Mondays. The hardest part about Mondays is waking up in the morning. Kudos to those to feel otherwise. Getting back to the rhythm of our early weekday start is typically more difficult for people who are naturally night owls. Each of us has a unique circadian rhythm and are characterized as early, intermediate or late chronotypes. Late chronotypes that are forced to wake up earlier than their body would incline to suffers from what researchers call “social jet lag“.

A growing body of research has been finding that sleeping and waking out of sync of your chronotype is detrimental to your health, especially for innately late risers. This includes elevated risk for obesity and depression. A notable potential confound in the relationship is the effects of lack of sleep, rather than chronotype. Indeed, studies on sleep deprivation have documented similar effects of increased caloric consumption and increases in negative mood/decreases in positive mood. Sleep is good and very important to maintaining health. In addition to quantity of sleep, there is also evidence that quality of sleep is also critical for well-being. For example, having at least 20-25% of rapid eye movement (REM) sleep is associated with better cognitive functioning in adults.

Knowing this, I am very keen on getting at least 20% of REM sleep every night. An interesting study done by researchers in Colorado College have found that believing one has slept appears to positively influence cognitive functioning. In the study, participants rated how deeply they slept the night before and were then hooked onto nonfunctional sensors. Researchers informed the participants that they were trying a new technique (which doesn’t actually exist!) to measure the quality of sleep from the previous night. In actuality, the participants were randomly assigned to two groups. One group was told that they had received 28.7% REM sleep and were informed that this was great for mental alertness. Another group was told that they had only received 16.2% REM sleep the night before.

Then both groups were lectured on the relation between quality of sleep and mental functioning. Participants were informed that individuals who spend less than 20% of their sleep in REM tend to do worse on learning and memory tasks while those that spent greater that 25% of their sleep in REM do better. Finally they were told that this metric of REM was a more accurate index of sleep quality than how they actually felt they slept.

Participants were given cognitive tests which assessed attention and speed of processing, skills most affected by sleep deprivation. Participants in the above average REM condition performed significantly better on the test, regardless of how they felt they had actually slept. That’s pretty cool. The researchers coined the phrase “placebo sleep”, and concluded that placebo information about sleep quality can mediate cognitive functioning. This puts some locus of control into our own health and well-being.

A word of caution: generally there isn’t a one to one correspondence about how research findings on a group level translate to an individual basis. But for this Monday it wouldn’t hurt to try out this placebo sleep on myself. I slept superbly well last night with tons of REM.