Summary: Researchers share clear findings about sleep and correct common misconceptions about sleep problems.
Source: Baylor.
On average, you will spend roughly one third of your life asleep or trying to fall asleep. For many people, that adds up to more than 25 years spent in bed. Given how much time we devote to sleep, it makes sense to understand what helps, what hinders, and what actually happens during slumber.
Michael K. Scullin, Ph.D., director of the Sleep Neuroscience and Cognition Laboratory at Baylor University, studies and teaches about these questions full time.
“One reason I’m passionate about sleep research is that you can’t fully observe sleep from the inside,” Scullin explains. “When you are asleep you are unconscious, so you can’t report on the experience in the same way you can for most psychological processes. That makes sleep mysterious. With the right equipment we can design experiments to see what the brain is doing during sleep and why those processes matter.”
Below, Scullin addresses common sleep beliefs and summarizes the scientific evidence that supports or refutes them.
MYTH: If you die in a dream, you will die in real life.
There has been a long-standing rumor that dying in a dream can cause death in waking life. This claim is not supported by evidence. People frequently report dreaming that they die and then wake up unharmed.
“Your brain can tolerate a lot,” Scullin says. “Nightmares are not always purely harmful; one theory holds that they are an adaptive response, giving the brain simulated stressors during an offline state to help prepare us for threats. Nightmares can be clinically significant for some, but for many people they are an occasional function of how the brain processes fear and threat.”
FACT: Loud snoring can be a sign of disease.
Snoring and obstructive sleep apnea are closely related, though not every snorer has sleep apnea. Snoring results from partial obstruction of the airway and, in many cases, people wake gasping for air—an indication of sleep apnea. If a partner or observer reports breathing pauses or gasping, Scullin recommends consulting a clinical sleep physician.
“Imagine if you stopped breathing every few minutes while awake,” he asks. “That would be alarming. Repeated breathing interruptions reduce oxygen delivery and place stress on the cardiovascular system. Untreated sleep apnea significantly increases the risk of heart problems and cardiovascular disease, but effective treatment reduces those risks back toward normal.”
FACT: If you can’t fall asleep within about 20 minutes, get out of bed.
Research supports leaving the bed when you can’t sleep. The reason is behavioral: staying in bed awake creates a negative association between the bed and wakefulness.
“If you lie awake, you train your brain to link the bed with frustration and alertness,” Scullin explains. “The recommended approach is to get up, do something boring and quiet with low lighting until you feel sleepy, then go back to bed. That way your bed becomes a cue for sleep rather than for wakefulness.”
MYTH: One night of ‘recovery sleep’ fully repairs the effects of an all-nighter.
Neuroimaging studies show that sleep deprivation impairs frontal lobe function, which affects memory, attention, decision-making and executive control. Even after a full night of recovery sleep, the frontal lobe’s activity often only partially rebounds.
Many people shorten sleep during the workweek and try to make up on weekends. That pattern disrupts circadian timing and can lead to difficulty falling asleep Sunday night—commonly called “Sunday night insomnia”—because the body’s clock has been shifted later by weekend behavior.
MYTH: A full moon causes a large increase in sleep problems.
Media reports have sometimes claimed worse sleep around full moons, but pooled scientific data do not support a meaningful link between lunar phase and sleep quality. Why does the belief persist? Confirmation bias appears to play a role: people who expect poor sleep during full moons remember or notice those nights more, and overlook nights that contradict the expectation.
FACT: You can fall asleep at the wheel without noticing.
Drivers sometimes swerve not because they are distracted but because they experience micro-sleeps—brief episodes of sleep lasting a few seconds. People tend to believe they are immune, yet sleep is a biological need like hunger or thirst. When severely tired, the brain can briefly shut down even while you appear to be awake, especially during long monotonous tasks such as highway driving.
FACT: Some people experience temporary paralysis upon waking.
Sleep paralysis happens when parts of the brain wake before the systems that suppress muscle activity during REM sleep. During REM, the brain normally immobilizes the body to prevent acting out dreams. If the brain’s wakefulness centers activate while muscle atonia persists, a person can be fully conscious but unable to move for seconds or minutes. Hallucinations sometimes accompany these episodes when dream imagery intrudes into waking awareness.
“Sleep paralysis and associated hallucinations can be terrifying, but they often diminish with development and improved sleep,” Scullin notes. “They’re not usually a sign of a major clinical disorder unless they’re frequent or distressing.”
MYTH: Smartphone apps reliably measure your sleep.
Consumer sleep apps are popular, but they cannot match clinical sleep measurement. The most reliable method to assess sleep stages and quality is polysomnography—electrodes on the scalp and other physiological sensors used in a sleep clinic. Because clinical studies are costly, they are generally reserved for suspected sleep disorders such as sleep apnea. For research, Baylor’s sleep lab recruits volunteers and compensates participants for in-lab sleep studies.
FACT: Avoid caffeine within about six hours of bedtime.
A placebo-controlled study tested caffeine consumed one, two, four or six hours before bedtime. In each condition, caffeine made it harder to fall asleep and reduced sleep quality compared with placebo. Even caffeine taken six hours before bed produced lighter sleep and longer sleep latency. Scullin recommends keeping caffeine to the morning and avoiding it later in the day.
“If a strong coffee doesn’t keep you awake at all, it may mean you are so sleep-deprived that your brain overrides the stimulant,” he adds. That is a signal to prioritize regular, sufficient sleep rather than rely on stimulants.
Source: Eric Eckert, Baylor.
Publisher: Organized by NeuroscienceNews.com.
Image source: Image provided for illustrative purposes only.