A new study suggests that blocking out light during sleep with the wearing of a sleep mask can improve memory, alertness and reaction time.
A new study reminds us that lifestyle changes don’t always have to be expensive or complicated to improve wellbeing. According to a study published in the journal Sleep, people who slept with an eye mask, which can be purchased online for just a few dollars, improved their cognitive abilities such as memory, word association and reaction time.
The observed improvements in memory and reaction times have broad implications. For example, better learning could improve academic and job performance, while faster reaction times could be useful in sports, driving, or other situations where quick responses are essential. Participants who wore a sleep mask had better memory and reaction time the next day.
According to the authors, previous research has shown that ambient light can negatively influence sleep duration and quality, including the amount of deep or slow-wave sleep. Even if you turn off all the lights in your bedroom, you may still be exposed to ambient light from, say, your partner’s phone, or a lamp post outside your window, or even the moon.
For this study, the researchers designed two experiments to explore how wearing an eye mask to block out light at night might affect memory and alertness.
In the first experiment, 89 adults aged 18 to 35 wore an eye mask (the intervention) while they slept for one week. After getting used to wearing the mask for the first five days, the participants underwent a series of lab tests to record their memory and reaction time for the final two days. During the “control” week, the participants followed the same diet, but without a sleep mask.
Researchers found that subjects who wore the mask performed better on a word pair association task, which measures the ability to remember events and experiences, and on a psychomotor alertness test, which measures behavioral alertness and sustained attention. These results suggest that the sleep mask is associated with better episodic memory encoding and better alertness, the authors write.
For the second experiment, 33 adult volunteers between the ages of 18 and 35 spent two nights sleeping with an eye mask (the intervention), then two nights sleeping with an eye mask with cutouts so that no fabric covered the eyes of the subjects (the control). The aim was to ensure that the results were not influenced by the general feeling of wearing a mask. As in the first study, participants who wore the full face mask performed better on the paired-word tasks.
Light Blocking May Reduce Disruptions to Circadian Rhythms
These results are interesting, but not necessarily surprising. Researchers have known for many years that large amounts of ambient light disrupt sleep cycles. It makes people less alert and prevents them from functioning. This can be explained by the fact that our body’s internal clock, called the circadian rhythm, synchronizes important bodily processes, including sleep, cognition and health, all according to the day/night cycle. Disruptions to our circadian rhythm, such as exposure to light at night, can impact memory and alertness. In addition, it is widely recognized that a good night’s sleep is beneficial for cognitive functions.
Slow Wave Sleep: When the Body Restores and Repairs Itself
In the second study, participants also wore an EEG headband to track their sleep stages, and they were asked to keep a sleep diary. According to the participants’ sleep diaries, the mask made no difference in the duration or quality of sleep. In contrast, EEG headbands revealed that improved learning performance after wearing the mask was positively correlated with spending more time in NREM sleep (also known as NREM sleep, or non-rapid eye movement deep sleep). .
Slow-wave sleep is the body’s most restful state. It’s called “slow wave” because brain waves are slowest during this phase of sleep. It is during this period that the body physically restores itself. Research suggests that up to 95% of human growth hormone is produced during slow-wave sleep. Most adults spend 10-20% of their sleep time in slow wave sleep.
Quality sleep is associated with better cognition
Existing data supports the link between higher quality sleep and better cognition, and interrupted sleep may have the opposite effect. For example, people with obstructive sleep apnea (OSA), a condition in which breathing patterns change during sleep due to airway obstruction, score lower on cognitive tests. In general, they learn less well and retrieve new information less well, and their speed of attention and psychomotor processing is lower.
Aids that block light and sound may improve functioning the next day
Although the results of these two small studies are statistically significant, they are not huge by either measure. In your daily life, you may or may not notice a change. Wearing a mask to sleep will not turn you into a cognitive superman or superwoman.
But this new study adds to existing evidence that blocking out ambient light improves sleep quality, which is generally associated with improved cognition. Wearing a sleep mask is potentially very helpful in improving sleep. However, do not expect gigantic effects. Similarly, blocking out intermittent disruptive noises with earplugs or listening to “colored” sounds (brown or pink noise, similar to white noise) can also help improve sleep.
To sleep better, say goodnight to your phone
Spending too much time on your phone, iPad or computer as bedtime approaches can be a real problem for many people. For example, research suggests that when you keep your phone on in your bedroom at night, you “sleep with one eye open.” In other words, you are more likely to be vulnerable to alert stimuli (like tones or a screen that lights up) if the alert stimulus (your phone) is nearby. It disturbs sleep.
For people who have trouble getting enough or quality sleep, the phone should be in another room and it should be turned off. All screens should be turned off at least one hour before bedtime. A consistent bedtime and wakeup time, as well as avoiding alcohol and caffeine before bedtime, also improve sleep. Many little things done right can contribute to a better night’s sleep, but don’t beat yourself up when things don’t go your way. Often, we put pressure on ourselves to be the best performers in all areas, including sleep.