We’ve all had busy weeks with several late nights in a row, but figured we’ll stay sharp if we get some marathon sleep sessions later — but it’ll actually have the opposite effect, according to new research.
A study by Baylor University in Texas has determined you can’t catch up on lost sleep, finding that irregular sleep patterns ultimately dull our thinking and creativity.
While the findings have implications for everyone’s sleep patterns, the researchers specifically examined interior design students — who work in “a strange culture, one where sleep deprivation is almost a badge of honour,” according to Elise King, an assistant professor of interior design who worked on the study.
“When completing term projects, students restrict sleep, then rebound on sleep, then repeat,” added Dr Michael Scullin, director of Baylor’s Sleep Neuroscience and Cognition Laboratory and an assistant professor of psychology and neuroscience, in a statement.
The study showed that “the more variability [the studnets] showed in their night-to-night sleep, the worse their cognition declined across the week,” Scullin said.
Twenty-eight students’ sleep was measured both by wristbands that tracked their nocturnal movements, and by daily diaries they used to record their sleep quantity and quality.
On the first and last day of the seven-day study they completed cognitive testing sessions that judged both their executive attention and creativity — and both brain functions were found to suffer.
Executive attention is essentially a form of working memory that we need to maintain focus for planning, make decisions, correct errors and deal with new things.
The students’ executive attention was tested by showing them grids of black-and-white squares, which they rapidly had to decide were symmetrical or not.
“Symmetry decisions by themselves are easy. But after each decision, participants were shown a grid with one square highlighted in red,” said Scullin. “Then they made another symmetry decision, followed by a different square highlighted in red.
“They repeat that cycle up to five times before being asked to recall all the square locations in the correct order. It’s very challenging to cycle between those two tasks and keep the square locations in mind.”
Meanwhile, creativity was defined in the study as “people’s ability to see the link between things that at first glance seem unrelated”, Scullin said.
For example: students were given a list of three words — “sore,”’ “shoulder” and “sweat” — and asked what fourth word connected them all.
“What first comes to mind are words related to exercise, but in this case, no single exercise word really works,” said Scullin. “Instead, the ‘creative’ and correct answer is ‘cold’.”
(Don’t sweat it if you didn't get it — it just means you’re sleep deprived.)
If you think none of this applies to you because you definitely get enough sleep, well: the study also found the students were pretty bad at estimating their quantity of sleep, with most falling short of the minimum seven hours recommended every night.
“Most students think they’re getting about four more hours of sleep each week than they actually are,” Scullin said.
The takeaway message isn’t necessarily to get more sleep to keep your brain sharp — it’s to aim to go to bed and wake up at roughly the same time on most days, the most important factor for good sleep hygiene.
“Consistent habits are at least as important as total length of sleep,” Scullin said.
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