There have been a number of studies done on the placebo effect as it relates to people’s perception of how much good quality sleep people believe that they have gotten as compared to their actual quantity and quality of sleep. A placebo effect is described as the positive impact of believing that a medication or treatment that has been received will work, even if the medication or treatment did not actually have an impact at all. Typical examples of a placebo effect are when people are given pills that are actually nothing but sugar but which they are told will alleviate a symptom. Study participants often report that their symptoms are diminished despite the fact that the pills they received had no active ingredients to accomplish the effect. In sleep studies on the placebo effect, patients are given indications that their sleep quality was either better or worse than it actually was, and then they are tested for performance on a number of different tasks.
The placebo effect sleep studies that have gotten the most attention recently have shown that when participants believe that they scored badly on a sleep study based on data that was manipulated by the study’s authors, their follow-up performance on a set of math questions suffered, with those who were told that they had below-average quantities of REM (Rapid Eye Movement) sleep scoring as much as one third lower on test scores as those who were told that they’d experienced above average levels of sleep. But follow-up studies to that initial test have recently been conducted and reveal even more interesting results.
In the follow-up study researchers provided the same manipulated information regarding how well participants slept, but went beyond testing for performance on math questions. The later studies also conducted word-choice tests, short-term memory and visual-motor processing speed. The follow-up study also differed by including data on control groups that were not subjected to the manipulation of the results of sleep studies. The results confirmed that the placebo effect, which in this case translates into the belief that we’ve slept well, has a profound impact o mental performance, but not on performance on memory or physical tests. Those who were led to believe that they’d slept poorly performed well below those who believed they had slept well on the math and word completion tests, but both groups’ performance was the same on the memory tasks and the visual-motor skills test. Perhaps most interestingly, those who were falsely told that they had gotten better-than-average quality sleep performed better on the word choice test than anybody taking the test, including the control group.
Knowing that the belief in having gotten a good night sleep is strong enough to counteract the actual quality of sleep that we’ve gotten on mental tasks may be helpful in a number of different applications, including preparing students for standardized tests. However, the most important thing to aid overall performance of all kinds is actually getting a good night’s sleep.