“To die, to sleep — perchance to dream — ay, there’s the rub, for in this sleep of death what dreams may come…” – William Shakespeare, Hamlet
Everyone requires sleep in order to function properly.
Sleep is known to aid in healing, in memory formation, reducing stress, eliminating toxins – literally wiping the slate clean of the day’s experiences to begin anew. The subject of decades of research, sleep science continues to amass evidence of new health benefits from sleep.
A Single Gene Ties Sleep to Immunity
A newly discovered single gene, called nemuri, increases the human body’s need for sleep, according to researchers from the University of Pennsylvania’s Perelman School of Medicine, whose work was published in Science.
Studying more than 12 lines of fruit flies, researchers found direct links between the immune system and sleep, which provides a possible explanation for how sleep increases during sickness. In their next phase of research, the scientists plan to investigate the mechanism by which nemuri drives sleep.
Learning New Vocabulary During Sleep
While it may seem mysterious, it’s actually logical. Researchers from the University of Bern found that the introduction of new foreign words and their translation words could be associated during deep sleep in a midday nap and stored. Upon waking, those associations could be retrieved unconsciously and reactivated – essentially learning a new vocabulary during sleep. Results, published in Current Biology, showed the memory formation seems to be mediated by the same brain structures mediating wake vocabulary learning.
Gaps in Life Memories Created by Sleep Apnea
An estimated 936 million people worldwide are affected by obstructive sleep apnea (OSA) and OSA sufferers have memory problems and depression. A 2019 study by researchers at RMIT University in Melbourne, Australia built upon known links between memory and depression, and found that untreated OSA leads to problems recalling specific life details. Researchers said their work suggested that sleep apnea may impair the brain’s capacity to encode or consolidate certain types of life memories, which explains why it is difficult for people to recall past details. Since sleep apnea is also a significant risk factor for depression, researchers hope that a better understanding of the neurobiological mechanisms at work may help improve the mental health of millions of people.
Virtual Reality May Treat Recurring Nightmares
Nobody likes nightmares, especially recurring ones. Indeed, researchers have found that recurring nightmares are significant predictors of mental health problems, especially for children. About half to two-thirds of kids and up to 15 percent of adults have frequent nightmares. A consequence of recurring nightmares in children may be adolescent and adult psychosis, including anxiety, depression, stress and suicidal ideation; while in adults it may signal post-traumatic stress disorder (PTSD). Yet there are few effective and easy-to-use treatments for nightmare disorders.
Two researchers from Boston University co-founded the Center for Mind and Culture and created a pilot study using a virtual reality program to help combat recurring nightmares. The study used moderately frightening virtual reality imagery, such as underwater environment with an approaching great white shark, to stimulate a manageable fear level in participants. By exposing them to disturbing and arousing images, but not very scary ones, the goal is to treat distress, not inflict more.
Participants used a joystick and gesture controls to modify the visuals they saw. At the end of a month of two sessions weekly, during which participants were monitored for anxiety, nightmare distress and nightmare effects, researchers found significantly lower levels in all three.
What’s really exciting about these results, say researchers, is the potential to bring this to kids suffering nightmare disorder. Treating them early with such technology may ward off or slow down conversion to psychosis.
Lack of Sleep Contributes to Anger
You know you’re out of sorts after a fitful night’s sleep, or when you’re not able to sleep your regular amount of hours. Now researchers from Iowa State University have found evidence that sleep loss causes anger. For the study, participants were split in two groups, one getting their normal seven hours of sleep, while the other was restricted to about 4.5 hours per night. Anger was measured before and after sleep manipulations by having participants listen to noise products creating uncomfortable conditions, which tend to provoke anger. In the sleep-restricted group, anger was “substantially higher” than in the unrestricted sleep group.
Next, researchers plan to study whether loss of sleep causes actual aggressive behavior toward others.
Sleep Deprivation Creates Dramatic Increase in Errors
In the largest to-date experimentally controlled study on sleep deprivation, researchers at Michigan State University found that small distractions can result in serious consequences for people who are sleep deprived.
The research differs from other sleep deprivation studies in that it focuses on the impact of sleep deprivation on completing tasks. The study involved requiring people to complete a task that required a number of steps in order, and periodically interrupting them in the process, after which they had to remember the steps in order to proceed.
Members of the sleep-deprived group had a roughly 15 percent increase in errors the following morning when they were asked to perform the step-by-step task again. In addition to showing more errors, the sleep-deprived group showed a progressive increase in errors that was associated with memory while performing the task. The non-restricted sleep group did not exhibit this effect.
Life Purpose Can Be a Drug-Free Way to Improve Sleep
Researchers at Northwestern University’s Feinberg School of Medicine conducted a study including 853 adults without dementia, from age 60 to 100, in which they were asked to complete a 10- and 32-question survey on purpose of life, and sleep, respectively. Those who felt their lives had meaning were 63 percent less likely to report sleep apnea and 52 percent less likely to say they had restless leg syndrome. In addition, the study participants who felt a purpose in life had moderately better quality of sleep, a global sleep disturbance measure.
Researchers said that although the study involved older people, they believed the results would be applicable to younger individuals as well. The next step in their research, said study first author, “should be to study the use of mindfulness-based therapies to target purpose in life and resulting sleep quality.”
Toda, H., Williams, J.A., Gulledge, M., & Sehgal, A. (2019, February 1). A sleep-inducing gene, nemuri, links sleep and immune function in Drosophila. Science. Retrieved from http://science.sciencemag.org/content/363/6426/509
Zust, M.A., Ruch, S., Wiest, R., & Henke, K. (2019, January 31). Implicit Vocabulary Learning during Sleep Is Bound to Slow-Wave Peaks. Current Biology. Retrieved from https://doi.org/10.1016/j.cub.2018.12.038
Delhikar, N., Sommers, L., Rayner, G., Schembri, R., Robinson, S.R., Wilson, S., & Jackson, M.L. (2019, January 31). Autobiographical Memory From Different Life Stages in Individuals With Obstructive Sleep Apnea. Journal of the International Neuropsychology Society. Retrieved from https://doi.org/10.1017/S1355617718001091
McAlpine, K.J. (2019, January 17). How Virtual Reality Might Help Fight Recurring Nightmares [blog post]. Boston University Research. Retrieved from https://www.bu.edu/research/articles/virtual-reality-therapy-for-recurring-nightmares/
Lack of sleep intensifies anger, impairs adaptation to frustrating circumstances [release].(2018, November 27). Iowa State University New Service. Retrieved from https://www.news.iastate.edu/news/2018/11/27/sleepanger
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Turner, A.D., Smith, C.E., & Ong, J.C. (2017). Is purpose in life associated with less sleep disturbance in older adults? Sleep Science and Practice, 1: 14.Retrieved from https://sleep.biomedcentral.com/articles/10.1186/s41606-017-0015-6