking to each other.”
By the end of the summer, Nguyen will know more about brain activity during and following a nap. “I think the most surprising part is going to be what goes on inside the brain because that’s something that no one has looked at before,” said Nguyen.
The study might also bring up new knowledge about power naps because it looks at the effects of these naps on brain connectivity. Dr. Melodee Mograss, a neurocognitive psychology research associate at the PERFORM Centre Sleep laboratory, also conducts research to find out more on the effects of nap and exercise on productivity. She said naps can be beneficial if they do not occur too close to bedtime. “The nap does help fend off fatigue and it’s important to take a nap if you are tired because there’s a chance of accidents, and performance errors because your cognition is impaired,” she said.
About 32 per cent of Canadians aged between 18 and 64 years old are sleeping less than the recommended seven to nine hours per night, according to Statistics Canada. Nguyen said his study targeted a key age group, which was 18 to 30 years old. Most participants were university students, whom Nguyen said are especially at risk for sleep deprivation. “As undergraduate students, we are staying up late a lot of times to complete work, academic needs, jobs,” and other responsibilities, he said.
Nguyen said research on sleep is crucial. “There’s an increase of people getting insomnia [and an] increase of people getting sleep deprived because of work demands, academic demands or social demands,” he said. “It’s something that still intrigues me every day, I keep learning and I think that’s [what’s] beautiful about research.”
Photo by Gabe Chevalier.