While sleep has been studied since the days of Aristotle in ancient Greece, it’s been the last few centuries that have seen the majority of developments in sleep science. Many concepts now familiar to us, like sleep stages, sleep disorders, and sleep hygiene were solidified over the past 50 years. We can largely thank advancing technology for our deeper understanding of sleep.
We’ve come a long way since Aristotle, but that doesn’t mean we know everything about sleep. That’s part of why sleep science is so exciting! There are always new developments that help us better understand sleep and its impact on our lives.
Keep reading to explore recent scientific discoveries shedding light on sleep and how Muse’s at-home sleep wearable, with an impressive 86% accuracy in detecting sleep patterns, can improve your sleep experience.
A quick review of sleep 101
Sleep is an essential restorative process that facilitates healing and regeneration throughout our body. Alongside repairing daily wear and tear, sleep is associated with memory, focus, mood, and cognitive performance.
In the short-term, poor quality sleep can impact our mood, learning, and our ability to make good choices. Long-term, chronic sleep deprivation can lead to numerous health issues, including obesity, diabetes, heart disease, and early mortality.
Sleep experts report that adults require 7-9 hours of sleep for optimal functioning – but we know that often, it’s hard to get restful sleep within the recommended hours. This is where power naps come in handy as they can provide the restorative sleep you need to feel refreshed and energized throughout the day.
Your sleep quality matters
The quality of sleep matters just as much as the hours. To understand how you can get quality sleep, it’s helpful to know the sleep cycle stages. While most people are aware of the four stages of sleep cycle: stage 1, stage 2, stage 3, and REM sleep, there are five sleep phases to know:
- Awake (Alert or Relaxed)
- Stage 1 NREM (Non-REM) sleep
- Stage 2 NREM (Non-REM) sleep
- Stage 3 NREM (Non-REM) sleep - deep sleep
- REM sleep
Each sleep stage exhibits specific brain wave patterns that influence the overall sleep quality. Even the first stage of wakefulness, when we’re still awake and not yet fallen asleep, involves distinct EEG-detected brainwaves. These waves differ based on whether our eyes are open and we're alert (beta waves) or if we're relaxed with closed eyes (alpha waves).
Once we have started to drift off, we enter stage 1 of sleep – then stage 2, stage 3, and REM sleep – with a full cycle running about 90 minutes and occurring several times throughout the night.
While a quick nap lasting 20-30 minutes may not lead to deep sleep, it still offers valuable benefits in terms of quality. These power naps can bypass the grogginess associated with waking up, known as sleep inertia, leaving you feeling more alert, focused, and productive. By steering clear of the deep sleep stages, you'll be refreshed and energized without needing a longer sleep.
New developments in our understanding of sleep
As we’ve grown more technologically advanced over the years, we’ve made huge leaps in our understanding of sleep science. Below are a few of the exciting new developments in sleep.
1. Creativity and “eureka” moments linked with stage 1 sleep!
Stage 1 sleep often takes a backseat regarding scientific curiosity, but new studies show it may support creativity. One study published in Sleep Advances sought to explore stage 1 sleep’s relationship with creativity.
In the study, experimenters instructed participants to solve a math problem using a series of steps. Participants were left unaware that there was a simpler, hidden rule they could use to find the answers faster.
Participants repeated the math problem numerous times, before being instructed to sit in a semi-reclined position and close their eyes. They were given an object to hold outstretched in their hand. Participants would fall asleep and drop the object, which would then startle them awake. Upon waking, participants were asked to share everything in their minds.
(This trick was inspired by Salvador Dali and Thomas Edison, who both would allegedly nap with something in their hands. Dropping the object would wake them up at the perfect moment for creativity.)
The result: people who spent at least 15 seconds in stage 1 sleep saw their odds of identifying the hidden rule to the math problem tripled. This effect was not seen if subjects transitioned into deeper sleep stages.
The study authors write that, “our findings suggest there is a creative sweet spot within the sleep-onset period” and that stage 1 activity may help ignite “creative sparks.” The opportunity for creativity may be heightened in this stage due to the interplay of activity in brain networks related to increased spontaneous thinking and decreased cognitive control.
2. Targeted memory reactivation (TMR) could help you improve memory formation and consolidation and cognitive performance!
Remember that fantasy in high school and college where you wished you could learn in your sleep? Well, research published last year in The Annual Review of Psychology suggests that may be possible!
Included in the review was a meta-analysis of 90 studies exploring targeted memory reactivation (TMR). TMR involves presenting a stimulus to someone while they’re awake and attaching it to a sound or scent. Once the person falls asleep, the scent or sound is presented again, which triggers stimuli in the mind and strengthens the learning and memory process. The meta-analysis confirmed that TMR was most successful during stage 2 and slow wave sleep.
For instance, one experiment sought to test whether TMR could help reduce implicit gender and racial bias. 40 people were exposed to counter-stereotype information which was paired with a distinct auditory cue for each type of bias. When the participants fell asleep, researchers played specific auditory cues to trigger memories of their bias reduction training.
Bias was immediately reduced following the experiment, with results lasting another full week. The researchers concluded that reactivation of training memories during sleep was a key component in maintaining reduced bias.
Studies exploring TMR have found it can benefit skill learning, vocabulary development, word recall, and spatial awareness.
3. Background noise in the brain may contribute to your brain’s health.
Electrical activity in the brain typically comes in two forms: clean brain waves and irregular, random electrical activity. However, recent inquiry suggests this “irregular, electrical activity” may not be as random as previously thought.
At a sleep symposium in 2020, Janna Lendner discussed possibilities for using brain wave activity to identify states of consciousness. REM sleep states mirror waking states, making this research important for doctors working with anesthesia or comatose patients. The answer, according to Lendner, lies in irregular brain activity.
Also known as free-scale activity, arrhythmic brain activity, and aperiodic activity, irregular brain activity has long been dismissed by researchers. Instead, it’s been viewed as irrelevant background noise, unlike the purposeful regular rhythms of our heartbeat and breath. It’s very similar to white noise that’s now popularized and sought out by many people who want to improve their sleep habits.
What is aperiodic brain activity?
To understand irregular activity, it’s important to understand what causes electrical activity in the brain in the first place. When the brain activates glutamate signals, they prompt excitatory activity. When gamma amino-butyric acid (GABA) signals are sent out, brain activity is inhibited. Cycles in excitatory and inhibitory signals are what create different brain wave patterns and mental states.
In taking a closer look at brain waves though, the slopes to the curve’s peaks and valleys are not smooth. Instead, they’re usually rough, jittering up and down. Sometimes the electrical activity doesn’t follow any identifiable pattern and looks more like TV static or white noise.
Neuroscientist Bradley Voltek was involved in creating software that could eliminate “white noise” brain activity when he grew curious. In breaking down the activity even further, Voltek found the “random” activity wasn’t actually random at all. Instead, it followed a curve called 1/f, which has been found in all sorts of electrical noise, from stock market activity to music.
Aperiodic activity and brain health
Using his cutting-edge software, Voytek found that older adults seemed to experience more aperiodic activity. In collaboration with Berkeley neuroscience professor Robert Knight, they observed that the brain experiences more “background noise” as it ages. Increased irregular activity was also linked with age related declines in working memory.
One possible theory? Aperiodic brain activity may relate to the delicate balance between excitatory and inhibitory signals attempting to regulate brain processes.
4. A new lucid dreaming study suggests you may be able to learn and solve real world problems in your sleep!
In this exciting study, researchers recruited participants who had experience with lucid dreaming. As the participants slept, researchers asked participants a series of simple yes/no questions and math problems. Participants indicated their answers using pre-instructed eye movements.
The results: six students were able to answer the 29 questions correctly. These results are incredibly exciting, because they suggest that new information can be introduced and learned as we sleep!
Lucid dreaming is associated with freedom from the limitations of waking life and can provide access to a vast creativity. In this way, lucid dreaming allows us to consider novel approaches and come up with innovative and creative solutions.
The implications of this research are far-reaching, impacting everything from students wanting to prepare for tests as they sleep to artistic endeavors to psychotherapy.
5. The COVID-19 pandemic had a huge impact on our sleep patterns.
While it may not come as a shock, the COVID-19 pandemic has taken a toll on our ability to sleep. After analyzing 44 sleep studies involving 54,213 participants across 13 countries, a meta-review published in the Journal of Clinical Sleep Medicine found that many of us are struggling to get quality sleep.
During the pandemic, the study found that 32.5% of the general population experienced sleep issues. This was a critical finding, as COVID-19 anxiety has been positively linked with severe insomnia and thoughts of suicide.
Another study published in the British Medical Journal found the pandemic worsened sleep and daytime problems by 10% or more. Surprisingly, while about 20% of the 22,151 participants experienced worsening sleep quality, about 5% saw improvements.
Specifically, this study found the pandemic led to poor quality of sleep, early morning wakefulness, and increased levels of daytime sleepiness. Financial suffering was additionally linked with nightmares and fatigue. Confinement and isolation were also associated with problems falling asleep and poor sleep.
While the majority of us live lives as normal with post-pandemic alerts softening over the last year, there are still Long COVID survivors suffering with symptoms like poor sleep. According to National Institutes of Health, 40% of those with Long COVID report sleep issues with symptoms such as insomnia and daytime sleepiness. Poor sleep from Long COVID can heighten sensitivity to pain, as sleep deprivation impacts the central nervous system, hindering its optimal functioning.
Need better sleep for 2024? Discover the Muse S Headband
If you find yourself tossing and turning despite trying various sleep remedies, it might be time to explore an advanced solution, the Muse S headband.
While there are many fitness trackers out there that help monitor sleep, true improvements come from understanding your sleep patterns at a deeper level, measured through brain activity. The Muse S Headband achieves just that, using EEG sensors to track your brainwaves during sleep.
Beyond simply revealing the duration of each sleep stage, Muse S dives deep into the 'how' and 'when' of your sleep data, catching when your deep sleep is most restorative and how your sleep position affects your awakening.
In addition to these powerful detections, Muse also provides enriching sleep experiences such as Digital Sleeping Pill (DSP), designed to guide you to sleep and bring you back if you wake up at night. After each DSP session, your sleep stats offer a valuable understanding of the quality of your sleep, pinpointing areas for improvement.
With a proven 20% improvement in sleep quality, Muse S acts as a practical alternative to sleep clinics. Its accessibility and user-friendly sleep assessment make it an invaluable tool for enhancing your sleep journey. Say goodbye to restless nights and embrace the potential of Muse S to revolutionize your sleep habits.