It’s widely accepted that sleep is critical to a healthy brain. While we rest, the brain performs important tasks like consolidating memories and clearing toxins. Add stress to lack of sleep, and the brain really starts to stumble. A recently published study from Uppsala University finds that sleep loss paired with acute stress negatively affects cognitive functions.

“In everyday situations—parenting, exams, doctors on call—stress and short sleep often go hand in hand,” says Dr. Jonathan Cedernaes, a neuroscientist and the study’s lead author. “Even politicians often have overnight meetings and resume talks after just a couple of hours of sleep, under very time-pressed and thereby presumably very stressful conditions.”

During the study, 15 male participants engaged in an evening learning session, where they were asked to remember 15 card pairing locations on a computer screen. Next, about half of the participants were allowed to sleep for four hours, while the other half slept eight hours. When the participants were asked to recall the card locations the next morning, the men who slept for four hours performed as well as those who slept for eight.

However, a second experiment yielded different results. When researchers exposed both groups of men to acute stress for 30 minutes (they were asked to recall a list of newly learned words while hearing loud noise) before taking the same test in the morning, those who slept four hours experienced a 10 percent reduction in recall ability. The men who slept for eight hours showed no stress-related impairment.

Of course, the 10 percent reduction in recall was after a single night of sleep loss and a limited period of stress. Researchers next hope to examine how chronic sleep loss and chronic stress might actually affect the ability to access memories.

The importance of sleep inspired the development of Silent Nights*, one of LifeWave’s most popular patch products. With no drugs or pills to take, Silent Nights is clinically shown to increase length of sleep by 66 percent.

*Learn more about Silent Nights in the EU.