According to Dr. Nissen, University of Freiburg, “Sleep is irreplaceable for the recovery of the brain. It cannot be replaced by periods of rest for improved performance. The state of the brain during sleep is unique.” End quote. Improved performance is linked typical with deep-sleep activity of the brain, which has an important function for the connectivity of nerve cells. Co-study leader Dieter Riemann, PhD, head of the sleep laboratory at the University of Freiburg, pointed out that their study quote, “shows that it is sleep itself that makes the difference.” Sleep cannot be replaced by rest during phases of intensive activity performance demands at work or in everyday life. Therefore, while the old saying that a change is as good as a rest for the brain may provide some benefit to the brain and body—recent studies have shown that a change is not as good as a sleep for the brain. In other words, a rest and a sleep are not interchangeable when it comes to the benefit on brain function.