Just believing that you’ve slept better than you really have is enough to boost cognitive performance the next day, a recent study finds.
Both were given a lecture on the importance of sleep quality and dangers of lack of sleep.
They were also told that the average amount of REM (Rapid Eye Movement) sleep that people get each night is 20%.
Their ‘brainwave frequency’ was then measured and they were shown formulas and spreadsheets.
All these measurements were a sham.
- One group was told they’d got ‘above average’ sleep quality, spending 28.7% in REM sleep.
- The other group was told they’d got ‘below average’ sleep, spending just 16.2% in REM sleep.
Afterwards, all the participants were given a battery of cognitive tests.
Those told they’d slept better scored higher on tests of attention and memory than those told they’d slept poorly.
Interestingly, the researchers also collected self-reported data on how people thought they had slept the previous night.