How just THINKING you've had a good night's sleep can help you function better - even if you've not slept for long

Feeling tired after a bad night's sleep?

The good news is that simply being told you've slept well could help perk you up.

The phenomenon - coined placebo sleep - involves telling people they've been in a deep sleep even when they haven't.

Students who were told they got a good night’s sleep performed better on tests measuring their attention and memory skills than those who thought they slept poorly.

Researchers at Colorado College in the U.S. devised a ruse in which students were told that a new technique – which doesn’t actually exist – could measure their sleep quality from the night before.

They were connected to a machine that measured brainwave frequency and shown dense spreadsheets and formulas.

Some were informed that their deep, or REM, sleep had been above average the night before, a sign that they were mentally alert.

Others were told their REM sleep from the night before had been below average. Students in both groups got a five-minute lesson on sleep quality and its importance to cognitive functioning.

Those who thought they got a good night’s sleep performed much better on real tests that assessed their ability to listen and process information.

Placebo sleep follows the general thinking of placebos - that the outcome of the information was a placebo effect, which has to do with the person’s mindset regarding his or her treatment.

source