It’s fairly well known that sleep has a powerful impact on our cognitive abilities, both in terms of how we learn new things and how we perform at work.  There have been numerous studies showing that excellent sleep at night is crucial, but also that a short ‘power nap’ during the day can give our afternoon performance a jolt.

Which is great, except research also shows that we generally don’t get enough sleep, and very few companies have been brave enough to let employees have a nap at work.

Thinking your way to great sleep

So what is the answer?  Well, a new study suggests that the key may be in our own minds.  The study, published in the Journal of Experimental Psychology, suggests that how we perceive the sleep we had the night before matters as much as the actual sleep we had.  In other words, if we think we had a great nights sleep, then we’ll act as though we really did.

The research saw participants given a tutorial on the power of sleep, and the value a good nights sleep provides us the next day.  They were then informed that they would be tested the next day on how they slept that night.

In addition to this, they were primed to believe that we each get around 20% of our sleep in the form of REM, or Rapid Eye Movement, sleep.

Priming the participants

Each participant then had their brainwave frequency measured, before they were shown the formulas for how it worked.  Except the measurements were largely fake ones.  Here’s the catch.

One of the groups was told that they’d had a great nights sleep, spending nearly 29% of their time in REM mode.

The second group however were told that their sleep was not so great, and that they’d spent just over 16% of their time in REM mode.

How did this information make them feel?

Lets remember here, this information is fake.  It had no bearing on how they actually slept at all.  Well, not long after the tests had been completed, each participant was given some cognitive tasks to complete.  The results are amazing.

Those who believed that their sleep had been great scored higher on both attention and memory tests than those who believed that they had slept badly.

The placebo effect in action

The placebo effect is one of the more fascinating aspects of human behaviour, and this finding is a telling example of that.  It shows how people are well aware that bad sleep impacts our cognitive abilities, so dilute those abilities accordingly when they believe their sleep has been impaired.

Of course, why the placebo effect occurs is still something of a mystery.  The researchers believe however that it may have something to do with how we naturally link up stimuli with responses, in much the same way as Pavlov’s dog.

“It may be that expectancy directly creates the cognitive effects from perceived sleep quality or that they are mediated by increased anxiety or decreased motivation following information about poor sleep quality (or following actual sleep deprivation) or by increased motivation following information about high-quality sleep…” they say.

Now, the interesting thing from my perspective is that people were led to believe things about the quality of their sleep by someone seemingly able to accurately supply that information.  I wonder if it would be anywhere near as effective if we were trying to convince ourselves?

I’m less convinced on that, but maybe give it a go yourselves.