By Jonny Lupsha, Wondrium Staff Writer
Sleep researchers are parsing between good and bad bedtime habits to aid sleep, NPR reported. Experts at University of California, Berkeley, say that imagining a calming walk you’ve taken is better than counting sheep, among other practices. The road to deep sleep is long and uneven.
According to NPR, some ideas for getting a good night’s rest are being debunked as others come to light. “Not only will counting sheep not help you fall asleep, but a study by Allison Harvey at UC Berkeley found that it actually ‘made it harder to sleep, and it took you longer to fall asleep,'” the article said.
However, relaxation and meditation apps “can train you to meditate—to clear away regrets about the past and worries about the future so you can learn to be in the moment.” The article also recommended keeping your bedroom cool and passing along good sleep habits to your children.
Even the act of attaining a sleep state sends your brain through several states of electric activity, as do the stages of sleep.
It’s All Greek
Sleep researchers use electroencephalograms (EEGs) to study how our brains function while we sleep, and the stages of sleep they’ve discovered are distinct and revealing.
“First, preceding sleep there is usually a time of relaxed wakefulness and drowsiness,” said Dr. H. Craig Heller, the Lorry I. Lokey/Business Wire Professor of Biological Sciences and Human Biology at Stanford University. “During this period the EEG changes from the fast, desynchronized wave pattern of alert wakefulness to a slower, more regular pattern at a frequency of about 8 to 12 hertz.”
According to Dr. Heller, the different states of arousal and sleep can be distinguished from one another by EEG patterns that occur at specific ranges of frequencies. These ranges are indexed as characters from the Greek alphabet.
“The slow, regular waves in the 8 to 12 hertz frequency that characterize a relaxed, drowsy state are called alpha waves,” he said. As we transition to sleep, “the alpha waves disappear and a low-amplitude, mixed frequency pattern with a predominance of activity in the 4 to 8 hertz range is observed. The frequency band is referred to theta waves.”
A Bumpy Ride to Deep Sleep
Once our brain falls back on theta waves, another tool of sleep researchers—the electrooculogram (EOG), which measures eye movement—plays an important role. The EOG confirms that our eye movement begins to slow, and we transition into non-rapid eye movement (non-REM) sleep.
“During the transition into Stage 1, people sometimes experience occasional jerks, almost as if they are catching themselves from falling asleep, but they are really falling asleep,” Dr. Heller said. “During the descent into sleep, Stage 1 non-REM lasts only a few minutes.”
After this, people enter Stage 2 sleep, during which the frequency of EEG waves slows down more while their amplitude increases. Dr. Heller said that Stage 2 also features a phenomenon called K-complexes, which are random spikes of brain wave amplitude. Stage 3 sleep soon follows, with even slower EEG readings and high amplitude slow waves that characterize it.
“We used to distinguish also a Stage 4 non-REM sleep that was just sort of a deepening of Stage 3, but it’s common now just to refer to Stage 3 or deep sleep,” Dr. Heller said. “Stage 3 is also sometimes referred to as slow-wave sleep because the EEG shows a dominance of slow waves in the band of 0.5 to 4.5 hertz. Waves in this frequency band are called delta waves.”
This entire non-REM process takes about an hour and ends with the sleeper finally transitioning to REM sleep. Clearly, the work involved in getting a good night’s rest doesn’t end the moment we drift off to sleep.
Dr. H. Craig Heller contributed to this article. Dr. Heller is the Lorry I. Lokey/Business Wire Professor of Biological Sciences and Human Biology at Stanford University. He earned his PhD in Biology from Yale University.