Why sleep is so critical to mental clarity

Sleepless nights tend to make for lethargic, unfocused, and unproductive days. Indeed, anyone prone to tossing and turning can attest to the fact that poor sleep impairs cognition. But how bad is this impairment? And why, exactly, do we become so spacey when we don’t get the right amount of rest? To answer these questions, it helps to understand what goes on during those critical 7 to 9 hours.

While you were sleeping

Though sleep can feel like a bunch of nothing, a lot goes on in your head after you doze off. This action can be divided into four sleep stages that you cycle in and out of throughout the night.1

  • Stage 1: The brain is still active, but slowing down. You can think of this as a transitional period between wakefulness and deeper sleep. 
  • Stage 2: Breathing becomes more rhythmic–and so does your brain activity. Sleep-specific brain waves help you process and consolidate the memories formed throughout the day.   
  • Stage 3: Now in deep sleep, the brain can rest and recuperate so that it’s prepared to take on another demanding day. During this stage, the brain also clears out cellular waste that builds up during normal business hours.2,3
  • Rapid eye movement (REM) sleep: The brain once again becomes highly active. This is when vivid dreams occur, which may play an additional role in helping you store memories.

On top of these brain-specific functions, sleep is critical for keeping your immune system strong and helping your muscles recover after an active day. In short, sleep gives the brain and body a chance to rest, recuperate, and remember–processes that are essential to strong mental and physical performance.

What happens when you don’t get enough sleep

Given everything that the brain does at night, it’s no wonder that we struggle to think clearly when sleep is in short supply. Research shows that people with sleep problems often suffer from memory impairment, difficulty learning, and attention challenges.4,5 In particular, sleep deprivation has been shown to impair “selective attention”–your ability to ignore distractions and focus on the task at hand.6 

Poor sleep can also lead to slower reaction times, an effect that is often compared to that of drinking too much alcohol. People who suffer from ongoing sleep problems may therefore be prone to car accidents and other life-threatening mishaps.7 To be sure, most sleepy people are spared these extreme consequences; yet, they may still suffer a significant decline in mental performance. Put simply: when we don’t sleep well, we can’t bring our all to relationships, work, or hobbies.

Sleep better, think better

If you’ve been experiencing dips in attention, memory, or overall mental performance, poor sleep may be the culprit. Likewise, you may be able to improve your cognition by improving your sleep. Studies show that Cove can help with both. Daily users experience a 50% improvement in sleep, as well as a 39% increase in both memory and focus.






[1] Cherry, K. “The four stages of sleep.” Verywell Health. Available at:

[2] Dasgupta, R. “What is the purpose of sleep?” Healthline. Available at:

[3] Cohut, M. “How waste gets ‘washed out’ of our brains during sleep.” Medical News Today. Available at:

[4] Pacheco, D. “Memory and sleep.” Sleep Foundation. Available at:

[5] Peri, C. “What lack of sleep does to your mind.” WebMD. Available at:

[6] Miller, SG. “How a sleepless night affects your ability to focus.” LiveScience. Available at:

[7] Newsom, R. “Sleep Deprivation and Reaction Time.” Sleep Foundation. Available at: